46e56a25d2c8875966462bef4c53a225ac572090
[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 <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/HvTypes.h>
49 #include <asm/iSeries/HvLpEvent.h>
50 #include <asm/iSeries/HvLpConfig.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 #define VIOD_GENHD_DEVFS_NAME   "iseries/disc"
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 = sizeof(((struct gendisk *)0)->disk_name)
73 };
74
75 static DEFINE_SPINLOCK(viodasd_spinlock);
76
77 #define VIOMAXREQ               16
78 #define VIOMAXBLOCKDMA          12
79
80 #define DEVICE_NO(cell) ((struct viodasd_device *)(cell) - &viodasd_devices[0])
81
82 struct open_data {
83         u64     disk_size;
84         u16     max_disk;
85         u16     cylinders;
86         u16     tracks;
87         u16     sectors;
88         u16     bytes_per_sector;
89 };
90
91 struct rw_data {
92         u64     offset;
93         struct {
94                 u32     token;
95                 u32     reserved;
96                 u64     len;
97         } dma_info[VIOMAXBLOCKDMA];
98 };
99
100 struct vioblocklpevent {
101         struct HvLpEvent        event;
102         u32                     reserved;
103         u16                     version;
104         u16                     sub_result;
105         u16                     disk;
106         u16                     flags;
107         union {
108                 struct open_data        open_data;
109                 struct rw_data          rw_data;
110                 u64                     changed;
111         } u;
112 };
113
114 #define vioblockflags_ro   0x0001
115
116 enum vioblocksubtype {
117         vioblockopen = 0x0001,
118         vioblockclose = 0x0002,
119         vioblockread = 0x0003,
120         vioblockwrite = 0x0004,
121         vioblockflush = 0x0005,
122         vioblockcheck = 0x0007
123 };
124
125 struct viodasd_waitevent {
126         struct completion       com;
127         int                     rc;
128         u16                     sub_result;
129         int                     max_disk;       /* open */
130 };
131
132 static const struct vio_error_entry viodasd_err_table[] = {
133         { 0x0201, EINVAL, "Invalid Range" },
134         { 0x0202, EINVAL, "Invalid Token" },
135         { 0x0203, EIO, "DMA Error" },
136         { 0x0204, EIO, "Use Error" },
137         { 0x0205, EIO, "Release Error" },
138         { 0x0206, EINVAL, "Invalid Disk" },
139         { 0x0207, EBUSY, "Cant Lock" },
140         { 0x0208, EIO, "Already Locked" },
141         { 0x0209, EIO, "Already Unlocked" },
142         { 0x020A, EIO, "Invalid Arg" },
143         { 0x020B, EIO, "Bad IFS File" },
144         { 0x020C, EROFS, "Read Only Device" },
145         { 0x02FF, EIO, "Internal Error" },
146         { 0x0000, 0, NULL },
147 };
148
149 /*
150  * Figure out the biggest I/O request (in sectors) we can accept
151  */
152 #define VIODASD_MAXSECTORS (4096 / 512 * VIOMAXBLOCKDMA)
153
154 /*
155  * Number of disk I/O requests we've sent to OS/400
156  */
157 static int num_req_outstanding;
158
159 /*
160  * This is our internal structure for keeping track of disk devices
161  */
162 struct viodasd_device {
163         u16             cylinders;
164         u16             tracks;
165         u16             sectors;
166         u16             bytes_per_sector;
167         u64             size;
168         int             read_only;
169         spinlock_t      q_lock;
170         struct gendisk  *disk;
171         struct device   *dev;
172 } viodasd_devices[MAX_DISKNO];
173
174 /*
175  * External open entry point.
