drm/i915: SDVO hotplug have different interrupt status bits for i915/i965/g4x
[linux-2.6.git] / drivers / target / target_core_tmr.c
1 /*******************************************************************************
2  * Filename:  target_core_tmr.c
3  *
4  * This file contains SPC-3 task management infrastructure
5  *
6  * Copyright (c) 2009,2010 Rising Tide Systems
7  * Copyright (c) 2009,2010 Linux-iSCSI.org
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24  *
25  ******************************************************************************/
26
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <linux/list.h>
30 #include <linux/export.h>
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_cmnd.h>
33
34 #include <target/target_core_base.h>
35 #include <target/target_core_backend.h>
36 #include <target/target_core_fabric.h>
37 #include <target/target_core_configfs.h>
38
39 #include "target_core_internal.h"
40 #include "target_core_alua.h"
41 #include "target_core_pr.h"
42
43 int core_tmr_alloc_req(
44         struct se_cmd *se_cmd,
45         void *fabric_tmr_ptr,
46         u8 function,
47         gfp_t gfp_flags)
48 {
49         struct se_tmr_req *tmr;
50
51         tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags);
52         if (!tmr) {
53                 pr_err("Unable to allocate struct se_tmr_req\n");
54                 return -ENOMEM;
55         }
56
57         se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB;
58         se_cmd->se_tmr_req = tmr;
59         tmr->task_cmd = se_cmd;
60         tmr->fabric_tmr_ptr = fabric_tmr_ptr;
61         tmr->function = function;
62         INIT_LIST_HEAD(&tmr->tmr_list);
63
64         return 0;
65 }
66 EXPORT_SYMBOL(core_tmr_alloc_req);
67
68 void core_tmr_release_req(
69         struct se_tmr_req *tmr)
70 {
71         struct se_device *dev = tmr->tmr_dev;
72         unsigned long flags;
73
74         if (!dev) {
75                 kfree(tmr);
76                 return;
77         }
78
79         spin_lock_irqsave(&dev->se_tmr_lock, flags);
80         list_del(&tmr->tmr_list);
81         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
82
83         kfree(tmr);
84 }
85
86 static void core_tmr_handle_tas_abort(
87         struct se_node_acl *tmr_nacl,
88         struct se_cmd *cmd,
89         int tas,
90         int fe_count)
91 {
92         if (!fe_count) {
93                 transport_cmd_finish_abort(cmd, 1);
94                 return;
95         }
96         /*
97          * TASK ABORTED status (TAS) bit support
98         */
99         if ((tmr_nacl &&
100              (tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
101                 transport_send_task_abort(cmd);
102
103         transport_cmd_finish_abort(cmd, 0);
104 }
105
106 static int target_check_cdb_and_preempt(struct list_head *list,
107                 struct se_cmd *cmd)
108 {
109         struct t10_pr_registration *reg;
110
111         if (!list)
112                 return 0;
113         list_for_each_entry(reg, list, pr_reg_abort_list) {
114                 if (reg->pr_res_key == cmd->pr_res_key)
115                         return 0;
116         }
117
118         return 1;
119 }
120
121 void core_tmr_abort_task(
122         struct se_device *dev,
123         struct se_tmr_req *tmr,
124         struct se_session *se_sess)
125 {
126         struct se_cmd *se_cmd, *tmp_cmd;
127         unsigned long flags;
128         int ref_tag;
129
130         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
131         list_for_each_entry_safe(se_cmd, tmp_cmd,
132                         &se_sess->sess_cmd_list, se_cmd_list) {
133
134                 if (dev != se_cmd->se_dev)
135                         continue;
136                 ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd);
137                 if (tmr->ref_task_tag != ref_tag)
138                         continue;
139
140                 printk("ABORT_TASK: Found referenced %s task_tag: %u\n",
141                         se_cmd->se_tfo->get_fabric_name(), ref_tag);
142
143                 spin_lock(&se_cmd->t_state_lock);
144                 if (se_cmd->transport_state & CMD_T_COMPLETE) {
145                         printk("ABORT_TASK: ref_tag: %u already complete, skipping\n", ref_tag);
146                         spin_unlock(&se_cmd->t_state_lock);
147                         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
148                         goto out;
149                 }
150                 se_cmd->transport_state |= CMD_T_ABORTED;
151                 spin_unlock(&se_cmd->t_state_lock);
152
153                 list_del_init(&se_cmd->se_cmd_list);
154                 kref_get(&se_cmd->cmd_kref);
155                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
156
157                 cancel_work_sync(&se_cmd->work);
158                 transport_wait_for_tasks(se_cmd);
159                 /*
160                  * Now send SAM_STAT_TASK_ABORTED status for the referenced
161                  * se_cmd descriptor..
