5663d3c284c81939f0e15f7a2c44998fdfbe7fce
[linux-2.6.git] / drivers / block / viodasd.c
1 /* -*- linux-c -*-
2  * viodasd.c
3  *  Authors: Dave Boutcher <boutcher@us.ibm.com>
4  *           Ryan Arnold <ryanarn@us.ibm.com>
5  *           Colin Devilbiss <devilbis@us.ibm.com>
6  *           Stephen Rothwell
7  *
8  * (C) Copyright 2000-2004 IBM Corporation
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation; either version 2 of the
13  * License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23  *
24  * This routine provides access to disk space (termed "DASD" in historical
25  * IBM terms) owned and managed by an OS/400 partition running on the
26  * same box as this Linux partition.
27  *
28  * All disk operations are performed by sending messages back and forth to
29  * the OS/400 partition.
30  */
31
32 #define pr_fmt(fmt) "viod: " fmt
33
34 #include <linux/major.h>
35 #include <linux/fs.h>
36 #include <linux/module.h>
37 #include <linux/kernel.h>
38 #include <linux/blkdev.h>
39 #include <linux/genhd.h>
40 #include <linux/hdreg.h>
41 #include <linux/errno.h>
42 #include <linux/init.h>
43 #include <linux/string.h>
44 #include <linux/dma-mapping.h>
45 #include <linux/completion.h>
46 #include <linux/device.h>
47 #include <linux/scatterlist.h>
48
49 #include <asm/uaccess.h>
50 #include <asm/vio.h>
51 #include <asm/iseries/hv_types.h>
52 #include <asm/iseries/hv_lp_event.h>
53 #include <asm/iseries/hv_lp_config.h>
54 #include <asm/iseries/vio.h>
55 #include <asm/firmware.h>
56
57 MODULE_DESCRIPTION("iSeries Virtual DASD");
58 MODULE_AUTHOR("Dave Boutcher");
59 MODULE_LICENSE("GPL");
60
61 /*
62  * We only support 7 partitions per physical disk....so with minor
63  * numbers 0-255 we get a maximum of 32 disks.
64  */
65 #define VIOD_GENHD_NAME         "iseries/vd"
66
67 #define VIOD_VERS               "1.64"
68
69 enum {
70         PARTITION_SHIFT = 3,
71         MAX_DISKNO = HVMAXARCHITECTEDVIRTUALDISKS,
72         MAX_DISK_NAME = FIELD_SIZEOF(struct gendisk, disk_name)
73 };
74
75 static DEFINE_SPINLOCK(viodasd_spinlock);
76
77 #define VIOMAXREQ               16
78
79 #define DEVICE_NO(cell) ((struct viodasd_device *)(cell) - &viodasd_devices[0])
80
81 struct viodasd_waitevent {
82         struct completion       com;
83         int                     rc;
84         u16                     sub_result;
85         int                     max_disk;       /* open */
86 };
87
88 static const struct vio_error_entry viodasd_err_table[] = {
89         { 0x0201, EINVAL, "Invalid Range" },
90         { 0x0202, EINVAL, "Invalid Token" },
91         { 0x0203, EIO, "DMA Error" },
92         { 0x0204, EIO, "Use Error" },
93         { 0x0205, EIO, "Release Error" },
94         { 0x0206, EINVAL, "Invalid Disk" },
95         { 0x0207, EBUSY, "Cant Lock" },
96         { 0x0208, EIO, "Already Locked" },
97         { 0x0209, EIO, "Already Unlocked" },
98         { 0x020A, EIO, "Invalid Arg" },
99         { 0x020B, EIO, "Bad IFS File" },
100         { 0x020C, EROFS, "Read Only Device" },
101         { 0x02FF, EIO, "Internal Error" },
102         { 0x0000, 0, NULL },
103 };
104
105 /*
106  * Figure out the biggest I/O request (in sectors) we can accept
107  */
108 #define VIODASD_MAXSECTORS (4096 / 512 * VIOMAXBLOCKDMA)
109
110 /*
111  * Number of disk I/O requests we've sent to OS/400
112  */
113 static int num_req_outstanding;
114
115 /*
116  * This is our internal structure for keeping track of disk devices
117  */
118 struct viodasd_device {
119         u16             cylinders;
120         u16             tracks;
121         u16             sectors;
122         u16             bytes_per_sector;
123         u64             size;
124         int             read_only;
125         spinlock_t      q_lock;
126         struct gendisk  *disk;
127         struct device   *dev;
128 } viodasd_devices[MAX_DISKNO];
129
130 /*
131  * External open entry point.
