[BLOCK] Get rid of request_queue_t typedef
[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/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 = 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_getgeo(struct block_device *bdev, struct hd_geometry *geo)
251 {
252         struct gendisk *disk = bdev->bd_disk;
253         struct viodasd_device *d = disk->private_data;
254
255         geo->sectors = d->sectors ? d->sectors : 32;
256         geo->heads = d->tracks ? d->tracks  : 64;
257         geo->cylinders = d->cylinders ? d->cylinders :
258                 get_capacity(disk) / (geo->sectors * geo->heads);
259
260         return 0;
261 }
262
263 /*
264  * Our file operations table
265  */
266 static struct block_device_operations viodasd_fops = {
267         .owner = THIS_MODULE,
268         .open = viodasd_open,
269         .release = viodasd_release,
270         .getgeo = viodasd_getgeo,
271 };
272
273 /*
274  * End a request
275  */
276 static void viodasd_end_request(struct request *req, int uptodate,
277                 int num_sectors)
278 {
279         if (end_that_request_first(req, uptodate, num_sectors))
280                 return;
281         add_disk_randomness(req->rq_disk);
282         end_that_request_last(req, uptodate);
283 }
284
285 /*
286  * Send an actual I/O request to OS/400
287  */
288 static int send_request(struct request *req)
289 {
290         u64 start;
291         int direction;
292         int nsg;
293         u16 viocmd;
294         HvLpEvent_Rc hvrc;
295         struct vioblocklpevent *bevent;
296         struct HvLpEvent *hev;
297         struct scatterlist sg[VIOMAXBLOCKDMA];
298         int sgindex;
299         int statindex;
300         struct viodasd_device *d;
301         unsigned long flags;
302
303         start = (u64)req->sector << 9;
304
305         if (rq_data_dir(req) == READ) {
306                 direction = DMA_FROM_DEVICE;
307                 viocmd = viomajorsubtype_blockio | vioblockread;
308                 statindex = 0;
309         } else {
310                 direction = DMA_TO_DEVICE;
311                 viocmd = viomajorsubtype_blockio | vioblockwrite;
312                 statindex = 1;
313         }
314
315         d = req->rq_disk->private_data;
316
317         /* Now build the scatter-gather list */
318         nsg = blk_rq_map_sg(req->q, req, sg);
319         nsg = dma_map_sg(d->dev, sg, nsg, direction);
320
321         spin_lock_irqsave(&viodasd_spinlock, flags);
322         num_req_outstanding++;
323
324         /* This optimization handles a single DMA block */
325         if (nsg == 1)
326                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
327                                 HvLpEvent_Type_VirtualIo, viocmd,
328                                 HvLpEvent_AckInd_DoAck,
329                                 HvLpEvent_AckType_ImmediateAck,
330                                 viopath_sourceinst(viopath_hostLp),
331                                 viopath_targetinst(viopath_hostLp),
332                                 (u64)(unsigned long)req, VIOVERSION << 16,
333                                 ((u64)DEVICE_NO(d) << 48), start,
334                                 ((u64)sg_dma_address(&sg[0])) << 32,
335                                 sg_dma_len(&sg[0]));
336         else {
337                 bevent = (struct vioblocklpevent *)
338                         vio_get_event_buffer(viomajorsubtype_blockio);
339                 if (bevent == NULL) {
340                         printk(VIOD_KERN_WARNING
341                                "error allocating disk event buffer\n");
342                         goto error_ret;
343                 }
344
345                 /*
346                  * Now build up the actual request.  Note that we store
347                  * the pointer to the request in the correlation
348                  * token so we can match the response up later
349                  */
350                 memset(bevent, 0, sizeof(struct vioblocklpevent));
351                 hev = &bevent->event;
352                 hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK |
353                         HV_LP_EVENT_INT;
354                 hev->xType = HvLpEvent_Type_VirtualIo;
355                 hev->xSubtype = viocmd;
356                 hev->xSourceLp = HvLpConfig_getLpIndex();
357                 hev->xTargetLp = viopath_hostLp;
358                 hev->xSizeMinus1 =
359                         offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
