xref: /openbmc/linux/drivers/block/sunvdc.c (revision c21b37f6)
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 
19 #include <asm/vio.h>
20 #include <asm/ldc.h>
21 
22 #define DRV_MODULE_NAME		"sunvdc"
23 #define PFX DRV_MODULE_NAME	": "
24 #define DRV_MODULE_VERSION	"1.0"
25 #define DRV_MODULE_RELDATE	"June 25, 2007"
26 
27 static char version[] __devinitdata =
28 	DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
29 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
30 MODULE_DESCRIPTION("Sun LDOM virtual disk client driver");
31 MODULE_LICENSE("GPL");
32 MODULE_VERSION(DRV_MODULE_VERSION);
33 
34 #define VDC_TX_RING_SIZE	256
35 
36 #define WAITING_FOR_LINK_UP	0x01
37 #define WAITING_FOR_TX_SPACE	0x02
38 #define WAITING_FOR_GEN_CMD	0x04
39 #define WAITING_FOR_ANY		-1
40 
41 struct vdc_req_entry {
42 	struct request		*req;
43 };
44 
45 struct vdc_port {
46 	struct vio_driver_state	vio;
47 
48 	struct gendisk		*disk;
49 
50 	struct vdc_completion	*cmp;
51 
52 	u64			req_id;
53 	u64			seq;
54 	struct vdc_req_entry	rq_arr[VDC_TX_RING_SIZE];
55 
56 	unsigned long		ring_cookies;
57 
58 	u64			max_xfer_size;
59 	u32			vdisk_block_size;
60 
61 	/* The server fills these in for us in the disk attribute
62 	 * ACK packet.
63 	 */
64 	u64			operations;
65 	u32			vdisk_size;
66 	u8			vdisk_type;
67 
68 	char			disk_name[32];
69 
70 	struct vio_disk_geom	geom;
71 	struct vio_disk_vtoc	label;
72 };
73 
74 static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
75 {
76 	return container_of(vio, struct vdc_port, vio);
77 }
78 
79 /* Ordered from largest major to lowest */
80 static struct vio_version vdc_versions[] = {
81 	{ .major = 1, .minor = 0 },
82 };
83 
84 #define VDCBLK_NAME	"vdisk"
85 static int vdc_major;
86 #define PARTITION_SHIFT	3
87 
88 static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
89 {
90 	return vio_dring_avail(dr, VDC_TX_RING_SIZE);
91 }
92 
93 static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
94 {
95 	struct gendisk *disk = bdev->bd_disk;
96 	struct vdc_port *port = disk->private_data;
97 
98 	geo->heads = (u8) port->geom.num_hd;
99 	geo->sectors = (u8) port->geom.num_sec;
100 	geo->cylinders = port->geom.num_cyl;
101 
102 	return 0;
103 }
104 
105 static struct block_device_operations vdc_fops = {
106 	.owner		= THIS_MODULE,
107 	.getgeo		= vdc_getgeo,
108 };
109 
110 static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
111 {
112 	if (vio->cmp &&
113 	    (waiting_for == -1 ||
114 	     vio->cmp->waiting_for == waiting_for)) {
115 		vio->cmp->err = err;
116 		complete(&vio->cmp->com);
117 		vio->cmp = NULL;
118 	}
119 }
120 
121 static void vdc_handshake_complete(struct vio_driver_state *vio)
122 {
123 	vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
124 }
125 
126 static int vdc_handle_unknown(struct vdc_port *port, void *arg)
127 {
128 	struct vio_msg_tag *pkt = arg;
129 
130 	printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
131 	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
132 	printk(KERN_ERR PFX "Resetting connection.\n");
133 
134 	ldc_disconnect(port->vio.lp);
135 
136 	return -ECONNRESET;
137 }
138 
139 static int vdc_send_attr(struct vio_driver_state *vio)
140 {
141 	struct vdc_port *port = to_vdc_port(vio);
142 	struct vio_disk_attr_info pkt;
143 
144 	memset(&pkt, 0, sizeof(pkt));
145 
146 	pkt.tag.type = VIO_TYPE_CTRL;
147 	pkt.tag.stype = VIO_SUBTYPE_INFO;
148 	pkt.tag.stype_env = VIO_ATTR_INFO;
149 	pkt.tag.sid = vio_send_sid(vio);
150 
151 	pkt.xfer_mode = VIO_DRING_MODE;
