drbd: Only downgrade the disk state in case of disk failures
[linux-2.6.git] / drivers / block / sunvdc.c
1 /* sunvdc.c: Sun LDOM Virtual Disk Client.
2  *
3  * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
4  */
5
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/types.h>
9 #include <linux/blkdev.h>
10 #include <linux/hdreg.h>
11 #include <linux/genhd.h>
12 #include <linux/slab.h>
13 #include <linux/spinlock.h>
14 #include <linux/completion.h>
15 #include <linux/delay.h>
16 #include <linux/init.h>
17 #include <linux/list.h>
18 #include <linux/scatterlist.h>
19
20 #include <asm/vio.h>
21 #include <asm/ldc.h>
22
23 #define DRV_MODULE_NAME         "sunvdc"
24 #define PFX DRV_MODULE_NAME     ": "
25 #define DRV_MODULE_VERSION      "1.0"
26 #define DRV_MODULE_RELDATE      "June 25, 2007"
27
28 static char version[] __devinitdata =
29         DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
30 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
31 MODULE_DESCRIPTION("Sun LDOM virtual disk client driver");
32 MODULE_LICENSE("GPL");
33 MODULE_VERSION(DRV_MODULE_VERSION);
34
35 #define VDC_TX_RING_SIZE        256
36
37 #define WAITING_FOR_LINK_UP     0x01
38 #define WAITING_FOR_TX_SPACE    0x02
39 #define WAITING_FOR_GEN_CMD     0x04
40 #define WAITING_FOR_ANY         -1
41
42 struct vdc_req_entry {
43         struct request          *req;
44 };
45
46 struct vdc_port {
47         struct vio_driver_state vio;
48
49         struct gendisk          *disk;
50
51         struct vdc_completion   *cmp;
52
53         u64                     req_id;
54         u64                     seq;
55         struct vdc_req_entry    rq_arr[VDC_TX_RING_SIZE];
56
57         unsigned long           ring_cookies;
58
59         u64                     max_xfer_size;
60         u32                     vdisk_block_size;
61
62         /* The server fills these in for us in the disk attribute
63          * ACK packet.
64          */
65         u64                     operations;
66         u32                     vdisk_size;
67         u8                      vdisk_type;
68
69         char                    disk_name[32];
70
71         struct vio_disk_geom    geom;
72         struct vio_disk_vtoc    label;
73 };
74
75 static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
76 {
77         return container_of(vio, struct vdc_port, vio);
78 }
79
80 /* Ordered from largest major to lowest */
81 static struct vio_version vdc_versions[] = {
82         { .major = 1, .minor = 0 },
83 };
84
85 #define VDCBLK_NAME     "vdisk"
86 static int vdc_major;
87 #define PARTITION_SHIFT 3
88
89 static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
90 {
91         return vio_dring_avail(dr, VDC_TX_RING_SIZE);
92 }
93
94 static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
95 {
96         struct gendisk *disk = bdev->bd_disk;
97         struct vdc_port *port = disk->private_data;
98
99         geo->heads = (u8) port->geom.num_hd;
100         geo->sectors = (u8) port->geom.num_sec;
101         geo->cylinders = port->geom.num_cyl;
102
103         return 0;
104 }
105
106 static const struct block_device_operations vdc_fops = {
107         .owner          = THIS_MODULE,
108         .getgeo         = vdc_getgeo,
109 };
110
111 static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
112 {
113         if (vio->cmp &&
114             (waiting_for == -1 ||
115              vio->cmp->waiting_for == waiting_for)) {
116                 vio->cmp->err = err;
117                 complete(&vio->cmp->com);
118                 vio->cmp = NULL;
119         }
120 }
121
122 static void vdc_handshake_complete(struct vio_driver_state *vio)
123 {
124         vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
125 }
126
127 static int vdc_handle_unknown(struct vdc_port *port, void *arg)
128 {
129         struct vio_msg_tag *pkt = arg;
130
131         printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
132                pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
133         printk(KERN_ERR PFX "Resetting connection.\n");
134
135         ldc_disconnect(port->vio.lp);
136
137         return -ECONNRESET;
138 }
139
140 static int vdc_send_attr(struct vio_driver_state *vio)
141 {
142         struct vdc_port *port = to_vdc_port(vio);
143         struct vio_disk_attr_info pkt;
144
145         memset(&pkt, 0, sizeof(pkt));
146
147         pkt.tag.type = VIO_TYPE_CTRL;
148         pkt.tag.stype = VIO_SUBTYPE_INFO;
149         pkt.tag.stype_env = VIO_ATTR_INFO;
150         pkt.tag.sid = vio_send_sid(vio);
151
152         pkt.xfer_mode = VIO_DRING_MODE;
153         pkt.vdisk_block_size = port->vdisk_block_size;
154         pkt.max_xfer_size = port->max_xfer_size;
155
156         viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
157                pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);
158
159         return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