132  */
133 static int viodasd_open(struct block_device *bdev, fmode_t mode)
134 {
135         struct viodasd_device *d = bdev->bd_disk->private_data;
136         HvLpEvent_Rc hvrc;
137         struct viodasd_waitevent we;
138         u16 flags = 0;
139
140         if (d->read_only) {
141                 if (mode & FMODE_WRITE)
142                         return -EROFS;
143                 flags = vioblockflags_ro;
144         }
145
146         init_completion(&we.com);
147
148         /* Send the open event to OS/400 */
149         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
150                         HvLpEvent_Type_VirtualIo,
151                         viomajorsubtype_blockio | vioblockopen,
152                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
153                         viopath_sourceinst(viopath_hostLp),
154                         viopath_targetinst(viopath_hostLp),
155                         (u64)(unsigned long)&we, VIOVERSION << 16,
156                         ((u64)DEVICE_NO(d) << 48) | ((u64)flags << 32),
157                         0, 0, 0);
158         if (hvrc != 0) {
159                 pr_warning("HV open failed %d\n", (int)hvrc);
160                 return -EIO;
161         }
162
163         wait_for_completion(&we.com);
164
165         /* Check the return code */
166         if (we.rc != 0) {
167                 const struct vio_error_entry *err =
168                         vio_lookup_rc(viodasd_err_table, we.sub_result);
169
170                 pr_warning("bad rc opening disk: %d:0x%04x (%s)\n",
171                            (int)we.rc, we.sub_result, err->msg);
172                 return -EIO;
173         }
174
175         return 0;
176 }
177
178 /*
179  * External release entry point.
180  */
181 static int viodasd_release(struct gendisk *disk, fmode_t mode)
182 {
183         struct viodasd_device *d = disk->private_data;
184         HvLpEvent_Rc hvrc;
185
186         /* Send the event to OS/400.  We DON'T expect a response */
187         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
188                         HvLpEvent_Type_VirtualIo,
189                         viomajorsubtype_blockio | vioblockclose,
190                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
191                         viopath_sourceinst(viopath_hostLp),
192                         viopath_targetinst(viopath_hostLp),
193                         0, VIOVERSION << 16,
194                         ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
195                         0, 0, 0);
196         if (hvrc != 0)
197                 pr_warning("HV close call failed %d\n", (int)hvrc);
198         return 0;
199 }
200
201
202 /* External ioctl entry point.
203  */
204 static int viodasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
205 {
206         struct gendisk *disk = bdev->bd_disk;
207         struct viodasd_device *d = disk->private_data;
208
209         geo->sectors = d->sectors ? d->sectors : 32;
210         geo->heads = d->tracks ? d->tracks  : 64;
211         geo->cylinders = d->cylinders ? d->cylinders :
212                 get_capacity(disk) / (geo->sectors * geo->heads);
213
214         return 0;
215 }
216
217 /*
218  * Our file operations table
219  */
220 static const struct block_device_operations viodasd_fops = {
221         .owner = THIS_MODULE,
222         .open = viodasd_open,
223         .release = viodasd_release,
224         .getgeo = viodasd_getgeo,
225 };
226
227 /*
228  * End a request
229  */
230 static void viodasd_end_request(struct request *req, int error,
231                 int num_sectors)
232 {
233         __blk_end_request(req, error, num_sectors << 9);
234 }
235
236 /*
237  * Send an actual I/O request to OS/400
238  */
239 static int send_request(struct request *req)
240 {
241         u64 start;
242         int direction;
243         int nsg;
244         u16 viocmd;
245         HvLpEvent_Rc hvrc;
246         struct vioblocklpevent *bevent;
247         struct HvLpEvent *hev;
248         struct scatterlist sg[VIOMAXBLOCKDMA];
249         int sgindex;
250         struct viodasd_device *d;
251         unsigned long flags;
252
253         start = (u64)blk_rq_pos(req) << 9;
254
255         if (rq_data_dir(req) == READ) {
256                 direction = DMA_FROM_DEVICE;
257                 viocmd = viomajorsubtype_blockio | vioblockread;
258         } else {
259                 direction = DMA_TO_DEVICE;
260                 viocmd = viomajorsubtype_blockio | vioblockwrite;
261         }
262
263         d = req->rq_disk->private_data;
264
265         /* Now build the scatter-gather list */
266         sg_init_table(sg, VIOMAXBLOCKDMA);
267         nsg = blk_rq_map_sg(req->q, req, sg);
268         nsg = dma_map_sg(d->dev, sg, nsg, direction);
269
