xref: /linux/drivers/block/sunvdc.c (revision 6b2d2cec1081a979e0efd6a1e9559e5a01a3c10e)
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);
890