160 }
161
162 static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
163 {
164         struct vdc_port *port = to_vdc_port(vio);
165         struct vio_disk_attr_info *pkt = arg;
166
167         viodbg(HS, "GOT ATTR stype[0x%x] ops[%llx] disk_size[%llu] disk_type[%x] "
168                "xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
169                pkt->tag.stype, pkt->operations,
170                pkt->vdisk_size, pkt->vdisk_type,
171                pkt->xfer_mode, pkt->vdisk_block_size,
172                pkt->max_xfer_size);
173
174         if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
175                 switch (pkt->vdisk_type) {
176                 case VD_DISK_TYPE_DISK:
177                 case VD_DISK_TYPE_SLICE:
178                         break;
179
180                 default:
181                         printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n",
182                                vio->name, pkt->vdisk_type);
183                         return -ECONNRESET;
184                 }
185
186                 if (pkt->vdisk_block_size > port->vdisk_block_size) {
187                         printk(KERN_ERR PFX "%s: BLOCK size increased "
188                                "%u --> %u\n",
189                                vio->name,
190                                port->vdisk_block_size, pkt->vdisk_block_size);
191                         return -ECONNRESET;
192                 }
193
194                 port->operations = pkt->operations;
195                 port->vdisk_size = pkt->vdisk_size;
196                 port->vdisk_type = pkt->vdisk_type;
197                 if (pkt->max_xfer_size < port->max_xfer_size)
198                         port->max_xfer_size = pkt->max_xfer_size;
199                 port->vdisk_block_size = pkt->vdisk_block_size;
200                 return 0;
201         } else {
202                 printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name);
203
204                 return -ECONNRESET;
205         }
206 }
207
208 static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc)
209 {
210         int err = desc->status;
211
212         vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
213 }
214
215 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
216                         unsigned int index)
217 {
218         struct vio_disk_desc *desc = vio_dring_entry(dr, index);
219         struct vdc_req_entry *rqe = &port->rq_arr[index];
220         struct request *req;
221
222         if (unlikely(desc->hdr.state != VIO_DESC_DONE))
223                 return;
224
225         ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
226         desc->hdr.state = VIO_DESC_FREE;
227         dr->cons = (index + 1) & (VDC_TX_RING_SIZE - 1);
228
229         req = rqe->req;
230         if (req == NULL) {
231                 vdc_end_special(port, desc);
232                 return;
233         }
234
235         rqe->req = NULL;
236
237         __blk_end_request(req, (desc->status ? -EIO : 0), desc->size);
238
239         if (blk_queue_stopped(port->disk->queue))
240                 blk_start_queue(port->disk->queue);
241 }
242
243 static int vdc_ack(struct vdc_port *port, void *msgbuf)
244 {
245         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
246         struct vio_dring_data *pkt = msgbuf;
247
248         if (unlikely(pkt->dring_ident != dr->ident ||
249                      pkt->start_idx != pkt->end_idx ||
250                      pkt->start_idx >= VDC_TX_RING_SIZE))
251                 return 0;
252
253         vdc_end_one(port, dr, pkt->start_idx);
254
255         return 0;
256 }
257
258 static int vdc_nack(struct vdc_port *port, void *msgbuf)
259 {
260         /* XXX Implement me XXX */
261         return 0;
262 }
263
264 static void vdc_event(void *arg, int event)
265 {
266         struct vdc_port *port = arg;
267         struct vio_driver_state *vio = &port->vio;
268         unsigned long flags;
269         int err;
270
271         spin_lock_irqsave(&vio->lock, flags);
272
273         if (unlikely(event == LDC_EVENT_RESET ||
274                      event == LDC_EVENT_UP)) {
275                 vio_link_state_change(vio, event);
276                 spin_unlock_irqrestore(&vio->lock, flags);
277                 return;
278         }
279
280         if (unlikely(event != LDC_EVENT_DATA_READY)) {
281                 printk(KERN_WARNING PFX "Unexpected LDC event %d\n", event);
282                 spin_unlock_irqrestore(&vio->lock, flags);
283                 return;
284         }
285
286         err = 0;
287         while (1) {
288                 union {
289                         struct vio_msg_tag tag;
290                         u64 raw[8];
291                 } msgbuf;
292
293                 err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
294                 if (unlikely(err < 0)) {
295                         if (err == -ECONNRESET)