270         spin_lock_irqsave(&viodasd_spinlock, flags);
271         num_req_outstanding++;
272
273         /* This optimization handles a single DMA block */
274         if (nsg == 1)
275                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
276                                 HvLpEvent_Type_VirtualIo, viocmd,
277                                 HvLpEvent_AckInd_DoAck,
278                                 HvLpEvent_AckType_ImmediateAck,
279                                 viopath_sourceinst(viopath_hostLp),
280                                 viopath_targetinst(viopath_hostLp),
281                                 (u64)(unsigned long)req, VIOVERSION << 16,
282                                 ((u64)DEVICE_NO(d) << 48), start,
283                                 ((u64)sg_dma_address(&sg[0])) << 32,
284                                 sg_dma_len(&sg[0]));
285         else {
286                 bevent = (struct vioblocklpevent *)
287                         vio_get_event_buffer(viomajorsubtype_blockio);
288                 if (bevent == NULL) {
289                         pr_warning("error allocating disk event buffer\n");
290                         goto error_ret;
291                 }
292
293                 /*
294                  * Now build up the actual request.  Note that we store
295                  * the pointer to the request in the correlation
296                  * token so we can match the response up later
297                  */
298                 memset(bevent, 0, sizeof(struct vioblocklpevent));
299                 hev = &bevent->event;
300                 hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK |
301                         HV_LP_EVENT_INT;
302                 hev->xType = HvLpEvent_Type_VirtualIo;
303                 hev->xSubtype = viocmd;
304                 hev->xSourceLp = HvLpConfig_getLpIndex();
305                 hev->xTargetLp = viopath_hostLp;
306                 hev->xSizeMinus1 =
307                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
308                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
309                 hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp);
310                 hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp);
311                 hev->xCorrelationToken = (u64)req;
312                 bevent->version = VIOVERSION;
313                 bevent->disk = DEVICE_NO(d);
314                 bevent->u.rw_data.offset = start;
315
316                 /*
317                  * Copy just the dma information from the sg list
318                  * into the request
319                  */
320                 for (sgindex = 0; sgindex < nsg; sgindex++) {
321                         bevent->u.rw_data.dma_info[sgindex].token =
322                                 sg_dma_address(&sg[sgindex]);
323                         bevent->u.rw_data.dma_info[sgindex].len =
324                                 sg_dma_len(&sg[sgindex]);
325                 }
326
327                 /* Send the request */
328                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
329                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
330         }
331
332         if (hvrc != HvLpEvent_Rc_Good) {
333                 pr_warning("error sending disk event to OS/400 (rc %d)\n",
334                            (int)hvrc);
335                 goto error_ret;
336         }
337         spin_unlock_irqrestore(&viodasd_spinlock, flags);
338         return 0;
339
340 error_ret:
341         num_req_outstanding--;
342         spin_unlock_irqrestore(&viodasd_spinlock, flags);
343         dma_unmap_sg(d->dev, sg, nsg, direction);
344         return -1;
345 }
346
347 /*
348  * This is the external request processing routine
349  */
350 static void do_viodasd_request(struct request_queue *q)
351 {
352         struct request *req;
353
354         /*
355          * If we already have the maximum number of requests
356          * outstanding to OS/400 just bail out. We'll come
357          * back later.
358          */
359         while (num_req_outstanding < VIOMAXREQ) {
360                 req = blk_fetch_request(q);
361                 if (req == NULL)
362                         return;
363                 /* check that request contains a valid command */
364                 if (req->cmd_type != REQ_TYPE_FS) {
365                         viodasd_end_request(req, -EIO, blk_rq_sectors(req));
366                         continue;
367                 }
368                 /* Try sending the request */
369                 if (send_request(req) != 0)
370                         viodasd_end_request(req, -EIO, blk_rq_sectors(req));
371         }
372 }
373
374 /*
375  * Probe a single disk and fill in the viodasd_device structure
376  * for it.
