ecccf65dce2f07a7a41a12cdfcbab7633da409c5
[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 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)req->sector << 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 = elv_next_request(q);
365                 if (req == NULL)
366                         return;
367                 /* dequeue the current request from the queue */
368                 blkdev_dequeue_request(req);
369                 /* check that request contains a valid command */
370                 if (!blk_fs_request(req)) {
371                         viodasd_end_request(req, -EIO, req->hard_nr_sectors);
372                         continue;
373                 }
374                 /* Try sending the request */
375                 if (send_request(req) != 0)
376                         viodasd_end_request(req, -EIO, req->hard_nr_sectors);
377         }
378 }
379
380 /*
381  * Probe a single disk and fill in the viodasd_device structure
382  * for it.
383  */
384 static int probe_disk(struct viodasd_device *d)
385 {
386         HvLpEvent_Rc hvrc;
387         struct viodasd_waitevent we;
388         int dev_no = DEVICE_NO(d);
389         struct gendisk *g;
390         struct request_queue *q;
391         u16 flags = 0;
392
393 retry:
394         init_completion(&we.com);
395
396         /* Send the open event to OS/400 */
397         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
398                         HvLpEvent_Type_VirtualIo,
399                         viomajorsubtype_blockio | vioblockopen,
400                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
401                         viopath_sourceinst(viopath_hostLp),
402                         viopath_targetinst(viopath_hostLp),
403                         (u64)(unsigned long)&we, VIOVERSION << 16,
404                         ((u64)dev_no << 48) | ((u64)flags<< 32),
405                         0, 0, 0);
406         if (hvrc != 0) {
407                 printk(VIOD_KERN_WARNING "bad rc on HV open %d\n", (int)hvrc);
408                 return 0;
409         }
410
411         wait_for_completion(&we.com);
412
413         if (we.rc != 0) {
414                 if (flags != 0)
415                         return 0;
416                 /* try again with read only flag set */
417                 flags = vioblockflags_ro;
418                 goto retry;
419         }
420         if (we.max_disk > (MAX_DISKNO - 1)) {
421                 static int warned;
422
423                 if (warned == 0) {
424                         warned++;
425                         printk(VIOD_KERN_INFO
426                                 "Only examining the first %d "
427                                 "of %d disks connected\n",
428                                 MAX_DISKNO, we.max_disk + 1);
429                 }
430         }
431
432         /* Send the close event to OS/400.  We DON'T expect a response */
433         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
434                         HvLpEvent_Type_VirtualIo,
435                         viomajorsubtype_blockio | vioblockclose,
436                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
437                         viopath_sourceinst(viopath_hostLp),
438                         viopath_targetinst(viopath_hostLp),
439                         0, VIOVERSION << 16,
440                         ((u64)dev_no << 48) | ((u64)flags << 32),
441                         0, 0, 0);
442         if (hvrc != 0) {
443                 printk(VIOD_KERN_WARNING
444                        "bad rc sending event to OS/400 %d\n", (int)hvrc);
445                 return 0;
446         }
447
448         if (d->dev == NULL) {
449                 /* this is when we reprobe for new disks */
450                 if (vio_create_viodasd(dev_no) == NULL) {
451                         printk(VIOD_KERN_WARNING
452                                 "cannot allocate virtual device for disk %d\n",
453                                 dev_no);
454                         return 0;
455                 }
456                 /*
457                  * The vio_create_viodasd will have recursed into this
458                  * routine with d->dev set to the new vio device and
459                  * will finish the setup of the disk below.
