Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/usb-2.6
[linux-2.6] / 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 <sfr@au1.ibm.com>
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/kernel.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
53 MODULE_DESCRIPTION("iSeries Virtual DASD");
54 MODULE_AUTHOR("Dave Boutcher");
55 MODULE_LICENSE("GPL");
56
57 /*
58  * We only support 7 partitions per physical disk....so with minor
59  * numbers 0-255 we get a maximum of 32 disks.
60  */
61 #define VIOD_GENHD_NAME         "iseries/vd"
62
63 #define VIOD_VERS               "1.64"
64
65 #define VIOD_KERN_WARNING       KERN_WARNING "viod: "
66 #define VIOD_KERN_INFO          KERN_INFO "viod: "
67
68 enum {
69         PARTITION_SHIFT = 3,
70         MAX_DISKNO = HVMAXARCHITECTEDVIRTUALDISKS,
71         MAX_DISK_NAME = sizeof(((struct gendisk *)0)->disk_name)
72 };
73
74 static DEFINE_SPINLOCK(viodasd_spinlock);
75
76 #define VIOMAXREQ               16
77 #define VIOMAXBLOCKDMA          12
78
79 #define DEVICE_NO(cell) ((struct viodasd_device *)(cell) - &viodasd_devices[0])
80
81 struct open_data {
82         u64     disk_size;
83         u16     max_disk;
84         u16     cylinders;
85         u16     tracks;
86         u16     sectors;
87         u16     bytes_per_sector;
88 };
89
90 struct rw_data {
91         u64     offset;
92         struct {
93                 u32     token;
94                 u32     reserved;
95                 u64     len;
96         } dma_info[VIOMAXBLOCKDMA];
97 };
98
99 struct vioblocklpevent {
100         struct HvLpEvent        event;
101         u32                     reserved;
102         u16                     version;
103         u16                     sub_result;
104         u16                     disk;
105         u16                     flags;
106         union {
107                 struct open_data        open_data;
108                 struct rw_data          rw_data;
109                 u64                     changed;
110         } u;
111 };
112
113 #define vioblockflags_ro   0x0001
114
115 enum vioblocksubtype {
116         vioblockopen = 0x0001,
117         vioblockclose = 0x0002,
118         vioblockread = 0x0003,
119         vioblockwrite = 0x0004,
120         vioblockflush = 0x0005,
121         vioblockcheck = 0x0007
122 };
123
124 struct viodasd_waitevent {
125         struct completion       com;
126         int                     rc;
127         u16                     sub_result;
128         int                     max_disk;       /* open */
129 };
130
131 static const struct vio_error_entry viodasd_err_table[] = {
132         { 0x0201, EINVAL, "Invalid Range" },
133         { 0x0202, EINVAL, "Invalid Token" },
134         { 0x0203, EIO, "DMA Error" },
135         { 0x0204, EIO, "Use Error" },
136         { 0x0205, EIO, "Release Error" },
137         { 0x0206, EINVAL, "Invalid Disk" },
138         { 0x0207, EBUSY, "Cant Lock" },
139         { 0x0208, EIO, "Already Locked" },
140         { 0x0209, EIO, "Already Unlocked" },
141         { 0x020A, EIO, "Invalid Arg" },
142         { 0x020B, EIO, "Bad IFS File" },
143         { 0x020C, EROFS, "Read Only Device" },
144         { 0x02FF, EIO, "Internal Error" },
145         { 0x0000, 0, NULL },
146 };
147
148 /*
149  * Figure out the biggest I/O request (in sectors) we can accept
150  */
151 #define VIODASD_MAXSECTORS (4096 / 512 * VIOMAXBLOCKDMA)
152
153 /*
154  * Number of disk I/O requests we've sent to OS/400
155  */
156 static int num_req_outstanding;
157
158 /*
159  * This is our internal structure for keeping track of disk devices
160  */
161 struct viodasd_device {
162         u16             cylinders;
163         u16             tracks;
164         u16             sectors;
165         u16             bytes_per_sector;
166         u64             size;
167         int             read_only;
168         spinlock_t      q_lock;
169         struct gendisk  *disk;
170         struct device   *dev;
171 } viodasd_devices[MAX_DISKNO];
172
173 /*
174  * External open entry point.
