3290a57b248ec92d39f749c2ac1e07a785e81b5b
[linux-2.6.git] / drivers / infiniband / ulp / srpt / ib_srpt.c
1 /*
2  * Copyright (c) 2006 - 2009 Mellanox Technology Inc.  All rights reserved.
3  * Copyright (C) 2008 - 2011 Bart Van Assche <bvanassche@acm.org>.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  *
33  */
34
35 #include <linux/module.h>
36 #include <linux/init.h>
37 #include <linux/slab.h>
38 #include <linux/err.h>
39 #include <linux/ctype.h>
40 #include <linux/kthread.h>
41 #include <linux/string.h>
42 #include <linux/delay.h>
43 #include <linux/atomic.h>
44 #include <scsi/scsi_tcq.h>
45 #include <target/configfs_macros.h>
46 #include <target/target_core_base.h>
47 #include <target/target_core_fabric_configfs.h>
48 #include <target/target_core_fabric.h>
49 #include <target/target_core_configfs.h>
50 #include "ib_srpt.h"
51
52 /* Name of this kernel module. */
53 #define DRV_NAME                "ib_srpt"
54 #define DRV_VERSION             "2.0.0"
55 #define DRV_RELDATE             "2011-02-14"
56
57 #define SRPT_ID_STRING  "Linux SRP target"
58
59 #undef pr_fmt
60 #define pr_fmt(fmt) DRV_NAME " " fmt
61
62 MODULE_AUTHOR("Vu Pham and Bart Van Assche");
63 MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol target "
64                    "v" DRV_VERSION " (" DRV_RELDATE ")");
65 MODULE_LICENSE("Dual BSD/GPL");
66
67 /*
68  * Global Variables
69  */
70
71 static u64 srpt_service_guid;
72 static DEFINE_SPINLOCK(srpt_dev_lock);  /* Protects srpt_dev_list. */
73 static LIST_HEAD(srpt_dev_list);        /* List of srpt_device structures. */
74
75 static unsigned srp_max_req_size = DEFAULT_MAX_REQ_SIZE;
76 module_param(srp_max_req_size, int, 0444);
77 MODULE_PARM_DESC(srp_max_req_size,
78                  "Maximum size of SRP request messages in bytes.");
79
80 static int srpt_srq_size = DEFAULT_SRPT_SRQ_SIZE;
81 module_param(srpt_srq_size, int, 0444);
82 MODULE_PARM_DESC(srpt_srq_size,
83                  "Shared receive queue (SRQ) size.");
84
85 static int srpt_get_u64_x(char *buffer, struct kernel_param *kp)
86 {
87         return sprintf(buffer, "0x%016llx", *(u64 *)kp->arg);
88 }
89 module_param_call(srpt_service_guid, NULL, srpt_get_u64_x, &srpt_service_guid,
90                   0444);
91 MODULE_PARM_DESC(srpt_service_guid,
92                  "Using this value for ioc_guid, id_ext, and cm_listen_id"
93                  " instead of using the node_guid of the first HCA.");
94
95 static struct ib_client srpt_client;
96 static struct target_fabric_configfs *srpt_target;
97 static void srpt_release_channel(struct srpt_rdma_ch *ch);
98 static int srpt_queue_status(struct se_cmd *cmd);
99
100 /**
101  * opposite_dma_dir() - Swap DMA_TO_DEVICE and DMA_FROM_DEVICE.
102  */
103 static inline
104 enum dma_data_direction opposite_dma_dir(enum dma_data_direction dir)
105 {
106         switch (dir) {
107         case DMA_TO_DEVICE:     return DMA_FROM_DEVICE;
108         case DMA_FROM_DEVICE:   return DMA_TO_DEVICE;
109         default:                return dir;
110         }
111 }
112
113 /**
114  * srpt_sdev_name() - Return the name associated with the HCA.
115  *
116  * Examples are ib0, ib1, ...
117  */
118 static inline const char *srpt_sdev_name(struct srpt_device *sdev)
119 {
120         return sdev->device->name;
121 }
122
123 static enum rdma_ch_state srpt_get_ch_state(struct srpt_rdma_ch *ch)
124 {
125         unsigned long flags;
126         enum rdma_ch_state state;
127
128         spin_lock_irqsave(&ch->spinlock, flags);
129         state = ch->state;
130         spin_unlock_irqrestore(&ch->spinlock, flags);
131         return state;
132 }
133
134 static enum rdma_ch_state
135 srpt_set_ch_state(struct srpt_rdma_ch *ch, enum rdma_ch_state new_state)
136 {
137         unsigned long flags;
138         enum rdma_ch_state prev;
139
140         spin_lock_irqsave(&ch->spinlock, flags);
141         prev = ch->state;
142         ch->state = new_state;
143         spin_unlock_irqrestore(&ch->spinlock, flags);
144         return prev;
145 }
146
147 /**
148  * srpt_test_and_set_ch_state() - Test and set the channel state.
149  *
150  * Returns true if and only if the channel state has been set to the new state.
151  */
152 static bool
153 srpt_test_and_set_ch_state(struct srpt_rdma_ch *ch, enum rdma_ch_state old,
154                            enum rdma_ch_state new)
155 {
156         unsigned long flags;
157         enum rdma_ch_state prev;
158
159         spin_lock_irqsave(&ch->spinlock, flags);
160         prev = ch->state;
161         if (prev == old)
162                 ch->state = new;
163         spin_unlock_irqrestore(&ch->spinlock, flags);
164         return prev == old;
165 }
166
167 /**
168  * srpt_event_handler() - Asynchronous IB event callback function.
169  *
170  * Callback function called by the InfiniBand core when an asynchronous IB
171  * event occurs. This callback may occur in interrupt context. See also
172  * section 11.5.2, Set Asynchronous Event Handler in the InfiniBand
173  * Architecture Specification.
174  */
175 static void srpt_event_handler(struct ib_event_handler *handler,
176                                struct ib_event *event)
177 {
178         struct srpt_device *sdev;
179         struct srpt_port *sport;
180
181         sdev = ib_get_client_data(event->device, &srpt_client);
182         if (!sdev || sdev->device != event->device)
183                 return;
184
185         pr_debug("ASYNC event= %d on device= %s\n", event->event,
186                  srpt_sdev_name(sdev));
187
188         switch (event->event) {
189         case IB_EVENT_PORT_ERR:
190                 if (event->element.port_num <= sdev->device->phys_port_cnt) {
191                         sport = &sdev->port[event->element.port_num - 1];
192                         sport->lid = 0;
193                         sport->sm_lid = 0;
194                 }
195                 break;
196         case IB_EVENT_PORT_ACTIVE:
197         case IB_EVENT_LID_CHANGE:
198         case IB_EVENT_PKEY_CHANGE:
199         case IB_EVENT_SM_CHANGE:
200         case IB_EVENT_CLIENT_REREGISTER:
201                 /* Refresh port data asynchronously. */
202                 if (event->element.port_num <= sdev->device->phys_port_cnt) {
203                         sport = &sdev->port[event->element.port_num - 1];
204                         if (!sport->lid && !sport->sm_lid)
205                                 schedule_work(&sport->work);
206                 }
207                 break;
208         default:
209                 printk(KERN_ERR "received unrecognized IB event %d\n",
210                        event->event);
211                 break;
212         }
213 }
214
215 /**
216  * srpt_srq_event() - SRQ event callback function.
217  */
218 static void srpt_srq_event(struct ib_event *event, void *ctx)
219 {
220         printk(KERN_INFO "SRQ event %d\n", event->event);
221 }
222
223 /**
224  * srpt_qp_event() - QP event callback function.
225  */
226 static void srpt_qp_event(struct ib_event *event, struct srpt_rdma_ch *ch)
227 {
228         pr_debug("QP event %d on cm_id=%p sess_name=%s state=%d\n",
229                  event->event, ch->cm_id, ch->sess_name, srpt_get_ch_state(ch));
230
231         switch (event->event) {
232         case IB_EVENT_COMM_EST:
233                 ib_cm_notify(ch->cm_id, event->event);
234                 break;
235         case IB_EVENT_QP_LAST_WQE_REACHED:
236                 if (srpt_test_and_set_ch_state(ch, CH_DRAINING,
237                                                CH_RELEASING))
238                         srpt_release_channel(ch);
239                 else
240                         pr_debug("%s: state %d - ignored LAST_WQE.\n",
241                                  ch->sess_name, srpt_get_ch_state(ch));
242                 break;
243         default:
244                 printk(KERN_ERR "received unrecognized IB QP event %d\n",
245                        event->event);
246                 break;
247         }
248 }
249
250 /**
251  * srpt_set_ioc() - Helper function for initializing an IOUnitInfo structure.
252  *
253  * @slot: one-based slot number.
254  * @value: four-bit value.
255  *
256  * Copies the lowest four bits of value in element slot of the array of four
257  * bit elements called c_list (controller list). The index slot is one-based.
258  */
259 static void srpt_set_ioc(u8 *c_list, u32 slot, u8 value)
260 {
261         u16 id;
262         u8 tmp;
263
264         id = (slot - 1) / 2;
265         if (slot & 0x1) {
266                 tmp = c_list[id] & 0xf;
267                 c_list[id] = (value << 4) | tmp;
268         } else {
269                 tmp = c_list[id] & 0xf0;
270                 c_list[id] = (value & 0xf) | tmp;
271         }
272 }
273
274 /**
275  * srpt_get_class_port_info() - Copy ClassPortInfo to a management datagram.
276  *
277  * See also section 16.3.3.1 ClassPortInfo in the InfiniBand Architecture
278  * Specification.
279  */
280 static void srpt_get_class_port_info(struct ib_dm_mad *mad)
281 {
282         struct ib_class_port_info *cif;
283
284         cif = (struct ib_class_port_info *)mad->data;
285         memset(cif, 0, sizeof *cif);
286         cif->base_version = 1;
287         cif->class_version = 1;
288         cif->resp_time_value = 20;
289
290         mad->mad_hdr.status = 0;
291 }
292
293 /**
294  * srpt_get_iou() - Write IOUnitInfo to a management datagram.
295  *
296  * See also section 16.3.3.3 IOUnitInfo in the InfiniBand Architecture
297  * Specification. See also section B.7, table B.6 in the SRP r16a document.
298  */
299 static void srpt_get_iou(struct ib_dm_mad *mad)
300 {
301         struct ib_dm_iou_info *ioui;
302         u8 slot;
303         int i;
304
305         ioui = (struct ib_dm_iou_info *)mad->data;
306         ioui->change_id = __constant_cpu_to_be16(1);
307         ioui->max_controllers = 16;
308
309         /* set present for slot 1 and empty for the rest */
310         srpt_set_ioc(ioui->controller_list, 1, 1);
311         for (i = 1, slot = 2; i < 16; i++, slot++)
312                 srpt_set_ioc(ioui->controller_list, slot, 0);
313
314         mad->mad_hdr.status = 0;
315 }
316
317 /**
318  * srpt_get_ioc() - Write IOControllerprofile to a management datagram.
319  *
320  * See also section 16.3.3.4 IOControllerProfile in the InfiniBand
321  * Architecture Specification. See also section B.7, table B.7 in the SRP
322  * r16a document.
323  */
324 static void srpt_get_ioc(struct srpt_port *sport, u32 slot,
325                          struct ib_dm_mad *mad)
326 {
327         struct srpt_device *sdev = sport->sdev;
328         struct ib_dm_ioc_profile *iocp;
329
330         iocp = (struct ib_dm_ioc_profile *)mad->data;
331
332         if (!slot || slot > 16) {
333                 mad->mad_hdr.status
334                         = __constant_cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
335                 return;
336         }
337
338         if (slot > 2) {
339                 mad->mad_hdr.status
340                         = __constant_cpu_to_be16(DM_MAD_STATUS_NO_IOC);
341                 return;
342         }
343
344         memset(iocp, 0, sizeof *iocp);
345         strcpy(iocp->id_string, SRPT_ID_STRING);
346         iocp->guid = cpu_to_be64(srpt_service_guid);
347         iocp->vendor_id = cpu_to_be32(sdev->dev_attr.vendor_id);
348         iocp->device_id = cpu_to_be32(sdev->dev_attr.vendor_part_id);
349         iocp->device_version = cpu_to_be16(sdev->dev_attr.hw_ver);
350         iocp->subsys_vendor_id = cpu_to_be32(sdev->dev_attr.vendor_id);
351         iocp->subsys_device_id = 0x0;
352         iocp->io_class = __constant_cpu_to_be16(SRP_REV16A_IB_IO_CLASS);
353         iocp->io_subclass = __constant_cpu_to_be16(SRP_IO_SUBCLASS);
354         iocp->protocol = __constant_cpu_to_be16(SRP_PROTOCOL);
355         iocp->protocol_version = __constant_cpu_to_be16(SRP_PROTOCOL_VERSION);
356         iocp->send_queue_depth = cpu_to_be16(sdev->srq_size);
357         iocp->rdma_read_depth = 4;
358         iocp->send_size = cpu_to_be32(srp_max_req_size);
359         iocp->rdma_size = cpu_to_be32(min(sport->port_attrib.srp_max_rdma_size,
360                                           1U << 24));
361         iocp->num_svc_entries = 1;
362         iocp->op_cap_mask = SRP_SEND_TO_IOC | SRP_SEND_FROM_IOC |
363                 SRP_RDMA_READ_FROM_IOC | SRP_RDMA_WRITE_FROM_IOC;
364
365         mad->mad_hdr.status = 0;
366 }
367
368 /**
369  * srpt_get_svc_entries() - Write ServiceEntries to a management datagram.
370  *
371  * See also section 16.3.3.5 ServiceEntries in the InfiniBand Architecture
372  * Specification. See also section B.7, table B.8 in the SRP r16a document.
373  */
374 static void srpt_get_svc_entries(u64 ioc_guid,
375                                  u16 slot, u8 hi, u8 lo, struct ib_dm_mad *mad)
376 {
377         struct ib_dm_svc_entries *svc_entries;
378
379         WARN_ON(!ioc_guid);
380
381         if (!slot || slot > 16) {
382                 mad->mad_hdr.status
383                         = __constant_cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
384                 return;
385         }
386
387         if (slot > 2 || lo > hi || hi > 1) {
388                 mad->mad_hdr.status
389                         = __constant_cpu_to_be16(DM_MAD_STATUS_NO_IOC);
390                 return;
391         }
392
393         svc_entries = (struct ib_dm_svc_entries *)mad->data;
394         memset(svc_entries, 0, sizeof *svc_entries);
395         svc_entries->service_entries[0].id = cpu_to_be64(ioc_guid);
396         snprintf(svc_entries->service_entries[0].name,
397                  sizeof(svc_entries->service_entries[0].name),
398                  "%s%016llx",
399                  SRP_SERVICE_NAME_PREFIX,
400                  ioc_guid);
401
402         mad->mad_hdr.status = 0;
403 }
404
405 /**
406  * srpt_mgmt_method_get() - Process a received management datagram.
407  * @sp:      source port through which the MAD has been received.
408  * @rq_mad:  received MAD.
409  * @rsp_mad: response MAD.
410  */
411 static void srpt_mgmt_method_get(struct srpt_port *sp, struct ib_mad *rq_mad,
412                                  struct ib_dm_mad *rsp_mad)
413 {
414         u16 attr_id;
415         u32 slot;
416         u8 hi, lo;
417
418         attr_id = be16_to_cpu(rq_mad->mad_hdr.attr_id);
419         switch (attr_id) {
420         case DM_ATTR_CLASS_PORT_INFO:
421                 srpt_get_class_port_info(rsp_mad);
422                 break;
423         case DM_ATTR_IOU_INFO:
424                 srpt_get_iou(rsp_mad);
425                 break;
426         case DM_ATTR_IOC_PROFILE:
427                 slot = be32_to_cpu(rq_mad->mad_hdr.attr_mod);
428                 srpt_get_ioc(sp, slot, rsp_mad);
429                 break;
430         case DM_ATTR_SVC_ENTRIES:
431                 slot = be32_to_cpu(rq_mad->mad_hdr.attr_mod);
432                 hi = (u8) ((slot >> 8) & 0xff);
433                 lo = (u8) (slot & 0xff);
434                 slot = (u16) ((slot >> 16) & 0xffff);
435                 srpt_get_svc_entries(srpt_service_guid,
436                                      slot, hi, lo, rsp_mad);
437                 break;
438         default:
439                 rsp_mad->mad_hdr.status =
440                     __constant_cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
441                 break;
442         }
443 }
444
445 /**
446  * srpt_mad_send_handler() - Post MAD-send callback function.
447  */
448 static void srpt_mad_send_handler(struct ib_mad_agent *mad_agent,
449                                   struct ib_mad_send_wc *mad_wc)
450 {
451         ib_destroy_ah(mad_wc->send_buf->ah);
452         ib_free_send_mad(mad_wc->send_buf);
453 }
454
455 /**
456  * srpt_mad_recv_handler() - MAD reception callback function.
457  */
458 static void srpt_mad_recv_handler(struct ib_mad_agent *mad_agent,
459                                   struct ib_mad_recv_wc *mad_wc)
460 {
461         struct srpt_port *sport = (struct srpt_port *)mad_agent->context;
462         struct ib_ah *ah;
463         struct ib_mad_send_buf *rsp;
464         struct ib_dm_mad *dm_mad;
465
466         if (!mad_wc || !mad_wc->recv_buf.mad)
467                 return;
468
469         ah = ib_create_ah_from_wc(mad_agent->qp->pd, mad_wc->wc,
470                                   mad_wc->recv_buf.grh, mad_agent->port_num);
471         if (IS_ERR(ah))
472                 goto err;
473
474         BUILD_BUG_ON(offsetof(struct ib_dm_mad, data) != IB_MGMT_DEVICE_HDR);
475
476         rsp = ib_create_send_mad(mad_agent, mad_wc->wc->src_qp,
477                                  mad_wc->wc->pkey_index, 0,
478                                  IB_MGMT_DEVICE_HDR, IB_MGMT_DEVICE_DATA,
479                                  GFP_KERNEL);
480         if (IS_ERR(rsp))
481                 goto err_rsp;
482
483         rsp->ah = ah;
484
485         dm_mad = rsp->mad;
486         memcpy(dm_mad, mad_wc->recv_buf.mad, sizeof *dm_mad);
487         dm_mad->mad_hdr.method = IB_MGMT_METHOD_GET_RESP;
488         dm_mad->mad_hdr.status = 0;
489
490         switch (mad_wc->recv_buf.mad->mad_hdr.method) {
491         case IB_MGMT_METHOD_GET:
492                 srpt_mgmt_method_get(sport, mad_wc->recv_buf.mad, dm_mad);
493                 break;
494         case IB_MGMT_METHOD_SET:
495                 dm_mad->mad_hdr.status =
496                     __constant_cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
497                 break;
498         default:
499                 dm_mad->mad_hdr.status =
500                     __constant_cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD);
501                 break;
502         }
503
504         if (!ib_post_send_mad(rsp, NULL)) {
505                 ib_free_recv_mad(mad_wc);
506                 /* will destroy_ah & free_send_mad in send completion */
507                 return;
508         }
509
510         ib_free_send_mad(rsp);
511
512 err_rsp:
513         ib_destroy_ah(ah);
514 err:
515         ib_free_recv_mad(mad_wc);
516 }
517
518 /**
519  * srpt_refresh_port() - Configure a HCA port.
520  *
521  * Enable InfiniBand management datagram processing, update the cached sm_lid,
522  * lid and gid values, and register a callback function for processing MADs
523  * on the specified port.
524  *
525  * Note: It is safe to call this function more than once for the same port.