152 	pkt.vdisk_block_size = port->vdisk_block_size;
153 	pkt.max_xfer_size = port->max_xfer_size;
154 
155 	viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%lu]\n",
156 	       pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);
157 
158 	return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
159 }
160 
161 static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
162 {
163 	struct vdc_port *port = to_vdc_port(vio);
164 	struct vio_disk_attr_info *pkt = arg;
165 
166 	viodbg(HS, "GOT ATTR stype[0x%x] ops[%lx] disk_size[%lu] disk_type[%x] "
167 	       "xfer_mode[0x%x] blksz[%u] max_xfer[%lu]\n",
168 	       pkt->tag.stype, pkt->operations,
169 	       pkt->vdisk_size, pkt->vdisk_type,
170 	       pkt->xfer_mode, pkt->vdisk_block_size,
171 	       pkt->max_xfer_size);
172 
173 	if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
174 		switch (pkt->vdisk_type) {
175 		case VD_DISK_TYPE_DISK:
176 		case VD_DISK_TYPE_SLICE:
177 			break;
178 
179 		default:
180 			printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n",
181 			       vio->name, pkt->vdisk_type);
182 			return -ECONNRESET;
183 		}
184 
185 		if (pkt->vdisk_block_size > port->vdisk_block_size) {
186 			printk(KERN_ERR PFX "%s: BLOCK size increased "
187 			       "%u --> %u\n",
188 			       vio->name,
189 			       port->vdisk_block_size, pkt->vdisk_block_size);
190 			return -ECONNRESET;
191 		}
192 
193 		port->operations = pkt->operations;
194 		port->vdisk_size = pkt->vdisk_size;
195 		port->vdisk_type = pkt->vdisk_type;
196 		if (pkt->max_xfer_size < port->max_xfer_size)
197 			port->max_xfer_size = pkt->max_xfer_size;
198 		port->vdisk_block_size = pkt->vdisk_block_size;
199 		return 0;
200 	} else {
201 		printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name);
202 
203 		return -ECONNRESET;
204 	}
205 }
206 
207 static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc)
208 {
209 	int err = desc->status;
210 
211 	vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
212 }
213 
214 static void vdc_end_request(struct request *req, int uptodate, int num_sectors)
215 {
216 	if (end_that_request_first(req, uptodate, num_sectors))
217 		return;
218 	add_disk_randomness(req->rq_disk);
219 	end_that_request_last(req, uptodate);
220 }
221 
222 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
223 			unsigned int index)
224 {
225 	struct vio_disk_desc *desc = vio_dring_entry(dr, index);
226 	struct vdc_req_entry *rqe = &port->rq_arr[index];
227 	struct request *req;
228 
229 	if (unlikely(desc->hdr.state != VIO_DESC_DONE))
230 		return;
231 
232 	ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
233 	desc->hdr.state = VIO_DESC_FREE;
234 	dr->cons = (index + 1) & (VDC_TX_RING_SIZE - 1);
235 
236 	req = rqe->req;
237 	if (req == NULL) {
238 		vdc_end_special(port, desc);
239 		return;
240 	}
241 
242 	rqe->req = NULL;
243 
244 	vdc_end_request(req, !desc->status, desc->size >> 9);
245 
246 	if (blk_queue_stopped(port->disk->queue))
247 		blk_start_queue(port->disk->queue);
248 }
249 
250 static int vdc_ack(struct vdc_port *port, void *msgbuf)
251 {
252 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
253 	struct vio_dring_data *pkt = msgbuf;
254 
255 	if (unlikely(pkt->dring_ident != dr->ident ||
256 		     pkt->start_idx != pkt->end_idx ||
257 		     pkt->start_idx >= VDC_TX_RING_SIZE))
258 		return 0;
259 
260 	vdc_end_one(port, dr, pkt->start_idx);
261 
262 	return 0;
263 }
264 
265 static int vdc_nack(struct vdc_port *port, void *msgbuf)
266 {
267 	/* XXX Implement me XXX */