296                                 vio_conn_reset(vio);
297                         break;
298                 }
299                 if (err == 0)
300                         break;
301                 viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
302                        msgbuf.tag.type,
303                        msgbuf.tag.stype,
304                        msgbuf.tag.stype_env,
305                        msgbuf.tag.sid);
306                 err = vio_validate_sid(vio, &msgbuf.tag);
307                 if (err < 0)
308                         break;
309
310                 if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
311                         if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
312                                 err = vdc_ack(port, &msgbuf);
313                         else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
314                                 err = vdc_nack(port, &msgbuf);
315                         else
316                                 err = vdc_handle_unknown(port, &msgbuf);
317                 } else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
318                         err = vio_control_pkt_engine(vio, &msgbuf);
319                 } else {
320                         err = vdc_handle_unknown(port, &msgbuf);
321                 }
322                 if (err < 0)
323                         break;
324         }
325         if (err < 0)
326                 vdc_finish(&port->vio, err, WAITING_FOR_ANY);
327         spin_unlock_irqrestore(&vio->lock, flags);
328 }
329
330 static int __vdc_tx_trigger(struct vdc_port *port)
331 {
332         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
333         struct vio_dring_data hdr = {
334                 .tag = {
335                         .type           = VIO_TYPE_DATA,
336                         .stype          = VIO_SUBTYPE_INFO,
337                         .stype_env      = VIO_DRING_DATA,
338                         .sid            = vio_send_sid(&port->vio),
339                 },
340                 .dring_ident            = dr->ident,
341                 .start_idx              = dr->prod,
342                 .end_idx                = dr->prod,
343         };
344         int err, delay;
345
346         hdr.seq = dr->snd_nxt;
347         delay = 1;
348         do {
349                 err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
350                 if (err > 0) {
351                         dr->snd_nxt++;
352                         break;
353                 }
354                 udelay(delay);
355                 if ((delay <<= 1) > 128)
356                         delay = 128;
357         } while (err == -EAGAIN);
358
359         return err;
360 }
361
362 static int __send_request(struct request *req)
363 {
364         struct vdc_port *port = req->rq_disk->private_data;
365         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
366         struct scatterlist sg[port->ring_cookies];
367         struct vdc_req_entry *rqe;
368         struct vio_disk_desc *desc;
369         unsigned int map_perm;
370         int nsg, err, i;
371         u64 len;
372         u8 op;
373
374         map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
375
376         if (rq_data_dir(req) == READ) {
377                 map_perm |= LDC_MAP_W;
378                 op = VD_OP_BREAD;
379         } else {
380                 map_perm |= LDC_MAP_R;
381                 op = VD_OP_BWRITE;
382         }
383
384         sg_init_table(sg, port->ring_cookies);
385         nsg = blk_rq_map_sg(req->q, req, sg);
386
387         len = 0;
388         for (i = 0; i < nsg; i++)
389                 len += sg[i].length;
390
391         if (unlikely(vdc_tx_dring_avail(dr) < 1)) {
392                 blk_stop_queue(port->disk->queue);
393                 err = -ENOMEM;
394                 goto out;
395         }
396
397         desc = vio_dring_cur(dr);
398
399         err = ldc_map_sg(port->vio.lp, sg, nsg,
400                          desc->cookies, port->ring_cookies,
401                          map_perm);
402         if (err < 0) {
403                 printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
404                 return err;
405         }
406
407         rqe = &port->rq_arr[dr->prod];
408         rqe->req = req;
409
410         desc->hdr.ack = VIO_ACK_ENABLE;
411         desc->req_id = port->req_id;
412         desc->operation = op;
413         if (port->vdisk_type == VD_DISK_TYPE_DISK) {
414                 desc->slice = 0xff;
415         } else {
416                 desc->slice = 0;
417         }
418         desc->status = ~0;
419         desc->offset = (blk_rq_pos(req) << 9) / port->vdisk_block_size;
420         desc->size = len;
421         desc->ncookies = err;
422
423         /* This has to be a non-SMP write barrier because we are writing
424          * to memory which is shared with the peer LDOM.