526  */
527 static int srpt_refresh_port(struct srpt_port *sport)
528 {
529         struct ib_mad_reg_req reg_req;
530         struct ib_port_modify port_modify;
531         struct ib_port_attr port_attr;
532         int ret;
533
534         memset(&port_modify, 0, sizeof port_modify);
535         port_modify.set_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP;
536         port_modify.clr_port_cap_mask = 0;
537
538         ret = ib_modify_port(sport->sdev->device, sport->port, 0, &port_modify);
539         if (ret)
540                 goto err_mod_port;
541
542         ret = ib_query_port(sport->sdev->device, sport->port, &port_attr);
543         if (ret)
544                 goto err_query_port;
545
546         sport->sm_lid = port_attr.sm_lid;
547         sport->lid = port_attr.lid;
548
549         ret = ib_query_gid(sport->sdev->device, sport->port, 0, &sport->gid);
550         if (ret)
551                 goto err_query_port;
552
553         if (!sport->mad_agent) {
554                 memset(&reg_req, 0, sizeof reg_req);
555                 reg_req.mgmt_class = IB_MGMT_CLASS_DEVICE_MGMT;
556                 reg_req.mgmt_class_version = IB_MGMT_BASE_VERSION;
557                 set_bit(IB_MGMT_METHOD_GET, reg_req.method_mask);
558                 set_bit(IB_MGMT_METHOD_SET, reg_req.method_mask);
559
560                 sport->mad_agent = ib_register_mad_agent(sport->sdev->device,
561                                                          sport->port,
562                                                          IB_QPT_GSI,
563                                                          &reg_req, 0,
564                                                          srpt_mad_send_handler,
565                                                          srpt_mad_recv_handler,
566                                                          sport);
567                 if (IS_ERR(sport->mad_agent)) {
568                         ret = PTR_ERR(sport->mad_agent);
569                         sport->mad_agent = NULL;
570                         goto err_query_port;
571                 }
572         }
573
574         return 0;
575
576 err_query_port:
577
578         port_modify.set_port_cap_mask = 0;
579         port_modify.clr_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP;
580         ib_modify_port(sport->sdev->device, sport->port, 0, &port_modify);
581
582 err_mod_port:
583
584         return ret;
585 }
586
587 /**
588  * srpt_unregister_mad_agent() - Unregister MAD callback functions.
589  *
590  * Note: It is safe to call this function more than once for the same device.
591  */
592 static void srpt_unregister_mad_agent(struct srpt_device *sdev)
593 {
594         struct ib_port_modify port_modify = {
595                 .clr_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP,
596         };
597         struct srpt_port *sport;
598         int i;
599
600         for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
601                 sport = &sdev->port[i - 1];
602                 WARN_ON(sport->port != i);
603                 if (ib_modify_port(sdev->device, i, 0, &port_modify) < 0)
604                         printk(KERN_ERR "disabling MAD processing failed.\n");
605                 if (sport->mad_agent) {
606                         ib_unregister_mad_agent(sport->mad_agent);
607                         sport->mad_agent = NULL;
608                 }
609         }
610 }
611
612 /**
613  * srpt_alloc_ioctx() - Allocate an SRPT I/O context structure.
614  */
615 static struct srpt_ioctx *srpt_alloc_ioctx(struct srpt_device *sdev,
616                                            int ioctx_size, int dma_size,
617                                            enum dma_data_direction dir)
618 {
619         struct srpt_ioctx *ioctx;
620
621         ioctx = kmalloc(ioctx_size, GFP_KERNEL);
622         if (!ioctx)
623                 goto err;
624
625         ioctx->buf = kmalloc(dma_size, GFP_KERNEL);
626         if (!ioctx->buf)
627                 goto err_free_ioctx;
628
629         ioctx->dma = ib_dma_map_single(sdev->device, ioctx->buf, dma_size, dir);
630         if (ib_dma_mapping_error(sdev->device, ioctx->dma))
631                 goto err_free_buf;
632
633         return ioctx;
634
635 err_free_buf:
636         kfree(ioctx->buf);
637 err_free_ioctx:
638         kfree(ioctx);
639 err:
640         return NULL;
641 }
642
643 /**
644  * srpt_free_ioctx() - Free an SRPT I/O context structure.
645  */
646 static void srpt_free_ioctx(struct srpt_device *sdev, struct srpt_ioctx *ioctx,
647                             int dma_size, enum dma_data_direction dir)
648 {
649         if (!ioctx)
650                 return;
651
652         ib_dma_unmap_single(sdev->device, ioctx->dma, dma_size, dir);
653         kfree(ioctx->buf);
654         kfree(ioctx);
655 }
656
657 /**
658  * srpt_alloc_ioctx_ring() - Allocate a ring of SRPT I/O context structures.
659  * @sdev:       Device to allocate the I/O context ring for.
660  * @ring_size:  Number of elements in the I/O context ring.
661  * @ioctx_size: I/O context size.
662  * @dma_size:   DMA buffer size.
663  * @dir:        DMA data direction.
664  */
665 static struct srpt_ioctx **srpt_alloc_ioctx_ring(struct srpt_device *sdev,
666                                 int ring_size, int ioctx_size,
667                                 int dma_size, enum dma_data_direction dir)
668 {
669         struct srpt_ioctx **ring;
670         int i;
671
672         WARN_ON(ioctx_size != sizeof(struct srpt_recv_ioctx)
673                 && ioctx_size != sizeof(struct srpt_send_ioctx));
674
675         ring = kmalloc(ring_size * sizeof(ring[0]), GFP_KERNEL);
676         if (!ring)
677                 goto out;
678         for (i = 0; i < ring_size; ++i) {
679                 ring[i] = srpt_alloc_ioctx(sdev, ioctx_size, dma_size, dir);
680                 if (!ring[i])
681                         goto err;
682                 ring[i]->index = i;
683         }
684         goto out;
685
686 err:
687         while (--i >= 0)
688                 srpt_free_ioctx(sdev, ring[i], dma_size, dir);
689         kfree(ring);
690         ring = NULL;
691 out:
692         return ring;
693 }
694
695 /**
696  * srpt_free_ioctx_ring() - Free the ring of SRPT I/O context structures.
697  */
698 static void srpt_free_ioctx_ring(struct srpt_ioctx **ioctx_ring,
699                                  struct srpt_device *sdev, int ring_size,
700                                  int dma_size, enum dma_data_direction dir)
701 {
702         int i;
703
704         for (i = 0; i < ring_size; ++i)
705                 srpt_free_ioctx(sdev, ioctx_ring[i], dma_size, dir);
706         kfree(ioctx_ring);
707 }
708
709 /**
710  * srpt_get_cmd_state() - Get the state of a SCSI command.
711  */
712 static enum srpt_command_state srpt_get_cmd_state(struct srpt_send_ioctx *ioctx)
713 {
714         enum srpt_command_state state;
715         unsigned long flags;
716
717         BUG_ON(!ioctx);
718
719         spin_lock_irqsave(&ioctx->spinlock, flags);
720         state = ioctx->state;
721         spin_unlock_irqrestore(&ioctx->spinlock, flags);
722         return state;
723 }
724
725 /**
726  * srpt_set_cmd_state() - Set the state of a SCSI command.
727  *
728  * Does not modify the state of aborted commands. Returns the previous command
729  * state.
730  */
731 static enum srpt_command_state srpt_set_cmd_state(struct srpt_send_ioctx *ioctx,
732                                                   enum srpt_command_state new)
733 {
734         enum srpt_command_state previous;
735         unsigned long flags;
736
737         BUG_ON(!ioctx);
738
739         spin_lock_irqsave(&ioctx->spinlock, flags);
740         previous = ioctx->state;
741         if (previous != SRPT_STATE_DONE)
742                 ioctx->state = new;
743         spin_unlock_irqrestore(&ioctx->spinlock, flags);
744
745         return previous;
746 }
747
748 /**
749  * srpt_test_and_set_cmd_state() - Test and set the state of a command.
750  *
751  * Returns true if and only if the previous command state was equal to 'old'.
752  */
753 static bool srpt_test_and_set_cmd_state(struct srpt_send_ioctx *ioctx,
754                                         enum srpt_command_state old,
755                                         enum srpt_command_state new)
756 {
757         enum srpt_command_state previous;
758         unsigned long flags;
759
760         WARN_ON(!ioctx);
761         WARN_ON(old == SRPT_STATE_DONE);
762         WARN_ON(new == SRPT_STATE_NEW);
763
764         spin_lock_irqsave(&ioctx->spinlock, flags);
765         previous = ioctx->state;
766         if (previous == old)
767                 ioctx->state = new;
768         spin_unlock_irqrestore(&ioctx->spinlock, flags);
769         return previous == old;
770 }
771
772 /**
773  * srpt_post_recv() - Post an IB receive request.
774  */
775 static int srpt_post_recv(struct srpt_device *sdev,
776                           struct srpt_recv_ioctx *ioctx)
777 {
778         struct ib_sge list;
779         struct ib_recv_wr wr, *bad_wr;
780
781         BUG_ON(!sdev);
782         wr.wr_id = encode_wr_id(SRPT_RECV, ioctx->ioctx.index);
783
784         list.addr = ioctx->ioctx.dma;
785         list.length = srp_max_req_size;
786         list.lkey = sdev->mr->lkey;
787
788         wr.next = NULL;
789         wr.sg_list = &list;
790         wr.num_sge = 1;
791
792         return ib_post_srq_recv(sdev->srq, &wr, &bad_wr);
793 }
794
795 /**
796  * srpt_post_send() - Post an IB send request.
797  *
798  * Returns zero upon success and a non-zero value upon failure.
799  */
800 static int srpt_post_send(struct srpt_rdma_ch *ch,
801                           struct srpt_send_ioctx *ioctx, int len)
802 {
803         struct ib_sge list;
804         struct ib_send_wr wr, *bad_wr;
805         struct srpt_device *sdev = ch->sport->sdev;
806         int ret;
807
808         atomic_inc(&ch->req_lim);
809
810         ret = -ENOMEM;
811         if (unlikely(atomic_dec_return(&ch->sq_wr_avail) < 0)) {
812                 printk(KERN_WARNING "IB send queue full (needed 1)\n");
813                 goto out;
814         }
815
816         ib_dma_sync_single_for_device(sdev->device, ioctx->ioctx.dma, len,
817                                       DMA_TO_DEVICE);
818
819         list.addr = ioctx->ioctx.dma;
820         list.length = len;
821         list.lkey = sdev->mr->lkey;
822
823         wr.next = NULL;
824         wr.wr_id = encode_wr_id(SRPT_SEND, ioctx->ioctx.index);
825         wr.sg_list = &list;
826         wr.num_sge = 1;
827         wr.opcode = IB_WR_SEND;
828         wr.send_flags = IB_SEND_SIGNALED;
829
830         ret = ib_post_send(ch->qp, &wr, &bad_wr);
831
832 out:
833         if (ret < 0) {
834                 atomic_inc(&ch->sq_wr_avail);
835                 atomic_dec(&ch->req_lim);
836         }
837         return ret;
838 }
839
840 /**
841  * srpt_get_desc_tbl() - Parse the data descriptors of an SRP_CMD request.
842  * @ioctx: Pointer to the I/O context associated with the request.
843  * @srp_cmd: Pointer to the SRP_CMD request data.
844  * @dir: Pointer to the variable to which the transfer direction will be
845  *   written.
846  * @data_len: Pointer to the variable to which the total data length of all
847  *   descriptors in the SRP_CMD request will be written.
848  *
849  * This function initializes ioctx->nrbuf and ioctx->r_bufs.
850  *
851  * Returns -EINVAL when the SRP_CMD request contains inconsistent descriptors;
852  * -ENOMEM when memory allocation fails and zero upon success.
853  */
854 static int srpt_get_desc_tbl(struct srpt_send_ioctx *ioctx,
855                              struct srp_cmd *srp_cmd,
856                              enum dma_data_direction *dir, u64 *data_len)
857 {
858         struct srp_indirect_buf *idb;
859         struct srp_direct_buf *db;
860         unsigned add_cdb_offset;
861         int ret;
862
863         /*
864          * The pointer computations below will only be compiled correctly
865          * if srp_cmd::add_data is declared as s8*, u8*, s8[] or u8[], so check
866          * whether srp_cmd::add_data has been declared as a byte pointer.
867          */
868         BUILD_BUG_ON(!__same_type(srp_cmd->add_data[0], (s8)0)
869                      && !__same_type(srp_cmd->add_data[0], (u8)0));
870
871         BUG_ON(!dir);
872         BUG_ON(!data_len);
873
874         ret = 0;
875         *data_len = 0;
876
877         /*
878          * The lower four bits of the buffer format field contain the DATA-IN
879          * buffer descriptor format, and the highest four bits contain the
880          * DATA-OUT buffer descriptor format.
881          */
882         *dir = DMA_NONE;
883         if (srp_cmd->buf_fmt & 0xf)
884                 /* DATA-IN: transfer data from target to initiator (read). */
885                 *dir = DMA_FROM_DEVICE;
886         else if (srp_cmd->buf_fmt >> 4)
887                 /* DATA-OUT: transfer data from initiator to target (write). */
888                 *dir = DMA_TO_DEVICE;
889
890         /*
891          * According to the SRP spec, the lower two bits of the 'ADDITIONAL
892          * CDB LENGTH' field are reserved and the size in bytes of this field
893          * is four times the value specified in bits 3..7. Hence the "& ~3".
894          */
895         add_cdb_offset = srp_cmd->add_cdb_len & ~3;
896         if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_DIRECT) ||
897             ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_DIRECT)) {
898                 ioctx->n_rbuf = 1;
899                 ioctx->rbufs = &ioctx->single_rbuf;
900
901                 db = (struct srp_direct_buf *)(srp_cmd->add_data
902                                                + add_cdb_offset);
903                 memcpy(ioctx->rbufs, db, sizeof *db);
904                 *data_len = be32_to_cpu(db->len);
905         } else if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_INDIRECT) ||
906                    ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_INDIRECT)) {
907                 idb = (struct srp_indirect_buf *)(srp_cmd->add_data
908                                                   + add_cdb_offset);
909
910                 ioctx->n_rbuf = be32_to_cpu(idb->table_desc.len) / sizeof *db;
911
912                 if (ioctx->n_rbuf >
913                     (srp_cmd->data_out_desc_cnt + srp_cmd->data_in_desc_cnt)) {
914                         printk(KERN_ERR "received unsupported SRP_CMD request"
915                                " type (%u out + %u in != %u / %zu)\n",
916                                srp_cmd->data_out_desc_cnt,
917                                srp_cmd->data_in_desc_cnt,
918                                be32_to_cpu(idb->table_desc.len),
919                                sizeof(*db));
920                         ioctx->n_rbuf = 0;
921                         ret = -EINVAL;
922                         goto out;
923                 }
924
925                 if (ioctx->n_rbuf == 1)
926                         ioctx->rbufs = &ioctx->single_rbuf;
927                 else {
928                         ioctx->rbufs =
929                                 kmalloc(ioctx->n_rbuf * sizeof *db, GFP_ATOMIC);
930                         if (!ioctx->rbufs) {
931                                 ioctx->n_rbuf = 0;
932                                 ret = -ENOMEM;
933                                 goto out;
934                         }
935                 }
936
937                 db = idb->desc_list;
938                 memcpy(ioctx->rbufs, db, ioctx->n_rbuf * sizeof *db);
939                 *data_len = be32_to_cpu(idb->len);
940         }
941 out:
942         return ret;
943 }
944
945 /**
946  * srpt_init_ch_qp() - Initialize queue pair attributes.
947  *
948  * Initialized the attributes of queue pair 'qp' by allowing local write,
949  * remote read and remote write. Also transitions 'qp' to state IB_QPS_INIT.
950  */
951 static int srpt_init_ch_qp(struct srpt_rdma_ch *ch, struct ib_qp *qp)
952 {
953         struct ib_qp_attr *attr;
954         int ret;
955
956         attr = kzalloc(sizeof *attr, GFP_KERNEL);
957         if (!attr)
958                 return -ENOMEM;
959
960         attr->qp_state = IB_QPS_INIT;
961         attr->qp_access_flags = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_READ |
962             IB_ACCESS_REMOTE_WRITE;
963         attr->port_num = ch->sport->port;
964         attr->pkey_index = 0;
965
966         ret = ib_modify_qp(qp, attr,
967                            IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PORT |
968                            IB_QP_PKEY_INDEX);
969
970         kfree(attr);
971         return ret;
972 }
973
974 /**
975  * srpt_ch_qp_rtr() - Change the state of a channel to 'ready to receive' (RTR).
976  * @ch: channel of the queue pair.
977  * @qp: queue pair to change the state of.
978  *
979  * Returns zero upon success and a negative value upon failure.
980  *
981  * Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
982  * If this structure ever becomes larger, it might be necessary to allocate
983  * it dynamically instead of on the stack.
984  */
985 static int srpt_ch_qp_rtr(struct srpt_rdma_ch *ch, struct ib_qp *qp)
986 {
987         struct ib_qp_attr qp_attr;
988         int attr_mask;
989         int ret;
990
991         qp_attr.qp_state = IB_QPS_RTR;
992         ret = ib_cm_init_qp_attr(ch->cm_id, &qp_attr, &attr_mask);
993         if (ret)
994                 goto out;
995
996         qp_attr.max_dest_rd_atomic = 4;
997
998         ret = ib_modify_qp(qp, &qp_attr, attr_mask);
999
1000 out:
1001         return ret;
1002 }
1003
1004 /**
1005  * srpt_ch_qp_rts() - Change the state of a channel to 'ready to send' (RTS).
1006  * @ch: channel of the queue pair.
1007  * @qp: queue pair to change the state of.
1008  *
1009  * Returns zero upon success and a negative value upon failure.
1010  *
1011  * Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
1012  * If this structure ever becomes larger, it might be necessary to allocate
1013  * it dynamically instead of on the stack.
1014  */
1015 static int srpt_ch_qp_rts(struct srpt_rdma_ch *ch, struct ib_qp *qp)
1016 {
1017         struct ib_qp_attr qp_attr;
1018         int attr_mask;
1019         int ret;
1020
1021         qp_attr.qp_state = IB_QPS_RTS;
1022         ret = ib_cm_init_qp_attr(ch->cm_id, &qp_attr, &attr_mask);
1023         if (ret)
1024                 goto out;
1025
1026         qp_attr.max_rd_atomic = 4;
1027
1028         ret = ib_modify_qp(qp, &qp_attr, attr_mask);
1029
1030 out:
1031         return ret;
1032 }
1033
1034 /**
1035  * srpt_ch_qp_err() - Set the channel queue pair state to 'error'.
1036  */
1037 static int srpt_ch_qp_err(struct srpt_rdma_ch *ch)
1038 {
1039         struct ib_qp_attr qp_attr;
1040
1041         qp_attr.qp_state = IB_QPS_ERR;
1042         return ib_modify_qp(ch->qp, &qp_attr, IB_QP_STATE);
1043 }
1044
1045 /**
1046  * srpt_unmap_sg_to_ib_sge() - Unmap an IB SGE list.
1047  */
1048 static void srpt_unmap_sg_to_ib_sge(struct srpt_rdma_ch *ch,
1049                                     struct srpt_send_ioctx *ioctx)
1050 {
1051         struct scatterlist *sg;
1052         enum dma_data_direction dir;
1053
1054         BUG_ON(!ch);
1055         BUG_ON(!ioctx);
1056         BUG_ON(ioctx->n_rdma && !ioctx->rdma_ius);
1057
1058         while (ioctx->n_rdma)
1059                 kfree(ioctx->rdma_ius[--ioctx->n_rdma].sge);
1060
1061         kfree(ioctx->rdma_ius);
1062         ioctx->rdma_ius = NULL;
1063
1064         if (ioctx->mapped_sg_count) {
1065                 sg = ioctx->sg;
1066                 WARN_ON(!sg);
1067                 dir = ioctx->cmd.data_direction;
1068                 BUG_ON(dir == DMA_NONE);
1069                 ib_dma_unmap_sg(ch->sport->sdev->device, sg, ioctx->sg_cnt,
1070                                 opposite_dma_dir(dir));
1071                 ioctx->mapped_sg_count = 0;
1072         }
1073 }
1074
1075 /**
1076  * srpt_map_sg_to_ib_sge() - Map an SG list to an IB SGE list.