175  */
176 static int viodasd_open(struct inode *ino, struct file *fil)
177 {
178         struct viodasd_device *d = ino->i_bdev->bd_disk->private_data;
179         HvLpEvent_Rc hvrc;
180         struct viodasd_waitevent we;
181         u16 flags = 0;
182
183         if (d->read_only) {
184                 if ((fil != NULL) && (fil->f_mode & FMODE_WRITE))
185                         return -EROFS;
186                 flags = vioblockflags_ro;
187         }
188
189         init_completion(&we.com);
190
191         /* Send the open event to OS/400 */
192         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
193                         HvLpEvent_Type_VirtualIo,
194                         viomajorsubtype_blockio | vioblockopen,
195                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
196                         viopath_sourceinst(viopath_hostLp),
197                         viopath_targetinst(viopath_hostLp),
198                         (u64)(unsigned long)&we, VIOVERSION << 16,
199                         ((u64)DEVICE_NO(d) << 48) | ((u64)flags << 32),
200                         0, 0, 0);
201         if (hvrc != 0) {
202                 printk(VIOD_KERN_WARNING "HV open failed %d\n", (int)hvrc);
203                 return -EIO;
204         }
205
206         wait_for_completion(&we.com);
207
208         /* Check the return code */
209         if (we.rc != 0) {
210                 const struct vio_error_entry *err =
211                         vio_lookup_rc(viodasd_err_table, we.sub_result);
212
213                 printk(VIOD_KERN_WARNING
214                                 "bad rc opening disk: %d:0x%04x (%s)\n",
215                                 (int)we.rc, we.sub_result, err->msg);
216                 return -EIO;
217         }
218
219         return 0;
220 }
221
222 /*
223  * External release entry point.
224  */
225 static int viodasd_release(struct inode *ino, struct file *fil)
226 {
227         struct viodasd_device *d = ino->i_bdev->bd_disk->private_data;
228         HvLpEvent_Rc hvrc;
229
230         /* Send the event to OS/400.  We DON'T expect a response */
231         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
232                         HvLpEvent_Type_VirtualIo,
233                         viomajorsubtype_blockio | vioblockclose,
234                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
235                         viopath_sourceinst(viopath_hostLp),
236                         viopath_targetinst(viopath_hostLp),
237                         0, VIOVERSION << 16,
238                         ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
239                         0, 0, 0);
240         if (hvrc != 0)
241                 printk(VIOD_KERN_WARNING "HV close call failed %d\n",
242                                 (int)hvrc);
243         return 0;
244 }
245
246
247 /* External ioctl entry point.
248  */
249 static int viodasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
250 {
251         struct gendisk *disk = bdev->bd_disk;
252         struct viodasd_device *d = disk->private_data;
253
254         geo->sectors = d->sectors ? d->sectors : 0;
255         geo->heads = d->tracks ? d->tracks  : 64;
256         geo->cylinders = d->cylinders ? d->cylinders :
257                 get_capacity(disk) / (geo->cylinders * geo->heads);
258
259         return 0;
260 }
261
262 /*
263  * Our file operations table
264  */
265 static struct block_device_operations viodasd_fops = {
266         .owner = THIS_MODULE,
267         .open = viodasd_open,
268         .release = viodasd_release,
269         .getgeo = viodasd_getgeo,
270 };
271
272 /*
273  * End a request
274  */
275 static void viodasd_end_request(struct request *req, int uptodate,
276                 int num_sectors)
277 {
278         if (end_that_request_first(req, uptodate, num_sectors))
279                 return;
280         add_disk_randomness(req->rq_disk);
281         end_that_request_last(req, uptodate);
282 }
283
284 /*
285  * Send an actual I/O request to OS/400
286  */
287 static int send_request(struct request *req)
288 {
289         u64 start;
290         int direction;
291         int nsg;
292         u16 viocmd;
293         HvLpEvent_Rc hvrc;
294         struct vioblocklpevent *bevent;
295         struct HvLpEvent *hev;
296         struct scatterlist sg[VIOMAXBLOCKDMA];
297         int sgindex;
298         int statindex;
299         struct viodasd_device *d;
300         unsigned long flags;
301
302         start = (u64)req->sector << 9;
303
304         if (rq_data_dir(req) == READ) {
305                 direction = DMA_FROM_DEVICE;
306                 viocmd = viomajorsubtype_blockio | vioblockread;
307                 statindex = 0;
308         } else {
309                 direction = DMA_TO_DEVICE;
310                 viocmd = viomajorsubtype_blockio | vioblockwrite;
311                 statindex = 1;
312         }
313
314         d = req->rq_disk->private_data;
315
316         /* Now build the scatter-gather list */
317         nsg = blk_rq_map_sg(req->q, req, sg);
