cciss: fix some magic numbers in the raid-level decoding
[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 #include <linux/major.h>
32 #include <linux/fs.h>
33 #include <linux/module.h>
34 #include <linux/kernel.h>
35 #include <linux/blkdev.h>
36 #include <linux/genhd.h>
37 #include <linux/hdreg.h>
38 #include <linux/errno.h>
39 #include <linux/init.h>
40 #include <linux/string.h>
41 #include <linux/dma-mapping.h>
42 #include <linux/completion.h>
43 #include <linux/device.h>
44 #include <linux/scatterlist.h>
45
46 #include <asm/uaccess.h>
47 #include <asm/vio.h>
48 #include <asm/iseries/hv_types.h>
49 #include <asm/iseries/hv_lp_event.h>
50 #include <asm/iseries/hv_lp_config.h>
51 #include <asm/iseries/vio.h>
52 #include <asm/firmware.h>
53
54 MODULE_DESCRIPTION("iSeries Virtual DASD");
55 MODULE_AUTHOR("Dave Boutcher");
56 MODULE_LICENSE("GPL");
57
58 /*
59  * We only support 7 partitions per physical disk....so with minor
60  * numbers 0-255 we get a maximum of 32 disks.
61  */
62 #define VIOD_GENHD_NAME         "iseries/vd"
63
64 #define VIOD_VERS               "1.64"
65
66 #define VIOD_KERN_WARNING       KERN_WARNING "viod: "
67 #define VIOD_KERN_INFO          KERN_INFO "viod: "
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                 printk(VIOD_KERN_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                 printk(VIOD_KERN_WARNING
171                                 "bad rc opening disk: %d:0x%04x (%s)\n",
172                                 (int)we.rc, we.sub_result, err->msg);
173                 return -EIO;
174         }
175
176         return 0;
177 }
178
179 /*
180  * External release entry point.
181  */
182 static int viodasd_release(struct gendisk *disk, fmode_t mode)
183 {
184         struct viodasd_device *d = disk->private_data;
185         HvLpEvent_Rc hvrc;
186
187         /* Send the event to OS/400.  We DON'T expect a response */
188         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
189                         HvLpEvent_Type_VirtualIo,
190                         viomajorsubtype_blockio | vioblockclose,
191                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
192                         viopath_sourceinst(viopath_hostLp),
193                         viopath_targetinst(viopath_hostLp),
194                         0, VIOVERSION << 16,
195                         ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
196                         0, 0, 0);
197         if (hvrc != 0)
198                 printk(VIOD_KERN_WARNING "HV close call failed %d\n",
199                                 (int)hvrc);
200         return 0;
201 }
202
203
204 /* External ioctl entry point.
205  */
206 static int viodasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
207 {
208         struct gendisk *disk = bdev->bd_disk;
209         struct viodasd_device *d = disk->private_data;
210
211         geo->sectors = d->sectors ? d->sectors : 32;
212         geo->heads = d->tracks ? d->tracks  : 64;
213         geo->cylinders = d->cylinders ? d->cylinders :
214                 get_capacity(disk) / (geo->sectors * geo->heads);
215
216         return 0;
217 }
218
219 /*
220  * Our file operations table
221  */
222 static const struct block_device_operations viodasd_fops = {
223         .owner = THIS_MODULE,
224         .open = viodasd_open,
225         .release = viodasd_release,
226         .getgeo = viodasd_getgeo,
227 };
228
229 /*
230  * End a request
231  */
232 static void viodasd_end_request(struct request *req, int error,
233                 int num_sectors)
234 {
235         __blk_end_request(req, error, num_sectors << 9);
236 }
237
238 /*
239  * Send an actual I/O request to OS/400
240  */
241 static int send_request(struct request *req)
242 {
243         u64 start;
244         int direction;
245         int nsg;
246         u16 viocmd;
247         HvLpEvent_Rc hvrc;
248         struct vioblocklpevent *bevent;
249         struct HvLpEvent *hev;
250         struct scatterlist sg[VIOMAXBLOCKDMA];
251         int sgindex;
252         struct viodasd_device *d;
253         unsigned long flags;
254
255         start = (u64)blk_rq_pos(req) << 9;
256
257         if (rq_data_dir(req) == READ) {
258                 direction = DMA_FROM_DEVICE;
259                 viocmd = viomajorsubtype_blockio | vioblockread;
260         } else {
261                 direction = DMA_TO_DEVICE;
262                 viocmd = viomajorsubtype_blockio | vioblockwrite;
263         }
264
265         d = req->rq_disk->private_data;
266
267         /* Now build the scatter-gather list */
268         sg_init_table(sg, VIOMAXBLOCKDMA);
269         nsg = blk_rq_map_sg(req->q, req, sg);
270         nsg = dma_map_sg(d->dev, sg, nsg, direction);
271
272         spin_lock_irqsave(&viodasd_spinlock, flags);
