xref: /openbmc/linux/drivers/block/sunvdc.c (revision 384740dc)
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 error, int num_sectors)
216 {
217 	__blk_end_request(req, error, num_sectors << 9);
218 }
219 
220 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
221 			unsigned int index)
222 {
223 	struct vio_disk_desc *desc = vio_dring_entry(dr, index);
224 	struct vdc_req_entry *rqe = &port->rq_arr[index];
225 	struct request *req;
226 
227 	if (unlikely(desc->hdr.state != VIO_DESC_DONE))
228 		return;
229 
230 	ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
231 	desc->hdr.state = VIO_DESC_FREE;
232 	dr->cons = (index + 1) & (VDC_TX_RING_SIZE - 1);
233 
234 	req = rqe->req;
235 	if (req == NULL) {
236 		vdc_end_special(port, desc);
237 		return;
238 	}
239 
240 	rqe->req = NULL;
241 
242 	vdc_end_request(req, (desc->status ? -EIO : 0), desc->size >> 9);
243 
244 	if (blk_queue_stopped(port->disk->queue))
245 		blk_start_queue(port->disk->queue);
246 }
247 
248 static int vdc_ack(struct vdc_port *port, void *msgbuf)
249 {
250 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
251 	struct vio_dring_data *pkt = msgbuf;
252 
253 	if (unlikely(pkt->dring_ident != dr->ident ||
254 		     pkt->start_idx != pkt->end_idx ||
255 		     pkt->start_idx >= VDC_TX_RING_SIZE))
256 		return 0;
257 
258 	vdc_end_one(port, dr, pkt->start_idx);
259 
260 	return 0;
261 }
262 
263 static int vdc_nack(struct vdc_port *port, void *msgbuf)
264 {
265 	/* XXX Implement me XXX */
266 	return 0;
267 }
268 
269 static void vdc_event(void *arg, int event)
270 {
271 	struct vdc_port *port = arg;
272 	struct vio_driver_state *vio = &port->vio;
273 	unsigned long flags;
274 	int err;
275 
276 	spin_lock_irqsave(&vio->lock, flags);
277 
278 	if (unlikely(event == LDC_EVENT_RESET ||
279 		     event == LDC_EVENT_UP)) {
280 		vio_link_state_change(vio, event);
281 		spin_unlock_irqrestore(&vio->lock, flags);
282 		return;
283 	}
284 
285 	if (unlikely(event != LDC_EVENT_DATA_READY)) {
286 		printk(KERN_WARNING PFX "Unexpected LDC event %d\n", event);
287 		spin_unlock_irqrestore(&vio->lock, flags);
288 		return;
289 	}
290 
291 	err = 0;
292 	while (1) {
293 		union {
294 			struct vio_msg_tag tag;
295 			u64 raw[8];
296 		} msgbuf;
297 
298 		err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
299 		if (unlikely(err < 0)) {
300 			if (err == -ECONNRESET)
301 				vio_conn_reset(vio);
302 			break;
303 		}
304 		if (err == 0)
305 			break;
306 		viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
307 		       msgbuf.tag.type,
308 		       msgbuf.tag.stype,
309 		       msgbuf.tag.stype_env,
310 		       msgbuf.tag.sid);
311 		err = vio_validate_sid(vio, &msgbuf.tag);
312 		if (err < 0)
313 			break;
314 
315 		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
316 			if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
317 				err = vdc_ack(port, &msgbuf);
318 			else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
319 				err = vdc_nack(port, &msgbuf);
320 			else
321 				err = vdc_handle_unknown(port, &msgbuf);
322 		} else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
