More SG build fixes
[linux-2.6.git] / drivers / block / sunvdc.c
1 /* sunvdc.c: Sun LDOM Virtual Disk Client.
2  *
3  * Copyright (C) 2007 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 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[%lu]\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[%lx] disk_size[%lu] disk_type[%x] "
168                "xfer_mode[0x%x] blksz[%u] max_xfer[%lu]\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_request(struct request *req, int uptodate, int num_sectors)
216 {
217         if (end_that_request_first(req, uptodate, num_sectors))
218                 return;
219         add_disk_randomness(req->rq_disk);
220         end_that_request_last(req, uptodate);
221 }
222
223 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
224                         unsigned int index)
225 {
226         struct vio_disk_desc *desc = vio_dring_entry(dr, index);
227         struct vdc_req_entry *rqe = &port->rq_arr[index];
228         struct request *req;
229
230         if (unlikely(desc->hdr.state != VIO_DESC_DONE))
231                 return;
232
233         ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
234         desc->hdr.state = VIO_DESC_FREE;
235         dr->cons = (index + 1) & (VDC_TX_RING_SIZE - 1);
236
237         req = rqe->req;
238         if (req == NULL) {
239                 vdc_end_special(port, desc);
240                 return;
241         }
242
243         rqe->req = NULL;
244
245         vdc_end_request(req, !desc->status, desc->size >> 9);
246
247         if (blk_queue_stopped(port->disk->queue))
248                 blk_start_queue(port->disk->queue);
249 }
250
251 static int vdc_ack(struct vdc_port *port, void *msgbuf)
252 {
253         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
254         struct vio_dring_data *pkt = msgbuf;
255
256         if (unlikely(pkt->dring_ident != dr->ident ||
257                      pkt->start_idx != pkt->end_idx ||
258                      pkt->start_idx >= VDC_TX_RING_SIZE))
259                 return 0;
260
261         vdc_end_one(port, dr, pkt->start_idx);
262
263         return 0;
264 }
265
266 static int vdc_nack(struct vdc_port *port, void *msgbuf)
267 {
268         /* XXX Implement me XXX */
269         return 0;
270 }
271
272 static void vdc_event(void *arg, int event)
273 {
274         struct vdc_port *port = arg;
275         struct vio_driver_state *vio = &port->vio;
276         unsigned long flags;
277         int err;
278
279         spin_lock_irqsave(&vio->lock, flags);
280
281         if (unlikely(event == LDC_EVENT_RESET ||
282                      event == LDC_EVENT_UP)) {
283                 vio_link_state_change(vio, event);
284                 spin_unlock_irqrestore(&vio->lock, flags);
285                 return;
286         }
287
288         if (unlikely(event != LDC_EVENT_DATA_READY)) {
289                 printk(KERN_WARNING PFX "Unexpected LDC event %d\n", event);
290                 spin_unlock_irqrestore(&vio->lock, flags);
291                 return;
292         }
293
294         err = 0;
295         while (1) {
296                 union {
297                         struct vio_msg_tag tag;
298                         u64 raw[8];
299                 } msgbuf;
300
301                 err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
302                 if (unlikely(err < 0)) {
303                         if (err == -ECONNRESET)
304                                 vio_conn_reset(vio);
305                         break;
306                 }
307                 if (err == 0)
308                         break;
309                 viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
310                        msgbuf.tag.type,
311                        msgbuf.tag.stype,
312                        msgbuf.tag.stype_env,
313                        msgbuf.tag.sid);
314                 err = vio_validate_sid(vio, &msgbuf.tag);
315                 if (err < 0)
316                         break;
317
318                 if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
319                         if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