273         num_req_outstanding++;
274
275         /* This optimization handles a single DMA block */
276         if (nsg == 1)
277                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
278                                 HvLpEvent_Type_VirtualIo, viocmd,
279                                 HvLpEvent_AckInd_DoAck,
280                                 HvLpEvent_AckType_ImmediateAck,
281                                 viopath_sourceinst(viopath_hostLp),
282                                 viopath_targetinst(viopath_hostLp),
283                                 (u64)(unsigned long)req, VIOVERSION << 16,
284                                 ((u64)DEVICE_NO(d) << 48), start,
285                                 ((u64)sg_dma_address(&sg[0])) << 32,
286                                 sg_dma_len(&sg[0]));
287         else {
288                 bevent = (struct vioblocklpevent *)
289                         vio_get_event_buffer(viomajorsubtype_blockio);
290                 if (bevent == NULL) {
291                         printk(VIOD_KERN_WARNING
292                                "error allocating disk event buffer\n");
293                         goto error_ret;
294                 }
295
296                 /*
297                  * Now build up the actual request.  Note that we store
298                  * the pointer to the request in the correlation
299                  * token so we can match the response up later
300                  */
301                 memset(bevent, 0, sizeof(struct vioblocklpevent));
302                 hev = &bevent->event;
303                 hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK |
304                         HV_LP_EVENT_INT;
305                 hev->xType = HvLpEvent_Type_VirtualIo;
306                 hev->xSubtype = viocmd;
307                 hev->xSourceLp = HvLpConfig_getLpIndex();
308                 hev->xTargetLp = viopath_hostLp;
309                 hev->xSizeMinus1 =
310                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
311                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
312                 hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp);
313                 hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp);
314                 hev->xCorrelationToken = (u64)req;
315                 bevent->version = VIOVERSION;
316                 bevent->disk = DEVICE_NO(d);
317                 bevent->u.rw_data.offset = start;
318
319                 /*
320                  * Copy just the dma information from the sg list
321                  * into the request
322                  */
323                 for (sgindex = 0; sgindex < nsg; sgindex++) {
324                         bevent->u.rw_data.dma_info[sgindex].token =
325                                 sg_dma_address(&sg[sgindex]);
326                         bevent->u.rw_data.dma_info[sgindex].len =
327                                 sg_dma_len(&sg[sgindex]);
328                 }
329
330                 /* Send the request */
331                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
332                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
333         }
334
335         if (hvrc != HvLpEvent_Rc_Good) {
336                 printk(VIOD_KERN_WARNING
337                        "error sending disk event to OS/400 (rc %d)\n",
338                        (int)hvrc);
339                 goto error_ret;
340         }
341         spin_unlock_irqrestore(&viodasd_spinlock, flags);
342         return 0;
343
344 error_ret:
345         num_req_outstanding--;
346         spin_unlock_irqrestore(&viodasd_spinlock, flags);
347         dma_unmap_sg(d->dev, sg, nsg, direction);
348         return -1;
349 }
350
351 /*
352  * This is the external request processing routine
353  */
354 static void do_viodasd_request(struct request_queue *q)
355 {
356         struct request *req;
357
358         /*
359          * If we already have the maximum number of requests
360          * outstanding to OS/400 just bail out. We'll come
361          * back later.
362          */
363         while (num_req_outstanding < VIOMAXREQ) {
364                 req = blk_fetch_request(q);
365                 if (req == NULL)
366                         return;
367                 /* check that request contains a valid command */
368                 if (!blk_fs_request(req)) {
369                         viodasd_end_request(req, -EIO, blk_rq_sectors(req));
370                         continue;
371                 }
372                 /* Try sending the request */
373                 if (send_request(req) != 0)
374                         viodasd_end_request(req, -EIO, blk_rq_sectors(req));
375         }
376 }
377
378 /*
379  * Probe a single disk and fill in the viodasd_device structure
380  * for it.