323 			err = vio_control_pkt_engine(vio, &msgbuf);
324 		} else {
325 			err = vdc_handle_unknown(port, &msgbuf);
326 		}
327 		if (err < 0)
328 			break;
329 	}
330 	if (err < 0)
331 		vdc_finish(&port->vio, err, WAITING_FOR_ANY);
332 	spin_unlock_irqrestore(&vio->lock, flags);
333 }
334 
335 static int __vdc_tx_trigger(struct vdc_port *port)
336 {
337 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
338 	struct vio_dring_data hdr = {
339 		.tag = {
340 			.type		= VIO_TYPE_DATA,
341 			.stype		= VIO_SUBTYPE_INFO,
342 			.stype_env	= VIO_DRING_DATA,
343 			.sid		= vio_send_sid(&port->vio),
344 		},
345 		.dring_ident		= dr->ident,
346 		.start_idx		= dr->prod,
347 		.end_idx		= dr->prod,
348 	};
349 	int err, delay;
350 
351 	hdr.seq = dr->snd_nxt;
352 	delay = 1;
353 	do {
354 		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
355 		if (err > 0) {
356 			dr->snd_nxt++;
357 			break;
358 		}
359 		udelay(delay);
360 		if ((delay <<= 1) > 128)
361 			delay = 128;
362 	} while (err == -EAGAIN);
363 
364 	return err;
365 }
366 
367 static int __send_request(struct request *req)
368 {
369 	struct vdc_port *port = req->rq_disk->private_data;
370 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
371 	struct scatterlist sg[port->ring_cookies];
372 	struct vdc_req_entry *rqe;
373 	struct vio_disk_desc *desc;
374 	unsigned int map_perm;
375 	int nsg, err, i;
376 	u64 len;
377 	u8 op;
378 
379 	map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
380 
381 	if (rq_data_dir(req) == READ) {
382 		map_perm |= LDC_MAP_W;
383 		op = VD_OP_BREAD;
384 	} else {
385 		map_perm |= LDC_MAP_R;
386 		op = VD_OP_BWRITE;
387 	}
388 
389 	sg_init_table(sg, port->ring_cookies);
390 	nsg = blk_rq_map_sg(req->q, req, sg);
391 
392 	len = 0;
393 	for (i = 0; i < nsg; i++)
394 		len += sg[i].length;
395 
396 	if (unlikely(vdc_tx_dring_avail(dr) < 1)) {
397 		blk_stop_queue(port->disk->queue);
398 		err = -ENOMEM;
399 		goto out;
400 	}
401 
402 	desc = vio_dring_cur(dr);
403 
404 	err = ldc_map_sg(port->vio.lp, sg, nsg,
405 			 desc->cookies, port->ring_cookies,
406 			 map_perm);
407 	if (err < 0) {
408 		printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
409 		return err;
410 	}
411 
412 	rqe = &port->rq_arr[dr->prod];
413 	rqe->req = req;
414 
415 	desc->hdr.ack = VIO_ACK_ENABLE;
416 	desc->req_id = port->req_id;
417 	desc->operation = op;
418 	if (port->vdisk_type == VD_DISK_TYPE_DISK) {
419 		desc->slice = 0xff;
420 	} else {
421 		desc->slice = 0;
422 	}
423 	desc->status = ~0;
424 	desc->offset = (req->sector << 9) / port->vdisk_block_size;
425 	desc->size = len;
426 	desc->ncookies = err;
427 
428 	/* This has to be a non-SMP write barrier because we are writing
429 	 * to memory which is shared with the peer LDOM.
430 	 */
431 	wmb();
432 	desc->hdr.state = VIO_DESC_READY;
433 
434 	err = __vdc_tx_trigger(port);
435 	if (err < 0) {
436 		printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
437 	} else {
438 		port->req_id++;
439 		dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
440 	}
441 out:
442 
443 	return err;
444 }
445 