268 	return 0;
269 }
270 
271 static void vdc_event(void *arg, int event)
272 {
273 	struct vdc_port *port = arg;
274 	struct vio_driver_state *vio = &port->vio;
275 	unsigned long flags;
276 	int err;
277 
278 	spin_lock_irqsave(&vio->lock, flags);
279 
280 	if (unlikely(event == LDC_EVENT_RESET ||
281 		     event == LDC_EVENT_UP)) {
282 		vio_link_state_change(vio, event);
283 		spin_unlock_irqrestore(&vio->lock, flags);
284 		return;
285 	}
286 
287 	if (unlikely(event != LDC_EVENT_DATA_READY)) {
288 		printk(KERN_WARNING PFX "Unexpected LDC event %d\n", event);
289 		spin_unlock_irqrestore(&vio->lock, flags);
290 		return;
291 	}
292 
293 	err = 0;
294 	while (1) {
295 		union {
296 			struct vio_msg_tag tag;
297 			u64 raw[8];
298 		} msgbuf;
299 
300 		err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
301 		if (unlikely(err < 0)) {
302 			if (err == -ECONNRESET)
303 				vio_conn_reset(vio);
304 			break;
305 		}
306 		if (err == 0)
307 			break;
308 		viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
309 		       msgbuf.tag.type,
310 		       msgbuf.tag.stype,
311 		       msgbuf.tag.stype_env,
312 		       msgbuf.tag.sid);
313 		err = vio_validate_sid(vio, &msgbuf.tag);
314 		if (err < 0)
315 			break;
316 
317 		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
318 			if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
319 				err = vdc_ack(port, &msgbuf);
320 			else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
321 				err = vdc_nack(port, &msgbuf);
322 			else
323 				err = vdc_handle_unknown(port, &msgbuf);
324 		} else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
325 			err = vio_control_pkt_engine(vio, &msgbuf);
326 		} else {
327 			err = vdc_handle_unknown(port, &msgbuf);
328 		}
329 		if (err < 0)
330 			break;
331 	}
332 	if (err < 0)
333 		vdc_finish(&port->vio, err, WAITING_FOR_ANY);
334 	spin_unlock_irqrestore(&vio->lock, flags);
335 }
336 
337 static int __vdc_tx_trigger(struct vdc_port *port)
338 {
339 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
340 	struct vio_dring_data hdr = {
341 		.tag = {
342 			.type		= VIO_TYPE_DATA,
343 			.stype		= VIO_SUBTYPE_INFO,
344 			.stype_env	= VIO_DRING_DATA,
345 			.sid		= vio_send_sid(&port->vio),
346 		},
347 		.dring_ident		= dr->ident,
348 		.start_idx		= dr->prod,
349 		.end_idx		= dr->prod,
350 	};
351 	int err, delay;
352 
353 	hdr.seq = dr->snd_nxt;
354 	delay = 1;
355 	do {
356 		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
357 		if (err > 0) {
358 			dr->snd_nxt++;
359 			break;
360 		}
361 		udelay(delay);
362 		if ((delay <<= 1) > 128)
363 			delay = 128;
364 	} while (err == -EAGAIN);
365 
366 	return err;
367 }
368 
369 static int __send_request(struct request *req)
370 {
371 	struct vdc_port *port = req->rq_disk->private_data;
372 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
373 	struct scatterlist sg[port->ring_cookies];
374 	struct vdc_req_entry *rqe;
375 	struct vio_disk_desc *desc;
376 	unsigned int map_perm;
377 	int nsg, err, i;
378 	u64 len;
379 	u8 op;
380 
381 	map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
382 
383 	if (rq_data_dir(req) == READ) {
384 		map_perm |= LDC_MAP_W;
385 		op = VD_OP_BREAD;
386 	} else {
387 		map_perm |= LDC_MAP_R;
388 		op = VD_OP_BWRITE;
389 	}
390 
391 	nsg = blk_rq_map_sg(req->q, req, sg);
392 
393 	len = 0;
394 	for (i = 0; i < nsg; i++)
395 		len += sg[i].length;
396 
397 	if (unlikely(vdc_tx_dring_avail(dr) < 1)) {
398 		blk_stop_queue(port->disk->queue);
399 		err = -ENOMEM;