381  */
382 static int probe_disk(struct viodasd_device *d)
383 {
384         HvLpEvent_Rc hvrc;
385         struct viodasd_waitevent we;
386         int dev_no = DEVICE_NO(d);
387         struct gendisk *g;
388         struct request_queue *q;
389         u16 flags = 0;
390
391 retry:
392         init_completion(&we.com);
393
394         /* Send the open event to OS/400 */
395         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
396                         HvLpEvent_Type_VirtualIo,
397                         viomajorsubtype_blockio | vioblockopen,
398                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
399                         viopath_sourceinst(viopath_hostLp),
400                         viopath_targetinst(viopath_hostLp),
401                         (u64)(unsigned long)&we, VIOVERSION << 16,
402                         ((u64)dev_no << 48) | ((u64)flags<< 32),
403                         0, 0, 0);
404         if (hvrc != 0) {
405                 printk(VIOD_KERN_WARNING "bad rc on HV open %d\n", (int)hvrc);
406                 return 0;
407         }
408
409         wait_for_completion(&we.com);
410
411         if (we.rc != 0) {
412                 if (flags != 0)
413                         return 0;
414                 /* try again with read only flag set */
415                 flags = vioblockflags_ro;
416                 goto retry;
417         }
418         if (we.max_disk > (MAX_DISKNO - 1)) {
419                 printk_once(VIOD_KERN_INFO
420                         "Only examining the first %d of %d disks connected\n",
421                         MAX_DISKNO, we.max_disk + 1);
422         }
423
424         /* Send the close event to OS/400.  We DON'T expect a response */
425         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
426                         HvLpEvent_Type_VirtualIo,
427                         viomajorsubtype_blockio | vioblockclose,
428                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
429                         viopath_sourceinst(viopath_hostLp),
430                         viopath_targetinst(viopath_hostLp),
431                         0, VIOVERSION << 16,
432                         ((u64)dev_no << 48) | ((u64)flags << 32),
433                         0, 0, 0);
434         if (hvrc != 0) {
435                 printk(VIOD_KERN_WARNING
436                        "bad rc sending event to OS/400 %d\n", (int)hvrc);
437                 return 0;
438         }
439
440         if (d->dev == NULL) {
441                 /* this is when we reprobe for new disks */
442                 if (vio_create_viodasd(dev_no) == NULL) {
443                         printk(VIOD_KERN_WARNING
444                                 "cannot allocate virtual device for disk %d\n",
445                                 dev_no);
446                         return 0;
447                 }
448                 /*
449                  * The vio_create_viodasd will have recursed into this
450                  * routine with d->dev set to the new vio device and
451                  * will finish the setup of the disk below.
452                  */
453                 return 1;
454         }
455
456         /* create the request queue for the disk */
457         spin_lock_init(&d->q_lock);
458         q = blk_init_queue(do_viodasd_request, &d->q_lock);
459         if (q == NULL) {
460                 printk(VIOD_KERN_WARNING "cannot allocate queue for disk %d\n",
461                                 dev_no);
462                 return 0;
463         }
464         g = alloc_disk(1 << PARTITION_SHIFT);
465         if (g == NULL) {
466                 printk(VIOD_KERN_WARNING
467                                 "cannot allocate disk structure for disk %d\n",
468                                 dev_no);
469                 blk_cleanup_queue(q);
470                 return 0;
471         }
472
473         d->disk = g;
474         blk_queue_max_hw_segments(q, VIOMAXBLOCKDMA);
475         blk_queue_max_phys_segments(q, VIOMAXBLOCKDMA);
476         blk_queue_max_sectors(q, VIODASD_MAXSECTORS);
477         g->major = VIODASD_MAJOR;
478         g->first_minor = dev_no << PARTITION_SHIFT;
479         if (dev_no >= 26)
480                 snprintf(g->disk_name, sizeof(g->disk_name),
481                                 VIOD_GENHD_NAME "%c%c",
482                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
483         else
484                 snprintf(g->disk_name, sizeof(g->disk_name),
485                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
486         g->fops = &viodasd_fops;
487         g->queue = q;
488         g->private_data = d;
489         g->driverfs_dev = d->dev;
490         set_capacity(g, d->size >> 9);
491
492         printk(VIOD_KERN_INFO "disk %d: %lu sectors (%lu MB) "
493                         "CHS=%d/%d/%d sector size %d%s\n",
494                         dev_no, (unsigned long)(d->size >> 9),
495                         (unsigned long)(d->size >> 20),
496                         (int)d->cylinders, (int)d->tracks,
497                         (int)d->sectors, (int)d->bytes_per_sector,
498                         d->read_only ? " (RO)" : "");
499
500         /* register us in the global list */
501         add_disk(g);
502         return 1;
503 }
504
505 /* returns the total number of scatterlist elements converted */
506 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
507                 struct scatterlist *sg, int *total_len)
508 {
509         int i, numsg;
510         const struct rw_data *rw_data = &bevent->u.rw_data;
511         static const int offset =
512                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
513         static const int element_size = sizeof(rw_data->dma_info[0]);
514
515         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
516         if (numsg > VIOMAXBLOCKDMA)
517                 numsg = VIOMAXBLOCKDMA;
518
519         *total_len = 0;
520         sg_init_table(sg, VIOMAXBLOCKDMA);
521         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
522                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
523                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
524                 *total_len += rw_data->dma_info[i].len;
525         }
526         return i;
527 }
528
529 /*
530  * Restart all queues, starting with the one _after_ the disk given,
531  * thus reducing the chance of starvation of higher numbered disks.