1077  */
1078 static int srpt_map_sg_to_ib_sge(struct srpt_rdma_ch *ch,
1079                                  struct srpt_send_ioctx *ioctx)
1080 {
1081         struct se_cmd *cmd;
1082         struct scatterlist *sg, *sg_orig;
1083         int sg_cnt;
1084         enum dma_data_direction dir;
1085         struct rdma_iu *riu;
1086         struct srp_direct_buf *db;
1087         dma_addr_t dma_addr;
1088         struct ib_sge *sge;
1089         u64 raddr;
1090         u32 rsize;
1091         u32 tsize;
1092         u32 dma_len;
1093         int count, nrdma;
1094         int i, j, k;
1095
1096         BUG_ON(!ch);
1097         BUG_ON(!ioctx);
1098         cmd = &ioctx->cmd;
1099         dir = cmd->data_direction;
1100         BUG_ON(dir == DMA_NONE);
1101
1102         transport_do_task_sg_chain(cmd);
1103         ioctx->sg = sg = sg_orig = cmd->t_tasks_sg_chained;
1104         ioctx->sg_cnt = sg_cnt = cmd->t_tasks_sg_chained_no;
1105
1106         count = ib_dma_map_sg(ch->sport->sdev->device, sg, sg_cnt,
1107                               opposite_dma_dir(dir));
1108         if (unlikely(!count))
1109                 return -EAGAIN;
1110
1111         ioctx->mapped_sg_count = count;
1112
1113         if (ioctx->rdma_ius && ioctx->n_rdma_ius)
1114                 nrdma = ioctx->n_rdma_ius;
1115         else {
1116                 nrdma = (count + SRPT_DEF_SG_PER_WQE - 1) / SRPT_DEF_SG_PER_WQE
1117                         + ioctx->n_rbuf;
1118
1119                 ioctx->rdma_ius = kzalloc(nrdma * sizeof *riu, GFP_KERNEL);
1120                 if (!ioctx->rdma_ius)
1121                         goto free_mem;
1122
1123                 ioctx->n_rdma_ius = nrdma;
1124         }
1125
1126         db = ioctx->rbufs;
1127         tsize = cmd->data_length;
1128         dma_len = sg_dma_len(&sg[0]);
1129         riu = ioctx->rdma_ius;
1130
1131         /*
1132          * For each remote desc - calculate the #ib_sge.
1133          * If #ib_sge < SRPT_DEF_SG_PER_WQE per rdma operation then
1134          *      each remote desc rdma_iu is required a rdma wr;
1135          * else
1136          *      we need to allocate extra rdma_iu to carry extra #ib_sge in
1137          *      another rdma wr
1138          */
1139         for (i = 0, j = 0;
1140              j < count && i < ioctx->n_rbuf && tsize > 0; ++i, ++riu, ++db) {
1141                 rsize = be32_to_cpu(db->len);
1142                 raddr = be64_to_cpu(db->va);
1143                 riu->raddr = raddr;
1144                 riu->rkey = be32_to_cpu(db->key);
1145                 riu->sge_cnt = 0;
1146
1147                 /* calculate how many sge required for this remote_buf */
1148                 while (rsize > 0 && tsize > 0) {
1149
1150                         if (rsize >= dma_len) {
1151                                 tsize -= dma_len;
1152                                 rsize -= dma_len;
1153                                 raddr += dma_len;
1154
1155                                 if (tsize > 0) {
1156                                         ++j;
1157                                         if (j < count) {
1158                                                 sg = sg_next(sg);
1159                                                 dma_len = sg_dma_len(sg);
1160                                         }
1161                                 }
1162                         } else {
1163                                 tsize -= rsize;
1164                                 dma_len -= rsize;
1165                                 rsize = 0;
1166                         }
1167
1168                         ++riu->sge_cnt;
1169
1170                         if (rsize > 0 && riu->sge_cnt == SRPT_DEF_SG_PER_WQE) {
1171                                 ++ioctx->n_rdma;
1172                                 riu->sge =
1173                                     kmalloc(riu->sge_cnt * sizeof *riu->sge,
1174                                             GFP_KERNEL);
1175                                 if (!riu->sge)
1176                                         goto free_mem;
1177
1178                                 ++riu;
1179                                 riu->sge_cnt = 0;
1180                                 riu->raddr = raddr;
1181                                 riu->rkey = be32_to_cpu(db->key);
1182                         }
1183                 }
1184
1185                 ++ioctx->n_rdma;
1186                 riu->sge = kmalloc(riu->sge_cnt * sizeof *riu->sge,
1187                                    GFP_KERNEL);
1188                 if (!riu->sge)
1189                         goto free_mem;
1190         }
1191
1192         db = ioctx->rbufs;
1193         tsize = cmd->data_length;
1194         riu = ioctx->rdma_ius;
1195         sg = sg_orig;
1196         dma_len = sg_dma_len(&sg[0]);
1197         dma_addr = sg_dma_address(&sg[0]);
1198
1199         /* this second loop is really mapped sg_addres to rdma_iu->ib_sge */
1200         for (i = 0, j = 0;
1201              j < count && i < ioctx->n_rbuf && tsize > 0; ++i, ++riu, ++db) {
1202                 rsize = be32_to_cpu(db->len);
1203                 sge = riu->sge;
1204                 k = 0;
1205
1206                 while (rsize > 0 && tsize > 0) {
1207                         sge->addr = dma_addr;
1208                         sge->lkey = ch->sport->sdev->mr->lkey;
1209
1210                         if (rsize >= dma_len) {
1211                                 sge->length =
1212                                         (tsize < dma_len) ? tsize : dma_len;
1213                                 tsize -= dma_len;
1214                                 rsize -= dma_len;
1215
1216                                 if (tsize > 0) {
1217                                         ++j;
1218                                         if (j < count) {
1219                                                 sg = sg_next(sg);
1220                                                 dma_len = sg_dma_len(sg);
1221                                                 dma_addr = sg_dma_address(sg);
1222                                         }
1223                                 }
1224                         } else {
1225                                 sge->length = (tsize < rsize) ? tsize : rsize;
1226                                 tsize -= rsize;
1227                                 dma_len -= rsize;
1228                                 dma_addr += rsize;
1229                                 rsize = 0;
1230                         }
1231
1232                         ++k;
1233                         if (k == riu->sge_cnt && rsize > 0 && tsize > 0) {
1234                                 ++riu;
1235                                 sge = riu->sge;
1236                                 k = 0;
1237                         } else if (rsize > 0 && tsize > 0)
1238                                 ++sge;
1239                 }
1240         }
1241
1242         return 0;
1243
1244 free_mem:
1245         srpt_unmap_sg_to_ib_sge(ch, ioctx);
1246
1247         return -ENOMEM;
1248 }
1249
1250 /**
1251  * srpt_get_send_ioctx() - Obtain an I/O context for sending to the initiator.
1252  */
1253 static struct srpt_send_ioctx *srpt_get_send_ioctx(struct srpt_rdma_ch *ch)
1254 {
1255         struct srpt_send_ioctx *ioctx;
1256         unsigned long flags;
1257
1258         BUG_ON(!ch);
1259
1260         ioctx = NULL;
1261         spin_lock_irqsave(&ch->spinlock, flags);
1262         if (!list_empty(&ch->free_list)) {
1263                 ioctx = list_first_entry(&ch->free_list,
1264                                          struct srpt_send_ioctx, free_list);
1265                 list_del(&ioctx->free_list);
1266         }
1267         spin_unlock_irqrestore(&ch->spinlock, flags);
1268
1269         if (!ioctx)
1270                 return ioctx;
1271
1272         BUG_ON(ioctx->ch != ch);
1273         kref_init(&ioctx->kref);
1274         spin_lock_init(&ioctx->spinlock);
1275         ioctx->state = SRPT_STATE_NEW;
1276         ioctx->n_rbuf = 0;
1277         ioctx->rbufs = NULL;
1278         ioctx->n_rdma = 0;
1279         ioctx->n_rdma_ius = 0;
1280         ioctx->rdma_ius = NULL;
1281         ioctx->mapped_sg_count = 0;
1282         init_completion(&ioctx->tx_done);
1283         ioctx->queue_status_only = false;
1284         /*
1285          * transport_init_se_cmd() does not initialize all fields, so do it
1286          * here.
1287          */
1288         memset(&ioctx->cmd, 0, sizeof(ioctx->cmd));
1289         memset(&ioctx->sense_data, 0, sizeof(ioctx->sense_data));
1290
1291         return ioctx;
1292 }
1293
1294 /**
1295  * srpt_put_send_ioctx() - Free up resources.
1296  */
1297 static void srpt_put_send_ioctx(struct srpt_send_ioctx *ioctx)
1298 {
1299         struct srpt_rdma_ch *ch;
1300         unsigned long flags;
1301
1302         BUG_ON(!ioctx);
1303         ch = ioctx->ch;
1304         BUG_ON(!ch);
1305
1306         WARN_ON(srpt_get_cmd_state(ioctx) != SRPT_STATE_DONE);
1307
1308         srpt_unmap_sg_to_ib_sge(ioctx->ch, ioctx);
1309         transport_generic_free_cmd(&ioctx->cmd, 0);
1310
1311         if (ioctx->n_rbuf > 1) {
1312                 kfree(ioctx->rbufs);
1313                 ioctx->rbufs = NULL;
1314                 ioctx->n_rbuf = 0;
1315         }
1316
1317         spin_lock_irqsave(&ch->spinlock, flags);
1318         list_add(&ioctx->free_list, &ch->free_list);
1319         spin_unlock_irqrestore(&ch->spinlock, flags);
1320 }
1321
1322 static void srpt_put_send_ioctx_kref(struct kref *kref)
1323 {
1324         srpt_put_send_ioctx(container_of(kref, struct srpt_send_ioctx, kref));
1325 }
1326
1327 /**
1328  * srpt_abort_cmd() - Abort a SCSI command.
1329  * @ioctx:   I/O context associated with the SCSI command.
1330  * @context: Preferred execution context.
1331  */
1332 static int srpt_abort_cmd(struct srpt_send_ioctx *ioctx)
1333 {
1334         enum srpt_command_state state;
1335         unsigned long flags;
1336
1337         BUG_ON(!ioctx);
1338
1339         /*
1340          * If the command is in a state where the target core is waiting for
1341          * the ib_srpt driver, change the state to the next state. Changing
1342          * the state of the command from SRPT_STATE_NEED_DATA to
1343          * SRPT_STATE_DATA_IN ensures that srpt_xmit_response() will call this
1344          * function a second time.
1345          */
1346
1347         spin_lock_irqsave(&ioctx->spinlock, flags);
1348         state = ioctx->state;
1349         switch (state) {
1350         case SRPT_STATE_NEED_DATA:
1351                 ioctx->state = SRPT_STATE_DATA_IN;
1352                 break;
1353         case SRPT_STATE_DATA_IN:
1354         case SRPT_STATE_CMD_RSP_SENT:
1355         case SRPT_STATE_MGMT_RSP_SENT:
1356                 ioctx->state = SRPT_STATE_DONE;
1357                 break;
1358         default:
1359                 break;
1360         }
1361         spin_unlock_irqrestore(&ioctx->spinlock, flags);
1362
1363         if (state == SRPT_STATE_DONE)
1364                 goto out;
1365
1366         pr_debug("Aborting cmd with state %d and tag %lld\n", state,
1367                  ioctx->tag);
1368
1369         switch (state) {
1370         case SRPT_STATE_NEW:
1371         case SRPT_STATE_DATA_IN:
1372         case SRPT_STATE_MGMT:
1373                 /*
1374                  * Do nothing - defer abort processing until
1375                  * srpt_queue_response() is invoked.
1376                  */
1377                 WARN_ON(!transport_check_aborted_status(&ioctx->cmd, false));
1378                 break;
1379         case SRPT_STATE_NEED_DATA:
1380                 /* DMA_TO_DEVICE (write) - RDMA read error. */
1381                 spin_lock_irqsave(&ioctx->cmd.t_state_lock, flags);
1382                 ioctx->cmd.transport_state |= CMD_T_LUN_STOP;
1383                 spin_unlock_irqrestore(&ioctx->cmd.t_state_lock, flags);
1384                 transport_generic_handle_data(&ioctx->cmd);
1385                 break;
1386         case SRPT_STATE_CMD_RSP_SENT:
1387                 /*
1388                  * SRP_RSP sending failed or the SRP_RSP send completion has
1389                  * not been received in time.
1390                  */
1391                 srpt_unmap_sg_to_ib_sge(ioctx->ch, ioctx);
1392                 spin_lock_irqsave(&ioctx->cmd.t_state_lock, flags);
1393                 ioctx->cmd.transport_state |= CMD_T_LUN_STOP;
1394                 spin_unlock_irqrestore(&ioctx->cmd.t_state_lock, flags);
1395                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1396                 break;
1397         case SRPT_STATE_MGMT_RSP_SENT:
1398                 srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
1399                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1400                 break;
1401         default:
1402                 WARN_ON("ERROR: unexpected command state");
1403                 break;
1404         }
1405
1406 out:
1407         return state;
1408 }
1409
1410 /**
1411  * srpt_handle_send_err_comp() - Process an IB_WC_SEND error completion.
1412  */
1413 static void srpt_handle_send_err_comp(struct srpt_rdma_ch *ch, u64 wr_id)
1414 {
1415         struct srpt_send_ioctx *ioctx;
1416         enum srpt_command_state state;
1417         struct se_cmd *cmd;
1418         u32 index;
1419
1420         atomic_inc(&ch->sq_wr_avail);
1421
1422         index = idx_from_wr_id(wr_id);
1423         ioctx = ch->ioctx_ring[index];
1424         state = srpt_get_cmd_state(ioctx);
1425         cmd = &ioctx->cmd;
1426
1427         WARN_ON(state != SRPT_STATE_CMD_RSP_SENT
1428                 && state != SRPT_STATE_MGMT_RSP_SENT
1429                 && state != SRPT_STATE_NEED_DATA
1430                 && state != SRPT_STATE_DONE);
1431
1432         /* If SRP_RSP sending failed, undo the ch->req_lim change. */
1433         if (state == SRPT_STATE_CMD_RSP_SENT
1434             || state == SRPT_STATE_MGMT_RSP_SENT)
1435                 atomic_dec(&ch->req_lim);
1436
1437         srpt_abort_cmd(ioctx);
1438 }
1439
1440 /**
1441  * srpt_handle_send_comp() - Process an IB send completion notification.
1442  */
1443 static void srpt_handle_send_comp(struct srpt_rdma_ch *ch,
1444                                   struct srpt_send_ioctx *ioctx)
1445 {
1446         enum srpt_command_state state;
1447
1448         atomic_inc(&ch->sq_wr_avail);
1449
1450         state = srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
1451
1452         if (WARN_ON(state != SRPT_STATE_CMD_RSP_SENT
1453                     && state != SRPT_STATE_MGMT_RSP_SENT
1454                     && state != SRPT_STATE_DONE))
1455                 pr_debug("state = %d\n", state);
1456
1457         if (state != SRPT_STATE_DONE)
1458                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1459         else
1460                 printk(KERN_ERR "IB completion has been received too late for"
1461                        " wr_id = %u.\n", ioctx->ioctx.index);
1462 }
1463
1464 /**
1465  * srpt_handle_rdma_comp() - Process an IB RDMA completion notification.
1466  *
1467  * Note: transport_generic_handle_data() is asynchronous so unmapping the
1468  * data that has been transferred via IB RDMA must be postponed until the
1469  * check_stop_free() callback.
1470  */
1471 static void srpt_handle_rdma_comp(struct srpt_rdma_ch *ch,
1472                                   struct srpt_send_ioctx *ioctx,
1473                                   enum srpt_opcode opcode)
1474 {
1475         WARN_ON(ioctx->n_rdma <= 0);
1476         atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
1477
1478         if (opcode == SRPT_RDMA_READ_LAST) {
1479                 if (srpt_test_and_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA,
1480                                                 SRPT_STATE_DATA_IN))
1481                         transport_generic_handle_data(&ioctx->cmd);
1482                 else
1483                         printk(KERN_ERR "%s[%d]: wrong state = %d\n", __func__,
1484                                __LINE__, srpt_get_cmd_state(ioctx));
1485         } else if (opcode == SRPT_RDMA_ABORT) {
1486                 ioctx->rdma_aborted = true;
1487         } else {
1488                 WARN(true, "unexpected opcode %d\n", opcode);
1489         }
1490 }
1491
1492 /**
1493  * srpt_handle_rdma_err_comp() - Process an IB RDMA error completion.
1494  */
1495 static void srpt_handle_rdma_err_comp(struct srpt_rdma_ch *ch,
1496                                       struct srpt_send_ioctx *ioctx,
1497                                       enum srpt_opcode opcode)
1498 {
1499         struct se_cmd *cmd;
1500         enum srpt_command_state state;
1501         unsigned long flags;
1502
1503         cmd = &ioctx->cmd;
1504         state = srpt_get_cmd_state(ioctx);
1505         switch (opcode) {
1506         case SRPT_RDMA_READ_LAST:
1507                 if (ioctx->n_rdma <= 0) {
1508                         printk(KERN_ERR "Received invalid RDMA read"
1509                                " error completion with idx %d\n",
1510                                ioctx->ioctx.index);
1511                         break;
1512                 }
1513                 atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
1514                 if (state == SRPT_STATE_NEED_DATA)
1515                         srpt_abort_cmd(ioctx);
1516                 else
1517                         printk(KERN_ERR "%s[%d]: wrong state = %d\n",
1518                                __func__, __LINE__, state);
1519                 break;
1520         case SRPT_RDMA_WRITE_LAST:
1521                 spin_lock_irqsave(&ioctx->cmd.t_state_lock, flags);
1522                 ioctx->cmd.transport_state |= CMD_T_LUN_STOP;
1523                 spin_unlock_irqrestore(&ioctx->cmd.t_state_lock, flags);
1524                 break;
1525         default:
1526                 printk(KERN_ERR "%s[%d]: opcode = %u\n", __func__,
1527                        __LINE__, opcode);
1528                 break;
1529         }
1530 }
1531
1532 /**
1533  * srpt_build_cmd_rsp() - Build an SRP_RSP response.
1534  * @ch: RDMA channel through which the request has been received.
1535  * @ioctx: I/O context associated with the SRP_CMD request. The response will
1536  *   be built in the buffer ioctx->buf points at and hence this function will
1537  *   overwrite the request data.
1538  * @tag: tag of the request for which this response is being generated.
1539  * @status: value for the STATUS field of the SRP_RSP information unit.
1540  *
1541  * Returns the size in bytes of the SRP_RSP response.
1542  *
1543  * An SRP_RSP response contains a SCSI status or service response. See also
1544  * section 6.9 in the SRP r16a document for the format of an SRP_RSP
1545  * response. See also SPC-2 for more information about sense data.
1546  */
1547 static int srpt_build_cmd_rsp(struct srpt_rdma_ch *ch,
1548                               struct srpt_send_ioctx *ioctx, u64 tag,
1549                               int status)
1550 {
1551         struct srp_rsp *srp_rsp;
1552         const u8 *sense_data;
1553         int sense_data_len, max_sense_len;
1554
1555         /*
1556          * The lowest bit of all SAM-3 status codes is zero (see also
1557          * paragraph 5.3 in SAM-3).