425          */
426         wmb();
427         desc->hdr.state = VIO_DESC_READY;
428
429         err = __vdc_tx_trigger(port);
430         if (err < 0) {
431                 printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
432         } else {
433                 port->req_id++;
434                 dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
435         }
436 out:
437
438         return err;
439 }
440
441 static void do_vdc_request(struct request_queue *q)
442 {
443         while (1) {
444                 struct request *req = blk_fetch_request(q);
445
446                 if (!req)
447                         break;
448
449                 if (__send_request(req) < 0)
450                         __blk_end_request_all(req, -EIO);
451         }
452 }
453
454 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
455 {
456         struct vio_dring_state *dr;
457         struct vio_completion comp;
458         struct vio_disk_desc *desc;
459         unsigned int map_perm;
460         unsigned long flags;
461         int op_len, err;
462         void *req_buf;
463
464         if (!(((u64)1 << ((u64)op - 1)) & port->operations))
465                 return -EOPNOTSUPP;
466
467         switch (op) {
468         case VD_OP_BREAD:
469         case VD_OP_BWRITE:
470         default:
471                 return -EINVAL;
472
473         case VD_OP_FLUSH:
474                 op_len = 0;
475                 map_perm = 0;
476                 break;
477
478         case VD_OP_GET_WCE:
479                 op_len = sizeof(u32);
480                 map_perm = LDC_MAP_W;
481                 break;
482
483         case VD_OP_SET_WCE:
484                 op_len = sizeof(u32);
485                 map_perm = LDC_MAP_R;
486                 break;
487
488         case VD_OP_GET_VTOC:
489                 op_len = sizeof(struct vio_disk_vtoc);
490                 map_perm = LDC_MAP_W;
491                 break;
492
493         case VD_OP_SET_VTOC:
494                 op_len = sizeof(struct vio_disk_vtoc);
495                 map_perm = LDC_MAP_R;
496                 break;
497
498         case VD_OP_GET_DISKGEOM:
499                 op_len = sizeof(struct vio_disk_geom);
500                 map_perm = LDC_MAP_W;
501                 break;
502
503         case VD_OP_SET_DISKGEOM:
504                 op_len = sizeof(struct vio_disk_geom);
505                 map_perm = LDC_MAP_R;
506                 break;
507
508         case VD_OP_SCSICMD:
509                 op_len = 16;
510                 map_perm = LDC_MAP_RW;
511                 break;
512
513         case VD_OP_GET_DEVID:
514                 op_len = sizeof(struct vio_disk_devid);
515                 map_perm = LDC_MAP_W;
516                 break;
517
518         case VD_OP_GET_EFI:
519         case VD_OP_SET_EFI:
520                 return -EOPNOTSUPP;
521                 break;
522         };
523
524         map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
525
526         op_len = (op_len + 7) & ~7;
527         req_buf = kzalloc(op_len, GFP_KERNEL);
528         if (!req_buf)
529                 return -ENOMEM;
530
531         if (len > op_len)
532                 len = op_len;
533
534         if (map_perm & LDC_MAP_R)
535                 memcpy(req_buf, buf, len);
536
537         spin_lock_irqsave(&port->vio.lock, flags);
538
539         dr = &port->vio.drings[VIO_DRIVER_TX_RING];
540
541         /* XXX If we want to use this code generically we have to
542          * XXX handle TX ring exhaustion etc.
543          */
544         desc = vio_dring_cur(dr);
545
546         err = ldc_map_single(port->vio.lp, req_buf, op_len,
547                              desc->cookies, port->ring_cookies,
548                              map_perm);
549         if (err < 0) {
550                 spin_unlock_irqrestore(&port->vio.lock, flags);
551                 kfree(req_buf);
552                 return err;
553         }
554
555         init_completion(&comp.com);
556         comp.waiting_for = WAITING_FOR_GEN_CMD;
557         port->vio.cmp = &comp;
558
559         desc->hdr.ack = VIO_ACK_ENABLE;
560         desc->req_id = port->req_id;
561         desc->operation = op;
562         desc->slice = 0;
563         desc->status = ~0;
564         desc->offset = 0;
565         desc->size = op_len;
566         desc->ncookies = err;
567
568         /* This has to be a non-SMP write barrier because we are writing
569          * to memory which is shared with the peer LDOM.