320                                 err = vdc_ack(port, &msgbuf);
321                         else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
322                                 err = vdc_nack(port, &msgbuf);
323                         else
324                                 err = vdc_handle_unknown(port, &msgbuf);
325                 } else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
326                         err = vio_control_pkt_engine(vio, &msgbuf);
327                 } else {
328                         err = vdc_handle_unknown(port, &msgbuf);
329                 }
330                 if (err < 0)
331                         break;
332         }
333         if (err < 0)
334                 vdc_finish(&port->vio, err, WAITING_FOR_ANY);
335         spin_unlock_irqrestore(&vio->lock, flags);
336 }
337
338 static int __vdc_tx_trigger(struct vdc_port *port)
339 {
340         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
341         struct vio_dring_data hdr = {
342                 .tag = {
343                         .type           = VIO_TYPE_DATA,
344                         .stype          = VIO_SUBTYPE_INFO,
345                         .stype_env      = VIO_DRING_DATA,
346                         .sid            = vio_send_sid(&port->vio),
347                 },
348                 .dring_ident            = dr->ident,
349                 .start_idx              = dr->prod,
350                 .end_idx                = dr->prod,
351         };
352         int err, delay;
353
354         hdr.seq = dr->snd_nxt;
355         delay = 1;
356         do {
357                 err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
358                 if (err > 0) {
359                         dr->snd_nxt++;
360                         break;
361                 }
362                 udelay(delay);
363                 if ((delay <<= 1) > 128)
364                         delay = 128;
365         } while (err == -EAGAIN);
366
367         return err;
368 }
369
370 static int __send_request(struct request *req)
371 {
372         struct vdc_port *port = req->rq_disk->private_data;
373         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
374         struct scatterlist sg[port->ring_cookies];
375         struct vdc_req_entry *rqe;
376         struct vio_disk_desc *desc;
377         unsigned int map_perm;
378         int nsg, err, i;
379         u64 len;
380         u8 op;
381
382         map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
383
384         if (rq_data_dir(req) == READ) {
385                 map_perm |= LDC_MAP_W;
386                 op = VD_OP_BREAD;
387         } else {
388                 map_perm |= LDC_MAP_R;
389                 op = VD_OP_BWRITE;
390         }
391
392         sg_init_table(sg, port->ring_cookies);
393         nsg = blk_rq_map_sg(req->q, req, sg);
394
395         len = 0;
396         for (i = 0; i < nsg; i++)
397                 len += sg[i].length;
398
399         if (unlikely(vdc_tx_dring_avail(dr) < 1)) {
400                 blk_stop_queue(port->disk->queue);
401                 err = -ENOMEM;
402                 goto out;
403         }
404
405         desc = vio_dring_cur(dr);
406
407         err = ldc_map_sg(port->vio.lp, sg, nsg,
408                          desc->cookies, port->ring_cookies,
409                          map_perm);
410         if (err < 0) {
411                 printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
412                 return err;
413         }
414
415         rqe = &port->rq_arr[dr->prod];
416         rqe->req = req;
417
418         desc->hdr.ack = VIO_ACK_ENABLE;
419         desc->req_id = port->req_id;
420         desc->operation = op;
421         if (port->vdisk_type == VD_DISK_TYPE_DISK) {
422                 desc->slice = 0xff;
423         } else {
424                 desc->slice = 0;
425         }
426         desc->status = ~0;
427         desc->offset = (req->sector << 9) / port->vdisk_block_size;
428         desc->size = len;
429         desc->ncookies = err;
430
431         /* This has to be a non-SMP write barrier because we are writing
432          * to memory which is shared with the peer LDOM.