1558          */
1559         WARN_ON(status & 1);
1560
1561         srp_rsp = ioctx->ioctx.buf;
1562         BUG_ON(!srp_rsp);
1563
1564         sense_data = ioctx->sense_data;
1565         sense_data_len = ioctx->cmd.scsi_sense_length;
1566         WARN_ON(sense_data_len > sizeof(ioctx->sense_data));
1567
1568         memset(srp_rsp, 0, sizeof *srp_rsp);
1569         srp_rsp->opcode = SRP_RSP;
1570         srp_rsp->req_lim_delta =
1571                 __constant_cpu_to_be32(1 + atomic_xchg(&ch->req_lim_delta, 0));
1572         srp_rsp->tag = tag;
1573         srp_rsp->status = status;
1574
1575         if (sense_data_len) {
1576                 BUILD_BUG_ON(MIN_MAX_RSP_SIZE <= sizeof(*srp_rsp));
1577                 max_sense_len = ch->max_ti_iu_len - sizeof(*srp_rsp);
1578                 if (sense_data_len > max_sense_len) {
1579                         printk(KERN_WARNING "truncated sense data from %d to %d"
1580                                " bytes\n", sense_data_len, max_sense_len);
1581                         sense_data_len = max_sense_len;
1582                 }
1583
1584                 srp_rsp->flags |= SRP_RSP_FLAG_SNSVALID;
1585                 srp_rsp->sense_data_len = cpu_to_be32(sense_data_len);
1586                 memcpy(srp_rsp + 1, sense_data, sense_data_len);
1587         }
1588
1589         return sizeof(*srp_rsp) + sense_data_len;
1590 }
1591
1592 /**
1593  * srpt_build_tskmgmt_rsp() - Build a task management response.
1594  * @ch:       RDMA channel through which the request has been received.
1595  * @ioctx:    I/O context in which the SRP_RSP response will be built.
1596  * @rsp_code: RSP_CODE that will be stored in the response.
1597  * @tag:      Tag of the request for which this response is being generated.
1598  *
1599  * Returns the size in bytes of the SRP_RSP response.
1600  *
1601  * An SRP_RSP response contains a SCSI status or service response. See also
1602  * section 6.9 in the SRP r16a document for the format of an SRP_RSP
1603  * response.
1604  */
1605 static int srpt_build_tskmgmt_rsp(struct srpt_rdma_ch *ch,
1606                                   struct srpt_send_ioctx *ioctx,
1607                                   u8 rsp_code, u64 tag)
1608 {
1609         struct srp_rsp *srp_rsp;
1610         int resp_data_len;
1611         int resp_len;
1612
1613         resp_data_len = (rsp_code == SRP_TSK_MGMT_SUCCESS) ? 0 : 4;
1614         resp_len = sizeof(*srp_rsp) + resp_data_len;
1615
1616         srp_rsp = ioctx->ioctx.buf;
1617         BUG_ON(!srp_rsp);
1618         memset(srp_rsp, 0, sizeof *srp_rsp);
1619
1620         srp_rsp->opcode = SRP_RSP;
1621         srp_rsp->req_lim_delta = __constant_cpu_to_be32(1
1622                                     + atomic_xchg(&ch->req_lim_delta, 0));
1623         srp_rsp->tag = tag;
1624
1625         if (rsp_code != SRP_TSK_MGMT_SUCCESS) {
1626                 srp_rsp->flags |= SRP_RSP_FLAG_RSPVALID;
1627                 srp_rsp->resp_data_len = cpu_to_be32(resp_data_len);
1628                 srp_rsp->data[3] = rsp_code;
1629         }
1630
1631         return resp_len;
1632 }
1633
1634 #define NO_SUCH_LUN ((uint64_t)-1LL)
1635
1636 /*
1637  * SCSI LUN addressing method. See also SAM-2 and the section about
1638  * eight byte LUNs.
1639  */
1640 enum scsi_lun_addr_method {
1641         SCSI_LUN_ADDR_METHOD_PERIPHERAL   = 0,
1642         SCSI_LUN_ADDR_METHOD_FLAT         = 1,
1643         SCSI_LUN_ADDR_METHOD_LUN          = 2,
1644         SCSI_LUN_ADDR_METHOD_EXTENDED_LUN = 3,
1645 };
1646
1647 /*
1648  * srpt_unpack_lun() - Convert from network LUN to linear LUN.
1649  *
1650  * Convert an 2-byte, 4-byte, 6-byte or 8-byte LUN structure in network byte
1651  * order (big endian) to a linear LUN. Supports three LUN addressing methods:
1652  * peripheral, flat and logical unit. See also SAM-2, section 4.9.4 (page 40).
1653  */
1654 static uint64_t srpt_unpack_lun(const uint8_t *lun, int len)
1655 {
1656         uint64_t res = NO_SUCH_LUN;
1657         int addressing_method;
1658
1659         if (unlikely(len < 2)) {
1660                 printk(KERN_ERR "Illegal LUN length %d, expected 2 bytes or "
1661                        "more", len);
1662                 goto out;
1663         }
1664
1665         switch (len) {
1666         case 8:
1667                 if ((*((__be64 *)lun) &
1668                      __constant_cpu_to_be64(0x0000FFFFFFFFFFFFLL)) != 0)
1669                         goto out_err;
1670                 break;
1671         case 4:
1672                 if (*((__be16 *)&lun[2]) != 0)
1673                         goto out_err;
1674                 break;
1675         case 6:
1676                 if (*((__be32 *)&lun[2]) != 0)
1677                         goto out_err;
1678                 break;
1679         case 2:
1680                 break;
1681         default:
1682                 goto out_err;
1683         }
1684
1685         addressing_method = (*lun) >> 6; /* highest two bits of byte 0 */
1686         switch (addressing_method) {
1687         case SCSI_LUN_ADDR_METHOD_PERIPHERAL:
1688         case SCSI_LUN_ADDR_METHOD_FLAT:
1689         case SCSI_LUN_ADDR_METHOD_LUN:
1690                 res = *(lun + 1) | (((*lun) & 0x3f) << 8);
1691                 break;
1692
1693         case SCSI_LUN_ADDR_METHOD_EXTENDED_LUN:
1694         default:
1695                 printk(KERN_ERR "Unimplemented LUN addressing method %u",
1696                        addressing_method);
1697                 break;
1698         }
1699
1700 out:
1701         return res;
1702
1703 out_err:
1704         printk(KERN_ERR "Support for multi-level LUNs has not yet been"
1705                " implemented");
1706         goto out;
1707 }
1708
1709 static int srpt_check_stop_free(struct se_cmd *cmd)
1710 {
1711         struct srpt_send_ioctx *ioctx;
1712
1713         ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
1714         return kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1715 }
1716
1717 /**
1718  * srpt_handle_cmd() - Process SRP_CMD.
1719  */
1720 static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
1721                            struct srpt_recv_ioctx *recv_ioctx,
1722                            struct srpt_send_ioctx *send_ioctx)
1723 {
1724         struct se_cmd *cmd;
1725         struct srp_cmd *srp_cmd;
1726         uint64_t unpacked_lun;
1727         u64 data_len;
1728         enum dma_data_direction dir;
1729         int ret;
1730
1731         BUG_ON(!send_ioctx);
1732
1733         srp_cmd = recv_ioctx->ioctx.buf;
1734         kref_get(&send_ioctx->kref);
1735         cmd = &send_ioctx->cmd;
1736         send_ioctx->tag = srp_cmd->tag;
1737
1738         switch (srp_cmd->task_attr) {
1739         case SRP_CMD_SIMPLE_Q:
1740                 cmd->sam_task_attr = MSG_SIMPLE_TAG;
1741                 break;
1742         case SRP_CMD_ORDERED_Q:
1743         default:
1744                 cmd->sam_task_attr = MSG_ORDERED_TAG;
1745                 break;
1746         case SRP_CMD_HEAD_OF_Q:
1747                 cmd->sam_task_attr = MSG_HEAD_TAG;
1748                 break;
1749         case SRP_CMD_ACA:
1750                 cmd->sam_task_attr = MSG_ACA_TAG;
1751                 break;
1752         }
1753
1754         ret = srpt_get_desc_tbl(send_ioctx, srp_cmd, &dir, &data_len);
1755         if (ret) {
1756                 printk(KERN_ERR "0x%llx: parsing SRP descriptor table failed.\n",
1757                        srp_cmd->tag);
1758                 cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1759                 cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1760                 goto send_sense;
1761         }
1762
1763         cmd->data_length = data_len;
1764         cmd->data_direction = dir;
1765         unpacked_lun = srpt_unpack_lun((uint8_t *)&srp_cmd->lun,
1766                                        sizeof(srp_cmd->lun));
1767         if (transport_lookup_cmd_lun(cmd, unpacked_lun) < 0)
1768                 goto send_sense;
1769         ret = transport_generic_allocate_tasks(cmd, srp_cmd->cdb);
1770         if (cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
1771                 srpt_queue_status(cmd);
1772         else if (cmd->se_cmd_flags & SCF_SCSI_CDB_EXCEPTION)
1773                 goto send_sense;
1774         else
1775                 WARN_ON_ONCE(ret);
1776
1777         transport_handle_cdb_direct(cmd);
1778         return 0;
1779
1780 send_sense:
1781         transport_send_check_condition_and_sense(cmd, cmd->scsi_sense_reason,
1782                                                  0);
1783         return -1;
1784 }
1785
1786 /**
1787  * srpt_rx_mgmt_fn_tag() - Process a task management function by tag.
1788  * @ch: RDMA channel of the task management request.
1789  * @fn: Task management function to perform.
1790  * @req_tag: Tag of the SRP task management request.
1791  * @mgmt_ioctx: I/O context of the task management request.
1792  *
1793  * Returns zero if the target core will process the task management
1794  * request asynchronously.
1795  *
1796  * Note: It is assumed that the initiator serializes tag-based task management
1797  * requests.
1798  */
1799 static int srpt_rx_mgmt_fn_tag(struct srpt_send_ioctx *ioctx, u64 tag)
1800 {
1801         struct srpt_device *sdev;
1802         struct srpt_rdma_ch *ch;
1803         struct srpt_send_ioctx *target;
1804         int ret, i;
1805
1806         ret = -EINVAL;
1807         ch = ioctx->ch;
1808         BUG_ON(!ch);
1809         BUG_ON(!ch->sport);
1810         sdev = ch->sport->sdev;
1811         BUG_ON(!sdev);
1812         spin_lock_irq(&sdev->spinlock);
1813         for (i = 0; i < ch->rq_size; ++i) {
1814                 target = ch->ioctx_ring[i];
1815                 if (target->cmd.se_lun == ioctx->cmd.se_lun &&
1816                     target->tag == tag &&
1817                     srpt_get_cmd_state(target) != SRPT_STATE_DONE) {
1818                         ret = 0;
1819                         /* now let the target core abort &target->cmd; */
1820                         break;
1821                 }
1822         }
1823         spin_unlock_irq(&sdev->spinlock);
1824         return ret;
1825 }
1826
1827 static int srp_tmr_to_tcm(int fn)
1828 {
1829         switch (fn) {
1830         case SRP_TSK_ABORT_TASK:
1831                 return TMR_ABORT_TASK;
1832         case SRP_TSK_ABORT_TASK_SET:
1833                 return TMR_ABORT_TASK_SET;
1834         case SRP_TSK_CLEAR_TASK_SET:
1835                 return TMR_CLEAR_TASK_SET;
1836         case SRP_TSK_LUN_RESET:
1837                 return TMR_LUN_RESET;
1838         case SRP_TSK_CLEAR_ACA:
1839                 return TMR_CLEAR_ACA;
1840         default:
1841                 return -1;
1842         }
1843 }
1844
1845 /**
1846  * srpt_handle_tsk_mgmt() - Process an SRP_TSK_MGMT information unit.
1847  *
1848  * Returns 0 if and only if the request will be processed by the target core.
1849  *
1850  * For more information about SRP_TSK_MGMT information units, see also section
1851  * 6.7 in the SRP r16a document.
1852  */
1853 static void srpt_handle_tsk_mgmt(struct srpt_rdma_ch *ch,
1854                                  struct srpt_recv_ioctx *recv_ioctx,
1855                                  struct srpt_send_ioctx *send_ioctx)
1856 {
1857         struct srp_tsk_mgmt *srp_tsk;
1858         struct se_cmd *cmd;
1859         uint64_t unpacked_lun;
1860         int tcm_tmr;
1861         int res;
1862
1863         BUG_ON(!send_ioctx);
1864
1865         srp_tsk = recv_ioctx->ioctx.buf;
1866         cmd = &send_ioctx->cmd;
1867
1868         pr_debug("recv tsk_mgmt fn %d for task_tag %lld and cmd tag %lld"
1869                  " cm_id %p sess %p\n", srp_tsk->tsk_mgmt_func,
1870                  srp_tsk->task_tag, srp_tsk->tag, ch->cm_id, ch->sess);
1871
1872         srpt_set_cmd_state(send_ioctx, SRPT_STATE_MGMT);
1873         send_ioctx->tag = srp_tsk->tag;
1874         tcm_tmr = srp_tmr_to_tcm(srp_tsk->tsk_mgmt_func);
1875         if (tcm_tmr < 0) {
1876                 send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1877                 send_ioctx->cmd.se_tmr_req->response =
1878                         TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
1879                 goto process_tmr;
1880         }
1881         res = core_tmr_alloc_req(cmd, NULL, tcm_tmr, GFP_KERNEL);
1882         if (res < 0) {
1883                 send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1884                 send_ioctx->cmd.se_tmr_req->response = TMR_FUNCTION_REJECTED;
1885                 goto process_tmr;
1886         }
1887
1888         unpacked_lun = srpt_unpack_lun((uint8_t *)&srp_tsk->lun,
1889                                        sizeof(srp_tsk->lun));
1890         res = transport_lookup_tmr_lun(&send_ioctx->cmd, unpacked_lun);
1891         if (res) {
1892                 pr_debug("rejecting TMR for LUN %lld\n", unpacked_lun);
1893                 send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1894                 send_ioctx->cmd.se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1895                 goto process_tmr;
1896         }
1897
1898         if (srp_tsk->tsk_mgmt_func == SRP_TSK_ABORT_TASK)
1899                 srpt_rx_mgmt_fn_tag(send_ioctx, srp_tsk->task_tag);
1900
1901 process_tmr:
1902         kref_get(&send_ioctx->kref);
1903         if (!(send_ioctx->cmd.se_cmd_flags & SCF_SCSI_CDB_EXCEPTION))
1904                 transport_generic_handle_tmr(&send_ioctx->cmd);
1905         else
1906                 transport_send_check_condition_and_sense(cmd,
1907                                                 cmd->scsi_sense_reason, 0);
1908
1909 }
1910
1911 /**
1912  * srpt_handle_new_iu() - Process a newly received information unit.
1913  * @ch:    RDMA channel through which the information unit has been received.
1914  * @ioctx: SRPT I/O context associated with the information unit.
1915  */
1916 static void srpt_handle_new_iu(struct srpt_rdma_ch *ch,
1917                                struct srpt_recv_ioctx *recv_ioctx,
1918                                struct srpt_send_ioctx *send_ioctx)
1919 {
1920         struct srp_cmd *srp_cmd;
1921         enum rdma_ch_state ch_state;
1922
1923         BUG_ON(!ch);
1924         BUG_ON(!recv_ioctx);
1925
1926         ib_dma_sync_single_for_cpu(ch->sport->sdev->device,
1927                                    recv_ioctx->ioctx.dma, srp_max_req_size,
1928                                    DMA_FROM_DEVICE);
1929
1930         ch_state = srpt_get_ch_state(ch);
1931         if (unlikely(ch_state == CH_CONNECTING)) {
1932                 list_add_tail(&recv_ioctx->wait_list, &ch->cmd_wait_list);
1933                 goto out;
1934         }
1935
1936         if (unlikely(ch_state != CH_LIVE))
1937                 goto out;
1938
1939         srp_cmd = recv_ioctx->ioctx.buf;
1940         if (srp_cmd->opcode == SRP_CMD || srp_cmd->opcode == SRP_TSK_MGMT) {
1941                 if (!send_ioctx)
1942                         send_ioctx = srpt_get_send_ioctx(ch);
1943                 if (unlikely(!send_ioctx)) {
1944                         list_add_tail(&recv_ioctx->wait_list,
1945                                       &ch->cmd_wait_list);
1946                         goto out;
1947                 }
1948         }
1949
1950         transport_init_se_cmd(&send_ioctx->cmd, &srpt_target->tf_ops, ch->sess,
1951                               0, DMA_NONE, MSG_SIMPLE_TAG,
1952                               send_ioctx->sense_data);
1953
1954         switch (srp_cmd->opcode) {
1955         case SRP_CMD:
1956                 srpt_handle_cmd(ch, recv_ioctx, send_ioctx);
1957                 break;
1958         case SRP_TSK_MGMT:
1959                 srpt_handle_tsk_mgmt(ch, recv_ioctx, send_ioctx);
1960                 break;
1961         case SRP_I_LOGOUT:
1962                 printk(KERN_ERR "Not yet implemented: SRP_I_LOGOUT\n");
1963                 break;
1964         case SRP_CRED_RSP:
1965                 pr_debug("received SRP_CRED_RSP\n");
1966                 break;
1967         case SRP_AER_RSP:
1968                 pr_debug("received SRP_AER_RSP\n");
1969                 break;
1970         case SRP_RSP:
1971                 printk(KERN_ERR "Received SRP_RSP\n");
1972                 break;
1973         default:
1974                 printk(KERN_ERR "received IU with unknown opcode 0x%x\n",
1975                        srp_cmd->opcode);
1976                 break;
1977         }
1978
1979         srpt_post_recv(ch->sport->sdev, recv_ioctx);
1980 out:
1981         return;
1982 }
1983
1984 static void srpt_process_rcv_completion(struct ib_cq *cq,
1985                                         struct srpt_rdma_ch *ch,
1986                                         struct ib_wc *wc)
1987 {
1988         struct srpt_device *sdev = ch->sport->sdev;
1989         struct srpt_recv_ioctx *ioctx;
1990         u32 index;
1991
1992         index = idx_from_wr_id(wc->wr_id);
1993         if (wc->status == IB_WC_SUCCESS) {
1994                 int req_lim;
1995
1996                 req_lim = atomic_dec_return(&ch->req_lim);
1997                 if (unlikely(req_lim < 0))
1998                         printk(KERN_ERR "req_lim = %d < 0\n", req_lim);
1999                 ioctx = sdev->ioctx_ring[index];
2000                 srpt_handle_new_iu(ch, ioctx, NULL);
2001         } else {
2002                 printk(KERN_INFO "receiving failed for idx %u with status %d\n",
2003                        index, wc->status);
2004         }
2005 }
2006
2007 /**
2008  * srpt_process_send_completion() - Process an IB send completion.
2009  *
2010  * Note: Although this has not yet been observed during tests, at least in
2011  * theory it is possible that the srpt_get_send_ioctx() call invoked by
2012  * srpt_handle_new_iu() fails. This is possible because the req_lim_delta
2013  * value in each response is set to one, and it is possible that this response
2014  * makes the initiator send a new request before the send completion for that
2015  * response has been processed. This could e.g. happen if the call to
2016  * srpt_put_send_iotcx() is delayed because of a higher priority interrupt or
2017  * if IB retransmission causes generation of the send completion to be
2018  * delayed. Incoming information units for which srpt_get_send_ioctx() fails
2019  * are queued on cmd_wait_list. The code below processes these delayed
2020  * requests one at a time.