318         nsg = dma_map_sg(d->dev, sg, nsg, direction);
319
320         spin_lock_irqsave(&viodasd_spinlock, flags);
321         num_req_outstanding++;
322
323         /* This optimization handles a single DMA block */
324         if (nsg == 1)
325                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
326                                 HvLpEvent_Type_VirtualIo, viocmd,
327                                 HvLpEvent_AckInd_DoAck,
328                                 HvLpEvent_AckType_ImmediateAck,
329                                 viopath_sourceinst(viopath_hostLp),
330                                 viopath_targetinst(viopath_hostLp),
331                                 (u64)(unsigned long)req, VIOVERSION << 16,
332                                 ((u64)DEVICE_NO(d) << 48), start,
333                                 ((u64)sg_dma_address(&sg[0])) << 32,
334                                 sg_dma_len(&sg[0]));
335         else {
336                 bevent = (struct vioblocklpevent *)
337                         vio_get_event_buffer(viomajorsubtype_blockio);
338                 if (bevent == NULL) {
339                         printk(VIOD_KERN_WARNING
340                                "error allocating disk event buffer\n");
341                         goto error_ret;
342                 }
343
344                 /*
345                  * Now build up the actual request.  Note that we store
346                  * the pointer to the request in the correlation
347                  * token so we can match the response up later
348                  */
349                 memset(bevent, 0, sizeof(struct vioblocklpevent));
350                 hev = &bevent->event;
351                 hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK |
352                         HV_LP_EVENT_INT;
353                 hev->xType = HvLpEvent_Type_VirtualIo;
354                 hev->xSubtype = viocmd;
355                 hev->xSourceLp = HvLpConfig_getLpIndex();
356                 hev->xTargetLp = viopath_hostLp;
357                 hev->xSizeMinus1 =
358                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
359                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
360                 hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp);
361                 hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp);
362                 hev->xCorrelationToken = (u64)req;
363                 bevent->version = VIOVERSION;
364                 bevent->disk = DEVICE_NO(d);
365                 bevent->u.rw_data.offset = start;
366
367                 /*
368                  * Copy just the dma information from the sg list
369                  * into the request
370                  */
371                 for (sgindex = 0; sgindex < nsg; sgindex++) {
372                         bevent->u.rw_data.dma_info[sgindex].token =
373                                 sg_dma_address(&sg[sgindex]);
374                         bevent->u.rw_data.dma_info[sgindex].len =
375                                 sg_dma_len(&sg[sgindex]);
376                 }
377
378                 /* Send the request */
379                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
380                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
381         }
382
383         if (hvrc != HvLpEvent_Rc_Good) {
384                 printk(VIOD_KERN_WARNING
385                        "error sending disk event to OS/400 (rc %d)\n",
386                        (int)hvrc);
387                 goto error_ret;
388         }
389         spin_unlock_irqrestore(&viodasd_spinlock, flags);
390         return 0;
391
392 error_ret:
393         num_req_outstanding--;
394         spin_unlock_irqrestore(&viodasd_spinlock, flags);
395         dma_unmap_sg(d->dev, sg, nsg, direction);
396         return -1;
397 }
398
399 /*
400  * This is the external request processing routine
401  */
402 static void do_viodasd_request(request_queue_t *q)
403 {
404         struct request *req;
405
406         /*
407          * If we already have the maximum number of requests
408          * outstanding to OS/400 just bail out. We'll come
409          * back later.
410          */
411         while (num_req_outstanding < VIOMAXREQ) {
412                 req = elv_next_request(q);
413                 if (req == NULL)
414                         return;
415                 /* dequeue the current request from the queue */
416                 blkdev_dequeue_request(req);
417                 /* check that request contains a valid command */
418                 if (!blk_fs_request(req)) {
419                         viodasd_end_request(req, 0, req->hard_nr_sectors);
420                         continue;
421                 }
422                 /* Try sending the request */
423                 if (send_request(req) != 0)
424                         viodasd_end_request(req, 0, req->hard_nr_sectors);
425         }
426 }
427
428 /*
429  * Probe a single disk and fill in the viodasd_device structure
430  * for it.