162                  */
163                 transport_send_task_abort(se_cmd);
164                 /*
165                  * Also deal with possible extra acknowledge reference..
166                  */
167                 if (se_cmd->se_cmd_flags & SCF_ACK_KREF)
168                         target_put_sess_cmd(se_sess, se_cmd);
169
170                 target_put_sess_cmd(se_sess, se_cmd);
171
172                 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
173                                 " ref_tag: %d\n", ref_tag);
174                 tmr->response = TMR_FUNCTION_COMPLETE;
175                 return;
176         }
177         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
178
179 out:
180         printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n",
181                         tmr->ref_task_tag);
182         tmr->response = TMR_TASK_DOES_NOT_EXIST;
183 }
184
185 static void core_tmr_drain_tmr_list(
186         struct se_device *dev,
187         struct se_tmr_req *tmr,
188         struct list_head *preempt_and_abort_list)
189 {
190         LIST_HEAD(drain_tmr_list);
191         struct se_tmr_req *tmr_p, *tmr_pp;
192         struct se_cmd *cmd;
193         unsigned long flags;
194         /*
195          * Release all pending and outgoing TMRs aside from the received
196          * LUN_RESET tmr..
197          */
198         spin_lock_irqsave(&dev->se_tmr_lock, flags);
199         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
200                 /*
201                  * Allow the received TMR to return with FUNCTION_COMPLETE.
202                  */
203                 if (tmr_p == tmr)
204                         continue;
205
206                 cmd = tmr_p->task_cmd;
207                 if (!cmd) {
208                         pr_err("Unable to locate struct se_cmd for TMR\n");
209                         continue;
210                 }
211                 /*
212                  * If this function was called with a valid pr_res_key
213                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
214                  * skip non regisration key matching TMRs.
215                  */
216                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
217                         continue;
218
219                 spin_lock(&cmd->t_state_lock);
220                 if (!(cmd->transport_state & CMD_T_ACTIVE)) {
221                         spin_unlock(&cmd->t_state_lock);
222                         continue;
223                 }
224                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
225                         spin_unlock(&cmd->t_state_lock);
226                         continue;
227                 }
228                 spin_unlock(&cmd->t_state_lock);
229
230                 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
231         }
232         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
233
234         list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
235                 list_del_init(&tmr_p->tmr_list);
236                 cmd = tmr_p->task_cmd;
237
238                 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
239                         " Response: 0x%02x, t_state: %d\n",
240                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
241                         tmr_p->function, tmr_p->response, cmd->t_state);
242
243                 transport_cmd_finish_abort(cmd, 1);
244         }
245 }
246
247 static void core_tmr_drain_task_list(
248         struct se_device *dev,
249         struct se_cmd *prout_cmd,
250         struct se_node_acl *tmr_nacl,
251         int tas,
252         struct list_head *preempt_and_abort_list)
253 {
254         LIST_HEAD(drain_task_list);
255         struct se_cmd *cmd;
256         struct se_task *task, *task_tmp;
257         unsigned long flags;
258         int fe_count;
259         /*
260          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
261          * This is following sam4r17, section 5.6 Aborting commands, Table 38
262          * for TMR LUN_RESET:
263          *
264          * a) "Yes" indicates that each command that is aborted on an I_T nexus
265          * other than the one that caused the SCSI device condition is
266          * completed with TASK ABORTED status, if the TAS bit is set to one in
267          * the Control mode page (see SPC-4). "No" indicates that no status is
268          * returned for aborted commands.