570          */
571         wmb();
572         desc->hdr.state = VIO_DESC_READY;
573
574         err = __vdc_tx_trigger(port);
575         if (err >= 0) {
576                 port->req_id++;
577                 dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
578                 spin_unlock_irqrestore(&port->vio.lock, flags);
579
580                 wait_for_completion(&comp.com);
581                 err = comp.err;
582         } else {
583                 port->vio.cmp = NULL;
584                 spin_unlock_irqrestore(&port->vio.lock, flags);
585         }
586
587         if (map_perm & LDC_MAP_W)
588                 memcpy(buf, req_buf, len);
589
590         kfree(req_buf);
591
592         return err;
593 }
594
595 static int __devinit vdc_alloc_tx_ring(struct vdc_port *port)
596 {
597         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
598         unsigned long len, entry_size;
599         int ncookies;
600         void *dring;
601
602         entry_size = sizeof(struct vio_disk_desc) +
603                 (sizeof(struct ldc_trans_cookie) * port->ring_cookies);
604         len = (VDC_TX_RING_SIZE * entry_size);
605
606         ncookies = VIO_MAX_RING_COOKIES;
607         dring = ldc_alloc_exp_dring(port->vio.lp, len,
608                                     dr->cookies, &ncookies,
609                                     (LDC_MAP_SHADOW |
610                                      LDC_MAP_DIRECT |
611                                      LDC_MAP_RW));
612         if (IS_ERR(dring))
613                 return PTR_ERR(dring);
614
615         dr->base = dring;
616         dr->entry_size = entry_size;
617         dr->num_entries = VDC_TX_RING_SIZE;
618         dr->prod = dr->cons = 0;
619         dr->pending = VDC_TX_RING_SIZE;
620         dr->ncookies = ncookies;
621
622         return 0;
623 }
624
625 static void vdc_free_tx_ring(struct vdc_port *port)
626 {
627         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
628
629         if (dr->base) {
630                 ldc_free_exp_dring(port->vio.lp, dr->base,
631                                    (dr->entry_size * dr->num_entries),
632                                    dr->cookies, dr->ncookies);
633                 dr->base = NULL;
634                 dr->entry_size = 0;
635                 dr->num_entries = 0;
636                 dr->pending = 0;
637                 dr->ncookies = 0;
638         }
639 }
640
641 static int probe_disk(struct vdc_port *port)
642 {
643         struct vio_completion comp;
644         struct request_queue *q;
645         struct gendisk *g;
646         int err;
647
648         init_completion(&comp.com);
649         comp.err = 0;
650         comp.waiting_for = WAITING_FOR_LINK_UP;
651         port->vio.cmp = &comp;
652
653         vio_port_up(&port->vio);
654
655         wait_for_completion(&comp.com);
656         if (comp.err)
657                 return comp.err;
658
659         err = generic_request(port, VD_OP_GET_VTOC,
660                               &port->label, sizeof(port->label));
661         if (err < 0) {
662                 printk(KERN_ERR PFX "VD_OP_GET_VTOC returns error %d\n", err);
663                 return err;
664         }
665
666         err = generic_request(port, VD_OP_GET_DISKGEOM,
667                               &port->geom, sizeof(port->geom));
668         if (err < 0) {
669                 printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
670                        "error %d\n", err);
671                 return err;
672         }
673
674         port->vdisk_size = ((u64)port->geom.num_cyl *
675                             (u64)port->geom.num_hd *
676                             (u64)port->geom.num_sec);
677
678         q = blk_init_queue(do_vdc_request, &port->vio.lock);
679         if (!q) {
680                 printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
681                        port->vio.name);
682                 return -ENOMEM;
683         }
684         g = alloc_disk(1 << PARTITION_SHIFT);
685         if (!g) {
686                 printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
687                        port->vio.name);
688                 blk_cleanup_queue(q);
689                 return -ENOMEM;
690         }
691
692         port->disk = g;
693
694         blk_queue_max_segments(q, port->ring_cookies);
695         blk_queue_max_hw_sectors(q, port->max_xfer_size);
696         g->major = vdc_major;
697         g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
698         strcpy(g->disk_name, port->disk_name);
699
700         g->fops = &vdc_fops;
701         g->queue = q;
702         g->private_data = port;
703         g->driverfs_dev = &port->vio.vdev->dev;
704
705         set_capacity(g, port->vdisk_size);
706
707         printk(KERN_INFO PFX "%s: %u sectors (%u MB)\n",
708                g->disk_name,
709                port->vdisk_size, (port->vdisk_size >> (20 - 9)));
710