360                         (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
361                 hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp);
362                 hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp);
363                 hev->xCorrelationToken = (u64)req;
364                 bevent->version = VIOVERSION;
365                 bevent->disk = DEVICE_NO(d);
366                 bevent->u.rw_data.offset = start;
367
368                 /*
369                  * Copy just the dma information from the sg list
370                  * into the request
371                  */
372                 for (sgindex = 0; sgindex < nsg; sgindex++) {
373                         bevent->u.rw_data.dma_info[sgindex].token =
374                                 sg_dma_address(&sg[sgindex]);
375                         bevent->u.rw_data.dma_info[sgindex].len =
376                                 sg_dma_len(&sg[sgindex]);
377                 }
378
379                 /* Send the request */
380                 hvrc = HvCallEvent_signalLpEvent(&bevent->event);
381                 vio_free_event_buffer(viomajorsubtype_blockio, bevent);
382         }
383
384         if (hvrc != HvLpEvent_Rc_Good) {
385                 printk(VIOD_KERN_WARNING
386                        "error sending disk event to OS/400 (rc %d)\n",
387                        (int)hvrc);
388                 goto error_ret;
389         }
390         spin_unlock_irqrestore(&viodasd_spinlock, flags);
391         return 0;
392
393 error_ret:
394         num_req_outstanding--;
395         spin_unlock_irqrestore(&viodasd_spinlock, flags);
396         dma_unmap_sg(d->dev, sg, nsg, direction);
397         return -1;
398 }
399
400 /*
401  * This is the external request processing routine
402  */
403 static void do_viodasd_request(struct request_queue *q)
404 {
405         struct request *req;
406
407         /*
408          * If we already have the maximum number of requests
409          * outstanding to OS/400 just bail out. We'll come
410          * back later.
411          */
412         while (num_req_outstanding < VIOMAXREQ) {
413                 req = elv_next_request(q);
414                 if (req == NULL)
415                         return;
416                 /* dequeue the current request from the queue */
417                 blkdev_dequeue_request(req);
418                 /* check that request contains a valid command */
419                 if (!blk_fs_request(req)) {
420                         viodasd_end_request(req, 0, req->hard_nr_sectors);
421                         continue;
422                 }
423                 /* Try sending the request */
424                 if (send_request(req) != 0)
425                         viodasd_end_request(req, 0, req->hard_nr_sectors);
426         }
427 }
428
429 /*
430  * Probe a single disk and fill in the viodasd_device structure
431  * for it.
432  */
433 static void probe_disk(struct viodasd_device *d)
434 {
435         HvLpEvent_Rc hvrc;
436         struct viodasd_waitevent we;
437         int dev_no = DEVICE_NO(d);
438         struct gendisk *g;
439         struct request_queue *q;
440         u16 flags = 0;
441
442 retry:
443         init_completion(&we.com);
444
445         /* Send the open event to OS/400 */
446         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
447                         HvLpEvent_Type_VirtualIo,
448                         viomajorsubtype_blockio | vioblockopen,
449                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
450                         viopath_sourceinst(viopath_hostLp),
451                         viopath_targetinst(viopath_hostLp),
452                         (u64)(unsigned long)&we, VIOVERSION << 16,
453                         ((u64)dev_no << 48) | ((u64)flags<< 32),
454                         0, 0, 0);
455         if (hvrc != 0) {
456                 printk(VIOD_KERN_WARNING "bad rc on HV open %d\n", (int)hvrc);
457                 return;
458         }
459
460         wait_for_completion(&we.com);
461
462         if (we.rc != 0) {
463                 if (flags != 0)
464                         return;
465                 /* try again with read only flag set */
466                 flags = vioblockflags_ro;
467                 goto retry;
468         }
469         if (we.max_disk > (MAX_DISKNO - 1)) {
470                 static int warned;
471
472                 if (warned == 0) {