269          *
270          * d) If the logical unit reset is caused by a particular I_T nexus
271          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
272          * (TASK_ABORTED status) applies.
273          *
274          * Otherwise (e.g., if triggered by a hard reset), "no"
275          * (no TASK_ABORTED SAM status) applies.
276          *
277          * Note that this seems to be independent of TAS (Task Aborted Status)
278          * in the Control Mode Page.
279          */
280         spin_lock_irqsave(&dev->execute_task_lock, flags);
281         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
282                                 t_state_list) {
283                 if (!task->task_se_cmd) {
284                         pr_err("task->task_se_cmd is NULL!\n");
285                         continue;
286                 }
287                 cmd = task->task_se_cmd;
288
289                 /*
290                  * For PREEMPT_AND_ABORT usage, only process commands
291                  * with a matching reservation key.
292                  */
293                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
294                         continue;
295                 /*
296                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
297                  */
298                 if (prout_cmd == cmd)
299                         continue;
300
301                 list_move_tail(&task->t_state_list, &drain_task_list);
302                 task->t_state_active = false;
303                 /*
304                  * Remove from task execute list before processing drain_task_list
305                  */
306                 if (!list_empty(&task->t_execute_list))
307                         __transport_remove_task_from_execute_queue(task, dev);
308         }
309         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
310
311         while (!list_empty(&drain_task_list)) {
312                 task = list_entry(drain_task_list.next, struct se_task, t_state_list);
313                 list_del(&task->t_state_list);
314                 cmd = task->task_se_cmd;
315
316                 pr_debug("LUN_RESET: %s cmd: %p task: %p"
317                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d"
318                         "cdb: 0x%02x\n",
319                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
320                         cmd->se_tfo->get_task_tag(cmd), 0,
321                         cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
322                         cmd->t_task_cdb[0]);
323                 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
324                         " t_task_cdbs: %d t_task_cdbs_left: %d"
325                         " t_task_cdbs_sent: %d -- CMD_T_ACTIVE: %d"
326                         " CMD_T_STOP: %d CMD_T_SENT: %d\n",
327                         cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
328                         cmd->t_task_list_num,
329                         atomic_read(&cmd->t_task_cdbs_left),
330                         atomic_read(&cmd->t_task_cdbs_sent),
331                         (cmd->transport_state & CMD_T_ACTIVE) != 0,
332                         (cmd->transport_state & CMD_T_STOP) != 0,
333                         (cmd->transport_state & CMD_T_SENT) != 0);
334
335                 /*
336                  * If the command may be queued onto a workqueue cancel it now.
337                  *
338                  * This is equivalent to removal from the execute queue in the
339                  * loop above, but we do it down here given that
340                  * cancel_work_sync may block.
341                  */
342                 if (cmd->t_state == TRANSPORT_COMPLETE)
343                         cancel_work_sync(&cmd->work);
344
345                 spin_lock_irqsave(&cmd->t_state_lock, flags);
346                 target_stop_task(task, &flags);
347
348                 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
349                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
350                         pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
351                                 " t_task_cdbs_ex_left: %d\n", task, dev,
352                                 atomic_read(&cmd->t_task_cdbs_ex_left));
353                         continue;
354                 }
355                 fe_count = atomic_read(&cmd->t_fe_count);
356
357                 if (!(cmd->transport_state & CMD_T_ACTIVE)) {
358                         pr_debug("LUN_RESET: got CMD_T_ACTIVE for"
359                                 " task: %p, t_fe_count: %d dev: %p\n", task,
360                                 fe_count, dev);
361                         cmd->transport_state |= CMD_T_ABORTED;
362                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
363
364                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
365                         continue;
366                 }
367                 pr_debug("LUN_RESET: Got !CMD_T_ACTIVE for task: %p,"
368                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
369                 cmd->transport_state |= CMD_T_ABORTED;
370                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
371
372                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
373         }
374 }
375
376 static void core_tmr_drain_cmd_list(
377         struct se_device *dev,
378         struct se_cmd *prout_cmd,
379         struct se_node_acl *tmr_nacl,
380         int tas,
381         struct list_head *preempt_and_abort_list)
382 {
383         LIST_HEAD(drain_cmd_list);
384         struct se_queue_obj *qobj = &dev->dev_queue_obj;
385         struct se_cmd *cmd, *tcmd;
386         unsigned long flags;
387         /*
388          * Release all commands remaining in the struct se_device cmd queue.