400 		goto out;
401 	}
402 
403 	desc = vio_dring_cur(dr);
404 
405 	err = ldc_map_sg(port->vio.lp, sg, nsg,
406 			 desc->cookies, port->ring_cookies,
407 			 map_perm);
408 	if (err < 0) {
409 		printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
410 		return err;
411 	}
412 
413 	rqe = &port->rq_arr[dr->prod];
414 	rqe->req = req;
415 
416 	desc->hdr.ack = VIO_ACK_ENABLE;
417 	desc->req_id = port->req_id;
418 	desc->operation = op;
419 	if (port->vdisk_type == VD_DISK_TYPE_DISK) {
420 		desc->slice = 2;
421 	} else {
422 		desc->slice = 0;
423 	}
424 	desc->status = ~0;
425 	desc->offset = (req->sector << 9) / port->vdisk_block_size;
426 	desc->size = len;
427 	desc->ncookies = err;
428 
429 	/* This has to be a non-SMP write barrier because we are writing
430 	 * to memory which is shared with the peer LDOM.
431 	 */
432 	wmb();
433 	desc->hdr.state = VIO_DESC_READY;
434 
435 	err = __vdc_tx_trigger(port);
436 	if (err < 0) {
437 		printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
438 	} else {
439 		port->req_id++;
440 		dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
441 	}
442 out:
443 
444 	return err;
445 }
446 
447 static void do_vdc_request(struct request_queue *q)
448 {
449 	while (1) {
450 		struct request *req = elv_next_request(q);
451 
452 		if (!req)
453 			break;
454 
455 		blkdev_dequeue_request(req);
456 		if (__send_request(req) < 0)
457 			vdc_end_request(req, 0, req->hard_nr_sectors);
458 	}
459 }
460 
461 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
462 {
463 	struct vio_dring_state *dr;
464 	struct vio_completion comp;
465 	struct vio_disk_desc *desc;
466 	unsigned int map_perm;
467 	unsigned long flags;
468 	int op_len, err;
469 	void *req_buf;
470 
471 	if (!(((u64)1 << ((u64)op - 1)) & port->operations))
472 		return -EOPNOTSUPP;
473 
474 	switch (op) {
475 	case VD_OP_BREAD:
476 	case VD_OP_BWRITE:
477 	default:
478 		return -EINVAL;
479 
480 	case VD_OP_FLUSH:
481 		op_len = 0;
482 		map_perm = 0;
483 		break;
484 
485 	case VD_OP_GET_WCE:
486 		op_len = sizeof(u32);
487 		map_perm = LDC_MAP_W;
488 		break;
489 
490 	case VD_OP_SET_WCE:
491 		op_len = sizeof(u32);
492 		map_perm = LDC_MAP_R;
493 		break;
494 
495 	case VD_OP_GET_VTOC:
496 		op_len = sizeof(struct vio_disk_vtoc);
497 		map_perm = LDC_MAP_W;
498 		break;
499 
500 	case VD_OP_SET_VTOC:
501 		op_len = sizeof(struct vio_disk_vtoc);
502 		map_perm = LDC_MAP_R;
503 		break;
504 
505 	case VD_OP_GET_DISKGEOM:
506 		op_len = sizeof(struct vio_disk_geom);
507 		map_perm = LDC_MAP_W;
508 		break;
509 
510 	case VD_OP_SET_DISKGEOM:
511 		op_len = sizeof(struct vio_disk_geom);
512 		map_perm = LDC_MAP_R;
513 		break;
514 
515 	case VD_OP_SCSICMD:
516 		op_len = 16;
517 		map_perm = LDC_MAP_RW;
518 		break;
519 
520 	case VD_OP_GET_DEVID:
521 		op_len = sizeof(struct vio_disk_devid);
522 		map_perm = LDC_MAP_W;
523 		break;
524 
525 	case VD_OP_GET_EFI:
526 	case VD_OP_SET_EFI:
527 		return -EOPNOTSUPP;
528 		break;
529 	};
530 
531 	map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
532 
533 	op_len = (op_len + 7) & ~7;
534 	req_buf = kzalloc(op_len, GFP_KERNEL);
535 	if (!req_buf)
536 		return -ENOMEM;
537 
538 	if (len > op_len)
539 		len = op_len;
540 
541 	if (map_perm & LDC_MAP_R)
542 		memcpy(req_buf, buf, len);
543 
544 	spin_lock_irqsave(&port->vio.lock, flags);
545 
546 	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
547 
548 	/* XXX If we want to use this code generically we have to
549 	 * XXX handle TX ring exhaustion etc.