431  */
432 static void probe_disk(struct viodasd_device *d)
433 {
434         HvLpEvent_Rc hvrc;
435         struct viodasd_waitevent we;
436         int dev_no = DEVICE_NO(d);
437         struct gendisk *g;
438         struct request_queue *q;
439         u16 flags = 0;
440
441 retry:
442         init_completion(&we.com);
443
444         /* Send the open event to OS/400 */
445         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
446                         HvLpEvent_Type_VirtualIo,
447                         viomajorsubtype_blockio | vioblockopen,
448                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
449                         viopath_sourceinst(viopath_hostLp),
450                         viopath_targetinst(viopath_hostLp),
451                         (u64)(unsigned long)&we, VIOVERSION << 16,
452                         ((u64)dev_no << 48) | ((u64)flags<< 32),
453                         0, 0, 0);
454         if (hvrc != 0) {
455                 printk(VIOD_KERN_WARNING "bad rc on HV open %d\n", (int)hvrc);
456                 return;
457         }
458
459         wait_for_completion(&we.com);
460
461         if (we.rc != 0) {
462                 if (flags != 0)
463                         return;
464                 /* try again with read only flag set */
465                 flags = vioblockflags_ro;
466                 goto retry;
467         }
468         if (we.max_disk > (MAX_DISKNO - 1)) {
469                 static int warned;
470
471                 if (warned == 0) {
472                         warned++;
473                         printk(VIOD_KERN_INFO
474                                 "Only examining the first %d "
475                                 "of %d disks connected\n",
476                                 MAX_DISKNO, we.max_disk + 1);
477                 }
478         }
479
480         /* Send the close event to OS/400.  We DON'T expect a response */
481         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
482                         HvLpEvent_Type_VirtualIo,
483                         viomajorsubtype_blockio | vioblockclose,
484                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
485                         viopath_sourceinst(viopath_hostLp),
486                         viopath_targetinst(viopath_hostLp),
487                         0, VIOVERSION << 16,
488                         ((u64)dev_no << 48) | ((u64)flags << 32),
489                         0, 0, 0);
490         if (hvrc != 0) {
491                 printk(VIOD_KERN_WARNING
492                        "bad rc sending event to OS/400 %d\n", (int)hvrc);
493                 return;
494         }
495         /* create the request queue for the disk */
496         spin_lock_init(&d->q_lock);
497         q = blk_init_queue(do_viodasd_request, &d->q_lock);
498         if (q == NULL) {
499                 printk(VIOD_KERN_WARNING "cannot allocate queue for disk %d\n",
500                                 dev_no);
501                 return;
502         }
503         g = alloc_disk(1 << PARTITION_SHIFT);
504         if (g == NULL) {
505                 printk(VIOD_KERN_WARNING
506                                 "cannot allocate disk structure for disk %d\n",
507                                 dev_no);
508                 blk_cleanup_queue(q);
509                 return;
510         }
511
512         d->disk = g;
513         blk_queue_max_hw_segments(q, VIOMAXBLOCKDMA);
514         blk_queue_max_phys_segments(q, VIOMAXBLOCKDMA);
515         blk_queue_max_sectors(q, VIODASD_MAXSECTORS);
516         g->major = VIODASD_MAJOR;
517         g->first_minor = dev_no << PARTITION_SHIFT;
518         if (dev_no >= 26)
519                 snprintf(g->disk_name, sizeof(g->disk_name),
520                                 VIOD_GENHD_NAME "%c%c",
521                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
522         else
523                 snprintf(g->disk_name, sizeof(g->disk_name),
524                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
525         g->fops = &viodasd_fops;
526         g->queue = q;
527         g->private_data = d;
528         g->driverfs_dev = d->dev;
529         set_capacity(g, d->size >> 9);
530
531         printk(VIOD_KERN_INFO "disk %d: %lu sectors (%lu MB) "
532                         "CHS=%d/%d/%d sector size %d%s\n",
533                         dev_no, (unsigned long)(d->size >> 9),
534                         (unsigned long)(d->size >> 20),
535                         (int)d->cylinders, (int)d->tracks,
536                         (int)d->sectors, (int)d->bytes_per_sector,
537                         d->read_only ? " (RO)" : "");
538
539         /* register us in the global list */
540         add_disk(g);
541 }
542
543 /* returns the total number of scatterlist elements converted */
544 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
545                 struct scatterlist *sg, int *total_len)
546 {
547         int i, numsg;
548         const struct rw_data *rw_data = &bevent->u.rw_data;
549         static const int offset =
550                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
551         static const int element_size = sizeof(rw_data->dma_info[0]);
552
553         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
554         if (numsg > VIOMAXBLOCKDMA)
555                 numsg = VIOMAXBLOCKDMA;
556
557         *total_len = 0;
558         memset(sg, 0, sizeof(sg[0]) * VIOMAXBLOCKDMA);
559
560         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
561                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
562                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
563                 *total_len += rw_data->dma_info[i].len;
564         }
565         return i;
566 }
567
568 /*
569  * Restart all queues, starting with the one _after_ the disk given,
570  * thus reducing the chance of starvation of higher numbered disks.