389          *
390          * This follows the same logic as above for the struct se_device
391          * struct se_task state list, where commands are returned with
392          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
393          * reference, otherwise the struct se_cmd is released.
394          */
395         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
396         list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
397                 /*
398                  * For PREEMPT_AND_ABORT usage, only process commands
399                  * with a matching reservation key.
400                  */
401                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
402                         continue;
403                 /*
404                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
405                  */
406                 if (prout_cmd == cmd)
407                         continue;
408
409                 cmd->transport_state &= ~CMD_T_QUEUED;
410                 atomic_dec(&qobj->queue_cnt);
411                 list_move_tail(&cmd->se_queue_node, &drain_cmd_list);
412         }
413         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
414
415         while (!list_empty(&drain_cmd_list)) {
416                 cmd = list_entry(drain_cmd_list.next, struct se_cmd, se_queue_node);
417                 list_del_init(&cmd->se_queue_node);
418
419                 pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
420                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
421                         "Preempt" : "", cmd, cmd->t_state,
422                         atomic_read(&cmd->t_fe_count));
423
424                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
425                                 atomic_read(&cmd->t_fe_count));
426         }
427 }
428
429 int core_tmr_lun_reset(
430         struct se_device *dev,
431         struct se_tmr_req *tmr,
432         struct list_head *preempt_and_abort_list,
433         struct se_cmd *prout_cmd)
434 {
435         struct se_node_acl *tmr_nacl = NULL;
436         struct se_portal_group *tmr_tpg = NULL;
437         int tas;
438         /*
439          * TASK_ABORTED status bit, this is configurable via ConfigFS
440          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
441          *
442          * A task aborted status (TAS) bit set to zero specifies that aborted
443          * tasks shall be terminated by the device server without any response
444          * to the application client. A TAS bit set to one specifies that tasks
445          * aborted by the actions of an I_T nexus other than the I_T nexus on
446          * which the command was received shall be completed with TASK ABORTED
447          * status (see SAM-4).
448          */
449         tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
450         /*
451          * Determine if this se_tmr is coming from a $FABRIC_MOD
452          * or struct se_device passthrough..
453          */
454         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
455                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
456                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
457                 if (tmr_nacl && tmr_tpg) {
458                         pr_debug("LUN_RESET: TMR caller fabric: %s"
459                                 " initiator port %s\n",
460                                 tmr_tpg->se_tpg_tfo->get_fabric_name(),
461                                 tmr_nacl->initiatorname);
462                 }
463         }
464         pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
465                 (preempt_and_abort_list) ? "Preempt" : "TMR",
466                 dev->transport->name, tas);
467
468         core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
469         core_tmr_drain_task_list(dev, prout_cmd, tmr_nacl, tas,
470                                 preempt_and_abort_list);
471         core_tmr_drain_cmd_list(dev, prout_cmd, tmr_nacl, tas,
472                                 preempt_and_abort_list);
473         /*
474          * Clear any legacy SPC-2 reservation when called during
475          * LOGICAL UNIT RESET
476          */
477         if (!preempt_and_abort_list &&
478              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
479                 spin_lock(&dev->dev_reservation_lock);
480                 dev->dev_reserved_node_acl = NULL;
481                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
482                 spin_unlock(&dev->dev_reservation_lock);
483                 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
484         }
485
486         spin_lock_irq(&dev->stats_lock);
487         dev->num_resets++;
488         spin_unlock_irq(&dev->stats_lock);
489
490         pr_debug("LUN_RESET: %s for [%s] Complete\n",
491                         (preempt_and_abort_list) ? "Preempt" : "TMR",
492                         dev->transport->name);
493         return 0;
494 }
495