176  */
177 static int viodasd_open(struct inode *ino, struct file *fil)
178 {
179         struct viodasd_device *d = ino->i_bdev->bd_disk->private_data;
180         HvLpEvent_Rc hvrc;
181         struct viodasd_waitevent we;
182         u16 flags = 0;
183
184         if (d->read_only) {
185                 if ((fil != NULL) && (fil->f_mode & FMODE_WRITE))
186                         return -EROFS;
187                 flags = vioblockflags_ro;
188         }
189
190         init_completion(&we.com);
191
192         /* Send the open event to OS/400 */
193         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
194                         HvLpEvent_Type_VirtualIo,
195                         viomajorsubtype_blockio | vioblockopen,
196                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
197                         viopath_sourceinst(viopath_hostLp),
198                         viopath_targetinst(viopath_hostLp),
199                         (u64)(unsigned long)&we, VIOVERSION << 16,
200                         ((u64)DEVICE_NO(d) << 48) | ((u64)flags << 32),
201                         0, 0, 0);
202         if (hvrc != 0) {
203                 printk(VIOD_KERN_WARNING "HV open failed %d\n", (int)hvrc);
204                 return -EIO;
205         }
206
207         wait_for_completion(&we.com);
208
209         /* Check the return code */
210         if (we.rc != 0) {
211                 const struct vio_error_entry *err =
212                         vio_lookup_rc(viodasd_err_table, we.sub_result);
213
214                 printk(VIOD_KERN_WARNING
215                                 "bad rc opening disk: %d:0x%04x (%s)\n",
216                                 (int)we.rc, we.sub_result, err->msg);
217                 return -EIO;
218         }
219
220         return 0;
221 }
222
223 /*
224  * External release entry point.
225  */
226 static int viodasd_release(struct inode *ino, struct file *fil)
227 {
228         struct viodasd_device *d = ino->i_bdev->bd_disk->private_data;
229         HvLpEvent_Rc hvrc;
230
231         /* Send the event to OS/400.  We DON'T expect a response */
232         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
233                         HvLpEvent_Type_VirtualIo,
234                         viomajorsubtype_blockio | vioblockclose,
235                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
236                         viopath_sourceinst(viopath_hostLp),
237                         viopath_targetinst(viopath_hostLp),
238                         0, VIOVERSION << 16,
239                         ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
240                         0, 0, 0);
241         if (hvrc != 0)
242                 printk(VIOD_KERN_WARNING "HV close call failed %d\n",
243                                 (int)hvrc);
244         return 0;
245 }
246
247
248 /* External ioctl entry point.
249  */
250 static int viodasd_ioctl(struct inode *ino, struct file *fil,
251                          unsigned int cmd, unsigned long arg)
252 {
253         unsigned char sectors;
254         unsigned char heads;
255         unsigned short cylinders;
256         struct hd_geometry *geo;
257         struct gendisk *gendisk;
258         struct viodasd_device *d;
259
260         switch (cmd) {
261         case HDIO_GETGEO:
262                 geo = (struct hd_geometry *)arg;
263                 if (geo == NULL)
264                         return -EINVAL;
265                 if (!access_ok(VERIFY_WRITE, geo, sizeof(*geo)))
266                         return -EFAULT;
267                 gendisk = ino->i_bdev->bd_disk;
268                 d = gendisk->private_data;
269                 sectors = d->sectors;
270                 if (sectors == 0)
271                         sectors = 32;
272                 heads = d->tracks;
273                 if (heads == 0)
274                         heads = 64;
275                 cylinders = d->cylinders;
276                 if (cylinders == 0)
277                         cylinders = get_capacity(gendisk) / (sectors * heads);
278                 if (__put_user(sectors, &geo->sectors) ||
279                     __put_user(heads, &geo->heads) ||
280                     __put_user(cylinders, &geo->cylinders) ||
281                     __put_user(get_start_sect(ino->i_bdev), &geo->start))
282                         return -EFAULT;
283                 return 0;
284         }
285
286         return -EINVAL;
287 }
288
289 /*
290  * Our file operations table
291  */
292 static struct block_device_operations viodasd_fops = {
293         .owner = THIS_MODULE,
294         .open = viodasd_open,
295         .release = viodasd_release,
296         .ioctl = viodasd_ioctl,
297 };
298
299 /*
300  * End a request
301  */
302 static void viodasd_end_request(struct request *req, int uptodate,
303                 int num_sectors)
304 {
305         if (end_that_request_first(req, uptodate, num_sectors))
306                 return;
307         add_disk_randomness(req->rq_disk);
308         end_that_request_last(req);
309 }
310
311 /*
312  * Send an actual I/O request to OS/400
313  */
314 static int send_request(struct request *req)
315 {
316         u64 start;
317         int direction;
318         int nsg;
319         u16 viocmd;