473                         warned++;
474                         printk(VIOD_KERN_INFO
475                                 "Only examining the first %d "
476                                 "of %d disks connected\n",
477                                 MAX_DISKNO, we.max_disk + 1);
478                 }
479         }
480
481         /* Send the close event to OS/400.  We DON'T expect a response */
482         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
483                         HvLpEvent_Type_VirtualIo,
484                         viomajorsubtype_blockio | vioblockclose,
485                         HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
486                         viopath_sourceinst(viopath_hostLp),
487                         viopath_targetinst(viopath_hostLp),
488                         0, VIOVERSION << 16,
489                         ((u64)dev_no << 48) | ((u64)flags << 32),
490                         0, 0, 0);
491         if (hvrc != 0) {
492                 printk(VIOD_KERN_WARNING
493                        "bad rc sending event to OS/400 %d\n", (int)hvrc);
494                 return;
495         }
496         /* create the request queue for the disk */
497         spin_lock_init(&d->q_lock);
498         q = blk_init_queue(do_viodasd_request, &d->q_lock);
499         if (q == NULL) {
500                 printk(VIOD_KERN_WARNING "cannot allocate queue for disk %d\n",
501                                 dev_no);
502                 return;
503         }
504         g = alloc_disk(1 << PARTITION_SHIFT);
505         if (g == NULL) {
506                 printk(VIOD_KERN_WARNING
507                                 "cannot allocate disk structure for disk %d\n",
508                                 dev_no);
509                 blk_cleanup_queue(q);
510                 return;
511         }
512
513         d->disk = g;
514         blk_queue_max_hw_segments(q, VIOMAXBLOCKDMA);
515         blk_queue_max_phys_segments(q, VIOMAXBLOCKDMA);
516         blk_queue_max_sectors(q, VIODASD_MAXSECTORS);
517         g->major = VIODASD_MAJOR;
518         g->first_minor = dev_no << PARTITION_SHIFT;
519         if (dev_no >= 26)
520                 snprintf(g->disk_name, sizeof(g->disk_name),
521                                 VIOD_GENHD_NAME "%c%c",
522                                 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
523         else
524                 snprintf(g->disk_name, sizeof(g->disk_name),
525                                 VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
526         g->fops = &viodasd_fops;
527         g->queue = q;
528         g->private_data = d;
529         g->driverfs_dev = d->dev;
530         set_capacity(g, d->size >> 9);
531
532         printk(VIOD_KERN_INFO "disk %d: %lu sectors (%lu MB) "
533                         "CHS=%d/%d/%d sector size %d%s\n",
534                         dev_no, (unsigned long)(d->size >> 9),
535                         (unsigned long)(d->size >> 20),
536                         (int)d->cylinders, (int)d->tracks,
537                         (int)d->sectors, (int)d->bytes_per_sector,
538                         d->read_only ? " (RO)" : "");
539
540         /* register us in the global list */
541         add_disk(g);
542 }
543
544 /* returns the total number of scatterlist elements converted */
545 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
546                 struct scatterlist *sg, int *total_len)
547 {
548         int i, numsg;
549         const struct rw_data *rw_data = &bevent->u.rw_data;
550         static const int offset =
551                 offsetof(struct vioblocklpevent, u.rw_data.dma_info);
552         static const int element_size = sizeof(rw_data->dma_info[0]);
553
554         numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
555         if (numsg > VIOMAXBLOCKDMA)
556                 numsg = VIOMAXBLOCKDMA;
557
558         *total_len = 0;
559         memset(sg, 0, sizeof(sg[0]) * VIOMAXBLOCKDMA);
560
561         for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
562                 sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
563                 sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
564                 *total_len += rw_data->dma_info[i].len;
565         }
566         return i;
567 }
568
569 /*
570  * Restart all queues, starting with the one _after_ the disk given,
571  * thus reducing the chance of starvation of higher numbered disks.