377  */
378 static int probe_disk(struct viodasd_device *d)
379 {
380         HvLpEvent_Rc hvrc;
381         struct viodasd_waitevent we;
382         int dev_no = DEVICE_NO(d);
383         struct gendisk *g;
384         struct request_queue *q;
385         u16 flags = 0;
386
387 retry:
388         init_completion(&we.com);
389
390         /* Send the open event to OS/400 */
391         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
392                         HvLpEvent_Type_VirtualIo,
393                         viomajorsubtype_blockio | vioblockopen,
394                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
395                         viopath_sourceinst(viopath_hostLp),
396                         viopath_targetinst(viopath_hostLp),
397                         (u64)(unsigned long)&we, VIOVERSION << 16,
398                         ((u64)dev_no << 48) | ((u64)flags<< 32),
399                         0, 0, 0);
400         if (hvrc != 0) {
401                 pr_warning("bad rc on HV open %d\n", (int)hvrc);
402                 return 0;
403         }
404
405         wait_for_completion(&we.com);
406
407         if (we.rc != 0) {
408                 if (flags != 0)
409                         return 0;
410                 /* try again with read only flag set */
411                 flags = vioblockflags_ro;
412                 goto retry;
413         }
414         if (we.max_disk > (MAX_DISKNO - 1)) {
415                 printk_once(KERN_INFO pr_fmt("Only examining the first %d of %d disks connected\n"),
416                             MAX_DISKNO, we.max_disk + 1);
417         }
418
419         /* Send the close event to OS/400.  We DON'T expect a response */
420         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
421                         HvLpEvent_Type_VirtualIo,
422                         viomajorsubtype_blockio | vioblockclose,
423                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
424                         viopath_sourceinst(viopath_hostLp),
425                         viopath_targetinst(viopath_hostLp),
426                         0, VIOVERSION << 16,
427                         ((u64)dev_no << 48) | ((u64)flags << 32),
428                         0, 0, 0);
429         if (hvrc != 0) {
430                 pr_warning("bad rc sending event to OS/400 %d\n", (int)hvrc);
431                 return 0;
432         }
433
434         if (d->dev == NULL) {
435                 /* this is when we reprobe for new disks */
436                 if (vio_create_viodasd(dev_no) == NULL) {
437                         pr_warning("cannot allocate virtual device for disk %d\n",
438                                    dev_no);
439                         return 0;
440                 }
441                 /*
442                  * The vio_create_viodasd will have recursed into this
443                  * routine with d->dev set to the new vio device and
444                  * will finish the setup of the disk below.
445                  */
446                 return 1;
447         }
448
449         /* create the request queue for the disk */
450         spin_lock_init(&d->q_lock);
451         q = blk_init_queue(do_viodasd_request, &d->q_lock);
452         if (q == NULL) {
453                 pr_warning("cannot allocate queue for disk %d\n", dev_no);
454                 return 0;
455         }
456         g = alloc_disk(1 << PARTITION_SHIFT);
457         if (g == NULL) {
458                 pr_warning("cannot allocate disk structure for disk %d\n",
459                            dev_no);
460                 blk_cleanup_queue(q);
461                 return 0;
462         }
463
464         d->disk = g;
465         blk_queue_max_segments(q, VIOMAXBLOCKDMA);
466         blk_queue_max_hw_sectors(q, VIODASD_MAXSECTORS);
467         g->major = VIODASD_MAJOR;
468         g->first_minor = dev_no << PARTITION_SHIFT;
469         if (dev_no >= 26)
470                 snprintf(g->disk_name, sizeof(g->disk_name),
471                                 VIOD_GENHD_NAME "%c%c",
472                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
473         else
474                 snprintf(g->disk_name, sizeof(g->disk_name),
475                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
476         g->fops = &viodasd_fops;
477         g->queue = q;
478         g->private_data = d;
479         g->driverfs_dev = d->dev;
480         set_capacity(g, d->size >> 9);
481
482         pr_info("disk %d: %lu sectors (%lu MB) CHS=%d/%d/%d sector size %d%s\n",
483                 dev_no, (unsigned long)(d->size >> 9),
484                 (unsigned long)(d->size >> 20),
485                 (int)d->cylinders, (int)d->tracks,
486                 (int)d->sectors, (int)d->bytes_per_sector,
487                 d->read_only ? " (RO)" : "");
488
489         /* register us in the global list */
490         add_disk(g);
491         return 1;
492 }
493
494 /* returns the total number of scatterlist elements converted */
495 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
496                 struct scatterlist *sg, int *total_len)
497 {
498         int i, numsg;
499         const struct rw_data *rw_data = &bevent->u.rw_data;
500         static const int offset =
501                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
502         static const int element_size = sizeof(rw_data->dma_info[0]);
503
504         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
505         if (numsg > VIOMAXBLOCKDMA)
506                 numsg = VIOMAXBLOCKDMA;
507
508         *total_len = 0;
509         sg_init_table(sg, VIOMAXBLOCKDMA);
510         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
511                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
512                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
513                 *total_len += rw_data->dma_info[i].len;
514         }
515         return i;
516 }
517
518 /*
519  * Restart all queues, starting with the one _after_ the disk given,
520  * thus reducing the chance of starvation of higher numbered disks.