2021  */
2022 static void srpt_process_send_completion(struct ib_cq *cq,
2023                                          struct srpt_rdma_ch *ch,
2024                                          struct ib_wc *wc)
2025 {
2026         struct srpt_send_ioctx *send_ioctx;
2027         uint32_t index;
2028         enum srpt_opcode opcode;
2029
2030         index = idx_from_wr_id(wc->wr_id);
2031         opcode = opcode_from_wr_id(wc->wr_id);
2032         send_ioctx = ch->ioctx_ring[index];
2033         if (wc->status == IB_WC_SUCCESS) {
2034                 if (opcode == SRPT_SEND)
2035                         srpt_handle_send_comp(ch, send_ioctx);
2036                 else {
2037                         WARN_ON(opcode != SRPT_RDMA_ABORT &&
2038                                 wc->opcode != IB_WC_RDMA_READ);
2039                         srpt_handle_rdma_comp(ch, send_ioctx, opcode);
2040                 }
2041         } else {
2042                 if (opcode == SRPT_SEND) {
2043                         printk(KERN_INFO "sending response for idx %u failed"
2044                                " with status %d\n", index, wc->status);
2045                         srpt_handle_send_err_comp(ch, wc->wr_id);
2046                 } else if (opcode != SRPT_RDMA_MID) {
2047                         printk(KERN_INFO "RDMA t %d for idx %u failed with"
2048                                 " status %d", opcode, index, wc->status);
2049                         srpt_handle_rdma_err_comp(ch, send_ioctx, opcode);
2050                 }
2051         }
2052
2053         while (unlikely(opcode == SRPT_SEND
2054                         && !list_empty(&ch->cmd_wait_list)
2055                         && srpt_get_ch_state(ch) == CH_LIVE
2056                         && (send_ioctx = srpt_get_send_ioctx(ch)) != NULL)) {
2057                 struct srpt_recv_ioctx *recv_ioctx;
2058
2059                 recv_ioctx = list_first_entry(&ch->cmd_wait_list,
2060                                               struct srpt_recv_ioctx,
2061                                               wait_list);
2062                 list_del(&recv_ioctx->wait_list);
2063                 srpt_handle_new_iu(ch, recv_ioctx, send_ioctx);
2064         }
2065 }
2066
2067 static void srpt_process_completion(struct ib_cq *cq, struct srpt_rdma_ch *ch)
2068 {
2069         struct ib_wc *const wc = ch->wc;
2070         int i, n;
2071
2072         WARN_ON(cq != ch->cq);
2073
2074         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
2075         while ((n = ib_poll_cq(cq, ARRAY_SIZE(ch->wc), wc)) > 0) {
2076                 for (i = 0; i < n; i++) {
2077                         if (opcode_from_wr_id(wc[i].wr_id) == SRPT_RECV)
2078                                 srpt_process_rcv_completion(cq, ch, &wc[i]);
2079                         else
2080                                 srpt_process_send_completion(cq, ch, &wc[i]);
2081                 }
2082         }
2083 }
2084
2085 /**
2086  * srpt_completion() - IB completion queue callback function.
2087  *
2088  * Notes:
2089  * - It is guaranteed that a completion handler will never be invoked
2090  *   concurrently on two different CPUs for the same completion queue. See also
2091  *   Documentation/infiniband/core_locking.txt and the implementation of
2092  *   handle_edge_irq() in kernel/irq/chip.c.
2093  * - When threaded IRQs are enabled, completion handlers are invoked in thread
2094  *   context instead of interrupt context.
2095  */
2096 static void srpt_completion(struct ib_cq *cq, void *ctx)
2097 {
2098         struct srpt_rdma_ch *ch = ctx;
2099
2100         wake_up_interruptible(&ch->wait_queue);
2101 }
2102
2103 static int srpt_compl_thread(void *arg)
2104 {
2105         struct srpt_rdma_ch *ch;
2106
2107         /* Hibernation / freezing of the SRPT kernel thread is not supported. */
2108         current->flags |= PF_NOFREEZE;
2109
2110         ch = arg;
2111         BUG_ON(!ch);
2112         printk(KERN_INFO "Session %s: kernel thread %s (PID %d) started\n",
2113                ch->sess_name, ch->thread->comm, current->pid);
2114         while (!kthread_should_stop()) {
2115                 wait_event_interruptible(ch->wait_queue,
2116                         (srpt_process_completion(ch->cq, ch),
2117                          kthread_should_stop()));
2118         }
2119         printk(KERN_INFO "Session %s: kernel thread %s (PID %d) stopped\n",
2120                ch->sess_name, ch->thread->comm, current->pid);
2121         return 0;
2122 }
2123
2124 /**
2125  * srpt_create_ch_ib() - Create receive and send completion queues.
2126  */
2127 static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
2128 {
2129         struct ib_qp_init_attr *qp_init;
2130         struct srpt_port *sport = ch->sport;
2131         struct srpt_device *sdev = sport->sdev;
2132         u32 srp_sq_size = sport->port_attrib.srp_sq_size;
2133         int ret;
2134
2135         WARN_ON(ch->rq_size < 1);
2136
2137         ret = -ENOMEM;
2138         qp_init = kzalloc(sizeof *qp_init, GFP_KERNEL);
2139         if (!qp_init)
2140                 goto out;
2141
2142         ch->cq = ib_create_cq(sdev->device, srpt_completion, NULL, ch,
2143                               ch->rq_size + srp_sq_size, 0);
2144         if (IS_ERR(ch->cq)) {
2145                 ret = PTR_ERR(ch->cq);
2146                 printk(KERN_ERR "failed to create CQ cqe= %d ret= %d\n",
2147                        ch->rq_size + srp_sq_size, ret);
2148                 goto out;
2149         }
2150
2151         qp_init->qp_context = (void *)ch;
2152         qp_init->event_handler
2153                 = (void(*)(struct ib_event *, void*))srpt_qp_event;
2154         qp_init->send_cq = ch->cq;
2155         qp_init->recv_cq = ch->cq;
2156         qp_init->srq = sdev->srq;
2157         qp_init->sq_sig_type = IB_SIGNAL_REQ_WR;
2158         qp_init->qp_type = IB_QPT_RC;
2159         qp_init->cap.max_send_wr = srp_sq_size;
2160         qp_init->cap.max_send_sge = SRPT_DEF_SG_PER_WQE;
2161
2162         ch->qp = ib_create_qp(sdev->pd, qp_init);
2163         if (IS_ERR(ch->qp)) {
2164                 ret = PTR_ERR(ch->qp);
2165                 printk(KERN_ERR "failed to create_qp ret= %d\n", ret);
2166                 goto err_destroy_cq;
2167         }
2168
2169         atomic_set(&ch->sq_wr_avail, qp_init->cap.max_send_wr);
2170
2171         pr_debug("%s: max_cqe= %d max_sge= %d sq_size = %d cm_id= %p\n",
2172                  __func__, ch->cq->cqe, qp_init->cap.max_send_sge,
2173                  qp_init->cap.max_send_wr, ch->cm_id);
2174
2175         ret = srpt_init_ch_qp(ch, ch->qp);
2176         if (ret)
2177                 goto err_destroy_qp;
2178
2179         init_waitqueue_head(&ch->wait_queue);
2180
2181         pr_debug("creating thread for session %s\n", ch->sess_name);
2182
2183         ch->thread = kthread_run(srpt_compl_thread, ch, "ib_srpt_compl");
2184         if (IS_ERR(ch->thread)) {
2185                 printk(KERN_ERR "failed to create kernel thread %ld\n",
2186                        PTR_ERR(ch->thread));
2187                 ch->thread = NULL;
2188                 goto err_destroy_qp;
2189         }
2190
2191 out:
2192         kfree(qp_init);
2193         return ret;
2194
2195 err_destroy_qp:
2196         ib_destroy_qp(ch->qp);
2197 err_destroy_cq:
2198         ib_destroy_cq(ch->cq);
2199         goto out;
2200 }
2201
2202 static void srpt_destroy_ch_ib(struct srpt_rdma_ch *ch)
2203 {
2204         if (ch->thread)
2205                 kthread_stop(ch->thread);
2206
2207         ib_destroy_qp(ch->qp);
2208         ib_destroy_cq(ch->cq);
2209 }
2210
2211 /**
2212  * __srpt_close_ch() - Close an RDMA channel by setting the QP error state.
2213  *
2214  * Reset the QP and make sure all resources associated with the channel will
2215  * be deallocated at an appropriate time.
2216  *
2217  * Note: The caller must hold ch->sport->sdev->spinlock.
2218  */
2219 static void __srpt_close_ch(struct srpt_rdma_ch *ch)
2220 {
2221         struct srpt_device *sdev;
2222         enum rdma_ch_state prev_state;
2223         unsigned long flags;
2224
2225         sdev = ch->sport->sdev;
2226
2227         spin_lock_irqsave(&ch->spinlock, flags);
2228         prev_state = ch->state;
2229         switch (prev_state) {
2230         case CH_CONNECTING:
2231         case CH_LIVE:
2232                 ch->state = CH_DISCONNECTING;
2233                 break;
2234         default:
2235                 break;
2236         }
2237         spin_unlock_irqrestore(&ch->spinlock, flags);
2238
2239         switch (prev_state) {
2240         case CH_CONNECTING:
2241                 ib_send_cm_rej(ch->cm_id, IB_CM_REJ_NO_RESOURCES, NULL, 0,
2242                                NULL, 0);
2243                 /* fall through */
2244         case CH_LIVE:
2245                 if (ib_send_cm_dreq(ch->cm_id, NULL, 0) < 0)
2246                         printk(KERN_ERR "sending CM DREQ failed.\n");
2247                 break;
2248         case CH_DISCONNECTING:
2249                 break;
2250         case CH_DRAINING:
2251         case CH_RELEASING:
2252                 break;
2253         }
2254 }
2255
2256 /**
2257  * srpt_close_ch() - Close an RDMA channel.
2258  */
2259 static void srpt_close_ch(struct srpt_rdma_ch *ch)
2260 {
2261         struct srpt_device *sdev;
2262
2263         sdev = ch->sport->sdev;
2264         spin_lock_irq(&sdev->spinlock);
2265         __srpt_close_ch(ch);
2266         spin_unlock_irq(&sdev->spinlock);
2267 }
2268
2269 /**
2270  * srpt_drain_channel() - Drain a channel by resetting the IB queue pair.
2271  * @cm_id: Pointer to the CM ID of the channel to be drained.
2272  *
2273  * Note: Must be called from inside srpt_cm_handler to avoid a race between
2274  * accessing sdev->spinlock and the call to kfree(sdev) in srpt_remove_one()
2275  * (the caller of srpt_cm_handler holds the cm_id spinlock; srpt_remove_one()
2276  * waits until all target sessions for the associated IB device have been
2277  * unregistered and target session registration involves a call to
2278  * ib_destroy_cm_id(), which locks the cm_id spinlock and hence waits until
2279  * this function has finished).
2280  */
2281 static void srpt_drain_channel(struct ib_cm_id *cm_id)
2282 {
2283         struct srpt_device *sdev;
2284         struct srpt_rdma_ch *ch;
2285         int ret;
2286         bool do_reset = false;
2287
2288         WARN_ON_ONCE(irqs_disabled());
2289
2290         sdev = cm_id->context;
2291         BUG_ON(!sdev);
2292         spin_lock_irq(&sdev->spinlock);
2293         list_for_each_entry(ch, &sdev->rch_list, list) {
2294                 if (ch->cm_id == cm_id) {
2295                         do_reset = srpt_test_and_set_ch_state(ch,
2296                                         CH_CONNECTING, CH_DRAINING) ||
2297                                    srpt_test_and_set_ch_state(ch,
2298                                         CH_LIVE, CH_DRAINING) ||
2299                                    srpt_test_and_set_ch_state(ch,
2300                                         CH_DISCONNECTING, CH_DRAINING);
2301                         break;
2302                 }
2303         }
2304         spin_unlock_irq(&sdev->spinlock);
2305
2306         if (do_reset) {
2307                 ret = srpt_ch_qp_err(ch);
2308                 if (ret < 0)
2309                         printk(KERN_ERR "Setting queue pair in error state"
2310                                " failed: %d\n", ret);
2311         }
2312 }
2313
2314 /**
2315  * srpt_find_channel() - Look up an RDMA channel.
2316  * @cm_id: Pointer to the CM ID of the channel to be looked up.
2317  *
2318  * Return NULL if no matching RDMA channel has been found.
2319  */
2320 static struct srpt_rdma_ch *srpt_find_channel(struct srpt_device *sdev,
2321                                               struct ib_cm_id *cm_id)
2322 {
2323         struct srpt_rdma_ch *ch;
2324         bool found;
2325
2326         WARN_ON_ONCE(irqs_disabled());
2327         BUG_ON(!sdev);
2328
2329         found = false;
2330         spin_lock_irq(&sdev->spinlock);
2331         list_for_each_entry(ch, &sdev->rch_list, list) {
2332                 if (ch->cm_id == cm_id) {
2333                         found = true;
2334                         break;
2335                 }
2336         }
2337         spin_unlock_irq(&sdev->spinlock);
2338
2339         return found ? ch : NULL;
2340 }
2341
2342 /**
2343  * srpt_release_channel() - Release channel resources.
2344  *
2345  * Schedules the actual release because:
2346  * - Calling the ib_destroy_cm_id() call from inside an IB CM callback would
2347  *   trigger a deadlock.
2348  * - It is not safe to call TCM transport_* functions from interrupt context.
2349  */
2350 static void srpt_release_channel(struct srpt_rdma_ch *ch)
2351 {
2352         schedule_work(&ch->release_work);
2353 }
2354
2355 static void srpt_release_channel_work(struct work_struct *w)
2356 {
2357         struct srpt_rdma_ch *ch;
2358         struct srpt_device *sdev;
2359
2360         ch = container_of(w, struct srpt_rdma_ch, release_work);
2361         pr_debug("ch = %p; ch->sess = %p; release_done = %p\n", ch, ch->sess,
2362                  ch->release_done);
2363
2364         sdev = ch->sport->sdev;
2365         BUG_ON(!sdev);
2366
2367         transport_deregister_session_configfs(ch->sess);
2368         transport_deregister_session(ch->sess);
2369         ch->sess = NULL;
2370
2371         srpt_destroy_ch_ib(ch);
2372
2373         srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
2374                              ch->sport->sdev, ch->rq_size,
2375                              ch->rsp_size, DMA_TO_DEVICE);
2376
2377         spin_lock_irq(&sdev->spinlock);
2378         list_del(&ch->list);
2379         spin_unlock_irq(&sdev->spinlock);
2380
2381         ib_destroy_cm_id(ch->cm_id);
2382
2383         if (ch->release_done)
2384                 complete(ch->release_done);
2385
2386         wake_up(&sdev->ch_releaseQ);
2387
2388         kfree(ch);
2389 }
2390
2391 static struct srpt_node_acl *__srpt_lookup_acl(struct srpt_port *sport,
2392                                                u8 i_port_id[16])
2393 {
2394         struct srpt_node_acl *nacl;
2395
2396         list_for_each_entry(nacl, &sport->port_acl_list, list)
2397                 if (memcmp(nacl->i_port_id, i_port_id,
2398                            sizeof(nacl->i_port_id)) == 0)
2399                         return nacl;
2400
2401         return NULL;
2402 }
2403
2404 static struct srpt_node_acl *srpt_lookup_acl(struct srpt_port *sport,
2405                                              u8 i_port_id[16])
2406 {
2407         struct srpt_node_acl *nacl;
2408
2409         spin_lock_irq(&sport->port_acl_lock);
2410         nacl = __srpt_lookup_acl(sport, i_port_id);
2411         spin_unlock_irq(&sport->port_acl_lock);
2412
2413         return nacl;
2414 }
2415
2416 /**
2417  * srpt_cm_req_recv() - Process the event IB_CM_REQ_RECEIVED.
2418  *
2419  * Ownership of the cm_id is transferred to the target session if this
2420  * functions returns zero. Otherwise the caller remains the owner of cm_id.
2421  */
2422 static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
2423                             struct ib_cm_req_event_param *param,
2424                             void *private_data)
2425 {
2426         struct srpt_device *sdev = cm_id->context;
2427         struct srpt_port *sport = &sdev->port[param->port - 1];
2428         struct srp_login_req *req;
2429         struct srp_login_rsp *rsp;
2430         struct srp_login_rej *rej;
2431         struct ib_cm_rep_param *rep_param;
2432         struct srpt_rdma_ch *ch, *tmp_ch;
2433         struct srpt_node_acl *nacl;
2434         u32 it_iu_len;
2435         int i;
2436         int ret = 0;
2437
2438         WARN_ON_ONCE(irqs_disabled());
2439
2440         if (WARN_ON(!sdev || !private_data))
2441                 return -EINVAL;
2442
2443         req = (struct srp_login_req *)private_data;
2444
2445         it_iu_len = be32_to_cpu(req->req_it_iu_len);
2446
2447         printk(KERN_INFO "Received SRP_LOGIN_REQ with i_port_id 0x%llx:0x%llx,"
2448                " t_port_id 0x%llx:0x%llx and it_iu_len %d on port %d"
2449                " (guid=0x%llx:0x%llx)\n",
2450                be64_to_cpu(*(__be64 *)&req->initiator_port_id[0]),
2451                be64_to_cpu(*(__be64 *)&req->initiator_port_id[8]),
2452                be64_to_cpu(*(__be64 *)&req->target_port_id[0]),
2453                be64_to_cpu(*(__be64 *)&req->target_port_id[8]),
2454                it_iu_len,
2455                param->port,
2456                be64_to_cpu(*(__be64 *)&sdev->port[param->port - 1].gid.raw[0]),
2457                be64_to_cpu(*(__be64 *)&sdev->port[param->port - 1].gid.raw[8]));
2458
2459         rsp = kzalloc(sizeof *rsp, GFP_KERNEL);
2460         rej = kzalloc(sizeof *rej, GFP_KERNEL);
2461         rep_param = kzalloc(sizeof *rep_param, GFP_KERNEL);
2462
2463         if (!rsp || !rej || !rep_param) {
2464                 ret = -ENOMEM;
2465                 goto out;
2466         }
2467
2468         if (it_iu_len > srp_max_req_size || it_iu_len < 64) {
2469                 rej->reason = __constant_cpu_to_be32(
2470                                 SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE);
2471                 ret = -EINVAL;
2472                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because its"
2473                        " length (%d bytes) is out of range (%d .. %d)\n",
2474                        it_iu_len, 64, srp_max_req_size);
2475                 goto reject;
2476         }
2477
2478         if (!sport->enabled) {
2479                 rej->reason = __constant_cpu_to_be32(
2480                              SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2481                 ret = -EINVAL;
2482                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because the target port"
2483                        " has not yet been enabled\n");
2484                 goto reject;
2485         }
2486
2487         if ((req->req_flags & SRP_MTCH_ACTION) == SRP_MULTICHAN_SINGLE) {
2488                 rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_NO_CHAN;
2489
2490                 spin_lock_irq(&sdev->spinlock);
2491
2492                 list_for_each_entry_safe(ch, tmp_ch, &sdev->rch_list, list) {
2493                         if (!memcmp(ch->i_port_id, req->initiator_port_id, 16)
2494                             && !memcmp(ch->t_port_id, req->target_port_id, 16)
2495                             && param->port == ch->sport->port
2496                             && param->listen_id == ch->sport->sdev->cm_id
2497                             && ch->cm_id) {
2498                                 enum rdma_ch_state ch_state;
2499
2500                                 ch_state = srpt_get_ch_state(ch);
2501                                 if (ch_state != CH_CONNECTING
2502                                     && ch_state != CH_LIVE)
2503                                         continue;
2504
2505                                 /* found an existing channel */
2506                                 pr_debug("Found existing channel %s"
2507                                          " cm_id= %p state= %d\n",
2508                                          ch->sess_name, ch->cm_id, ch_state);
2509
2510                                 __srpt_close_ch(ch);
2511
2512                                 rsp->rsp_flags =
2513                                         SRP_LOGIN_RSP_MULTICHAN_TERMINATED;
2514                         }
2515                 }
2516
2517                 spin_unlock_irq(&sdev->spinlock);
2518
2519         } else
2520                 rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_MAINTAINED;
2521
2522         if (*(__be64 *)req->target_port_id != cpu_to_be64(srpt_service_guid)
2523             || *(__be64 *)(req->target_port_id + 8) !=
2524                cpu_to_be64(srpt_service_guid)) {
2525                 rej->reason = __constant_cpu_to_be32(
2526                                 SRP_LOGIN_REJ_UNABLE_ASSOCIATE_CHANNEL);
2527                 ret = -ENOMEM;
2528                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because it"
2529                        " has an invalid target port identifier.\n");
2530                 goto reject;
2531         }
2532
2533         ch = kzalloc(sizeof *ch, GFP_KERNEL);
2534         if (!ch) {
2535                 rej->reason = __constant_cpu_to_be32(
2536                                         SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2537                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because no memory.\n");
2538                 ret = -ENOMEM;
2539                 goto reject;
2540         }
2541
2542         INIT_WORK(&ch->release_work, srpt_release_channel_work);
2543         memcpy(ch->i_port_id, req->initiator_port_id, 16);
2544         memcpy(ch->t_port_id, req->target_port_id, 16);
2545         ch->sport = &sdev->port[param->port - 1];
2546         ch->cm_id = cm_id;
2547         /*
2548          * Avoid QUEUE_FULL conditions by limiting the number of buffers used
2549          * for the SRP protocol to the command queue size.