532  */
533 static void viodasd_restart_all_queues_starting_from(int first_index)
534 {
535         int i;
536
537         for (i = first_index + 1; i < MAX_DISKNO; ++i)
538                 if (viodasd_devices[i].disk)
539                         blk_run_queue(viodasd_devices[i].disk->queue);
540         for (i = 0; i <= first_index; ++i)
541                 if (viodasd_devices[i].disk)
542                         blk_run_queue(viodasd_devices[i].disk->queue);
543 }
544
545 /*
546  * For read and write requests, decrement the number of outstanding requests,
547  * Free the DMA buffers we allocated.
548  */
549 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
550 {
551         int num_sg, num_sect, pci_direction, total_len;
552         struct request *req;
553         struct scatterlist sg[VIOMAXBLOCKDMA];
554         struct HvLpEvent *event = &bevent->event;
555         unsigned long irq_flags;
556         struct viodasd_device *d;
557         int error;
558         spinlock_t *qlock;
559
560         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
561         num_sect = total_len >> 9;
562         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
563                 pci_direction = DMA_FROM_DEVICE;
564         else
565                 pci_direction = DMA_TO_DEVICE;
566         req = (struct request *)bevent->event.xCorrelationToken;
567         d = req->rq_disk->private_data;
568
569         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
570
571         /*
572          * Since this is running in interrupt mode, we need to make sure
573          * we're not stepping on any global I/O operations
574          */
575         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
576         num_req_outstanding--;
577         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
578
579         error = (event->xRc == HvLpEvent_Rc_Good) ? 0 : -EIO;
580         if (error) {
581                 const struct vio_error_entry *err;
582                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
583                 printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
584                                 event->xRc, bevent->sub_result, err->msg);
585                 num_sect = blk_rq_sectors(req);
586         }
587         qlock = req->q->queue_lock;
588         spin_lock_irqsave(qlock, irq_flags);
589         viodasd_end_request(req, error, num_sect);
590         spin_unlock_irqrestore(qlock, irq_flags);
591
592         /* Finally, try to get more requests off of this device's queue */
593         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
594
595         return 0;
596 }
597
598 /* This routine handles incoming block LP events */
599 static void handle_block_event(struct HvLpEvent *event)
600 {
601         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
602         struct viodasd_waitevent *pwe;
603
604         if (event == NULL)
605                 /* Notification that a partition went away! */
606                 return;
607         /* First, we should NEVER get an int here...only acks */
608         if (hvlpevent_is_int(event)) {
609                 printk(VIOD_KERN_WARNING
610                        "Yikes! got an int in viodasd event handler!\n");
611                 if (hvlpevent_need_ack(event)) {
612                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
613                         HvCallEvent_ackLpEvent(event);
614                 }
615         }
616
617         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
618         case vioblockopen:
619                 /*
620                  * Handle a response to an open request.  We get all the
621                  * disk information in the response, so update it.  The
622                  * correlation token contains a pointer to a waitevent
623                  * structure that has a completion in it.  update the
624                  * return code in the waitevent structure and post the
625                  * completion to wake up the guy who sent the request
626                  */
627                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
628                 pwe->rc = event->xRc;
629                 pwe->sub_result = bevent->sub_result;
630                 if (event->xRc == HvLpEvent_Rc_Good) {
631                         const struct open_data *data = &bevent->u.open_data;
632                         struct viodasd_device *device =
633                                 &viodasd_devices[bevent->disk];
634                         device->read_only =
635                                 bevent->flags & vioblockflags_ro;
636                         device->size = data->disk_size;
637                         device->cylinders = data->cylinders;
638                         device->tracks = data->tracks;
639                         device->sectors = data->sectors;
640                         device->bytes_per_sector = data->bytes_per_sector;
641                         pwe->max_disk = data->max_disk;
642                 }
643                 complete(&pwe->com);
644                 break;
645         case vioblockclose:
646                 break;
647         case vioblockread:
648         case vioblockwrite:
649                 viodasd_handle_read_write(bevent);
650                 break;
651
652         default:
653                 printk(VIOD_KERN_WARNING "invalid subtype!");
654                 if (hvlpevent_need_ack(event)) {
655                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
656                         HvCallEvent_ackLpEvent(event);
657                 }
658         }
659 }
660
661 /*
662  * Get the driver to reprobe for more disks.