446 static void do_vdc_request(struct request_queue *q)
447 {
448 	while (1) {
449 		struct request *req = elv_next_request(q);
450 
451 		if (!req)
452 			break;
453 
454 		blkdev_dequeue_request(req);
455 		if (__send_request(req) < 0)
456 			vdc_end_request(req, -EIO, req->hard_nr_sectors);
457 	}
458 }
459 
460 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
461 {
462 	struct vio_dring_state *dr;
463 	struct vio_completion comp;
464 	struct vio_disk_desc *desc;
465 	unsigned int map_perm;
466 	unsigned long flags;
467 	int op_len, err;
468 	void *req_buf;
469 
470 	if (!(((u64)1 << ((u64)op - 1)) & port->operations))
471 		return -EOPNOTSUPP;
472 
473 	switch (op) {
474 	case VD_OP_BREAD:
475 	case VD_OP_BWRITE:
476 	default:
477 		return -EINVAL;
478 
479 	case VD_OP_FLUSH:
480 		op_len = 0;
481 		map_perm = 0;
482 		break;
483 
484 	case VD_OP_GET_WCE:
485 		op_len = sizeof(u32);
486 		map_perm = LDC_MAP_W;
487 		break;
488 
489 	case VD_OP_SET_WCE:
490 		op_len = sizeof(u32);
491 		map_perm = LDC_MAP_R;
492 		break;
493 
494 	case VD_OP_GET_VTOC:
495 		op_len = sizeof(struct vio_disk_vtoc);
496 		map_perm = LDC_MAP_W;
497 		break;
498 
499 	case VD_OP_SET_VTOC:
500 		op_len = sizeof(struct vio_disk_vtoc);
501 		map_perm = LDC_MAP_R;
502 		break;
503 
504 	case VD_OP_GET_DISKGEOM:
505 		op_len = sizeof(struct vio_disk_geom);
506 		map_perm = LDC_MAP_W;
507 		break;
508 
509 	case VD_OP_SET_DISKGEOM:
510 		op_len = sizeof(struct vio_disk_geom);
511 		map_perm = LDC_MAP_R;
512 		break;
513 
514 	case VD_OP_SCSICMD:
515 		op_len = 16;
516 		map_perm = LDC_MAP_RW;
517 		break;
518 
519 	case VD_OP_GET_DEVID:
520 		op_len = sizeof(struct vio_disk_devid);
521 		map_perm = LDC_MAP_W;
522 		break;
523 
524 	case VD_OP_GET_EFI:
525 	case VD_OP_SET_EFI:
526 		return -EOPNOTSUPP;
527 		break;
528 	};
529 
530 	map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
531 
532 	op_len = (op_len + 7) & ~7;
533 	req_buf = kzalloc(op_len, GFP_KERNEL);
534 	if (!req_buf)
535 		return -ENOMEM;
536 
537 	if (len > op_len)
538 		len = op_len;
539 
540 	if (map_perm & LDC_MAP_R)
541 		memcpy(req_buf, buf, len);
542 
543 	spin_lock_irqsave(&port->vio.lock, flags);
544 
545 	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
546 
547 	/* XXX If we want to use this code generically we have to
548 	 * XXX handle TX ring exhaustion etc.
549 	 */
550 	desc = vio_dring_cur(dr);
551 
552 	err = ldc_map_single(port->vio.lp, req_buf, op_len,
553 			     desc->cookies, port->ring_cookies,
554 			     map_perm);
555 	if (err < 0) {
556 		spin_unlock_irqrestore(&port->vio.lock, flags);
557 		kfree(req_buf);
558 		return err;
559 	}
560 
561 	init_completion(&comp.com);
562 	comp.waiting_for = WAITING_FOR_GEN_CMD;
563 	port->vio.cmp = &comp;
564 
565 	desc->hdr.ack = VIO_ACK_ENABLE;
566 	desc->req_id = port->req_id;
567 	desc->operation = op;
568 	desc->slice = 0;
569 	desc->status = ~0;
570 	desc->offset = 0;
571 	desc->size = op_len;
572 	desc->ncookies = err;
573 
574 	/* This has to be a non-SMP write barrier because we are writing
575 	 * to memory which is shared with the peer LDOM.