433          */
434         wmb();
435         desc->hdr.state = VIO_DESC_READY;
436
437         err = __vdc_tx_trigger(port);
438         if (err < 0) {
439                 printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
440         } else {
441                 port->req_id++;
442                 dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
443         }
444 out:
445
446         return err;
447 }
448
449 static void do_vdc_request(struct request_queue *q)
450 {
451         while (1) {
452                 struct request *req = elv_next_request(q);
453
454                 if (!req)
455                         break;
456
457                 blkdev_dequeue_request(req);
458                 if (__send_request(req) < 0)
459                         vdc_end_request(req, 0, req->hard_nr_sectors);
460         }
461 }
462
463 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
464 {
465         struct vio_dring_state *dr;
466         struct vio_completion comp;
467         struct vio_disk_desc *desc;
468         unsigned int map_perm;
469         unsigned long flags;
470         int op_len, err;
471         void *req_buf;
472
473         if (!(((u64)1 << ((u64)op - 1)) & port->operations))
474                 return -EOPNOTSUPP;
475
476         switch (op) {
477         case VD_OP_BREAD:
478         case VD_OP_BWRITE:
479         default:
480                 return -EINVAL;
481
482         case VD_OP_FLUSH:
483                 op_len = 0;
484                 map_perm = 0;
485                 break;
486
487         case VD_OP_GET_WCE:
488                 op_len = sizeof(u32);
489                 map_perm = LDC_MAP_W;
490                 break;
491
492         case VD_OP_SET_WCE:
493                 op_len = sizeof(u32);
494                 map_perm = LDC_MAP_R;
495                 break;
496
497         case VD_OP_GET_VTOC:
498                 op_len = sizeof(struct vio_disk_vtoc);
499                 map_perm = LDC_MAP_W;
500                 break;
501
502         case VD_OP_SET_VTOC:
503                 op_len = sizeof(struct vio_disk_vtoc);
504                 map_perm = LDC_MAP_R;
505                 break;
506
507         case VD_OP_GET_DISKGEOM:
508                 op_len = sizeof(struct vio_disk_geom);
509                 map_perm = LDC_MAP_W;
510                 break;
511
512         case VD_OP_SET_DISKGEOM:
513                 op_len = sizeof(struct vio_disk_geom);
514                 map_perm = LDC_MAP_R;
515                 break;
516
517         case VD_OP_SCSICMD:
518                 op_len = 16;
519                 map_perm = LDC_MAP_RW;
520                 break;
521
522         case VD_OP_GET_DEVID:
523                 op_len = sizeof(struct vio_disk_devid);
524                 map_perm = LDC_MAP_W;
525                 break;
526
527         case VD_OP_GET_EFI:
528         case VD_OP_SET_EFI:
529                 return -EOPNOTSUPP;
530                 break;
531         };
532
533         map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
534
535         op_len = (op_len + 7) & ~7;
536         req_buf = kzalloc(op_len, GFP_KERNEL);
537         if (!req_buf)
538                 return -ENOMEM;
539
540         if (len > op_len)
541                 len = op_len;
542
543         if (map_perm & LDC_MAP_R)
544                 memcpy(req_buf, buf, len);
545
546         spin_lock_irqsave(&port->vio.lock, flags);
547
548         dr = &port->vio.drings[VIO_DRIVER_TX_RING];
549
550         /* XXX If we want to use this code generically we have to
551          * XXX handle TX ring exhaustion etc.
552          */
553         desc = vio_dring_cur(dr);
554
555         err = ldc_map_single(port->vio.lp, req_buf, op_len,
556                              desc->cookies, port->ring_cookies,
557                              map_perm);
558         if (err < 0) {
559                 spin_unlock_irqrestore(&port->vio.lock, flags);
560                 kfree(req_buf);
561                 return err;
562         }
563
564         init_completion(&comp.com);
565         comp.waiting_for = WAITING_FOR_GEN_CMD;
566         port->vio.cmp = &comp;
567
568         desc->hdr.ack = VIO_ACK_ENABLE;
569         desc->req_id = port->req_id;
570         desc->operation = op;
571         desc->slice = 0;
572         desc->status = ~0;
573         desc->offset = 0;
574         desc->size = op_len;
575         desc->ncookies = err;
576
577         /* This has to be a non-SMP write barrier because we are writing
578          * to memory which is shared with the peer LDOM.