521  */
522 static void viodasd_restart_all_queues_starting_from(int first_index)
523 {
524         int i;
525
526         for (i = first_index + 1; i < MAX_DISKNO; ++i)
527                 if (viodasd_devices[i].disk)
528                         blk_run_queue(viodasd_devices[i].disk->queue);
529         for (i = 0; i <= first_index; ++i)
530                 if (viodasd_devices[i].disk)
531                         blk_run_queue(viodasd_devices[i].disk->queue);
532 }
533
534 /*
535  * For read and write requests, decrement the number of outstanding requests,
536  * Free the DMA buffers we allocated.
537  */
538 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
539 {
540         int num_sg, num_sect, pci_direction, total_len;
541         struct request *req;
542         struct scatterlist sg[VIOMAXBLOCKDMA];
543         struct HvLpEvent *event = &bevent->event;
544         unsigned long irq_flags;
545         struct viodasd_device *d;
546         int error;
547         spinlock_t *qlock;
548
549         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
550         num_sect = total_len >> 9;
551         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
552                 pci_direction = DMA_FROM_DEVICE;
553         else
554                 pci_direction = DMA_TO_DEVICE;
555         req = (struct request *)bevent->event.xCorrelationToken;
556         d = req->rq_disk->private_data;
557
558         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
559
560         /*
561          * Since this is running in interrupt mode, we need to make sure
562          * we're not stepping on any global I/O operations
563          */
564         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
565         num_req_outstanding--;
566         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
567
568         error = (event->xRc == HvLpEvent_Rc_Good) ? 0 : -EIO;
569         if (error) {
570                 const struct vio_error_entry *err;
571                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
572                 pr_warning("read/write error %d:0x%04x (%s)\n",
573                            event->xRc, bevent->sub_result, err->msg);
574                 num_sect = blk_rq_sectors(req);
575         }
576         qlock = req->q->queue_lock;
577         spin_lock_irqsave(qlock, irq_flags);
578         viodasd_end_request(req, error, num_sect);
579         spin_unlock_irqrestore(qlock, irq_flags);
580
581         /* Finally, try to get more requests off of this device's queue */
582         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
583
584         return 0;
585 }
586
587 /* This routine handles incoming block LP events */
588 static void handle_block_event(struct HvLpEvent *event)
589 {
590         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
591         struct viodasd_waitevent *pwe;
592
593         if (event == NULL)
594                 /* Notification that a partition went away! */
595                 return;
596         /* First, we should NEVER get an int here...only acks */
597         if (hvlpevent_is_int(event)) {
598                 pr_warning("Yikes! got an int in viodasd event handler!\n");
599                 if (hvlpevent_need_ack(event)) {
600                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
601                         HvCallEvent_ackLpEvent(event);
602                 }
603         }
604
605         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
606         case vioblockopen:
607                 /*
608                  * Handle a response to an open request.  We get all the
609                  * disk information in the response, so update it.  The
610                  * correlation token contains a pointer to a waitevent
611                  * structure that has a completion in it.  update the
612                  * return code in the waitevent structure and post the
613                  * completion to wake up the guy who sent the request
614                  */
615                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
616                 pwe->rc = event->xRc;
617                 pwe->sub_result = bevent->sub_result;
618                 if (event->xRc == HvLpEvent_Rc_Good) {
619                         const struct open_data *data = &bevent->u.open_data;
620                         struct viodasd_device *device =
621                                 &viodasd_devices[bevent->disk];
622                         device->read_only =
623                                 bevent->flags & vioblockflags_ro;
624                         device->size = data->disk_size;
625                         device->cylinders = data->cylinders;
626                         device->tracks = data->tracks;
627                         device->sectors = data->sectors;
628                         device->bytes_per_sector = data->bytes_per_sector;
629                         pwe->max_disk = data->max_disk;
630                 }
631                 complete(&pwe->com);
632                 break;
633         case vioblockclose:
634                 break;
635         case vioblockread:
636         case vioblockwrite:
637                 viodasd_handle_read_write(bevent);
638                 break;
639
640         default:
641                 pr_warning("invalid subtype!");
642                 if (hvlpevent_need_ack(event)) {
643                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
644                         HvCallEvent_ackLpEvent(event);
645                 }
646         }
647 }
648
649 /*
650  * Get the driver to reprobe for more disks.