576 	 */
577 	wmb();
578 	desc->hdr.state = VIO_DESC_READY;
579 
580 	err = __vdc_tx_trigger(port);
581 	if (err >= 0) {
582 		port->req_id++;
583 		dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
584 		spin_unlock_irqrestore(&port->vio.lock, flags);
585 
586 		wait_for_completion(&comp.com);
587 		err = comp.err;
588 	} else {
589 		port->vio.cmp = NULL;
590 		spin_unlock_irqrestore(&port->vio.lock, flags);
591 	}
592 
593 	if (map_perm & LDC_MAP_W)
594 		memcpy(buf, req_buf, len);
595 
596 	kfree(req_buf);
597 
598 	return err;
599 }
600 
601 static int __devinit vdc_alloc_tx_ring(struct vdc_port *port)
602 {
603 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
604 	unsigned long len, entry_size;
605 	int ncookies;
606 	void *dring;
607 
608 	entry_size = sizeof(struct vio_disk_desc) +
609 		(sizeof(struct ldc_trans_cookie) * port->ring_cookies);
610 	len = (VDC_TX_RING_SIZE * entry_size);
611 
612 	ncookies = VIO_MAX_RING_COOKIES;
613 	dring = ldc_alloc_exp_dring(port->vio.lp, len,
614 				    dr->cookies, &ncookies,
615 				    (LDC_MAP_SHADOW |
616 				     LDC_MAP_DIRECT |
617 				     LDC_MAP_RW));
618 	if (IS_ERR(dring))
619 		return PTR_ERR(dring);
620 
621 	dr->base = dring;
622 	dr->entry_size = entry_size;
623 	dr->num_entries = VDC_TX_RING_SIZE;
624 	dr->prod = dr->cons = 0;
625 	dr->pending = VDC_TX_RING_SIZE;
626 	dr->ncookies = ncookies;
627 
628 	return 0;
629 }
630 
631 static void vdc_free_tx_ring(struct vdc_port *port)
632 {
633 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
634 
635 	if (dr->base) {
636 		ldc_free_exp_dring(port->vio.lp, dr->base,
637 				   (dr->entry_size * dr->num_entries),
638 				   dr->cookies, dr->ncookies);
639 		dr->base = NULL;
640 		dr->entry_size = 0;
641 		dr->num_entries = 0;
642 		dr->pending = 0;
643 		dr->ncookies = 0;
644 	}
645 }
646 
647 static int probe_disk(struct vdc_port *port)
648 {
649 	struct vio_completion comp;
650 	struct request_queue *q;
651 	struct gendisk *g;
652 	int err;
653 
654 	init_completion(&comp.com);
655 	comp.err = 0;
656 	comp.waiting_for = WAITING_FOR_LINK_UP;
657 	port->vio.cmp = &comp;
658 
659 	vio_port_up(&port->vio);
660 
661 	wait_for_completion(&comp.com);
662 	if (comp.err)
663 		return comp.err;
664 
665 	err = generic_request(port, VD_OP_GET_VTOC,
666 			      &port->label, sizeof(port->label));
667 	if (err < 0) {
668 		printk(KERN_ERR PFX "VD_OP_GET_VTOC returns error %d\n", err);
669 		return err;
670 	}
671 
672 	err = generic_request(port, VD_OP_GET_DISKGEOM,
673 			      &port->geom, sizeof(port->geom));
674 	if (err < 0) {
675 		printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
676 		       "error %d\n", err);
677 		return err;
678 	}
679 
680 	port->vdisk_size = ((u64)port->geom.num_cyl *
681 			    (u64)port->geom.num_hd *
682 			    (u64)port->geom.num_sec);
683 
684 	q = blk_init_queue(do_vdc_request, &port->vio.lock);
685 	if (!q) {
686 		printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
687 		       port->vio.name);
688 		return -ENOMEM;
689 	}
690 	g = alloc_disk(1 << PARTITION_SHIFT);
691 	if (!g) {
692 		printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
693 		       port->vio.name);
694 		blk_cleanup_queue(q);
695 		return -ENOMEM;
696 	}
697 
698 	port->disk = g;
699 
700 	blk_queue_max_hw_segments(q, port->ring_cookies);
701 	blk_queue_max_phys_segments(q, port->ring_cookies);
702 	blk_queue_max_sectors(q, port->max_xfer_size);
703 	g->major = vdc_major;
704 	g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
705 	strcpy(g->disk_name, port->disk_name);
706 
707 	g->fops = &vdc_fops;
708 	g->queue = q;
709 	g->private_data = port;
710 	g->driverfs_dev = &port->vio.vdev->dev;
711 
712 	set_capacity(g, port->vdisk_size);
713 
714 	printk(KERN_INFO PFX "%s: %u sectors (%u MB)\n",
715 	       g->disk_name,
716 	       port->vdisk_size, (port->vdisk_size >> (20 - 9)));
717 
718 	add_disk(g);
719 
720 	return 0;