320         HvLpEvent_Rc hvrc;
321         struct vioblocklpevent *bevent;
322         struct scatterlist sg[VIOMAXBLOCKDMA];
323         int sgindex;
324         int statindex;
325         struct viodasd_device *d;
326         unsigned long flags;
327
328         start = (u64)req->sector << 9;
329
330         if (rq_data_dir(req) == READ) {
331                 direction = DMA_FROM_DEVICE;
332                 viocmd = viomajorsubtype_blockio | vioblockread;
333                 statindex = 0;
334         } else {
335                 direction = DMA_TO_DEVICE;
336                 viocmd = viomajorsubtype_blockio | vioblockwrite;
337                 statindex = 1;
338         }
339
340         d = req->rq_disk->private_data;
341
342         /* Now build the scatter-gather list */
343         nsg = blk_rq_map_sg(req->q, req, sg);
344         nsg = dma_map_sg(d->dev, sg, nsg, direction);
345
346         spin_lock_irqsave(&viodasd_spinlock, flags);
347         num_req_outstanding++;
348
349         /* This optimization handles a single DMA block */
350         if (nsg == 1)
351                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
352                                 HvLpEvent_Type_VirtualIo, viocmd,
353                                 HvLpEvent_AckInd_DoAck,
354                                 HvLpEvent_AckType_ImmediateAck,
355                                 viopath_sourceinst(viopath_hostLp),
356                                 viopath_targetinst(viopath_hostLp),
357                                 (u64)(unsigned long)req, VIOVERSION << 16,
358                                 ((u64)DEVICE_NO(d) << 48), start,
359                                 ((u64)sg_dma_address(&sg[0])) << 32,
360                                 sg_dma_len(&sg[0]));
361         else {
362                 bevent = (struct vioblocklpevent *)
363                         vio_get_event_buffer(viomajorsubtype_blockio);
364                 if (bevent == NULL) {
365                         printk(VIOD_KERN_WARNING
366                                "error allocating disk event buffer\n");
367                         goto error_ret;
368                 }
369
370                 /*
371                  * Now build up the actual request.  Note that we store
372                  * the pointer to the request in the correlation
373                  * token so we can match the response up later
374                  */
375                 memset(bevent, 0, sizeof(struct vioblocklpevent));
376                 bevent->event.xFlags.xValid = 1;
377                 bevent->event.xFlags.xFunction = HvLpEvent_Function_Int;
378                 bevent->event.xFlags.xAckInd = HvLpEvent_AckInd_DoAck;
379                 bevent->event.xFlags.xAckType = HvLpEvent_AckType_ImmediateAck;
380                 bevent->event.xType = HvLpEvent_Type_VirtualIo;
381                 bevent->event.xSubtype = viocmd;
382                 bevent->event.xSourceLp = HvLpConfig_getLpIndex();
383                 bevent->event.xTargetLp = viopath_hostLp;
384                 bevent->event.xSizeMinus1 =
385                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
386                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
387                 bevent->event.xSourceInstanceId =
388                         viopath_sourceinst(viopath_hostLp);
389                 bevent->event.xTargetInstanceId =
390                         viopath_targetinst(viopath_hostLp);
391                 bevent->event.xCorrelationToken = (u64)req;
392                 bevent->version = VIOVERSION;
393                 bevent->disk = DEVICE_NO(d);
394                 bevent->u.rw_data.offset = start;
395
396                 /*
397                  * Copy just the dma information from the sg list
398                  * into the request
399                  */
400                 for (sgindex = 0; sgindex < nsg; sgindex++) {
401                         bevent->u.rw_data.dma_info[sgindex].token =
402                                 sg_dma_address(&sg[sgindex]);
403                         bevent->u.rw_data.dma_info[sgindex].len =
404                                 sg_dma_len(&sg[sgindex]);
405                 }
406
407                 /* Send the request */
408                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
409                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
410         }
411
412         if (hvrc != HvLpEvent_Rc_Good) {
413                 printk(VIOD_KERN_WARNING
414                        "error sending disk event to OS/400 (rc %d)\n",
415                        (int)hvrc);
416                 goto error_ret;
417         }
418         spin_unlock_irqrestore(&viodasd_spinlock, flags);
419         return 0;
420
421 error_ret:
422         num_req_outstanding--;
423         spin_unlock_irqrestore(&viodasd_spinlock, flags);
424         dma_unmap_sg(d->dev, sg, nsg, direction);
425         return -1;
426 }
427
428 /*
429  * This is the external request processing routine
430  */
431 static void do_viodasd_request(request_queue_t *q)
432 {
433         struct request *req;
434
435         /*
436          * If we already have the maximum number of requests
437          * outstanding to OS/400 just bail out. We'll come
438          * back later.