572  */
573 static void viodasd_restart_all_queues_starting_from(int first_index)
574 {
575         int i;
576
577         for (i = first_index + 1; i < MAX_DISKNO; ++i)
578                 if (viodasd_devices[i].disk)
579                         blk_run_queue(viodasd_devices[i].disk->queue);
580         for (i = 0; i <= first_index; ++i)
581                 if (viodasd_devices[i].disk)
582                         blk_run_queue(viodasd_devices[i].disk->queue);
583 }
584
585 /*
586  * For read and write requests, decrement the number of outstanding requests,
587  * Free the DMA buffers we allocated.
588  */
589 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
590 {
591         int num_sg, num_sect, pci_direction, total_len;
592         struct request *req;
593         struct scatterlist sg[VIOMAXBLOCKDMA];
594         struct HvLpEvent *event = &bevent->event;
595         unsigned long irq_flags;
596         struct viodasd_device *d;
597         int error;
598         spinlock_t *qlock;
599
600         num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
601         num_sect = total_len >> 9;
602         if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
603                 pci_direction = DMA_FROM_DEVICE;
604         else
605                 pci_direction = DMA_TO_DEVICE;
606         req = (struct request *)bevent->event.xCorrelationToken;
607         d = req->rq_disk->private_data;
608
609         dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
610
611         /*
612          * Since this is running in interrupt mode, we need to make sure
613          * we're not stepping on any global I/O operations
614          */
615         spin_lock_irqsave(&viodasd_spinlock, irq_flags);
616         num_req_outstanding--;
617         spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
618
619         error = event->xRc != HvLpEvent_Rc_Good;
620         if (error) {
621                 const struct vio_error_entry *err;
622                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
623                 printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
624                                 event->xRc, bevent->sub_result, err->msg);
625                 num_sect = req->hard_nr_sectors;
626         }
627         qlock = req->q->queue_lock;
628         spin_lock_irqsave(qlock, irq_flags);
629         viodasd_end_request(req, !error, num_sect);
630         spin_unlock_irqrestore(qlock, irq_flags);
631
632         /* Finally, try to get more requests off of this device's queue */
633         viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
634
635         return 0;
636 }
637
638 /* This routine handles incoming block LP events */
639 static void handle_block_event(struct HvLpEvent *event)
640 {
641         struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
642         struct viodasd_waitevent *pwe;
643
644         if (event == NULL)
645                 /* Notification that a partition went away! */
646                 return;
647         /* First, we should NEVER get an int here...only acks */
648         if (hvlpevent_is_int(event)) {
649                 printk(VIOD_KERN_WARNING
650                        "Yikes! got an int in viodasd event handler!\n");
651                 if (hvlpevent_need_ack(event)) {
652                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
653                         HvCallEvent_ackLpEvent(event);
654                 }
655         }
656
657         switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
658         case vioblockopen:
659                 /*
660                  * Handle a response to an open request.  We get all the
661                  * disk information in the response, so update it.  The
662                  * correlation token contains a pointer to a waitevent
663                  * structure that has a completion in it.  update the
664                  * return code in the waitevent structure and post the
665                  * completion to wake up the guy who sent the request
666                  */
667                 pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
668                 pwe->rc = event->xRc;
669                 pwe->sub_result = bevent->sub_result;
670                 if (event->xRc == HvLpEvent_Rc_Good) {
671                         const struct open_data *data = &bevent->u.open_data;
672                         struct viodasd_device *device =
673                                 &viodasd_devices[bevent->disk];
674                         device->read_only =
675                                 bevent->flags & vioblockflags_ro;
676                         device->size = data->disk_size;
677                         device->cylinders = data->cylinders;
678                         device->tracks = data->tracks;
679                         device->sectors = data->sectors;
680                         device->bytes_per_sector = data->bytes_per_sector;
681                         pwe->max_disk = data->max_disk;
682                 }
683                 complete(&pwe->com);
684                 break;
685         case vioblockclose:
686                 break;
687         case vioblockread:
688         case vioblockwrite:
689                 viodasd_handle_read_write(bevent);
690                 break;
691
692         default:
693                 printk(VIOD_KERN_WARNING "invalid subtype!");
694                 if (hvlpevent_need_ack(event)) {
695                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
696                         HvCallEvent_ackLpEvent(event);
697                 }
698         }
699 }
700
701 /*
702  * Get the driver to reprobe for more disks.