721 }
722 
723 static struct ldc_channel_config vdc_ldc_cfg = {
724 	.event		= vdc_event,
725 	.mtu		= 64,
726 	.mode		= LDC_MODE_UNRELIABLE,
727 };
728 
729 static struct vio_driver_ops vdc_vio_ops = {
730 	.send_attr		= vdc_send_attr,
731 	.handle_attr		= vdc_handle_attr,
732 	.handshake_complete	= vdc_handshake_complete,
733 };
734 
735 static void __devinit print_version(void)
736 {
737 	static int version_printed;
738 
739 	if (version_printed++ == 0)
740 		printk(KERN_INFO "%s", version);
741 }
742 
743 static int __devinit vdc_port_probe(struct vio_dev *vdev,
744 				    const struct vio_device_id *id)
745 {
746 	struct mdesc_handle *hp;
747 	struct vdc_port *port;
748 	int err;
749 
750 	print_version();
751 
752 	hp = mdesc_grab();
753 
754 	err = -ENODEV;
755 	if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
756 		printk(KERN_ERR PFX "Port id [%lu] too large.\n",
757 		       vdev->dev_no);
758 		goto err_out_release_mdesc;
759 	}
760 
761 	port = kzalloc(sizeof(*port), GFP_KERNEL);
762 	err = -ENOMEM;
763 	if (!port) {
764 		printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
765 		goto err_out_release_mdesc;
766 	}
767 
768 	if (vdev->dev_no >= 26)
769 		snprintf(port->disk_name, sizeof(port->disk_name),
770 			 VDCBLK_NAME "%c%c",
771 			 'a' + ((int)vdev->dev_no / 26) - 1,
772 			 'a' + ((int)vdev->dev_no % 26));
773 	else
774 		snprintf(port->disk_name, sizeof(port->disk_name),
775 			 VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
776 
777 	err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
778 			      vdc_versions, ARRAY_SIZE(vdc_versions),
779 			      &vdc_vio_ops, port->disk_name);
780 	if (err)
781 		goto err_out_free_port;
782 
783 	port->vdisk_block_size = 512;
784 	port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size);
785 	port->ring_cookies = ((port->max_xfer_size *
786 			       port->vdisk_block_size) / PAGE_SIZE) + 2;
787 
788 	err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
789 	if (err)
790 		goto err_out_free_port;
791 
792 	err = vdc_alloc_tx_ring(port);
793 	if (err)
794 		goto err_out_free_ldc;
795 
796 	err = probe_disk(port);
797 	if (err)
798 		goto err_out_free_tx_ring;
799 
800 	dev_set_drvdata(&vdev->dev, port);
801 
802 	mdesc_release(hp);
803 
804 	return 0;
805 
806 err_out_free_tx_ring:
807 	vdc_free_tx_ring(port);
808 
809 err_out_free_ldc:
810 	vio_ldc_free(&port->vio);
811 
812 err_out_free_port:
813 	kfree(port);
814 
815 err_out_release_mdesc:
816 	mdesc_release(hp);
817 	return err;
818 }
819 
820 static int vdc_port_remove(struct vio_dev *vdev)
821 {
822 	struct vdc_port *port = dev_get_drvdata(&vdev->dev);
823 
824 	if (port) {
825 		del_timer_sync(&port->vio.timer);
826 
827 		vdc_free_tx_ring(port);
828 		vio_ldc_free(&port->vio);
829 
830 		dev_set_drvdata(&vdev->dev, NULL);
831 
832 		kfree(port);
833 	}
834 	return 0;
835 }
836 
837 static struct vio_device_id vdc_port_match[] = {
838 	{
839 		.type = "vdc-port",
840 	},
841 	{},
842 };
843 MODULE_DEVICE_TABLE(vio, vdc_port_match);
844 
845 static struct vio_driver vdc_port_driver = {
846 	.id_table	= vdc_port_match,
847 	.probe		= vdc_port_probe,
848 	.remove		= vdc_port_remove,
849 	.driver		= {
850 		.name	= "vdc_port",
851 		.owner	= THIS_MODULE,
852 	}
853 };
854 
855 static int __init vdc_init(void)
856 {
857 	int err;
858 
859 	err = register_blkdev(0, VDCBLK_NAME);
860 	if (err < 0)
861 		goto out_err;
862 
863 	vdc_major = err;
864 
865 	err = vio_register_driver(&vdc_port_driver);
866 	if (err)
867 		goto out_unregister_blkdev;
868 
869 	return 0;
870 
871 out_unregister_blkdev:
872 	unregister_blkdev(vdc_major, VDCBLK_NAME);
873 	vdc_major = 0;
874 
875 out_err:
876 	return err;
877 }
878 
879 static void __exit vdc_exit(void)
880 {
881 	vio_unregister_driver(&vdc_port_driver);
882 	unregister_blkdev(vdc_major, VDCBLK_NAME);
883 }
884 
885 module_init(vdc_init);
886 module_exit(vdc_exit);
887