571  */
572 static void viodasd_restart_all_queues_starting_from(int first_index)
573 {
574         int i;
575
576         for (i = first_index + 1; i < MAX_DISKNO; ++i)
577                 if (viodasd_devices[i].disk)
578                         blk_run_queue(viodasd_devices[i].disk->queue);
579         for (i = 0; i <= first_index; ++i)
580                 if (viodasd_devices[i].disk)
581                         blk_run_queue(viodasd_devices[i].disk->queue);
582 }
583
584 /*
585  * For read and write requests, decrement the number of outstanding requests,
586  * Free the DMA buffers we allocated.
587  */
588 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
589 {
590         int num_sg, num_sect, pci_direction, total_len;
591         struct request *req;
592         struct scatterlist sg[VIOMAXBLOCKDMA];
593         struct HvLpEvent *event = &bevent->event;
594         unsigned long irq_flags;
595         struct viodasd_device *d;
596         int error;
597         spinlock_t *qlock;
598
599         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
600         num_sect = total_len >> 9;
601         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
602                 pci_direction = DMA_FROM_DEVICE;
603         else
604                 pci_direction = DMA_TO_DEVICE;
605         req = (struct request *)bevent->event.xCorrelationToken;
606         d = req->rq_disk->private_data;
607
608         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
609
610         /*
611          * Since this is running in interrupt mode, we need to make sure
612          * we're not stepping on any global I/O operations
613          */
614         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
615         num_req_outstanding--;
616         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
617
618         error = event->xRc != HvLpEvent_Rc_Good;
619         if (error) {
620                 const struct vio_error_entry *err;
621                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
622                 printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
623                                 event->xRc, bevent->sub_result, err->msg);
624                 num_sect = req->hard_nr_sectors;
625         }
626         qlock = req->q->queue_lock;
627         spin_lock_irqsave(qlock, irq_flags);
628         viodasd_end_request(req, !error, num_sect);
629         spin_unlock_irqrestore(qlock, irq_flags);
630
631         /* Finally, try to get more requests off of this device's queue */
632         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
633
634         return 0;
635 }
636
637 /* This routine handles incoming block LP events */
638 static void handle_block_event(struct HvLpEvent *event)
639 {
640         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
641         struct viodasd_waitevent *pwe;
642
643         if (event == NULL)
644                 /* Notification that a partition went away! */
645                 return;
646         /* First, we should NEVER get an int here...only acks */
647         if (hvlpevent_is_int(event)) {
648                 printk(VIOD_KERN_WARNING
649                        "Yikes! got an int in viodasd event handler!\n");
650                 if (hvlpevent_need_ack(event)) {
651                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
652                         HvCallEvent_ackLpEvent(event);
653                 }
654         }
655
656         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
657         case vioblockopen:
658                 /*
659                  * Handle a response to an open request.  We get all the
660                  * disk information in the response, so update it.  The
661                  * correlation token contains a pointer to a waitevent
662                  * structure that has a completion in it.  update the
663                  * return code in the waitevent structure and post the
664                  * completion to wake up the guy who sent the request
665                  */
666                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
667                 pwe->rc = event->xRc;
668                 pwe->sub_result = bevent->sub_result;
669                 if (event->xRc == HvLpEvent_Rc_Good) {
670                         const struct open_data *data = &bevent->u.open_data;
671                         struct viodasd_device *device =
672                                 &viodasd_devices[bevent->disk];
673                         device->read_only =
674                                 bevent->flags & vioblockflags_ro;
675                         device->size = data->disk_size;
676                         device->cylinders = data->cylinders;
677                         device->tracks = data->tracks;
678                         device->sectors = data->sectors;
679                         device->bytes_per_sector = data->bytes_per_sector;
680                         pwe->max_disk = data->max_disk;
681                 }
682                 complete(&pwe->com);
683                 break;
684         case vioblockclose:
685                 break;
686         case vioblockread:
687         case vioblockwrite:
688                 viodasd_handle_read_write(bevent);
689                 break;
690
691         default:
692                 printk(VIOD_KERN_WARNING "invalid subtype!");
693                 if (hvlpevent_need_ack(event)) {
694                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
695                         HvCallEvent_ackLpEvent(event);
696                 }
697         }
698 }
699
700 /*
701  * Get the driver to reprobe for more disks.