651  */
652 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
653                 size_t count)
654 {
655         struct viodasd_device *d;
656
657         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
658                 if (d->disk == NULL)
659                         probe_disk(d);
660         }
661         return count;
662 }
663 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
664
665 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
666 {
667         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
668
669         d->dev = &vdev->dev;
670         if (!probe_disk(d))
671                 return -ENODEV;
672         return 0;
673 }
674
675 static int viodasd_remove(struct vio_dev *vdev)
676 {
677         struct viodasd_device *d;
678
679         d = &viodasd_devices[vdev->unit_address];
680         if (d->disk) {
681                 del_gendisk(d->disk);
682                 blk_cleanup_queue(d->disk->queue);
683                 put_disk(d->disk);
684                 d->disk = NULL;
685         }
686         d->dev = NULL;
687         return 0;
688 }
689
690 /**
691  * viodasd_device_table: Used by vio.c to match devices that we
692  * support.
693  */
694 static struct vio_device_id viodasd_device_table[] __devinitdata = {
695         { "block", "IBM,iSeries-viodasd" },
696         { "", "" }
697 };
698 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
699
700 static struct vio_driver viodasd_driver = {
701         .id_table = viodasd_device_table,
702         .probe = viodasd_probe,
703         .remove = viodasd_remove,
704         .driver = {
705                 .name = "viodasd",
706                 .owner = THIS_MODULE,
707         }
708 };
709
710 static int need_delete_probe;
711
712 /*
713  * Initialize the whole device driver.  Handle module and non-module
714  * versions
715  */
716 static int __init viodasd_init(void)
717 {
718         int rc;
719
720         if (!firmware_has_feature(FW_FEATURE_ISERIES)) {
721                 rc = -ENODEV;
722                 goto early_fail;
723         }
724
725         /* Try to open to our host lp */
726         if (viopath_hostLp == HvLpIndexInvalid)
727                 vio_set_hostlp();
728
729         if (viopath_hostLp == HvLpIndexInvalid) {
730                 pr_warning("invalid hosting partition\n");
731                 rc = -EIO;
732                 goto early_fail;
733         }
734
735         pr_info("vers " VIOD_VERS ", hosting partition %d\n", viopath_hostLp);
736
737         /* register the block device */
738         rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
739         if (rc) {
740                 pr_warning("Unable to get major number %d for %s\n",
741                            VIODASD_MAJOR, VIOD_GENHD_NAME);
742                 goto early_fail;
743         }
744         /* Actually open the path to the hosting partition */
745         rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
746                                 VIOMAXREQ + 2);
747         if (rc) {
748                 pr_warning("error opening path to host partition %d\n",
749                            viopath_hostLp);
750                 goto unregister_blk;
751         }
752
753         /* Initialize our request handler */
754         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
755
756         rc = vio_register_driver(&viodasd_driver);
757         if (rc) {
758                 pr_warning("vio_register_driver failed\n");
759                 goto unset_handler;
760         }
761
762         /*
763          * If this call fails, it just means that we cannot dynamically
764          * add virtual disks, but the driver will still work fine for
765          * all existing disk, so ignore the failure.
766          */
767         if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
768                 need_delete_probe = 1;
769
770         return 0;
771
772 unset_handler:
773         vio_clearHandler(viomajorsubtype_blockio);
774         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
775 unregister_blk:
776         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
777 early_fail:
778         return rc;
779 }
780 module_init(viodasd_init);
781
782 void __exit viodasd_exit(void)
783 {
784         if (need_delete_probe)
785                 driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
786         vio_unregister_driver(&viodasd_driver);
787         vio_clearHandler(viomajorsubtype_blockio);
788         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
789         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
790 }
791 module_exit(viodasd_exit);