2550          */
2551         ch->rq_size = SRPT_RQ_SIZE;
2552         spin_lock_init(&ch->spinlock);
2553         ch->state = CH_CONNECTING;
2554         INIT_LIST_HEAD(&ch->cmd_wait_list);
2555         ch->rsp_size = ch->sport->port_attrib.srp_max_rsp_size;
2556
2557         ch->ioctx_ring = (struct srpt_send_ioctx **)
2558                 srpt_alloc_ioctx_ring(ch->sport->sdev, ch->rq_size,
2559                                       sizeof(*ch->ioctx_ring[0]),
2560                                       ch->rsp_size, DMA_TO_DEVICE);
2561         if (!ch->ioctx_ring)
2562                 goto free_ch;
2563
2564         INIT_LIST_HEAD(&ch->free_list);
2565         for (i = 0; i < ch->rq_size; i++) {
2566                 ch->ioctx_ring[i]->ch = ch;
2567                 list_add_tail(&ch->ioctx_ring[i]->free_list, &ch->free_list);
2568         }
2569
2570         ret = srpt_create_ch_ib(ch);
2571         if (ret) {
2572                 rej->reason = __constant_cpu_to_be32(
2573                                 SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2574                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because creating"
2575                        " a new RDMA channel failed.\n");
2576                 goto free_ring;
2577         }
2578
2579         ret = srpt_ch_qp_rtr(ch, ch->qp);
2580         if (ret) {
2581                 rej->reason = __constant_cpu_to_be32(
2582                                 SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2583                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because enabling"
2584                        " RTR failed (error code = %d)\n", ret);
2585                 goto destroy_ib;
2586         }
2587         /*
2588          * Use the initator port identifier as the session name.
2589          */
2590         snprintf(ch->sess_name, sizeof(ch->sess_name), "0x%016llx%016llx",
2591                         be64_to_cpu(*(__be64 *)ch->i_port_id),
2592                         be64_to_cpu(*(__be64 *)(ch->i_port_id + 8)));
2593
2594         pr_debug("registering session %s\n", ch->sess_name);
2595
2596         nacl = srpt_lookup_acl(sport, ch->i_port_id);
2597         if (!nacl) {
2598                 printk(KERN_INFO "Rejected login because no ACL has been"
2599                        " configured yet for initiator %s.\n", ch->sess_name);
2600                 rej->reason = __constant_cpu_to_be32(
2601                                 SRP_LOGIN_REJ_CHANNEL_LIMIT_REACHED);
2602                 goto destroy_ib;
2603         }
2604
2605         ch->sess = transport_init_session();
2606         if (IS_ERR(ch->sess)) {
2607                 rej->reason = __constant_cpu_to_be32(
2608                                 SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2609                 pr_debug("Failed to create session\n");
2610                 goto deregister_session;
2611         }
2612         ch->sess->se_node_acl = &nacl->nacl;
2613         transport_register_session(&sport->port_tpg_1, &nacl->nacl, ch->sess, ch);
2614
2615         pr_debug("Establish connection sess=%p name=%s cm_id=%p\n", ch->sess,
2616                  ch->sess_name, ch->cm_id);
2617
2618         /* create srp_login_response */
2619         rsp->opcode = SRP_LOGIN_RSP;
2620         rsp->tag = req->tag;
2621         rsp->max_it_iu_len = req->req_it_iu_len;
2622         rsp->max_ti_iu_len = req->req_it_iu_len;
2623         ch->max_ti_iu_len = it_iu_len;
2624         rsp->buf_fmt = __constant_cpu_to_be16(SRP_BUF_FORMAT_DIRECT
2625                                               | SRP_BUF_FORMAT_INDIRECT);
2626         rsp->req_lim_delta = cpu_to_be32(ch->rq_size);
2627         atomic_set(&ch->req_lim, ch->rq_size);
2628         atomic_set(&ch->req_lim_delta, 0);
2629
2630         /* create cm reply */
2631         rep_param->qp_num = ch->qp->qp_num;
2632         rep_param->private_data = (void *)rsp;
2633         rep_param->private_data_len = sizeof *rsp;
2634         rep_param->rnr_retry_count = 7;
2635         rep_param->flow_control = 1;
2636         rep_param->failover_accepted = 0;
2637         rep_param->srq = 1;
2638         rep_param->responder_resources = 4;
2639         rep_param->initiator_depth = 4;
2640
2641         ret = ib_send_cm_rep(cm_id, rep_param);
2642         if (ret) {
2643                 printk(KERN_ERR "sending SRP_LOGIN_REQ response failed"
2644                        " (error code = %d)\n", ret);
2645                 goto release_channel;
2646         }
2647
2648         spin_lock_irq(&sdev->spinlock);
2649         list_add_tail(&ch->list, &sdev->rch_list);
2650         spin_unlock_irq(&sdev->spinlock);
2651
2652         goto out;
2653
2654 release_channel:
2655         srpt_set_ch_state(ch, CH_RELEASING);
2656         transport_deregister_session_configfs(ch->sess);
2657
2658 deregister_session:
2659         transport_deregister_session(ch->sess);
2660         ch->sess = NULL;
2661
2662 destroy_ib:
2663         srpt_destroy_ch_ib(ch);
2664
2665 free_ring:
2666         srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
2667                              ch->sport->sdev, ch->rq_size,
2668                              ch->rsp_size, DMA_TO_DEVICE);
2669 free_ch:
2670         kfree(ch);
2671
2672 reject:
2673         rej->opcode = SRP_LOGIN_REJ;
2674         rej->tag = req->tag;
2675         rej->buf_fmt = __constant_cpu_to_be16(SRP_BUF_FORMAT_DIRECT
2676                                               | SRP_BUF_FORMAT_INDIRECT);
2677
2678         ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED, NULL, 0,
2679                              (void *)rej, sizeof *rej);
2680
2681 out:
2682         kfree(rep_param);
2683         kfree(rsp);
2684         kfree(rej);
2685
2686         return ret;
2687 }
2688
2689 static void srpt_cm_rej_recv(struct ib_cm_id *cm_id)
2690 {
2691         printk(KERN_INFO "Received IB REJ for cm_id %p.\n", cm_id);
2692         srpt_drain_channel(cm_id);
2693 }
2694
2695 /**
2696  * srpt_cm_rtu_recv() - Process an IB_CM_RTU_RECEIVED or USER_ESTABLISHED event.
2697  *
2698  * An IB_CM_RTU_RECEIVED message indicates that the connection is established
2699  * and that the recipient may begin transmitting (RTU = ready to use).
2700  */
2701 static void srpt_cm_rtu_recv(struct ib_cm_id *cm_id)
2702 {
2703         struct srpt_rdma_ch *ch;
2704         int ret;
2705
2706         ch = srpt_find_channel(cm_id->context, cm_id);
2707         BUG_ON(!ch);
2708
2709         if (srpt_test_and_set_ch_state(ch, CH_CONNECTING, CH_LIVE)) {
2710                 struct srpt_recv_ioctx *ioctx, *ioctx_tmp;
2711
2712                 ret = srpt_ch_qp_rts(ch, ch->qp);
2713
2714                 list_for_each_entry_safe(ioctx, ioctx_tmp, &ch->cmd_wait_list,
2715                                          wait_list) {
2716                         list_del(&ioctx->wait_list);
2717                         srpt_handle_new_iu(ch, ioctx, NULL);
2718                 }
2719                 if (ret)
2720                         srpt_close_ch(ch);
2721         }
2722 }
2723
2724 static void srpt_cm_timewait_exit(struct ib_cm_id *cm_id)
2725 {
2726         printk(KERN_INFO "Received IB TimeWait exit for cm_id %p.\n", cm_id);
2727         srpt_drain_channel(cm_id);
2728 }
2729
2730 static void srpt_cm_rep_error(struct ib_cm_id *cm_id)
2731 {
2732         printk(KERN_INFO "Received IB REP error for cm_id %p.\n", cm_id);
2733         srpt_drain_channel(cm_id);
2734 }
2735
2736 /**
2737  * srpt_cm_dreq_recv() - Process reception of a DREQ message.
2738  */
2739 static void srpt_cm_dreq_recv(struct ib_cm_id *cm_id)
2740 {
2741         struct srpt_rdma_ch *ch;
2742         unsigned long flags;
2743         bool send_drep = false;
2744
2745         ch = srpt_find_channel(cm_id->context, cm_id);
2746         BUG_ON(!ch);
2747
2748         pr_debug("cm_id= %p ch->state= %d\n", cm_id, srpt_get_ch_state(ch));
2749
2750         spin_lock_irqsave(&ch->spinlock, flags);
2751         switch (ch->state) {
2752         case CH_CONNECTING:
2753         case CH_LIVE:
2754                 send_drep = true;
2755                 ch->state = CH_DISCONNECTING;
2756                 break;
2757         case CH_DISCONNECTING:
2758         case CH_DRAINING:
2759         case CH_RELEASING:
2760                 WARN(true, "unexpected channel state %d\n", ch->state);
2761                 break;
2762         }
2763         spin_unlock_irqrestore(&ch->spinlock, flags);
2764
2765         if (send_drep) {
2766                 if (ib_send_cm_drep(ch->cm_id, NULL, 0) < 0)
2767                         printk(KERN_ERR "Sending IB DREP failed.\n");
2768                 printk(KERN_INFO "Received DREQ and sent DREP for session %s.\n",
2769                        ch->sess_name);
2770         }
2771 }
2772
2773 /**
2774  * srpt_cm_drep_recv() - Process reception of a DREP message.
2775  */
2776 static void srpt_cm_drep_recv(struct ib_cm_id *cm_id)
2777 {
2778         printk(KERN_INFO "Received InfiniBand DREP message for cm_id %p.\n",
2779                cm_id);
2780         srpt_drain_channel(cm_id);
2781 }
2782
2783 /**
2784  * srpt_cm_handler() - IB connection manager callback function.
2785  *
2786  * A non-zero return value will cause the caller destroy the CM ID.
2787  *
2788  * Note: srpt_cm_handler() must only return a non-zero value when transferring
2789  * ownership of the cm_id to a channel by srpt_cm_req_recv() failed. Returning
2790  * a non-zero value in any other case will trigger a race with the
2791  * ib_destroy_cm_id() call in srpt_release_channel().
2792  */
2793 static int srpt_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
2794 {
2795         int ret;
2796
2797         ret = 0;
2798         switch (event->event) {
2799         case IB_CM_REQ_RECEIVED:
2800                 ret = srpt_cm_req_recv(cm_id, &event->param.req_rcvd,
2801                                        event->private_data);
2802                 break;
2803         case IB_CM_REJ_RECEIVED:
2804                 srpt_cm_rej_recv(cm_id);
2805                 break;
2806         case IB_CM_RTU_RECEIVED:
2807         case IB_CM_USER_ESTABLISHED:
2808                 srpt_cm_rtu_recv(cm_id);
2809                 break;
2810         case IB_CM_DREQ_RECEIVED:
2811                 srpt_cm_dreq_recv(cm_id);
2812                 break;
2813         case IB_CM_DREP_RECEIVED:
2814                 srpt_cm_drep_recv(cm_id);
2815                 break;
2816         case IB_CM_TIMEWAIT_EXIT:
2817                 srpt_cm_timewait_exit(cm_id);
2818                 break;
2819         case IB_CM_REP_ERROR:
2820                 srpt_cm_rep_error(cm_id);
2821                 break;
2822         case IB_CM_DREQ_ERROR:
2823                 printk(KERN_INFO "Received IB DREQ ERROR event.\n");
2824                 break;
2825         case IB_CM_MRA_RECEIVED:
2826                 printk(KERN_INFO "Received IB MRA event\n");
2827                 break;
2828         default:
2829                 printk(KERN_ERR "received unrecognized IB CM event %d\n",
2830                        event->event);
2831                 break;
2832         }
2833
2834         return ret;
2835 }
2836
2837 /**
2838  * srpt_perform_rdmas() - Perform IB RDMA.
2839  *
2840  * Returns zero upon success or a negative number upon failure.
2841  */
2842 static int srpt_perform_rdmas(struct srpt_rdma_ch *ch,
2843                               struct srpt_send_ioctx *ioctx)
2844 {
2845         struct ib_send_wr wr;
2846         struct ib_send_wr *bad_wr;
2847         struct rdma_iu *riu;
2848         int i;
2849         int ret;
2850         int sq_wr_avail;
2851         enum dma_data_direction dir;
2852         const int n_rdma = ioctx->n_rdma;
2853
2854         dir = ioctx->cmd.data_direction;
2855         if (dir == DMA_TO_DEVICE) {
2856                 /* write */
2857                 ret = -ENOMEM;
2858                 sq_wr_avail = atomic_sub_return(n_rdma, &ch->sq_wr_avail);
2859                 if (sq_wr_avail < 0) {
2860                         printk(KERN_WARNING "IB send queue full (needed %d)\n",
2861                                n_rdma);
2862                         goto out;
2863                 }
2864         }
2865
2866         ioctx->rdma_aborted = false;
2867         ret = 0;
2868         riu = ioctx->rdma_ius;
2869         memset(&wr, 0, sizeof wr);
2870
2871         for (i = 0; i < n_rdma; ++i, ++riu) {
2872                 if (dir == DMA_FROM_DEVICE) {
2873                         wr.opcode = IB_WR_RDMA_WRITE;
2874                         wr.wr_id = encode_wr_id(i == n_rdma - 1 ?
2875                                                 SRPT_RDMA_WRITE_LAST :
2876                                                 SRPT_RDMA_MID,
2877                                                 ioctx->ioctx.index);
2878                 } else {
2879                         wr.opcode = IB_WR_RDMA_READ;
2880                         wr.wr_id = encode_wr_id(i == n_rdma - 1 ?
2881                                                 SRPT_RDMA_READ_LAST :
2882                                                 SRPT_RDMA_MID,
2883                                                 ioctx->ioctx.index);
2884                 }
2885                 wr.next = NULL;
2886                 wr.wr.rdma.remote_addr = riu->raddr;
2887                 wr.wr.rdma.rkey = riu->rkey;
2888                 wr.num_sge = riu->sge_cnt;
2889                 wr.sg_list = riu->sge;
2890
2891                 /* only get completion event for the last rdma write */
2892                 if (i == (n_rdma - 1) && dir == DMA_TO_DEVICE)
2893                         wr.send_flags = IB_SEND_SIGNALED;
2894
2895                 ret = ib_post_send(ch->qp, &wr, &bad_wr);
2896                 if (ret)
2897                         break;
2898         }
2899
2900         if (ret)
2901                 printk(KERN_ERR "%s[%d]: ib_post_send() returned %d for %d/%d",
2902                                  __func__, __LINE__, ret, i, n_rdma);
2903         if (ret && i > 0) {
2904                 wr.num_sge = 0;
2905                 wr.wr_id = encode_wr_id(SRPT_RDMA_ABORT, ioctx->ioctx.index);
2906                 wr.send_flags = IB_SEND_SIGNALED;
2907                 while (ch->state == CH_LIVE &&
2908                         ib_post_send(ch->qp, &wr, &bad_wr) != 0) {
2909                         printk(KERN_INFO "Trying to abort failed RDMA transfer [%d]",
2910                                 ioctx->ioctx.index);
2911                         msleep(1000);
2912                 }
2913                 while (ch->state != CH_RELEASING && !ioctx->rdma_aborted) {
2914                         printk(KERN_INFO "Waiting until RDMA abort finished [%d]",
2915                                 ioctx->ioctx.index);
2916                         msleep(1000);
2917                 }
2918         }
2919 out:
2920         if (unlikely(dir == DMA_TO_DEVICE && ret < 0))
2921                 atomic_add(n_rdma, &ch->sq_wr_avail);
2922         return ret;
2923 }
2924
2925 /**
2926  * srpt_xfer_data() - Start data transfer from initiator to target.
2927  */
2928 static int srpt_xfer_data(struct srpt_rdma_ch *ch,
2929                           struct srpt_send_ioctx *ioctx)
2930 {
2931         int ret;
2932
2933         ret = srpt_map_sg_to_ib_sge(ch, ioctx);
2934         if (ret) {
2935                 printk(KERN_ERR "%s[%d] ret=%d\n", __func__, __LINE__, ret);
2936                 goto out;
2937         }
2938
2939         ret = srpt_perform_rdmas(ch, ioctx);
2940         if (ret) {
2941                 if (ret == -EAGAIN || ret == -ENOMEM)
2942                         printk(KERN_INFO "%s[%d] queue full -- ret=%d\n",
2943                                    __func__, __LINE__, ret);
2944                 else
2945                         printk(KERN_ERR "%s[%d] fatal error -- ret=%d\n",
2946                                __func__, __LINE__, ret);
2947                 goto out_unmap;
2948         }
2949
2950 out:
2951         return ret;
2952 out_unmap:
2953         srpt_unmap_sg_to_ib_sge(ch, ioctx);
2954         goto out;
2955 }
2956
2957 static int srpt_write_pending_status(struct se_cmd *se_cmd)
2958 {
2959         struct srpt_send_ioctx *ioctx;
2960
2961         ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
2962         return srpt_get_cmd_state(ioctx) == SRPT_STATE_NEED_DATA;
2963 }
2964
2965 /*
2966  * srpt_write_pending() - Start data transfer from initiator to target (write).
2967  */
2968 static int srpt_write_pending(struct se_cmd *se_cmd)
2969 {
2970         struct srpt_rdma_ch *ch;
2971         struct srpt_send_ioctx *ioctx;
2972         enum srpt_command_state new_state;
2973         enum rdma_ch_state ch_state;
2974         int ret;
2975
2976         ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
2977
2978         new_state = srpt_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA);
2979         WARN_ON(new_state == SRPT_STATE_DONE);
2980
2981         ch = ioctx->ch;
2982         BUG_ON(!ch);
2983
2984         ch_state = srpt_get_ch_state(ch);
2985         switch (ch_state) {
2986         case CH_CONNECTING:
2987                 WARN(true, "unexpected channel state %d\n", ch_state);
2988                 ret = -EINVAL;
2989                 goto out;
2990         case CH_LIVE:
2991                 break;
2992         case CH_DISCONNECTING:
2993         case CH_DRAINING:
2994         case CH_RELEASING:
2995                 pr_debug("cmd with tag %lld: channel disconnecting\n",
2996                          ioctx->tag);
2997                 srpt_set_cmd_state(ioctx, SRPT_STATE_DATA_IN);
2998                 ret = -EINVAL;
2999                 goto out;
3000         }
3001         ret = srpt_xfer_data(ch, ioctx);
3002
3003 out:
3004         return ret;
3005 }
3006
3007 static u8 tcm_to_srp_tsk_mgmt_status(const int tcm_mgmt_status)
3008 {
3009         switch (tcm_mgmt_status) {
3010         case TMR_FUNCTION_COMPLETE:
3011                 return SRP_TSK_MGMT_SUCCESS;
3012         case TMR_FUNCTION_REJECTED:
3013                 return SRP_TSK_MGMT_FUNC_NOT_SUPP;
3014         }
3015         return SRP_TSK_MGMT_FAILED;
3016 }
3017
3018 /**
3019  * srpt_queue_response() - Transmits the response to a SCSI command.
3020  *
3021  * Callback function called by the TCM core. Must not block since it can be
3022  * invoked on the context of the IB completion handler.