702  */
703 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
704                 size_t count)
705 {
706         struct viodasd_device *d;
707
708         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
709                 if (d->disk == NULL)
710                         probe_disk(d);
711         }
712         return count;
713 }
714 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
715
716 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
717 {
718         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
719
720         d->dev = &vdev->dev;
721         probe_disk(d);
722         if (d->disk == NULL)
723                 return -ENODEV;
724         return 0;
725 }
726
727 static int viodasd_remove(struct vio_dev *vdev)
728 {
729         struct viodasd_device *d;
730
731         d = &viodasd_devices[vdev->unit_address];
732         if (d->disk) {
733                 del_gendisk(d->disk);
734                 blk_cleanup_queue(d->disk->queue);
735                 put_disk(d->disk);
736                 d->disk = NULL;
737         }
738         d->dev = NULL;
739         return 0;
740 }
741
742 /**
743  * viodasd_device_table: Used by vio.c to match devices that we
744  * support.
745  */
746 static struct vio_device_id viodasd_device_table[] __devinitdata = {
747         { "block", "IBM,iSeries-viodasd" },
748         { "", "" }
749 };
750 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
751
752 static struct vio_driver viodasd_driver = {
753         .id_table = viodasd_device_table,
754         .probe = viodasd_probe,
755         .remove = viodasd_remove,
756         .driver = {
757                 .name = "viodasd",
758                 .owner = THIS_MODULE,
759         }
760 };
761
762 /*
763  * Initialize the whole device driver.  Handle module and non-module
764  * versions
765  */
766 static int __init viodasd_init(void)
767 {
768         int rc;
769
770         /* Try to open to our host lp */
771         if (viopath_hostLp == HvLpIndexInvalid)
772                 vio_set_hostlp();
773
774         if (viopath_hostLp == HvLpIndexInvalid) {
775                 printk(VIOD_KERN_WARNING "invalid hosting partition\n");
776                 return -EIO;
777         }
778
779         printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
780                         viopath_hostLp);
781
782         /* register the block device */
783         if (register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME)) {
784                 printk(VIOD_KERN_WARNING
785                                 "Unable to get major number %d for %s\n",
786                                 VIODASD_MAJOR, VIOD_GENHD_NAME);
787                 return -EIO;
788         }
789         /* Actually open the path to the hosting partition */
790         if (viopath_open(viopath_hostLp, viomajorsubtype_blockio,
791                                 VIOMAXREQ + 2)) {
792                 printk(VIOD_KERN_WARNING
793                        "error opening path to host partition %d\n",
794                        viopath_hostLp);
795                 unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
796                 return -EIO;
797         }
798
799         /* Initialize our request handler */
800         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
801
802         rc = vio_register_driver(&viodasd_driver);
803         if (rc == 0)
804                 driver_create_file(&viodasd_driver.driver, &driver_attr_probe);
805         return rc;
806 }
807 module_init(viodasd_init);
808
809 void viodasd_exit(void)
810 {
811         driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
812         vio_unregister_driver(&viodasd_driver);
813         vio_clearHandler(viomajorsubtype_blockio);
814         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
815         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
816 }
817
818 module_exit(viodasd_exit);