460                  */
461                 return 1;
462         }
463
464         /* create the request queue for the disk */
465         spin_lock_init(&d->q_lock);
466         q = blk_init_queue(do_viodasd_request, &d->q_lock);
467         if (q == NULL) {
468                 printk(VIOD_KERN_WARNING "cannot allocate queue for disk %d\n",
469                                 dev_no);
470                 return 0;
471         }
472         g = alloc_disk(1 << PARTITION_SHIFT);
473         if (g == NULL) {
474                 printk(VIOD_KERN_WARNING
475                                 "cannot allocate disk structure for disk %d\n",
476                                 dev_no);
477                 blk_cleanup_queue(q);
478                 return 0;
479         }
480
481         d->disk = g;
482         blk_queue_max_hw_segments(q, VIOMAXBLOCKDMA);
483         blk_queue_max_phys_segments(q, VIOMAXBLOCKDMA);
484         blk_queue_max_sectors(q, VIODASD_MAXSECTORS);
485         g->major = VIODASD_MAJOR;
486         g->first_minor = dev_no << PARTITION_SHIFT;
487         if (dev_no >= 26)
488                 snprintf(g->disk_name, sizeof(g->disk_name),
489                                 VIOD_GENHD_NAME "%c%c",
490                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
491         else
492                 snprintf(g->disk_name, sizeof(g->disk_name),
493                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
494         g->fops = &viodasd_fops;
495         g->queue = q;
496         g->private_data = d;
497         g->driverfs_dev = d->dev;
498         set_capacity(g, d->size >> 9);
499
500         printk(VIOD_KERN_INFO "disk %d: %lu sectors (%lu MB) "
501                         "CHS=%d/%d/%d sector size %d%s\n",
502                         dev_no, (unsigned long)(d->size >> 9),
503                         (unsigned long)(d->size >> 20),
504                         (int)d->cylinders, (int)d->tracks,
505                         (int)d->sectors, (int)d->bytes_per_sector,
506                         d->read_only ? " (RO)" : "");
507
508         /* register us in the global list */
509         add_disk(g);
510         return 1;
511 }
512
513 /* returns the total number of scatterlist elements converted */
514 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
515                 struct scatterlist *sg, int *total_len)
516 {
517         int i, numsg;
518         const struct rw_data *rw_data = &bevent->u.rw_data;
519         static const int offset =
520                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
521         static const int element_size = sizeof(rw_data->dma_info[0]);
522
523         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
524         if (numsg > VIOMAXBLOCKDMA)
525                 numsg = VIOMAXBLOCKDMA;
526
527         *total_len = 0;
528         sg_init_table(sg, VIOMAXBLOCKDMA);
529         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
530                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
531                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
532                 *total_len += rw_data->dma_info[i].len;
533         }
534         return i;
535 }
536
537 /*
538  * Restart all queues, starting with the one _after_ the disk given,
539  * thus reducing the chance of starvation of higher numbered disks.
540  */
541 static void viodasd_restart_all_queues_starting_from(int first_index)
542 {
543         int i;
544
545         for (i = first_index + 1; i < MAX_DISKNO; ++i)
546                 if (viodasd_devices[i].disk)
547                         blk_run_queue(viodasd_devices[i].disk->queue);
548         for (i = 0; i <= first_index; ++i)
549                 if (viodasd_devices[i].disk)
550                         blk_run_queue(viodasd_devices[i].disk->queue);
551 }
552
553 /*
554  * For read and write requests, decrement the number of outstanding requests,
555  * Free the DMA buffers we allocated.
556  */
557 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
558 {
559         int num_sg, num_sect, pci_direction, total_len;
560         struct request *req;
561         struct scatterlist sg[VIOMAXBLOCKDMA];
562         struct HvLpEvent *event = &bevent->event;
563         unsigned long irq_flags;
564         struct viodasd_device *d;
565         int error;
566         spinlock_t *qlock;
567
568         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
569         num_sect = total_len >> 9;
570         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
571                 pci_direction = DMA_FROM_DEVICE;
572         else
573                 pci_direction = DMA_TO_DEVICE;
574         req = (struct request *)bevent->event.xCorrelationToken;
575         d = req->rq_disk->private_data;
576
577         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
578
579         /*
580          * Since this is running in interrupt mode, we need to make sure
581          * we're not stepping on any global I/O operations
582          */
583         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
584         num_req_outstanding--;
585         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
586
587         error = (event->xRc == HvLpEvent_Rc_Good) ? 0 : -EIO;
588         if (error) {
589                 const struct vio_error_entry *err;
590                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
591                 printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
592                                 event->xRc, bevent->sub_result, err->msg);
593                 num_sect = req->hard_nr_sectors;
594         }
595         qlock = req->q->queue_lock;
596         spin_lock_irqsave(qlock, irq_flags);
597         viodasd_end_request(req, error, num_sect);
598         spin_unlock_irqrestore(qlock, irq_flags);
599
600         /* Finally, try to get more requests off of this device's queue */
601         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
602
603         return 0;
604 }
605
606 /* This routine handles incoming block LP events */
607 static void handle_block_event(struct HvLpEvent *event)
608 {
609         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
610         struct viodasd_waitevent *pwe;
611
612         if (event == NULL)
613                 /* Notification that a partition went away! */
614                 return;
615         /* First, we should NEVER get an int here...only acks */
616         if (hvlpevent_is_int(event)) {
617                 printk(VIOD_KERN_WARNING
618                        "Yikes! got an int in viodasd event handler!\n");
619                 if (hvlpevent_need_ack(event)) {
620                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
621                         HvCallEvent_ackLpEvent(event);
622                 }
623         }
624
625         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
626         case vioblockopen:
627                 /*
628                  * Handle a response to an open request.  We get all the
629                  * disk information in the response, so update it.  The
630                  * correlation token contains a pointer to a waitevent
631                  * structure that has a completion in it.  update the
632                  * return code in the waitevent structure and post the
633                  * completion to wake up the guy who sent the request
634                  */
635                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
636                 pwe->rc = event->xRc;
637                 pwe->sub_result = bevent->sub_result;
638                 if (event->xRc == HvLpEvent_Rc_Good) {
639                         const struct open_data *data = &bevent->u.open_data;
640                         struct viodasd_device *device =
641                                 &viodasd_devices[bevent->disk];
642                         device->read_only =
643                                 bevent->flags & vioblockflags_ro;
644                         device->size = data->disk_size;
645                         device->cylinders = data->cylinders;
646                         device->tracks = data->tracks;
647                         device->sectors = data->sectors;
648                         device->bytes_per_sector = data->bytes_per_sector;
649                         pwe->max_disk = data->max_disk;
650                 }
651                 complete(&pwe->com);
652                 break;
653         case vioblockclose:
654                 break;
655         case vioblockread:
656         case vioblockwrite:
657                 viodasd_handle_read_write(bevent);
658                 break;
659
660         default:
661                 printk(VIOD_KERN_WARNING "invalid subtype!");
662                 if (hvlpevent_need_ack(event)) {
663                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
664                         HvCallEvent_ackLpEvent(event);
665                 }
666         }
667 }
668
669 /*
670  * Get the driver to reprobe for more disks.
