xref: /linux/drivers/block/sunvdc.c (revision bcefe12eff5dca6fdfa94ed85e5bee66380d5cd9)
1 /* sunvdc.c: Sun LDOM Virtual Disk Client.
2  *
3  * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
4  */
5 
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/types.h>
9 #include <linux/blkdev.h>
10 #include <linux/hdreg.h>
11 #include <linux/genhd.h>
12 #include <linux/slab.h>
13 #include <linux/spinlock.h>
14 #include <linux/completion.h>
15 #include <linux/delay.h>
16 #include <linux/init.h>
17 #include <linux/list.h>
18 #include <linux/scatterlist.h>
19 
20 #include <asm/vio.h>
21 #include <asm/ldc.h>
22 
23 #define DRV_MODULE_NAME		"sunvdc"
24 #define PFX DRV_MODULE_NAME	": "
25 #define DRV_MODULE_VERSION	"1.0"
26 #define DRV_MODULE_RELDATE	"June 25, 2007"
27 
28 static char version[] __devinitdata =
29 	DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
30 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
31 MODULE_DESCRIPTION("Sun LDOM virtual disk client driver");
32 MODULE_LICENSE("GPL");
33 MODULE_VERSION(DRV_MODULE_VERSION);
34 
35 #define VDC_TX_RING_SIZE	256
36 
37 #define WAITING_FOR_LINK_UP	0x01
38 #define WAITING_FOR_TX_SPACE	0x02
39 #define WAITING_FOR_GEN_CMD	0x04
40 #define WAITING_FOR_ANY		-1
41 
42 struct vdc_req_entry {
43 	struct request		*req;
44 };
45 
46 struct vdc_port {
47 	struct vio_driver_state	vio;
48 
49 	struct gendisk		*disk;
50 
51 	struct vdc_completion	*cmp;
52 
53 	u64			req_id;
54 	u64			seq;
55 	struct vdc_req_entry	rq_arr[VDC_TX_RING_SIZE];
56 
57 	unsigned long		ring_cookies;
58 
59 	u64			max_xfer_size;
60 	u32			vdisk_block_size;
61 
62 	/* The server fills these in for us in the disk attribute
63 	 * ACK packet.
64 	 */
65 	u64			operations;
66 	u32			vdisk_size;
67 	u8			vdisk_type;
68 
69 	char			disk_name[32];
70 
71 	struct vio_disk_geom	geom;
72 	struct vio_disk_vtoc	label;
73 };
74 
75 static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
76 {
77 	return container_of(vio, struct vdc_port, vio);
78 }
79 
80 /* Ordered from largest major to lowest */
81 static struct vio_version vdc_versions[] = {
82 	{ .major = 1, .minor = 0 },
83 };
84 
85 #define VDCBLK_NAME	"vdisk"
86 static int vdc_major;
87 #define PARTITION_SHIFT	3
88 
89 static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
90 {
91 	return vio_dring_avail(dr, VDC_TX_RING_SIZE);
92 }
93 
94 static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
95 {
96 	struct gendisk *disk = bdev->bd_disk;
97 	struct vdc_port *port = disk->private_data;
98 
99 	geo->heads = (u8) port->geom.num_hd;
100 	geo->sectors = (u8) port->geom.num_sec;
101 	geo->cylinders = port->geom.num_cyl;
102 
103 	return 0;
104 }
105 
106 static const struct block_device_operations vdc_fops = {
107 	.owner		= THIS_MODULE,
108 	.getgeo		= vdc_getgeo,
109 };
110 
111 static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
112 {
113 	if (vio->cmp &&
114 	    (waiting_for == -1 ||
115 	     vio->cmp->waiting_for == waiting_for)) {
116 		vio->cmp->err = err;
117 		complete(&vio->cmp->com);
118 		vio->cmp = NULL;
119 	}
120 }
121 
122 static void vdc_handshake_complete(struct vio_driver_state *vio)
123 {
124 	vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
125 }
126 
127 static int vdc_handle_unknown(struct vdc_port *port, void *arg)
128 {
129 	struct vio_msg_tag *pkt = arg;
130 
131 	printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
132 	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
133 	printk(KERN_ERR PFX "Resetting connection.\n");
134 
135 	ldc_disconnect(port->vio.lp);
136 
137 	return -ECONNRESET;
138 }
139 
140 static int vdc_send_attr(struct vio_driver_state *vio)
141 {