550 	 */
551 	desc = vio_dring_cur(dr);
552 
553 	err = ldc_map_single(port->vio.lp, req_buf, op_len,
554 			     desc->cookies, port->ring_cookies,
555 			     map_perm);
556 	if (err < 0) {
557 		spin_unlock_irqrestore(&port->vio.lock, flags);
558 		kfree(req_buf);
559 		return err;
560 	}
561 
562 	init_completion(&comp.com);
563 	comp.waiting_for = WAITING_FOR_GEN_CMD;
564 	port->vio.cmp = &comp;
565 
566 	desc->hdr.ack = VIO_ACK_ENABLE;
567 	desc->req_id = port->req_id;
568 	desc->operation = op;
569 	desc->slice = 0;
570 	desc->status = ~0;
571 	desc->offset = 0;
572 	desc->size = op_len;
573 	desc->ncookies = err;
574 
575 	/* This has to be a non-SMP write barrier because we are writing
576 	 * to memory which is shared with the peer LDOM.
577 	 */
578 	wmb();
579 	desc->hdr.state = VIO_DESC_READY;
580 
581 	err = __vdc_tx_trigger(port);
582 	if (err >= 0) {
583 		port->req_id++;
584 		dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
585 		spin_unlock_irqrestore(&port->vio.lock, flags);
586 
587 		wait_for_completion(&comp.com);
588 		err = comp.err;
589 	} else {
590 		port->vio.cmp = NULL;
591 		spin_unlock_irqrestore(&port->vio.lock, flags);
592 	}
593 
594 	if (map_perm & LDC_MAP_W)
595 		memcpy(buf, req_buf, len);
596 
597 	kfree(req_buf);
598 
599 	return err;
600 }
601 
602 static int __devinit vdc_alloc_tx_ring(struct vdc_port *port)
603 {
604 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
605 	unsigned long len, entry_size;
606 	int ncookies;
607 	void *dring;
608 
609 	entry_size = sizeof(struct vio_disk_desc) +
610 		(sizeof(struct ldc_trans_cookie) * port->ring_cookies);
611 	len = (VDC_TX_RING_SIZE * entry_size);
612 
613 	ncookies = VIO_MAX_RING_COOKIES;
614 	dring = ldc_alloc_exp_dring(port->vio.lp, len,
615 				    dr->cookies, &ncookies,
616 				    (LDC_MAP_SHADOW |
617 				     LDC_MAP_DIRECT |
618 				     LDC_MAP_RW));
619 	if (IS_ERR(dring))
620 		return PTR_ERR(dring);
621 
622 	dr->base = dring;
623 	dr->entry_size = entry_size;
624 	dr->num_entries = VDC_TX_RING_SIZE;
625 	dr->prod = dr->cons = 0;
626 	dr->pending = VDC_TX_RING_SIZE;
627 	dr->ncookies = ncookies;
628 
629 	return 0;
630 }
631 
632 static void vdc_free_tx_ring(struct vdc_port *port)
633 {
634 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
635 
636 	if (dr->base) {
637 		ldc_free_exp_dring(port->vio.lp, dr->base,
638 				   (dr->entry_size * dr->num_entries),
639 				   dr->cookies, dr->ncookies);
640 		dr->base = NULL;
641 		dr->entry_size = 0;
642 		dr->num_entries = 0;
643 		dr->pending = 0;
644 		dr->ncookies = 0;
645 	}
646 }
647 
648 static int probe_disk(struct vdc_port *port)
649 {
650 	struct vio_completion comp;
651 	struct request_queue *q;
652 	struct gendisk *g;
653 	int err;
654 
655 	init_completion(&comp.com);
656 	comp.err = 0;
657 	comp.waiting_for = WAITING_FOR_LINK_UP;
658 	port->vio.cmp = &comp;