663  */
664 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
665                 size_t count)
666 {
667         struct viodasd_device *d;
668
669         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
670                 if (d->disk == NULL)
671                         probe_disk(d);
672         }
673         return count;
674 }
675 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
676
677 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
678 {
679         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
680
681         d->dev = &vdev->dev;
682         if (!probe_disk(d))
683                 return -ENODEV;
684         return 0;
685 }
686
687 static int viodasd_remove(struct vio_dev *vdev)
688 {
689         struct viodasd_device *d;
690
691         d = &viodasd_devices[vdev->unit_address];
692         if (d->disk) {
693                 del_gendisk(d->disk);
694                 blk_cleanup_queue(d->disk->queue);
695                 put_disk(d->disk);
696                 d->disk = NULL;
697         }
698         d->dev = NULL;
699         return 0;
700 }
701
702 /**
703  * viodasd_device_table: Used by vio.c to match devices that we
704  * support.
705  */
706 static struct vio_device_id viodasd_device_table[] __devinitdata = {
707         { "block", "IBM,iSeries-viodasd" },
708         { "", "" }
709 };
710 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
711
712 static struct vio_driver viodasd_driver = {
713         .id_table = viodasd_device_table,
714         .probe = viodasd_probe,
715         .remove = viodasd_remove,
716         .driver = {
717                 .name = "viodasd",
718                 .owner = THIS_MODULE,
719         }
720 };
721
722 static int need_delete_probe;
723
724 /*
725  * Initialize the whole device driver.  Handle module and non-module
726  * versions
727  */
728 static int __init viodasd_init(void)
729 {
730         int rc;
731
732         if (!firmware_has_feature(FW_FEATURE_ISERIES)) {
733                 rc = -ENODEV;
734                 goto early_fail;
735         }
736
737         /* Try to open to our host lp */
738         if (viopath_hostLp == HvLpIndexInvalid)
739                 vio_set_hostlp();
740
741         if (viopath_hostLp == HvLpIndexInvalid) {
742                 printk(VIOD_KERN_WARNING "invalid hosting partition\n");
743                 rc = -EIO;
744                 goto early_fail;
745         }
746
747         printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
748                         viopath_hostLp);
749
750         /* register the block device */
751         rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
752         if (rc) {
753                 printk(VIOD_KERN_WARNING
754                                 "Unable to get major number %d for %s\n",
755                                 VIODASD_MAJOR, VIOD_GENHD_NAME);
756                 goto early_fail;
757         }
758         /* Actually open the path to the hosting partition */
759         rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
760                                 VIOMAXREQ + 2);
761         if (rc) {
762                 printk(VIOD_KERN_WARNING
763                        "error opening path to host partition %d\n",
764                        viopath_hostLp);
765                 goto unregister_blk;
766         }
767
768         /* Initialize our request handler */
769         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
770
771         rc = vio_register_driver(&viodasd_driver);
772         if (rc) {
773                 printk(VIOD_KERN_WARNING "vio_register_driver failed\n");
774                 goto unset_handler;
775         }
776
777         /*
778          * If this call fails, it just means that we cannot dynamically
779          * add virtual disks, but the driver will still work fine for
780          * all existing disk, so ignore the failure.
781          */
782         if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
783                 need_delete_probe = 1;
784
785         return 0;
786
787 unset_handler:
788         vio_clearHandler(viomajorsubtype_blockio);
789         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
790 unregister_blk:
791         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
792 early_fail:
793         return rc;
794 }
795 module_init(viodasd_init);
796
797 void __exit viodasd_exit(void)
798 {
799         if (need_delete_probe)
800                 driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
801         vio_unregister_driver(&viodasd_driver);
802         vio_clearHandler(viomajorsubtype_blockio);
803         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
804         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
805 }
806 module_exit(viodasd_exit);