3023  */
3024 static int srpt_queue_response(struct se_cmd *cmd)
3025 {
3026         struct srpt_rdma_ch *ch;
3027         struct srpt_send_ioctx *ioctx;
3028         enum srpt_command_state state;
3029         unsigned long flags;
3030         int ret;
3031         enum dma_data_direction dir;
3032         int resp_len;
3033         u8 srp_tm_status;
3034
3035         ret = 0;
3036
3037         ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
3038         ch = ioctx->ch;
3039         BUG_ON(!ch);
3040
3041         spin_lock_irqsave(&ioctx->spinlock, flags);
3042         state = ioctx->state;
3043         switch (state) {
3044         case SRPT_STATE_NEW:
3045         case SRPT_STATE_DATA_IN:
3046                 ioctx->state = SRPT_STATE_CMD_RSP_SENT;
3047                 break;
3048         case SRPT_STATE_MGMT:
3049                 ioctx->state = SRPT_STATE_MGMT_RSP_SENT;
3050                 break;
3051         default:
3052                 WARN(true, "ch %p; cmd %d: unexpected command state %d\n",
3053                         ch, ioctx->ioctx.index, ioctx->state);
3054                 break;
3055         }
3056         spin_unlock_irqrestore(&ioctx->spinlock, flags);
3057
3058         if (unlikely(transport_check_aborted_status(&ioctx->cmd, false)
3059                      || WARN_ON_ONCE(state == SRPT_STATE_CMD_RSP_SENT))) {
3060                 atomic_inc(&ch->req_lim_delta);
3061                 srpt_abort_cmd(ioctx);
3062                 goto out;
3063         }
3064
3065         dir = ioctx->cmd.data_direction;
3066
3067         /* For read commands, transfer the data to the initiator. */
3068         if (dir == DMA_FROM_DEVICE && ioctx->cmd.data_length &&
3069             !ioctx->queue_status_only) {
3070                 ret = srpt_xfer_data(ch, ioctx);
3071                 if (ret) {
3072                         printk(KERN_ERR "xfer_data failed for tag %llu\n",
3073                                ioctx->tag);
3074                         goto out;
3075                 }
3076         }
3077
3078         if (state != SRPT_STATE_MGMT)
3079                 resp_len = srpt_build_cmd_rsp(ch, ioctx, ioctx->tag,
3080                                               cmd->scsi_status);
3081         else {
3082                 srp_tm_status
3083                         = tcm_to_srp_tsk_mgmt_status(cmd->se_tmr_req->response);
3084                 resp_len = srpt_build_tskmgmt_rsp(ch, ioctx, srp_tm_status,
3085                                                  ioctx->tag);
3086         }
3087         ret = srpt_post_send(ch, ioctx, resp_len);
3088         if (ret) {
3089                 printk(KERN_ERR "sending cmd response failed for tag %llu\n",
3090                        ioctx->tag);
3091                 srpt_unmap_sg_to_ib_sge(ch, ioctx);
3092                 srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
3093                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
3094         }
3095
3096 out:
3097         return ret;
3098 }
3099
3100 static int srpt_queue_status(struct se_cmd *cmd)
3101 {
3102         struct srpt_send_ioctx *ioctx;
3103
3104         ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
3105         BUG_ON(ioctx->sense_data != cmd->sense_buffer);
3106         if (cmd->se_cmd_flags &
3107             (SCF_TRANSPORT_TASK_SENSE | SCF_EMULATED_TASK_SENSE))
3108                 WARN_ON(cmd->scsi_status != SAM_STAT_CHECK_CONDITION);
3109         ioctx->queue_status_only = true;
3110         return srpt_queue_response(cmd);
3111 }
3112
3113 static void srpt_refresh_port_work(struct work_struct *work)
3114 {
3115         struct srpt_port *sport = container_of(work, struct srpt_port, work);
3116
3117         srpt_refresh_port(sport);
3118 }
3119
3120 static int srpt_ch_list_empty(struct srpt_device *sdev)
3121 {
3122         int res;
3123
3124         spin_lock_irq(&sdev->spinlock);
3125         res = list_empty(&sdev->rch_list);
3126         spin_unlock_irq(&sdev->spinlock);
3127
3128         return res;
3129 }
3130
3131 /**
3132  * srpt_release_sdev() - Free the channel resources associated with a target.
3133  */
3134 static int srpt_release_sdev(struct srpt_device *sdev)
3135 {
3136         struct srpt_rdma_ch *ch, *tmp_ch;
3137         int res;
3138
3139         WARN_ON_ONCE(irqs_disabled());
3140
3141         BUG_ON(!sdev);
3142
3143         spin_lock_irq(&sdev->spinlock);
3144         list_for_each_entry_safe(ch, tmp_ch, &sdev->rch_list, list)
3145                 __srpt_close_ch(ch);
3146         spin_unlock_irq(&sdev->spinlock);
3147
3148         res = wait_event_interruptible(sdev->ch_releaseQ,
3149                                        srpt_ch_list_empty(sdev));
3150         if (res)
3151                 printk(KERN_ERR "%s: interrupted.\n", __func__);
3152
3153         return 0;
3154 }
3155
3156 static struct srpt_port *__srpt_lookup_port(const char *name)
3157 {
3158         struct ib_device *dev;
3159         struct srpt_device *sdev;
3160         struct srpt_port *sport;
3161         int i;
3162
3163         list_for_each_entry(sdev, &srpt_dev_list, list) {
3164                 dev = sdev->device;
3165                 if (!dev)
3166                         continue;
3167
3168                 for (i = 0; i < dev->phys_port_cnt; i++) {
3169                         sport = &sdev->port[i];
3170
3171                         if (!strcmp(sport->port_guid, name))
3172                                 return sport;
3173                 }
3174         }
3175
3176         return NULL;
3177 }
3178
3179 static struct srpt_port *srpt_lookup_port(const char *name)
3180 {
3181         struct srpt_port *sport;
3182
3183         spin_lock(&srpt_dev_lock);
3184         sport = __srpt_lookup_port(name);
3185         spin_unlock(&srpt_dev_lock);
3186
3187         return sport;
3188 }
3189
3190 /**
3191  * srpt_add_one() - Infiniband device addition callback function.
3192  */
3193 static void srpt_add_one(struct ib_device *device)
3194 {
3195         struct srpt_device *sdev;
3196         struct srpt_port *sport;
3197         struct ib_srq_init_attr srq_attr;
3198         int i;
3199
3200         pr_debug("device = %p, device->dma_ops = %p\n", device,
3201                  device->dma_ops);
3202
3203         sdev = kzalloc(sizeof *sdev, GFP_KERNEL);
3204         if (!sdev)
3205                 goto err;
3206
3207         sdev->device = device;
3208         INIT_LIST_HEAD(&sdev->rch_list);
3209         init_waitqueue_head(&sdev->ch_releaseQ);
3210         spin_lock_init(&sdev->spinlock);
3211
3212         if (ib_query_device(device, &sdev->dev_attr))
3213                 goto free_dev;
3214
3215         sdev->pd = ib_alloc_pd(device);
3216         if (IS_ERR(sdev->pd))
3217                 goto free_dev;
3218
3219         sdev->mr = ib_get_dma_mr(sdev->pd, IB_ACCESS_LOCAL_WRITE);
3220         if (IS_ERR(sdev->mr))
3221                 goto err_pd;
3222
3223         sdev->srq_size = min(srpt_srq_size, sdev->dev_attr.max_srq_wr);
3224
3225         srq_attr.event_handler = srpt_srq_event;
3226         srq_attr.srq_context = (void *)sdev;
3227         srq_attr.attr.max_wr = sdev->srq_size;
3228         srq_attr.attr.max_sge = 1;
3229         srq_attr.attr.srq_limit = 0;
3230
3231         sdev->srq = ib_create_srq(sdev->pd, &srq_attr);
3232         if (IS_ERR(sdev->srq))
3233                 goto err_mr;
3234
3235         pr_debug("%s: create SRQ #wr= %d max_allow=%d dev= %s\n",
3236                  __func__, sdev->srq_size, sdev->dev_attr.max_srq_wr,
3237                  device->name);
3238
3239         if (!srpt_service_guid)
3240                 srpt_service_guid = be64_to_cpu(device->node_guid);
3241
3242         sdev->cm_id = ib_create_cm_id(device, srpt_cm_handler, sdev);
3243         if (IS_ERR(sdev->cm_id))
3244                 goto err_srq;
3245
3246         /* print out target login information */
3247         pr_debug("Target login info: id_ext=%016llx,ioc_guid=%016llx,"
3248                  "pkey=ffff,service_id=%016llx\n", srpt_service_guid,
3249                  srpt_service_guid, srpt_service_guid);
3250
3251         /*
3252          * We do not have a consistent service_id (ie. also id_ext of target_id)
3253          * to identify this target. We currently use the guid of the first HCA
3254          * in the system as service_id; therefore, the target_id will change
3255          * if this HCA is gone bad and replaced by different HCA
3256          */
3257         if (ib_cm_listen(sdev->cm_id, cpu_to_be64(srpt_service_guid), 0, NULL))
3258                 goto err_cm;
3259
3260         INIT_IB_EVENT_HANDLER(&sdev->event_handler, sdev->device,
3261                               srpt_event_handler);
3262         if (ib_register_event_handler(&sdev->event_handler))
3263                 goto err_cm;
3264
3265         sdev->ioctx_ring = (struct srpt_recv_ioctx **)
3266                 srpt_alloc_ioctx_ring(sdev, sdev->srq_size,
3267                                       sizeof(*sdev->ioctx_ring[0]),
3268                                       srp_max_req_size, DMA_FROM_DEVICE);
3269         if (!sdev->ioctx_ring)
3270                 goto err_event;
3271
3272         for (i = 0; i < sdev->srq_size; ++i)
3273                 srpt_post_recv(sdev, sdev->ioctx_ring[i]);
3274
3275         WARN_ON(sdev->device->phys_port_cnt > ARRAY_SIZE(sdev->port));
3276
3277         for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
3278                 sport = &sdev->port[i - 1];
3279                 sport->sdev = sdev;
3280                 sport->port = i;
3281                 sport->port_attrib.srp_max_rdma_size = DEFAULT_MAX_RDMA_SIZE;
3282                 sport->port_attrib.srp_max_rsp_size = DEFAULT_MAX_RSP_SIZE;
3283                 sport->port_attrib.srp_sq_size = DEF_SRPT_SQ_SIZE;
3284                 INIT_WORK(&sport->work, srpt_refresh_port_work);
3285                 INIT_LIST_HEAD(&sport->port_acl_list);
3286                 spin_lock_init(&sport->port_acl_lock);
3287
3288                 if (srpt_refresh_port(sport)) {
3289                         printk(KERN_ERR "MAD registration failed for %s-%d.\n",
3290                                srpt_sdev_name(sdev), i);
3291                         goto err_ring;
3292                 }
3293                 snprintf(sport->port_guid, sizeof(sport->port_guid),
3294                         "0x%016llx%016llx",
3295                         be64_to_cpu(sport->gid.global.subnet_prefix),
3296                         be64_to_cpu(sport->gid.global.interface_id));
3297         }
3298
3299         spin_lock(&srpt_dev_lock);
3300         list_add_tail(&sdev->list, &srpt_dev_list);
3301         spin_unlock(&srpt_dev_lock);
3302
3303 out:
3304         ib_set_client_data(device, &srpt_client, sdev);
3305         pr_debug("added %s.\n", device->name);
3306         return;
3307
3308 err_ring:
3309         srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
3310                              sdev->srq_size, srp_max_req_size,
3311                              DMA_FROM_DEVICE);
3312 err_event:
3313         ib_unregister_event_handler(&sdev->event_handler);
3314 err_cm:
3315         ib_destroy_cm_id(sdev->cm_id);
3316 err_srq:
3317         ib_destroy_srq(sdev->srq);
3318 err_mr:
3319         ib_dereg_mr(sdev->mr);
3320 err_pd:
3321         ib_dealloc_pd(sdev->pd);
3322 free_dev:
3323         kfree(sdev);
3324 err:
3325         sdev = NULL;
3326         printk(KERN_INFO "%s(%s) failed.\n", __func__, device->name);
3327         goto out;
3328 }
3329
3330 /**
3331  * srpt_remove_one() - InfiniBand device removal callback function.
3332  */
3333 static void srpt_remove_one(struct ib_device *device)
3334 {
3335         struct srpt_device *sdev;
3336         int i;
3337
3338         sdev = ib_get_client_data(device, &srpt_client);
3339         if (!sdev) {
3340                 printk(KERN_INFO "%s(%s): nothing to do.\n", __func__,
3341                        device->name);
3342                 return;
3343         }
3344
3345         srpt_unregister_mad_agent(sdev);
3346
3347         ib_unregister_event_handler(&sdev->event_handler);
3348
3349         /* Cancel any work queued by the just unregistered IB event handler. */
3350         for (i = 0; i < sdev->device->phys_port_cnt; i++)
3351                 cancel_work_sync(&sdev->port[i].work);
3352
3353         ib_destroy_cm_id(sdev->cm_id);
3354
3355         /*
3356          * Unregistering a target must happen after destroying sdev->cm_id
3357          * such that no new SRP_LOGIN_REQ information units can arrive while
3358          * destroying the target.
3359          */
3360         spin_lock(&srpt_dev_lock);
3361         list_del(&sdev->list);
3362         spin_unlock(&srpt_dev_lock);
3363         srpt_release_sdev(sdev);
3364
3365         ib_destroy_srq(sdev->srq);
3366         ib_dereg_mr(sdev->mr);
3367         ib_dealloc_pd(sdev->pd);
3368
3369         srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
3370                              sdev->srq_size, srp_max_req_size, DMA_FROM_DEVICE);
3371         sdev->ioctx_ring = NULL;
3372         kfree(sdev);
3373 }
3374
3375 static struct ib_client srpt_client = {
3376         .name = DRV_NAME,
3377         .add = srpt_add_one,
3378         .remove = srpt_remove_one
3379 };
3380
3381 static int srpt_check_true(struct se_portal_group *se_tpg)
3382 {
3383         return 1;
3384 }
3385
3386 static int srpt_check_false(struct se_portal_group *se_tpg)
3387 {
3388         return 0;
3389 }
3390
3391 static char *srpt_get_fabric_name(void)
3392 {
3393         return "srpt";
3394 }
3395
3396 static u8 srpt_get_fabric_proto_ident(struct se_portal_group *se_tpg)
3397 {
3398         return SCSI_TRANSPORTID_PROTOCOLID_SRP;
3399 }
3400
3401 static char *srpt_get_fabric_wwn(struct se_portal_group *tpg)
3402 {
3403         struct srpt_port *sport = container_of(tpg, struct srpt_port, port_tpg_1);
3404
3405         return sport->port_guid;
3406 }
3407
3408 static u16 srpt_get_tag(struct se_portal_group *tpg)
3409 {
3410         return 1;
3411 }
3412
3413 static u32 srpt_get_default_depth(struct se_portal_group *se_tpg)
3414 {
3415         return 1;
3416 }
3417
3418 static u32 srpt_get_pr_transport_id(struct se_portal_group *se_tpg,
3419                                     struct se_node_acl *se_nacl,
3420                                     struct t10_pr_registration *pr_reg,
3421                                     int *format_code, unsigned char *buf)
3422 {
3423         struct srpt_node_acl *nacl;
3424         struct spc_rdma_transport_id *tr_id;
3425
3426         nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3427         tr_id = (void *)buf;
3428         tr_id->protocol_identifier = SCSI_TRANSPORTID_PROTOCOLID_SRP;
3429         memcpy(tr_id->i_port_id, nacl->i_port_id, sizeof(tr_id->i_port_id));
3430         return sizeof(*tr_id);
3431 }
3432
3433 static u32 srpt_get_pr_transport_id_len(struct se_portal_group *se_tpg,
3434                                         struct se_node_acl *se_nacl,
3435                                         struct t10_pr_registration *pr_reg,
3436                                         int *format_code)
3437 {
3438         *format_code = 0;
3439         return sizeof(struct spc_rdma_transport_id);
3440 }
3441
3442 static char *srpt_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
3443                                             const char *buf, u32 *out_tid_len,
3444                                             char **port_nexus_ptr)
3445 {
3446         struct spc_rdma_transport_id *tr_id;
3447
3448         *port_nexus_ptr = NULL;
3449         *out_tid_len = sizeof(struct spc_rdma_transport_id);
3450         tr_id = (void *)buf;
3451         return (char *)tr_id->i_port_id;
3452 }
3453
3454 static struct se_node_acl *srpt_alloc_fabric_acl(struct se_portal_group *se_tpg)
3455 {
3456         struct srpt_node_acl *nacl;
3457
3458         nacl = kzalloc(sizeof(struct srpt_node_acl), GFP_KERNEL);
3459         if (!nacl) {
3460                 printk(KERN_ERR "Unable to alocate struct srpt_node_acl\n");
3461                 return NULL;
3462         }
3463
3464         return &nacl->nacl;
3465 }
3466
3467 static void srpt_release_fabric_acl(struct se_portal_group *se_tpg,
3468                                     struct se_node_acl *se_nacl)
3469 {
3470         struct srpt_node_acl *nacl;
3471
3472         nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3473         kfree(nacl);
3474 }
3475
3476 static u32 srpt_tpg_get_inst_index(struct se_portal_group *se_tpg)
3477 {
3478         return 1;
3479 }
3480
3481 static void srpt_release_cmd(struct se_cmd *se_cmd)
3482 {
3483 }
3484
3485 /**
3486  * srpt_shutdown_session() - Whether or not a session may be shut down.
3487  */
3488 static int srpt_shutdown_session(struct se_session *se_sess)
3489 {
3490         return true;
3491 }
3492
3493 /**
3494  * srpt_close_session() - Forcibly close a session.
3495  *
3496  * Callback function invoked by the TCM core to clean up sessions associated
3497  * with a node ACL when the user invokes
3498  * rmdir /sys/kernel/config/target/$driver/$port/$tpg/acls/$i_port_id
3499  */
3500 static void srpt_close_session(struct se_session *se_sess)
3501 {
3502         DECLARE_COMPLETION_ONSTACK(release_done);
3503         struct srpt_rdma_ch *ch;
3504         struct srpt_device *sdev;
3505         int res;
3506
3507         ch = se_sess->fabric_sess_ptr;
3508         WARN_ON(ch->sess != se_sess);
3509
3510         pr_debug("ch %p state %d\n", ch, srpt_get_ch_state(ch));
3511
3512         sdev = ch->sport->sdev;
3513         spin_lock_irq(&sdev->spinlock);
3514         BUG_ON(ch->release_done);
3515         ch->release_done = &release_done;
3516         __srpt_close_ch(ch);
3517         spin_unlock_irq(&sdev->spinlock);
3518
3519         res = wait_for_completion_timeout(&release_done, 60 * HZ);
3520         WARN_ON(res <= 0);
3521 }
3522
3523 /**
3524  * To do: Find out whether stop_session() has a meaning for transports
3525  * other than iSCSI.
3526  */
3527 static void srpt_stop_session(struct se_session *se_sess, int sess_sleep,
3528                               int conn_sleep)
3529 {
3530 }
3531
3532 static void srpt_reset_nexus(struct se_session *sess)
3533 {
3534         printk(KERN_ERR "This is the SRP protocol, not iSCSI\n");
3535 }
3536
3537 static int srpt_sess_logged_in(struct se_session *se_sess)
3538 {
3539         return true;
3540 }
3541
3542 /**
3543  * srpt_sess_get_index() - Return the value of scsiAttIntrPortIndex (SCSI-MIB).
3544  *
3545  * A quote from RFC 4455 (SCSI-MIB) about this MIB object:
3546  * This object represents an arbitrary integer used to uniquely identify a
3547  * particular attached remote initiator port to a particular SCSI target port
3548  * within a particular SCSI target device within a particular SCSI instance.
3549  */
3550 static u32 srpt_sess_get_index(struct se_session *se_sess)
3551 {
3552         return 0;
3553 }
3554
3555 static void srpt_set_default_node_attrs(struct se_node_acl *nacl)
3556 {
3557 }
3558
3559 static u32 srpt_get_task_tag(struct se_cmd *se_cmd)
3560 {
3561         struct srpt_send_ioctx *ioctx;
3562
3563         ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
3564         return ioctx->tag;
3565 }
3566
3567 /* Note: only used from inside debug printk's by the TCM core. */
3568 static int srpt_get_tcm_cmd_state(struct se_cmd *se_cmd)
3569 {
3570         struct srpt_send_ioctx *ioctx;
3571
3572         ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
3573         return srpt_get_cmd_state(ioctx);
3574 }
3575
3576 static u16 srpt_set_fabric_sense_len(struct se_cmd *cmd, u32 sense_length)
3577 {
3578         return 0;
3579 }
3580
3581 static u16 srpt_get_fabric_sense_len(void)
3582 {
3583         return 0;
3584 }
3585
3586 static int srpt_is_state_remove(struct se_cmd *se_cmd)
3587 {
3588         return 0;
3589 }
3590
3591 /**
3592  * srpt_parse_i_port_id() - Parse an initiator port ID.