703  */
704 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
705                 size_t count)
706 {
707         struct viodasd_device *d;
708
709         for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
710                 if (d->disk == NULL)
711                         probe_disk(d);
712         }
713         return count;
714 }
715 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
716
717 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
718 {
719         struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
720
721         d->dev = &vdev->dev;
722         probe_disk(d);
723         if (d->disk == NULL)
724                 return -ENODEV;
725         return 0;
726 }
727
728 static int viodasd_remove(struct vio_dev *vdev)
729 {
730         struct viodasd_device *d;
731
732         d = &viodasd_devices[vdev->unit_address];
733         if (d->disk) {
734                 del_gendisk(d->disk);
735                 blk_cleanup_queue(d->disk->queue);
736                 put_disk(d->disk);
737                 d->disk = NULL;
738         }
739         d->dev = NULL;
740         return 0;
741 }
742
743 /**
744  * viodasd_device_table: Used by vio.c to match devices that we
745  * support.
746  */
747 static struct vio_device_id viodasd_device_table[] __devinitdata = {
748         { "block", "IBM,iSeries-viodasd" },
749         { "", "" }
750 };
751 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
752
753 static struct vio_driver viodasd_driver = {
754         .id_table = viodasd_device_table,
755         .probe = viodasd_probe,
756         .remove = viodasd_remove,
757         .driver = {
758                 .name = "viodasd",
759                 .owner = THIS_MODULE,
760         }
761 };
762
763 static int need_delete_probe;
764
765 /*
766  * Initialize the whole device driver.  Handle module and non-module
767  * versions
768  */
769 static int __init viodasd_init(void)
770 {
771         int rc;
772
773         if (!firmware_has_feature(FW_FEATURE_ISERIES)) {
774                 rc = -ENODEV;
775                 goto early_fail;
776         }
777
778         /* Try to open to our host lp */
779         if (viopath_hostLp == HvLpIndexInvalid)
780                 vio_set_hostlp();
781
782         if (viopath_hostLp == HvLpIndexInvalid) {
783                 printk(VIOD_KERN_WARNING "invalid hosting partition\n");
784                 rc = -EIO;
785                 goto early_fail;
786         }
787
788         printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
789                         viopath_hostLp);
790
791         /* register the block device */
792         rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
793         if (rc) {
794                 printk(VIOD_KERN_WARNING
795                                 "Unable to get major number %d for %s\n",
796                                 VIODASD_MAJOR, VIOD_GENHD_NAME);
797                 goto early_fail;
798         }
799         /* Actually open the path to the hosting partition */
800         rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
801                                 VIOMAXREQ + 2);
802         if (rc) {
803                 printk(VIOD_KERN_WARNING
804                        "error opening path to host partition %d\n",
805                        viopath_hostLp);
806                 goto unregister_blk;
807         }
808
809         /* Initialize our request handler */
810         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
811
812         rc = vio_register_driver(&viodasd_driver);
813         if (rc) {
814                 printk(VIOD_KERN_WARNING "vio_register_driver failed\n");
815                 goto unset_handler;
816         }
817
818         /*
819          * If this call fails, it just means that we cannot dynamically
820          * add virtual disks, but the driver will still work fine for
821          * all existing disk, so ignore the failure.
822          */
823         if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
824                 need_delete_probe = 1;
825
826         return 0;
827
828 unset_handler:
829         vio_clearHandler(viomajorsubtype_blockio);
830         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
831 unregister_blk:
832         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
833 early_fail:
834         return rc;
835 }
836 module_init(viodasd_init);
837
838 void __exit viodasd_exit(void)
839 {
840         if (need_delete_probe)
841                 driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
842         vio_unregister_driver(&viodasd_driver);
843         vio_clearHandler(viomajorsubtype_blockio);
844         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
845         unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
846 }
847 module_exit(viodasd_exit);