439          */
440         while (num_req_outstanding < VIOMAXREQ) {
441                 req = elv_next_request(q);
442                 if (req == NULL)
443                         return;
444                 /* dequeue the current request from the queue */
445                 blkdev_dequeue_request(req);
446                 /* check that request contains a valid command */
447                 if (!blk_fs_request(req)) {
448                         viodasd_end_request(req, 0, req->hard_nr_sectors);
449                         continue;
450                 }
451                 /* Try sending the request */
452                 if (send_request(req) != 0)
453                         viodasd_end_request(req, 0, req->hard_nr_sectors);
454         }
455 }
456
457 /*
458  * Probe a single disk and fill in the viodasd_device structure
459  * for it.
460  */
461 static void probe_disk(struct viodasd_device *d)
462 {
463         HvLpEvent_Rc hvrc;
464         struct viodasd_waitevent we;
465         int dev_no = DEVICE_NO(d);
466         struct gendisk *g;
467         struct request_queue *q;
468         u16 flags = 0;
469
470 retry:
471         init_completion(&we.com);
472
473         /* Send the open event to OS/400 */
474         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
475                         HvLpEvent_Type_VirtualIo,
476                         viomajorsubtype_blockio | vioblockopen,
477                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
478                         viopath_sourceinst(viopath_hostLp),
479                         viopath_targetinst(viopath_hostLp),
480                         (u64)(unsigned long)&we, VIOVERSION << 16,
481                         ((u64)dev_no << 48) | ((u64)flags<< 32),
482                         0, 0, 0);
483         if (hvrc != 0) {
484                 printk(VIOD_KERN_WARNING "bad rc on HV open %d\n", (int)hvrc);
485                 return;
486         }
487
488         wait_for_completion(&we.com);
489
490         if (we.rc != 0) {
491                 if (flags != 0)
492                         return;
493                 /* try again with read only flag set */
494                 flags = vioblockflags_ro;
495                 goto retry;
496         }
497         if (we.max_disk > (MAX_DISKNO - 1)) {
498                 static int warned;
499
500                 if (warned == 0) {
501                         warned++;
502                         printk(VIOD_KERN_INFO
503                                 "Only examining the first %d "
504                                 "of %d disks connected\n",
505                                 MAX_DISKNO, we.max_disk + 1);
506                 }
507         }
508
509         /* Send the close event to OS/400.  We DON'T expect a response */
510         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
511                         HvLpEvent_Type_VirtualIo,
512                         viomajorsubtype_blockio | vioblockclose,
513                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
514                         viopath_sourceinst(viopath_hostLp),
515                         viopath_targetinst(viopath_hostLp),
516                         0, VIOVERSION << 16,
517                         ((u64)dev_no << 48) | ((u64)flags << 32),
518                         0, 0, 0);
519         if (hvrc != 0) {
520                 printk(VIOD_KERN_WARNING
521                        "bad rc sending event to OS/400 %d\n", (int)hvrc);
522                 return;
523         }
524         /* create the request queue for the disk */
525         spin_lock_init(&d->q_lock);
526         q = blk_init_queue(do_viodasd_request, &d->q_lock);
527         if (q == NULL) {
528                 printk(VIOD_KERN_WARNING "cannot allocate queue for disk %d\n",
529                                 dev_no);
530                 return;
531         }
532         g = alloc_disk(1 << PARTITION_SHIFT);
533         if (g == NULL) {
534                 printk(VIOD_KERN_WARNING
535                                 "cannot allocate disk structure for disk %d\n",
536                                 dev_no);
537                 blk_cleanup_queue(q);
538                 return;
539         }
540
541         d->disk = g;
542         blk_queue_max_hw_segments(q, VIOMAXBLOCKDMA);
543         blk_queue_max_phys_segments(q, VIOMAXBLOCKDMA);
544         blk_queue_max_sectors(q, VIODASD_MAXSECTORS);
545         g->major = VIODASD_MAJOR;
546         g->first_minor = dev_no << PARTITION_SHIFT;
547         if (dev_no >= 26)
548                 snprintf(g->disk_name, sizeof(g->disk_name),
549                                 VIOD_GENHD_NAME "%c%c",
550                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
551         else
552                 snprintf(g->disk_name, sizeof(g->disk_name),
553                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
554         snprintf(g->devfs_name, sizeof(g->devfs_name),
555                         "%s%d", VIOD_GENHD_DEVFS_NAME, dev_no);
556         g->fops = &viodasd_fops;
557         g->queue = q;
558         g->private_data = d;
559         g->driverfs_dev = d->dev;
560         set_capacity(g, d->size >> 9);
561
562         printk(VIOD_KERN_INFO "disk %d: %lu sectors (%lu MB) "
563                         "CHS=%d/%d/%d sector size %d%s\n",
564                         dev_no, (unsigned long)(d->size >> 9),
565                         (unsigned long)(d->size >> 20),