671  */
672 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
673                 size_t count)
674 {
675         struct viodasd_device *d;
676
677         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
678                 if (d->disk == NULL)
679                         probe_disk(d);
680         }
681         return count;
682 }
683 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
684
685 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
686 {
687         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
688
689         d->dev = &vdev->dev;
690         if (!probe_disk(d))
691                 return -ENODEV;
692         return 0;
693 }
694
695 static int viodasd_remove(struct vio_dev *vdev)
696 {
697         struct viodasd_device *d;
698
699         d = &viodasd_devices[vdev->unit_address];
700         if (d->disk) {
701                 del_gendisk(d->disk);
702                 blk_cleanup_queue(d->disk->queue);
703                 put_disk(d->disk);
704                 d->disk = NULL;
705         }
706         d->dev = NULL;
707         return 0;
708 }
709
710 /**
711  * viodasd_device_table: Used by vio.c to match devices that we
712  * support.
713  */
714 static struct vio_device_id viodasd_device_table[] __devinitdata = {
715         { "block", "IBM,iSeries-viodasd" },
716         { "", "" }
717 };
718 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
719
720 static struct vio_driver viodasd_driver = {
721         .id_table = viodasd_device_table,
722         .probe = viodasd_probe,
723         .remove = viodasd_remove,
724         .driver = {
725                 .name = "viodasd",
726                 .owner = THIS_MODULE,
727         }
728 };
729
730 static int need_delete_probe;
731
732 /*
733  * Initialize the whole device driver.  Handle module and non-module
734  * versions
735  */
736 static int __init viodasd_init(void)
737 {
738         int rc;
739
740         if (!firmware_has_feature(FW_FEATURE_ISERIES)) {
741                 rc = -ENODEV;
742                 goto early_fail;
743         }
744
745         /* Try to open to our host lp */
746         if (viopath_hostLp == HvLpIndexInvalid)
747                 vio_set_hostlp();
748
749         if (viopath_hostLp == HvLpIndexInvalid) {
750                 printk(VIOD_KERN_WARNING "invalid hosting partition\n");
751                 rc = -EIO;
752                 goto early_fail;
753         }
754
755         printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
756                         viopath_hostLp);
757
758         /* register the block device */
759         rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
760         if (rc) {
761                 printk(VIOD_KERN_WARNING
762                                 "Unable to get major number %d for %s\n",
763                                 VIODASD_MAJOR, VIOD_GENHD_NAME);
764                 goto early_fail;
765         }
766         /* Actually open the path to the hosting partition */
767         rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
768                                 VIOMAXREQ + 2);
769         if (rc) {
770                 printk(VIOD_KERN_WARNING
771                        "error opening path to host partition %d\n",
772                        viopath_hostLp);
773                 goto unregister_blk;
774         }
775
776         /* Initialize our request handler */
777         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
778
779         rc = vio_register_driver(&viodasd_driver);
780         if (rc) {
781                 printk(VIOD_KERN_WARNING "vio_register_driver failed\n");
782                 goto unset_handler;
783         }
784
785         /*
786          * If this call fails, it just means that we cannot dynamically
787          * add virtual disks, but the driver will still work fine for
788          * all existing disk, so ignore the failure.
789          */
790         if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
791                 need_delete_probe = 1;
792
793         return 0;
794
795 unset_handler:
796         vio_clearHandler(viomajorsubtype_blockio);
797         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
798 unregister_blk:
799         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
800 early_fail:
801         return rc;
802 }
803 module_init(viodasd_init);
804
805 void __exit viodasd_exit(void)
806 {
807         if (need_delete_probe)
808                 driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
809         vio_unregister_driver(&viodasd_driver);
810         vio_clearHandler(viomajorsubtype_blockio);
811         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
812         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
813 }
814 module_exit(viodasd_exit);