659 
660 	vio_port_up(&port->vio);
661 
662 	wait_for_completion(&comp.com);
663 	if (comp.err)
664 		return comp.err;
665 
666 	err = generic_request(port, VD_OP_GET_VTOC,
667 			      &port->label, sizeof(port->label));
668 	if (err < 0) {
669 		printk(KERN_ERR PFX "VD_OP_GET_VTOC returns error %d\n", err);
670 		return err;
671 	}
672 
673 	err = generic_request(port, VD_OP_GET_DISKGEOM,
674 			      &port->geom, sizeof(port->geom));
675 	if (err < 0) {
676 		printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
677 		       "error %d\n", err);
678 		return err;
679 	}
680 
681 	port->vdisk_size = ((u64)port->geom.num_cyl *
682 			    (u64)port->geom.num_hd *
683 			    (u64)port->geom.num_sec);
684 
685 	q = blk_init_queue(do_vdc_request, &port->vio.lock);
686 	if (!q) {
687 		printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
688 		       port->vio.name);
689 		return -ENOMEM;
690 	}
691 	g = alloc_disk(1 << PARTITION_SHIFT);
692 	if (!g) {
693 		printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
694 		       port->vio.name);
695 		blk_cleanup_queue(q);
696 		return -ENOMEM;
697 	}
698 
699 	port->disk = g;
700 
701 	blk_queue_max_hw_segments(q, port->ring_cookies);
702 	blk_queue_max_phys_segments(q, port->ring_cookies);
703 	blk_queue_max_sectors(q, port->max_xfer_size);
704 	g->major = vdc_major;
705 	g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
706 	strcpy(g->disk_name, port->disk_name);
707 
708 	g->fops = &vdc_fops;
709 	g->queue = q;
710 	g->private_data = port;
711 	g->driverfs_dev = &port->vio.vdev->dev;
712 
713 	set_capacity(g, port->vdisk_size);
714 
715 	printk(KERN_INFO PFX "%s: %u sectors (%u MB)\n",
716 	       g->disk_name,
717 	       port->vdisk_size, (port->vdisk_size >> (20 - 9)));
718 
719 	add_disk(g);
720 
721 	return 0;
722 }
723 
724 static struct ldc_channel_config vdc_ldc_cfg = {
725 	.event		= vdc_event,
726 	.mtu		= 64,
727 	.mode		= LDC_MODE_UNRELIABLE,
728 };
729 
730 static struct vio_driver_ops vdc_vio_ops = {
731 	.send_attr		= vdc_send_attr,
732 	.handle_attr		= vdc_handle_attr,
733 	.handshake_complete	= vdc_handshake_complete,
734 };
735 
736 static void print_version(void)
737 {
738 	static int version_printed;
739 
740 	if (version_printed++ == 0)
741 		printk(KERN_INFO "%s", version);
742 }
743 
744 static int __devinit vdc_port_probe(struct vio_dev *vdev,
745 				    const struct vio_device_id *id)
746 {
747 	struct mdesc_handle *hp;
748 	struct vdc_port *port;
749 	int err;
750 
751 	print_version();
752 
753 	hp = mdesc_grab();
754 
755 	err = -ENODEV;
756 	if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
757 		printk(KERN_ERR PFX "Port id [%lu] too large.\n",
758 		       vdev->dev_no);
759 		goto err_out_release_mdesc;
760 	}
761 
762 	port = kzalloc(sizeof(*port), GFP_KERNEL);
763 	err = -ENOMEM;
764 	if (!port) {