142 	struct vdc_port *port = to_vdc_port(vio);
143 	struct vio_disk_attr_info pkt;
144 
145 	memset(&pkt, 0, sizeof(pkt));
146 
147 	pkt.tag.type = VIO_TYPE_CTRL;
148 	pkt.tag.stype = VIO_SUBTYPE_INFO;
149 	pkt.tag.stype_env = VIO_ATTR_INFO;
150 	pkt.tag.sid = vio_send_sid(vio);
151 
152 	pkt.xfer_mode = VIO_DRING_MODE;
153 	pkt.vdisk_block_size = port->vdisk_block_size;
154 	pkt.max_xfer_size = port->max_xfer_size;
155 
156 	viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
157 	       pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);
158 
159 	return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
160 }
161 
162 static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
163 {
164 	struct vdc_port *port = to_vdc_port(vio);
165 	struct vio_disk_attr_info *pkt = arg;
166 
167 	viodbg(HS, "GOT ATTR stype[0x%x] ops[%llx] disk_size[%llu] disk_type[%x] "
168 	       "xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
169 	       pkt->tag.stype, pkt->operations,
170 	       pkt->vdisk_size, pkt->vdisk_type,
171 	       pkt->xfer_mode, pkt->vdisk_block_size,
172 	       pkt->max_xfer_size);
173 
174 	if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
175 		switch (pkt->vdisk_type) {
176 		case VD_DISK_TYPE_DISK:
177 		case VD_DISK_TYPE_SLICE:
178 			break;
179 
180 		default:
181 			printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n",
182 			       vio->name, pkt->vdisk_type);
183 			return -ECONNRESET;
184 		}
185 
186 		if (pkt->vdisk_block_size > port->vdisk_block_size) {
187 			printk(KERN_ERR PFX "%s: BLOCK size increased "
188 			       "%u --> %u\n",
189 			       vio->name,
190 			       port->vdisk_block_size, pkt->vdisk_block_size);
191 			return -ECONNRESET;
192 		}
193 
194 		port->operations = pkt->operations;
195 		port->vdisk_size = pkt->vdisk_size;
196 		port->vdisk_type = pkt->vdisk_type;
197 		if (pkt->max_xfer_size < port->max_xfer_size)
198 			port->max_xfer_size = pkt->max_xfer_size;
199 		port->vdisk_block_size = pkt->vdisk_block_size;
200 		return 0;
201 	} else {
202 		printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name);
203 
204 		return -ECONNRESET;
205 	}
206 }
207 
208 static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc)
209 {
210 	int err = desc->status;
211 
212 	vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
213 }
214 
215 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
216 			unsigned int index)
217 {
218 	struct vio_disk_desc *desc = vio_dring_entry(dr, index);
219 	struct vdc_req_entry *rqe = &port->rq_arr[index];
220 	struct request *req;
221 
222 	if (unlikely(desc->hdr.state != VIO_DESC_DONE))
223 		return;
224 
225 	ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
226 	desc->hdr.state = VIO_DESC_FREE;
227 	dr->cons = (index + 1) & (VDC_TX_RING_SIZE - 1);
228 
229 	req = rqe->req;
230 	if (req == NULL) {
231 		vdc_end_special(port, desc);
232 		return;
233 	}
234 
235 	rqe->req = NULL;
236 
237 	__blk_end_request(req, (desc->status ? -EIO : 0), desc->size);
238 
239 	if (blk_queue_stopped(port->disk->queue))
240 		blk_start_queue(port->disk->queue);
241 }
242 
243 static int vdc_ack(struct vdc_port *port, void *msgbuf)
244 {
245 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
246 	struct vio_dring_data *pkt = msgbuf;
247 
248 	if (unlikely(pkt->dring_ident != dr->ident ||
249 		     pkt->start_idx != pkt->end_idx ||
250 		     pkt->start_idx >= VDC_TX_RING_SIZE))
251 		return 0;
252 
253 	vdc_end_one(port, dr, pkt->start_idx);
254 
255 	return 0;
256 }
257 
258 static int vdc_nack(struct vdc_port *port, void *msgbuf)
259 {
260 	/* XXX Implement me XXX */
261 	return 0;
262 }
263 