579          */
580         wmb();
581         desc->hdr.state = VIO_DESC_READY;
582
583         err = __vdc_tx_trigger(port);
584         if (err >= 0) {
585                 port->req_id++;
586                 dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
587                 spin_unlock_irqrestore(&port->vio.lock, flags);
588
589                 wait_for_completion(&comp.com);
590                 err = comp.err;
591         } else {
592                 port->vio.cmp = NULL;
593                 spin_unlock_irqrestore(&port->vio.lock, flags);
594         }
595
596         if (map_perm & LDC_MAP_W)
597                 memcpy(buf, req_buf, len);
598
599         kfree(req_buf);
600
601         return err;
602 }
603
604 static int __devinit vdc_alloc_tx_ring(struct vdc_port *port)
605 {
606         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
607         unsigned long len, entry_size;
608         int ncookies;
609         void *dring;
610
611         entry_size = sizeof(struct vio_disk_desc) +
612                 (sizeof(struct ldc_trans_cookie) * port->ring_cookies);
613         len = (VDC_TX_RING_SIZE * entry_size);
614
615         ncookies = VIO_MAX_RING_COOKIES;
616         dring = ldc_alloc_exp_dring(port->vio.lp, len,
617                                     dr->cookies, &ncookies,
618                                     (LDC_MAP_SHADOW |
619                                      LDC_MAP_DIRECT |
620                                      LDC_MAP_RW));
621         if (IS_ERR(dring))
622                 return PTR_ERR(dring);
623
624         dr->base = dring;
625         dr->entry_size = entry_size;
626         dr->num_entries = VDC_TX_RING_SIZE;
627         dr->prod = dr->cons = 0;
628         dr->pending = VDC_TX_RING_SIZE;
629         dr->ncookies = ncookies;
630
631         return 0;
632 }
633
634 static void vdc_free_tx_ring(struct vdc_port *port)
635 {
636         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
637
638         if (dr->base) {
639                 ldc_free_exp_dring(port->vio.lp, dr->base,
640                                    (dr->entry_size * dr->num_entries),
641                                    dr->cookies, dr->ncookies);
642                 dr->base = NULL;
643                 dr->entry_size = 0;
644                 dr->num_entries = 0;
645                 dr->pending = 0;
646                 dr->ncookies = 0;
647         }
648 }
649
650 static int probe_disk(struct vdc_port *port)
651 {
652         struct vio_completion comp;
653         struct request_queue *q;
654         struct gendisk *g;
655         int err;
656
657         init_completion(&comp.com);
658         comp.err = 0;
659         comp.waiting_for = WAITING_FOR_LINK_UP;
660         port->vio.cmp = &comp;
661
662         vio_port_up(&port->vio);
663
664         wait_for_completion(&comp.com);
665         if (comp.err)
666                 return comp.err;
667
668         err = generic_request(port, VD_OP_GET_VTOC,
669                               &port->label, sizeof(port->label));
670         if (err < 0) {
671                 printk(KERN_ERR PFX "VD_OP_GET_VTOC returns error %d\n", err);
672                 return err;
673         }
674
675         err = generic_request(port, VD_OP_GET_DISKGEOM,
676                               &port->geom, sizeof(port->geom));
677         if (err < 0) {
678                 printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
679                        "error %d\n", err);
680                 return err;
681         }
682
683         port->vdisk_size = ((u64)port->geom.num_cyl *
684                             (u64)port->geom.num_hd *
685                             (u64)port->geom.num_sec);
686
687         q = blk_init_queue(do_vdc_request, &port->vio.lock);
688         if (!q) {
689                 printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
690                        port->vio.name);
691                 return -ENOMEM;
692         }
693         g = alloc_disk(1 << PARTITION_SHIFT);
694         if (!g) {
695                 printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
696                        port->vio.name);
697                 blk_cleanup_queue(q);
698                 return -ENOMEM;
699         }
700
701         port->disk = g;
702
703         blk_queue_max_hw_segments(q, port->ring_cookies);
704         blk_queue_max_phys_segments(q, port->ring_cookies);
705         blk_queue_max_sectors(q, port->max_xfer_size);
706         g->major = vdc_major;
707         g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
708         strcpy(g->disk_name, port->disk_name);
709
710         g->fops = &vdc_fops;
711         g->queue = q;
712         g->private_data = port;
713         g->driverfs_dev = &port->vio.vdev->dev;
714
715         set_capacity(g, port->vdisk_size);
716
717         printk(KERN_INFO PFX "%s: %u sectors (%u MB)\n",
718                g->disk_name,
719                port->vdisk_size, (port->vdisk_size >> (20 - 9)));