765 		printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
766 		goto err_out_release_mdesc;
767 	}
768 
769 	if (vdev->dev_no >= 26)
770 		snprintf(port->disk_name, sizeof(port->disk_name),
771 			 VDCBLK_NAME "%c%c",
772 			 'a' + ((int)vdev->dev_no / 26) - 1,
773 			 'a' + ((int)vdev->dev_no % 26));
774 	else
775 		snprintf(port->disk_name, sizeof(port->disk_name),
776 			 VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
777 
778 	err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
779 			      vdc_versions, ARRAY_SIZE(vdc_versions),
780 			      &vdc_vio_ops, port->disk_name);
781 	if (err)
782 		goto err_out_free_port;
783 
784 	port->vdisk_block_size = 512;
785 	port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size);
786 	port->ring_cookies = ((port->max_xfer_size *
787 			       port->vdisk_block_size) / PAGE_SIZE) + 2;
788 
789 	err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
790 	if (err)
791 		goto err_out_free_port;
792 
793 	err = vdc_alloc_tx_ring(port);
794 	if (err)
795 		goto err_out_free_ldc;
796 
797 	err = probe_disk(port);
798 	if (err)
799 		goto err_out_free_tx_ring;
800 
801 	dev_set_drvdata(&vdev->dev, port);
802 
803 	mdesc_release(hp);
804 
805 	return 0;
806 
807 err_out_free_tx_ring:
808 	vdc_free_tx_ring(port);
809 
810 err_out_free_ldc:
811 	vio_ldc_free(&port->vio);
812 
813 err_out_free_port:
814 	kfree(port);
815 
816 err_out_release_mdesc:
817 	mdesc_release(hp);
818 	return err;
819 }
820 
821 static int vdc_port_remove(struct vio_dev *vdev)
822 {
823 	struct vdc_port *port = dev_get_drvdata(&vdev->dev);
824 
825 	if (port) {
826 		del_timer_sync(&port->vio.timer);
827 
828 		vdc_free_tx_ring(port);
829 		vio_ldc_free(&port->vio);
830 
831 		dev_set_drvdata(&vdev->dev, NULL);
832 
833 		kfree(port);
834 	}
835 	return 0;
836 }
837 
838 static struct vio_device_id vdc_port_match[] = {
839 	{
840 		.type = "vdc-port",
841 	},
842 	{},
843 };
844 MODULE_DEVICE_TABLE(vio, vdc_port_match);
845 
846 static struct vio_driver vdc_port_driver = {
847 	.id_table	= vdc_port_match,
848 	.probe		= vdc_port_probe,
849 	.remove		= vdc_port_remove,
850 	.driver		= {
851 		.name	= "vdc_port",
852 		.owner	= THIS_MODULE,
853 	}
854 };
855 
856 static int __init vdc_init(void)
857 {
858 	int err;
859 
860 	err = register_blkdev(0, VDCBLK_NAME);
861 	if (err < 0)
862 		goto out_err;
863 
864 	vdc_major = err;
865 
866 	err = vio_register_driver(&vdc_port_driver);
867 	if (err)
868 		goto out_unregister_blkdev;
869 
870 	return 0;
871 
872 out_unregister_blkdev:
873 	unregister_blkdev(vdc_major, VDCBLK_NAME);
874 	vdc_major = 0;
875 
876 out_err:
877 	return err;
878 }
879 
880 static void __exit vdc_exit(void)
881 {
882 	vio_unregister_driver(&vdc_port_driver);
883 	unregister_blkdev(vdc_major, VDCBLK_NAME);
884 }
885 
886 module_init(vdc_init);
887 module_exit(vdc_exit);
888