566                         (int)d->cylinders, (int)d->tracks,
567                         (int)d->sectors, (int)d->bytes_per_sector,
568                         d->read_only ? " (RO)" : "");
569
570         /* register us in the global list */
571         add_disk(g);
572 }
573
574 /* returns the total number of scatterlist elements converted */
575 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
576                 struct scatterlist *sg, int *total_len)
577 {
578         int i, numsg;
579         const struct rw_data *rw_data = &bevent->u.rw_data;
580         static const int offset =
581                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
582         static const int element_size = sizeof(rw_data->dma_info[0]);
583
584         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
585         if (numsg > VIOMAXBLOCKDMA)
586                 numsg = VIOMAXBLOCKDMA;
587
588         *total_len = 0;
589         memset(sg, 0, sizeof(sg[0]) * VIOMAXBLOCKDMA);
590
591         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
592                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
593                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
594                 *total_len += rw_data->dma_info[i].len;
595         }
596         return i;
597 }
598
599 /*
600  * Restart all queues, starting with the one _after_ the disk given,
601  * thus reducing the chance of starvation of higher numbered disks.
602  */
603 static void viodasd_restart_all_queues_starting_from(int first_index)
604 {
605         int i;
606
607         for (i = first_index + 1; i < MAX_DISKNO; ++i)
608                 if (viodasd_devices[i].disk)
609                         blk_run_queue(viodasd_devices[i].disk->queue);
610         for (i = 0; i <= first_index; ++i)
611                 if (viodasd_devices[i].disk)
612                         blk_run_queue(viodasd_devices[i].disk->queue);
613 }
614
615 /*
616  * For read and write requests, decrement the number of outstanding requests,
617  * Free the DMA buffers we allocated.
618  */
619 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
620 {
621         int num_sg, num_sect, pci_direction, total_len;
622         struct request *req;
623         struct scatterlist sg[VIOMAXBLOCKDMA];
624         struct HvLpEvent *event = &bevent->event;
625         unsigned long irq_flags;
626         struct viodasd_device *d;
627         int error;
628         spinlock_t *qlock;
629
630         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
631         num_sect = total_len >> 9;
632         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
633                 pci_direction = DMA_FROM_DEVICE;
634         else
635                 pci_direction = DMA_TO_DEVICE;
636         req = (struct request *)bevent->event.xCorrelationToken;
637         d = req->rq_disk->private_data;
638
639         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
640
641         /*
642          * Since this is running in interrupt mode, we need to make sure
643          * we're not stepping on any global I/O operations
644          */
645         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
646         num_req_outstanding--;
647         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
648
649         error = event->xRc != HvLpEvent_Rc_Good;
650         if (error) {
651                 const struct vio_error_entry *err;
652                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
653                 printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
654                                 event->xRc, bevent->sub_result, err->msg);
655                 num_sect = req->hard_nr_sectors;
656         }
657         qlock = req->q->queue_lock;
658         spin_lock_irqsave(qlock, irq_flags);
659         viodasd_end_request(req, !error, num_sect);
660         spin_unlock_irqrestore(qlock, irq_flags);
661
662         /* Finally, try to get more requests off of this device's queue */
663         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
664
665         return 0;
666 }
667
668 /* This routine handles incoming block LP events */
669 static void handle_block_event(struct HvLpEvent *event)
670 {
671         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
672         struct viodasd_waitevent *pwe;
673
674         if (event == NULL)
675                 /* Notification that a partition went away! */
676                 return;
677         /* First, we should NEVER get an int here...only acks */
678         if (event->xFlags.xFunction == HvLpEvent_Function_Int) {
679                 printk(VIOD_KERN_WARNING
680                        "Yikes! got an int in viodasd event handler!\n");
681                 if (event->xFlags.xAckInd == HvLpEvent_AckInd_DoAck) {
682                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
683                         HvCallEvent_ackLpEvent(event);
684                 }
685         }
686
687         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
688         case vioblockopen:
689                 /*
690                  * Handle a response to an open request.  We get all the
691                  * disk information in the response, so update it.  The
692                  * correlation token contains a pointer to a waitevent
693                  * structure that has a completion in it.  update the
694                  * return code in the waitevent structure and post the
695                  * completion to wake up the guy who sent the request