720
721         add_disk(g);
722
723         return 0;
724 }
725
726 static struct ldc_channel_config vdc_ldc_cfg = {
727         .event          = vdc_event,
728         .mtu            = 64,
729         .mode           = LDC_MODE_UNRELIABLE,
730 };
731
732 static struct vio_driver_ops vdc_vio_ops = {
733         .send_attr              = vdc_send_attr,
734         .handle_attr            = vdc_handle_attr,
735         .handshake_complete     = vdc_handshake_complete,
736 };
737
738 static void print_version(void)
739 {
740         static int version_printed;
741
742         if (version_printed++ == 0)
743                 printk(KERN_INFO "%s", version);
744 }
745
746 static int __devinit vdc_port_probe(struct vio_dev *vdev,
747                                     const struct vio_device_id *id)
748 {
749         struct mdesc_handle *hp;
750         struct vdc_port *port;
751         int err;
752
753         print_version();
754
755         hp = mdesc_grab();
756
757         err = -ENODEV;
758         if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
759                 printk(KERN_ERR PFX "Port id [%lu] too large.\n",
760                        vdev->dev_no);
761                 goto err_out_release_mdesc;
762         }
763
764         port = kzalloc(sizeof(*port), GFP_KERNEL);
765         err = -ENOMEM;
766         if (!port) {
767                 printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
768                 goto err_out_release_mdesc;
769         }
770
771         if (vdev->dev_no >= 26)
772                 snprintf(port->disk_name, sizeof(port->disk_name),
773                          VDCBLK_NAME "%c%c",
774                          'a' + ((int)vdev->dev_no / 26) - 1,
775                          'a' + ((int)vdev->dev_no % 26));
776         else
777                 snprintf(port->disk_name, sizeof(port->disk_name),
778                          VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
779
780         err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
781                               vdc_versions, ARRAY_SIZE(vdc_versions),
782                               &vdc_vio_ops, port->disk_name);
783         if (err)
784                 goto err_out_free_port;
785
786         port->vdisk_block_size = 512;
787         port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size);
788         port->ring_cookies = ((port->max_xfer_size *
789                                port->vdisk_block_size) / PAGE_SIZE) + 2;
790
791         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
792         if (err)
793                 goto err_out_free_port;
794
795         err = vdc_alloc_tx_ring(port);
796         if (err)
797                 goto err_out_free_ldc;
798
799         err = probe_disk(port);
800         if (err)
801                 goto err_out_free_tx_ring;
802
803         dev_set_drvdata(&vdev->dev, port);
804
805         mdesc_release(hp);
806
807         return 0;
808
809 err_out_free_tx_ring:
810         vdc_free_tx_ring(port);
811
812 err_out_free_ldc:
813         vio_ldc_free(&port->vio);
814
815 err_out_free_port:
816         kfree(port);
817
818 err_out_release_mdesc:
819         mdesc_release(hp);
820         return err;
821 }
822
823 static int vdc_port_remove(struct vio_dev *vdev)
824 {
825         struct vdc_port *port = dev_get_drvdata(&vdev->dev);
826
827         if (port) {
828                 del_timer_sync(&port->vio.timer);
829
830                 vdc_free_tx_ring(port);
831                 vio_ldc_free(&port->vio);
832
833                 dev_set_drvdata(&vdev->dev, NULL);
834
835                 kfree(port);
836         }
837         return 0;
838 }
839
840 static struct vio_device_id vdc_port_match[] = {
841         {
842                 .type = "vdc-port",
843         },
844         {},
845 };
846 MODULE_DEVICE_TABLE(vio, vdc_port_match);
847
848 static struct vio_driver vdc_port_driver = {
849         .id_table       = vdc_port_match,
850         .probe          = vdc_port_probe,
851         .remove         = vdc_port_remove,
852         .driver         = {
853                 .name   = "vdc_port",
854                 .owner  = THIS_MODULE,
855         }
856 };
857
858 static int __init vdc_init(void)
859 {
860         int err;
861
862         err = register_blkdev(0, VDCBLK_NAME);
863         if (err < 0)
864                 goto out_err;
865
866         vdc_major = err;
867
868         err = vio_register_driver(&vdc_port_driver);
869         if (err)
870                 goto out_unregister_blkdev;
871
872         return 0;
873
874 out_unregister_blkdev:
875         unregister_blkdev(vdc_major, VDCBLK_NAME);
876         vdc_major = 0;
877
878 out_err:
879         return err;
880 }
881
882 static void __exit vdc_exit(void)
883 {
884         vio_unregister_driver(&vdc_port_driver);
885         unregister_blkdev(vdc_major, VDCBLK_NAME);
886 }
887
888 module_init(vdc_init);
889 module_exit(vdc_exit);