711         add_disk(g);
712
713         return 0;
714 }
715
716 static struct ldc_channel_config vdc_ldc_cfg = {
717         .event          = vdc_event,
718         .mtu            = 64,
719         .mode           = LDC_MODE_UNRELIABLE,
720 };
721
722 static struct vio_driver_ops vdc_vio_ops = {
723         .send_attr              = vdc_send_attr,
724         .handle_attr            = vdc_handle_attr,
725         .handshake_complete     = vdc_handshake_complete,
726 };
727
728 static void __devinit print_version(void)
729 {
730         static int version_printed;
731
732         if (version_printed++ == 0)
733                 printk(KERN_INFO "%s", version);
734 }
735
736 static int __devinit vdc_port_probe(struct vio_dev *vdev,
737                                     const struct vio_device_id *id)
738 {
739         struct mdesc_handle *hp;
740         struct vdc_port *port;
741         int err;
742
743         print_version();
744
745         hp = mdesc_grab();
746
747         err = -ENODEV;
748         if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
749                 printk(KERN_ERR PFX "Port id [%llu] too large.\n",
750                        vdev->dev_no);
751                 goto err_out_release_mdesc;
752         }
753
754         port = kzalloc(sizeof(*port), GFP_KERNEL);
755         err = -ENOMEM;
756         if (!port) {
757                 printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
758                 goto err_out_release_mdesc;
759         }
760
761         if (vdev->dev_no >= 26)
762                 snprintf(port->disk_name, sizeof(port->disk_name),
763                          VDCBLK_NAME "%c%c",
764                          'a' + ((int)vdev->dev_no / 26) - 1,
765                          'a' + ((int)vdev->dev_no % 26));
766         else
767                 snprintf(port->disk_name, sizeof(port->disk_name),
768                          VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
769
770         err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
771                               vdc_versions, ARRAY_SIZE(vdc_versions),
772                               &vdc_vio_ops, port->disk_name);
773         if (err)
774                 goto err_out_free_port;
775
776         port->vdisk_block_size = 512;
777         port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size);
778         port->ring_cookies = ((port->max_xfer_size *
779                                port->vdisk_block_size) / PAGE_SIZE) + 2;
780
781         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
782         if (err)
783                 goto err_out_free_port;
784
785         err = vdc_alloc_tx_ring(port);
786         if (err)
787                 goto err_out_free_ldc;
788
789         err = probe_disk(port);
790         if (err)
791                 goto err_out_free_tx_ring;
792
793         dev_set_drvdata(&vdev->dev, port);
794
795         mdesc_release(hp);
796
797         return 0;
798
799 err_out_free_tx_ring:
800         vdc_free_tx_ring(port);
801
802 err_out_free_ldc:
803         vio_ldc_free(&port->vio);
804
805 err_out_free_port:
806         kfree(port);
807
808 err_out_release_mdesc:
809         mdesc_release(hp);
810         return err;
811 }
812
813 static int vdc_port_remove(struct vio_dev *vdev)
814 {
815         struct vdc_port *port = dev_get_drvdata(&vdev->dev);
816
817         if (port) {
818                 del_timer_sync(&port->vio.timer);
819
820                 vdc_free_tx_ring(port);
821                 vio_ldc_free(&port->vio);
822
823                 dev_set_drvdata(&vdev->dev, NULL);
824
825                 kfree(port);
826         }
827         return 0;
828 }
829
830 static const struct vio_device_id vdc_port_match[] = {
831         {
832                 .type = "vdc-port",
833         },
834         {},
835 };
836 MODULE_DEVICE_TABLE(vio, vdc_port_match);
837
838 static struct vio_driver vdc_port_driver = {
839         .id_table       = vdc_port_match,
840         .probe          = vdc_port_probe,
841         .remove         = vdc_port_remove,
842         .driver         = {
843                 .name   = "vdc_port",
844                 .owner  = THIS_MODULE,
845         }
846 };
847
848 static int __init vdc_init(void)
849 {
850         int err;
851
852         err = register_blkdev(0, VDCBLK_NAME);
853         if (err < 0)
854                 goto out_err;
855
856         vdc_major = err;
857
858         err = vio_register_driver(&vdc_port_driver);
859         if (err)
860                 goto out_unregister_blkdev;
861
862         return 0;
863
864 out_unregister_blkdev:
865         unregister_blkdev(vdc_major, VDCBLK_NAME);
866         vdc_major = 0;
867
868 out_err:
869         return err;
870 }
871
872 static void __exit vdc_exit(void)
873 {
874         vio_unregister_driver(&vdc_port_driver);
875         unregister_blkdev(vdc_major, VDCBLK_NAME);
876 }
877
878 module_init(vdc_init);
879 module_exit(vdc_exit);