3593  * @name: ASCII representation of a 128-bit initiator port ID.
3594  * @i_port_id: Binary 128-bit port ID.
3595  */
3596 static int srpt_parse_i_port_id(u8 i_port_id[16], const char *name)
3597 {
3598         const char *p;
3599         unsigned len, count, leading_zero_bytes;
3600         int ret, rc;
3601
3602         p = name;
3603         if (strnicmp(p, "0x", 2) == 0)
3604                 p += 2;
3605         ret = -EINVAL;
3606         len = strlen(p);
3607         if (len % 2)
3608                 goto out;
3609         count = min(len / 2, 16U);
3610         leading_zero_bytes = 16 - count;
3611         memset(i_port_id, 0, leading_zero_bytes);
3612         rc = hex2bin(i_port_id + leading_zero_bytes, p, count);
3613         if (rc < 0)
3614                 pr_debug("hex2bin failed for srpt_parse_i_port_id: %d\n", rc);
3615         ret = 0;
3616 out:
3617         return ret;
3618 }
3619
3620 /*
3621  * configfs callback function invoked for
3622  * mkdir /sys/kernel/config/target/$driver/$port/$tpg/acls/$i_port_id
3623  */
3624 static struct se_node_acl *srpt_make_nodeacl(struct se_portal_group *tpg,
3625                                              struct config_group *group,
3626                                              const char *name)
3627 {
3628         struct srpt_port *sport = container_of(tpg, struct srpt_port, port_tpg_1);
3629         struct se_node_acl *se_nacl, *se_nacl_new;
3630         struct srpt_node_acl *nacl;
3631         int ret = 0;
3632         u32 nexus_depth = 1;
3633         u8 i_port_id[16];
3634
3635         if (srpt_parse_i_port_id(i_port_id, name) < 0) {
3636                 printk(KERN_ERR "invalid initiator port ID %s\n", name);
3637                 ret = -EINVAL;
3638                 goto err;
3639         }
3640
3641         se_nacl_new = srpt_alloc_fabric_acl(tpg);
3642         if (!se_nacl_new) {
3643                 ret = -ENOMEM;
3644                 goto err;
3645         }
3646         /*
3647          * nacl_new may be released by core_tpg_add_initiator_node_acl()
3648          * when converting a node ACL from demo mode to explict
3649          */
3650         se_nacl = core_tpg_add_initiator_node_acl(tpg, se_nacl_new, name,
3651                                                   nexus_depth);
3652         if (IS_ERR(se_nacl)) {
3653                 ret = PTR_ERR(se_nacl);
3654                 goto err;
3655         }
3656         /* Locate our struct srpt_node_acl and set sdev and i_port_id. */
3657         nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3658         memcpy(&nacl->i_port_id[0], &i_port_id[0], 16);
3659         nacl->sport = sport;
3660
3661         spin_lock_irq(&sport->port_acl_lock);
3662         list_add_tail(&nacl->list, &sport->port_acl_list);
3663         spin_unlock_irq(&sport->port_acl_lock);
3664
3665         return se_nacl;
3666 err:
3667         return ERR_PTR(ret);
3668 }
3669
3670 /*
3671  * configfs callback function invoked for
3672  * rmdir /sys/kernel/config/target/$driver/$port/$tpg/acls/$i_port_id
3673  */
3674 static void srpt_drop_nodeacl(struct se_node_acl *se_nacl)
3675 {
3676         struct srpt_node_acl *nacl;
3677         struct srpt_device *sdev;
3678         struct srpt_port *sport;
3679
3680         nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3681         sport = nacl->sport;
3682         sdev = sport->sdev;
3683         spin_lock_irq(&sport->port_acl_lock);
3684         list_del(&nacl->list);
3685         spin_unlock_irq(&sport->port_acl_lock);
3686         core_tpg_del_initiator_node_acl(&sport->port_tpg_1, se_nacl, 1);
3687         srpt_release_fabric_acl(NULL, se_nacl);
3688 }
3689
3690 static ssize_t srpt_tpg_attrib_show_srp_max_rdma_size(
3691         struct se_portal_group *se_tpg,
3692         char *page)
3693 {
3694         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3695
3696         return sprintf(page, "%u\n", sport->port_attrib.srp_max_rdma_size);
3697 }
3698
3699 static ssize_t srpt_tpg_attrib_store_srp_max_rdma_size(
3700         struct se_portal_group *se_tpg,
3701         const char *page,
3702         size_t count)
3703 {
3704         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3705         unsigned long val;
3706         int ret;
3707
3708         ret = strict_strtoul(page, 0, &val);
3709         if (ret < 0) {
3710                 pr_err("strict_strtoul() failed with ret: %d\n", ret);
3711                 return -EINVAL;
3712         }
3713         if (val > MAX_SRPT_RDMA_SIZE) {
3714                 pr_err("val: %lu exceeds MAX_SRPT_RDMA_SIZE: %d\n", val,
3715                         MAX_SRPT_RDMA_SIZE);
3716                 return -EINVAL;
3717         }
3718         if (val < DEFAULT_MAX_RDMA_SIZE) {
3719                 pr_err("val: %lu smaller than DEFAULT_MAX_RDMA_SIZE: %d\n",
3720                         val, DEFAULT_MAX_RDMA_SIZE);
3721                 return -EINVAL;
3722         }
3723         sport->port_attrib.srp_max_rdma_size = val;
3724
3725         return count;
3726 }
3727
3728 TF_TPG_ATTRIB_ATTR(srpt, srp_max_rdma_size, S_IRUGO | S_IWUSR);
3729
3730 static ssize_t srpt_tpg_attrib_show_srp_max_rsp_size(
3731         struct se_portal_group *se_tpg,
3732         char *page)
3733 {
3734         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3735
3736         return sprintf(page, "%u\n", sport->port_attrib.srp_max_rsp_size);
3737 }
3738
3739 static ssize_t srpt_tpg_attrib_store_srp_max_rsp_size(
3740         struct se_portal_group *se_tpg,
3741         const char *page,
3742         size_t count)
3743 {
3744         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3745         unsigned long val;
3746         int ret;
3747
3748         ret = strict_strtoul(page, 0, &val);
3749         if (ret < 0) {
3750                 pr_err("strict_strtoul() failed with ret: %d\n", ret);
3751                 return -EINVAL;
3752         }
3753         if (val > MAX_SRPT_RSP_SIZE) {
3754                 pr_err("val: %lu exceeds MAX_SRPT_RSP_SIZE: %d\n", val,
3755                         MAX_SRPT_RSP_SIZE);
3756                 return -EINVAL;
3757         }
3758         if (val < MIN_MAX_RSP_SIZE) {
3759                 pr_err("val: %lu smaller than MIN_MAX_RSP_SIZE: %d\n", val,
3760                         MIN_MAX_RSP_SIZE);
3761                 return -EINVAL;
3762         }
3763         sport->port_attrib.srp_max_rsp_size = val;
3764
3765         return count;
3766 }
3767
3768 TF_TPG_ATTRIB_ATTR(srpt, srp_max_rsp_size, S_IRUGO | S_IWUSR);
3769
3770 static ssize_t srpt_tpg_attrib_show_srp_sq_size(
3771         struct se_portal_group *se_tpg,
3772         char *page)
3773 {
3774         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3775
3776         return sprintf(page, "%u\n", sport->port_attrib.srp_sq_size);
3777 }
3778
3779 static ssize_t srpt_tpg_attrib_store_srp_sq_size(
3780         struct se_portal_group *se_tpg,
3781         const char *page,
3782         size_t count)
3783 {
3784         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3785         unsigned long val;
3786         int ret;
3787
3788         ret = strict_strtoul(page, 0, &val);
3789         if (ret < 0) {
3790                 pr_err("strict_strtoul() failed with ret: %d\n", ret);
3791                 return -EINVAL;
3792         }
3793         if (val > MAX_SRPT_SRQ_SIZE) {
3794                 pr_err("val: %lu exceeds MAX_SRPT_SRQ_SIZE: %d\n", val,
3795                         MAX_SRPT_SRQ_SIZE);
3796                 return -EINVAL;
3797         }
3798         if (val < MIN_SRPT_SRQ_SIZE) {
3799                 pr_err("val: %lu smaller than MIN_SRPT_SRQ_SIZE: %d\n", val,
3800                         MIN_SRPT_SRQ_SIZE);
3801                 return -EINVAL;
3802         }
3803         sport->port_attrib.srp_sq_size = val;
3804
3805         return count;
3806 }
3807
3808 TF_TPG_ATTRIB_ATTR(srpt, srp_sq_size, S_IRUGO | S_IWUSR);
3809
3810 static struct configfs_attribute *srpt_tpg_attrib_attrs[] = {
3811         &srpt_tpg_attrib_srp_max_rdma_size.attr,
3812         &srpt_tpg_attrib_srp_max_rsp_size.attr,
3813         &srpt_tpg_attrib_srp_sq_size.attr,
3814         NULL,
3815 };
3816
3817 static ssize_t srpt_tpg_show_enable(
3818         struct se_portal_group *se_tpg,
3819         char *page)
3820 {
3821         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3822
3823         return snprintf(page, PAGE_SIZE, "%d\n", (sport->enabled) ? 1: 0);
3824 }
3825
3826 static ssize_t srpt_tpg_store_enable(
3827         struct se_portal_group *se_tpg,
3828         const char *page,
3829         size_t count)
3830 {
3831         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3832         unsigned long tmp;
3833         int ret;
3834
3835         ret = strict_strtoul(page, 0, &tmp);
3836         if (ret < 0) {
3837                 printk(KERN_ERR "Unable to extract srpt_tpg_store_enable\n");
3838                 return -EINVAL;
3839         }
3840
3841         if ((tmp != 0) && (tmp != 1)) {
3842                 printk(KERN_ERR "Illegal value for srpt_tpg_store_enable: %lu\n", tmp);
3843                 return -EINVAL;
3844         }
3845         if (tmp == 1)
3846                 sport->enabled = true;
3847         else
3848                 sport->enabled = false;
3849
3850         return count;
3851 }
3852
3853 TF_TPG_BASE_ATTR(srpt, enable, S_IRUGO | S_IWUSR);
3854
3855 static struct configfs_attribute *srpt_tpg_attrs[] = {
3856         &srpt_tpg_enable.attr,
3857         NULL,
3858 };
3859
3860 /**
3861  * configfs callback invoked for
3862  * mkdir /sys/kernel/config/target/$driver/$port/$tpg
3863  */
3864 static struct se_portal_group *srpt_make_tpg(struct se_wwn *wwn,
3865                                              struct config_group *group,
3866                                              const char *name)
3867 {
3868         struct srpt_port *sport = container_of(wwn, struct srpt_port, port_wwn);
3869         int res;
3870
3871         /* Initialize sport->port_wwn and sport->port_tpg_1 */
3872         res = core_tpg_register(&srpt_target->tf_ops, &sport->port_wwn,
3873                         &sport->port_tpg_1, sport, TRANSPORT_TPG_TYPE_NORMAL);
3874         if (res)
3875                 return ERR_PTR(res);
3876
3877         return &sport->port_tpg_1;
3878 }
3879
3880 /**
3881  * configfs callback invoked for
3882  * rmdir /sys/kernel/config/target/$driver/$port/$tpg
3883  */
3884 static void srpt_drop_tpg(struct se_portal_group *tpg)
3885 {
3886         struct srpt_port *sport = container_of(tpg,
3887                                 struct srpt_port, port_tpg_1);
3888
3889         sport->enabled = false;
3890         core_tpg_deregister(&sport->port_tpg_1);
3891 }
3892
3893 /**
3894  * configfs callback invoked for
3895  * mkdir /sys/kernel/config/target/$driver/$port
3896  */
3897 static struct se_wwn *srpt_make_tport(struct target_fabric_configfs *tf,
3898                                       struct config_group *group,
3899                                       const char *name)
3900 {
3901         struct srpt_port *sport;
3902         int ret;
3903
3904         sport = srpt_lookup_port(name);
3905         pr_debug("make_tport(%s)\n", name);
3906         ret = -EINVAL;
3907         if (!sport)
3908                 goto err;
3909
3910         return &sport->port_wwn;
3911
3912 err:
3913         return ERR_PTR(ret);
3914 }
3915
3916 /**
3917  * configfs callback invoked for
3918  * rmdir /sys/kernel/config/target/$driver/$port
3919  */
3920 static void srpt_drop_tport(struct se_wwn *wwn)
3921 {
3922         struct srpt_port *sport = container_of(wwn, struct srpt_port, port_wwn);
3923
3924         pr_debug("drop_tport(%s\n", config_item_name(&sport->port_wwn.wwn_group.cg_item));
3925 }
3926
3927 static ssize_t srpt_wwn_show_attr_version(struct target_fabric_configfs *tf,
3928                                               char *buf)
3929 {
3930         return scnprintf(buf, PAGE_SIZE, "%s\n", DRV_VERSION);
3931 }
3932
3933 TF_WWN_ATTR_RO(srpt, version);
3934
3935 static struct configfs_attribute *srpt_wwn_attrs[] = {
3936         &srpt_wwn_version.attr,
3937         NULL,
3938 };
3939
3940 static struct target_core_fabric_ops srpt_template = {
3941         .get_fabric_name                = srpt_get_fabric_name,
3942         .get_fabric_proto_ident         = srpt_get_fabric_proto_ident,
3943         .tpg_get_wwn                    = srpt_get_fabric_wwn,
3944         .tpg_get_tag                    = srpt_get_tag,
3945         .tpg_get_default_depth          = srpt_get_default_depth,
3946         .tpg_get_pr_transport_id        = srpt_get_pr_transport_id,
3947         .tpg_get_pr_transport_id_len    = srpt_get_pr_transport_id_len,
3948         .tpg_parse_pr_out_transport_id  = srpt_parse_pr_out_transport_id,
3949         .tpg_check_demo_mode            = srpt_check_false,
3950         .tpg_check_demo_mode_cache      = srpt_check_true,
3951         .tpg_check_demo_mode_write_protect = srpt_check_true,
3952         .tpg_check_prod_mode_write_protect = srpt_check_false,
3953         .tpg_alloc_fabric_acl           = srpt_alloc_fabric_acl,
3954         .tpg_release_fabric_acl         = srpt_release_fabric_acl,
3955         .tpg_get_inst_index             = srpt_tpg_get_inst_index,
3956         .release_cmd                    = srpt_release_cmd,
3957         .check_stop_free                = srpt_check_stop_free,
3958         .shutdown_session               = srpt_shutdown_session,
3959         .close_session                  = srpt_close_session,
3960         .stop_session                   = srpt_stop_session,
3961         .fall_back_to_erl0              = srpt_reset_nexus,
3962         .sess_logged_in                 = srpt_sess_logged_in,
3963         .sess_get_index                 = srpt_sess_get_index,
3964         .sess_get_initiator_sid         = NULL,
3965         .write_pending                  = srpt_write_pending,
3966         .write_pending_status           = srpt_write_pending_status,
3967         .set_default_node_attributes    = srpt_set_default_node_attrs,
3968         .get_task_tag                   = srpt_get_task_tag,
3969         .get_cmd_state                  = srpt_get_tcm_cmd_state,
3970         .queue_data_in                  = srpt_queue_response,
3971         .queue_status                   = srpt_queue_status,
3972         .queue_tm_rsp                   = srpt_queue_response,
3973         .get_fabric_sense_len           = srpt_get_fabric_sense_len,
3974         .set_fabric_sense_len           = srpt_set_fabric_sense_len,
3975         .is_state_remove                = srpt_is_state_remove,
3976         /*
3977          * Setup function pointers for generic logic in
3978          * target_core_fabric_configfs.c
3979          */
3980         .fabric_make_wwn                = srpt_make_tport,
3981         .fabric_drop_wwn                = srpt_drop_tport,
3982         .fabric_make_tpg                = srpt_make_tpg,
3983         .fabric_drop_tpg                = srpt_drop_tpg,
3984         .fabric_post_link               = NULL,
3985         .fabric_pre_unlink              = NULL,
3986         .fabric_make_np                 = NULL,
3987         .fabric_drop_np                 = NULL,
3988         .fabric_make_nodeacl            = srpt_make_nodeacl,
3989         .fabric_drop_nodeacl            = srpt_drop_nodeacl,
3990 };
3991
3992 /**
3993  * srpt_init_module() - Kernel module initialization.
3994  *
3995  * Note: Since ib_register_client() registers callback functions, and since at
3996  * least one of these callback functions (srpt_add_one()) calls target core
3997  * functions, this driver must be registered with the target core before
3998  * ib_register_client() is called.
3999  */
4000 static int __init srpt_init_module(void)
4001 {
4002         int ret;
4003
4004         ret = -EINVAL;
4005         if (srp_max_req_size < MIN_MAX_REQ_SIZE) {
4006                 printk(KERN_ERR "invalid value %d for kernel module parameter"
4007                        " srp_max_req_size -- must be at least %d.\n",
4008                        srp_max_req_size, MIN_MAX_REQ_SIZE);
4009                 goto out;
4010         }
4011
4012         if (srpt_srq_size < MIN_SRPT_SRQ_SIZE
4013             || srpt_srq_size > MAX_SRPT_SRQ_SIZE) {
4014                 printk(KERN_ERR "invalid value %d for kernel module parameter"
4015                        " srpt_srq_size -- must be in the range [%d..%d].\n",
4016                        srpt_srq_size, MIN_SRPT_SRQ_SIZE, MAX_SRPT_SRQ_SIZE);
4017                 goto out;
4018         }
4019
4020         srpt_target = target_fabric_configfs_init(THIS_MODULE, "srpt");
4021         if (IS_ERR(srpt_target)) {
4022                 printk(KERN_ERR "couldn't register\n");
4023                 ret = PTR_ERR(srpt_target);
4024                 goto out;
4025         }
4026
4027         srpt_target->tf_ops = srpt_template;
4028
4029         /* Enable SG chaining */
4030         srpt_target->tf_ops.task_sg_chaining = true;
4031
4032         /*
4033          * Set up default attribute lists.
4034          */
4035         srpt_target->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = srpt_wwn_attrs;
4036         srpt_target->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = srpt_tpg_attrs;
4037         srpt_target->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = srpt_tpg_attrib_attrs;
4038         srpt_target->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
4039         srpt_target->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
4040         srpt_target->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;
4041         srpt_target->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
4042         srpt_target->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
4043         srpt_target->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;
4044
4045         ret = target_fabric_configfs_register(srpt_target);
4046         if (ret < 0) {
4047                 printk(KERN_ERR "couldn't register\n");
4048                 goto out_free_target;
4049         }
4050
4051         ret = ib_register_client(&srpt_client);
4052         if (ret) {
4053                 printk(KERN_ERR "couldn't register IB client\n");
4054                 goto out_unregister_target;
4055         }
4056
4057         return 0;
4058
4059 out_unregister_target:
4060         target_fabric_configfs_deregister(srpt_target);
4061         srpt_target = NULL;
4062 out_free_target:
4063         if (srpt_target)
4064                 target_fabric_configfs_free(srpt_target);
4065 out:
4066         return ret;
4067 }
4068
4069 static void __exit srpt_cleanup_module(void)
4070 {
4071         ib_unregister_client(&srpt_client);
4072         target_fabric_configfs_deregister(srpt_target);
4073         srpt_target = NULL;
4074 }
4075
4076 module_init(srpt_init_module);
4077 module_exit(srpt_cleanup_module);