696                  */
697                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
698                 pwe->rc = event->xRc;
699                 pwe->sub_result = bevent->sub_result;
700                 if (event->xRc == HvLpEvent_Rc_Good) {
701                         const struct open_data *data = &bevent->u.open_data;
702                         struct viodasd_device *device =
703                                 &viodasd_devices[bevent->disk];
704                         device->read_only =
705                                 bevent->flags & vioblockflags_ro;
706                         device->size = data->disk_size;
707                         device->cylinders = data->cylinders;
708                         device->tracks = data->tracks;
709                         device->sectors = data->sectors;
710                         device->bytes_per_sector = data->bytes_per_sector;
711                         pwe->max_disk = data->max_disk;
712                 }
713                 complete(&pwe->com);
714                 break;
715         case vioblockclose:
716                 break;
717         case vioblockread:
718         case vioblockwrite:
719                 viodasd_handle_read_write(bevent);
720                 break;
721
722         default:
723                 printk(VIOD_KERN_WARNING "invalid subtype!");
724                 if (event->xFlags.xAckInd == HvLpEvent_AckInd_DoAck) {
725                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
726                         HvCallEvent_ackLpEvent(event);
727                 }
728         }
729 }
730
731 /*
732  * Get the driver to reprobe for more disks.
733  */
734 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
735                 size_t count)
736 {
737         struct viodasd_device *d;
738
739         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
740                 if (d->disk == NULL)
741                         probe_disk(d);
742         }
743         return count;
744 }
745 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
746
747 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
748 {
749         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
750
751         d->dev = &vdev->dev;
752         probe_disk(d);
753         if (d->disk == NULL)
754                 return -ENODEV;
755         return 0;
756 }
757
758 static int viodasd_remove(struct vio_dev *vdev)
759 {
760         struct viodasd_device *d;
761
762         d = &viodasd_devices[vdev->unit_address];
763         if (d->disk) {
764                 del_gendisk(d->disk);
765                 blk_cleanup_queue(d->disk->queue);
766                 put_disk(d->disk);
767                 d->disk = NULL;
768         }
769         d->dev = NULL;
770         return 0;
771 }
772
773 /**
774  * viodasd_device_table: Used by vio.c to match devices that we
775  * support.
776  */
777 static struct vio_device_id viodasd_device_table[] __devinitdata = {
778         { "viodasd", "" },
779         { 0, }
780 };
781
782 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
783 static struct vio_driver viodasd_driver = {
784         .name = "viodasd",
785         .id_table = viodasd_device_table,
786         .probe = viodasd_probe,
787         .remove = viodasd_remove
788 };
789
790 /*
791  * Initialize the whole device driver.  Handle module and non-module
792  * versions
793  */
794 static int __init viodasd_init(void)
795 {
796         int rc;
797
798         /* Try to open to our host lp */
799         if (viopath_hostLp == HvLpIndexInvalid)
800                 vio_set_hostlp();
801
802         if (viopath_hostLp == HvLpIndexInvalid) {
803                 printk(VIOD_KERN_WARNING "invalid hosting partition\n");
804                 return -EIO;
805         }
806
807         printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
808                         viopath_hostLp);
809
810         /* register the block device */
811         if (register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME)) {
812                 printk(VIOD_KERN_WARNING
813                                 "Unable to get major number %d for %s\n",
814                                 VIODASD_MAJOR, VIOD_GENHD_NAME);
815                 return -EIO;
816         }
817         /* Actually open the path to the hosting partition */
818         if (viopath_open(viopath_hostLp, viomajorsubtype_blockio,
819                                 VIOMAXREQ + 2)) {
820                 printk(VIOD_KERN_WARNING
821                        "error opening path to host partition %d\n",
822                        viopath_hostLp);
823                 unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
824                 return -EIO;
825         }
826
827         /* Initialize our request handler */
828         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
829
830         rc = vio_register_driver(&viodasd_driver);
831         if (rc == 0)
832                 driver_create_file(&viodasd_driver.driver, &driver_attr_probe);
833         return rc;
834 }
835 module_init(viodasd_init);
836
837 void viodasd_exit(void)
838 {
839         driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
840         vio_unregister_driver(&viodasd_driver);
841         vio_clearHandler(viomajorsubtype_blockio);
842         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
843         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
844 }
845
846 module_exit(viodasd_exit);