264 static void vdc_event(void *arg, int event)
265 {
266 	struct vdc_port *port = arg;
267 	struct vio_driver_state *vio = &port->vio;
268 	unsigned long flags;
269 	int err;
270 
271 	spin_lock_irqsave(&vio->lock, flags);
272 
273 	if (unlikely(event == LDC_EVENT_RESET ||
274 		     event == LDC_EVENT_UP)) {
275 		vio_link_state_change(vio, event);
276 		spin_unlock_irqrestore(&vio->lock, flags);
277 		return;
278 	}
279 
280 	if (unlikely(event != LDC_EVENT_DATA_READY)) {
281 		printk(KERN_WARNING PFX "Unexpected LDC event %d\n", event);
282 		spin_unlock_irqrestore(&vio->lock, flags);
283 		return;
284 	}
285 
286 	err = 0;
287 	while (1) {
288 		union {
289 			struct vio_msg_tag tag;
290 			u64 raw[8];
291 		} msgbuf;
292 
293 		err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
294 		if (unlikely(err < 0)) {
295 			if (err == -ECONNRESET)
296 				vio_conn_reset(vio);
297 			break;
298 		}
299 		if (err == 0)
300 			break;
301 		viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
302 		       msgbuf.tag.type,
303 		       msgbuf.tag.stype,
304 		       msgbuf.tag.stype_env,
305 		       msgbuf.tag.sid);
306 		err = vio_validate_sid(vio, &msgbuf.tag);
307 		if (err < 0)
308 			break;
309 
310 		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
311 			if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
312 				err = vdc_ack(port, &msgbuf);
313 			else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
314 				err = vdc_nack(port, &msgbuf);
315 			else
316 				err = vdc_handle_unknown(port, &msgbuf);
317 		} else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
318 			err = vio_control_pkt_engine(vio, &msgbuf);
319 		} else {
320 			err = vdc_handle_unknown(port, &msgbuf);
321 		}
322 		if (err < 0)
323 			break;
324 	}
325 	if (err < 0)
326 		vdc_finish(&port->vio, err, WAITING_FOR_ANY);
327 	spin_unlock_irqrestore(&vio->lock, flags);
328 }
329 
330 static int __vdc_tx_trigger(struct vdc_port *port)
331 {
332 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
333 	struct vio_dring_data hdr = {
334 		.tag = {
335 			.type		= VIO_TYPE_DATA,
336 			.stype		= VIO_SUBTYPE_INFO,
337 			.stype_env	= VIO_DRING_DATA,
338 			.sid		= vio_send_sid(&port->vio),
339 		},
340 		.dring_ident		= dr->ident,
341 		.start_idx		= dr->prod,
342 		.end_idx		= dr->prod,
343 	};
344 	int err, delay;
345 
346 	hdr.seq = dr->snd_nxt;
347 	delay = 1;
348 	do {
349 		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
350 		if (err > 0) {
351 			dr->snd_nxt++;
352 			break;
353 		}
354 		udelay(delay);
355 		if ((delay <<= 1) > 128)
356 			delay = 128;
357 	} while (err == -EAGAIN);
358 
359 	return err;
360 }
361 
362 static int __send_request(struct request *req)
363 {
364 	struct vdc_port *port = req->rq_disk->private_data;
365 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
366 	struct scatterlist sg[port->ring_cookies];
367 	struct vdc_req_entry *rqe;
368 	struct vio_disk_desc *desc;
369 	unsigned int map_perm;
370 	int nsg, err, i;
371 	u64 len;
372 	u8 op;
373 
374 	map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
375 
376 	if (rq_data_dir(req) == READ) {
377 		map_perm |= LDC_MAP_W;
378 		op = VD_OP_BREAD;
379 	} else {
380 		map_perm |= LDC_MAP_R;
381 		op = VD_OP_BWRITE;
382 	}
383 
384 	sg_init_table(sg, port->ring_cookies);
385 	nsg = blk_rq_map_sg(req->q, req, sg);
386 
387 	len = 0;
388 	for (i = 0; i < nsg; i++)
389 		len += sg[i].length;
390 
391 	if (unlikely(vdc_tx_dring_avail(dr) < 1)) {
392 		blk_stop_queue(port->disk->queue);
393 		err = -ENOMEM;
394 		goto out;
395 	}
396 
397 	desc = vio_dring_cur(dr);
398 
399 	err = ldc_map_sg(port->vio.lp, sg, nsg,
400 			 desc->cookies, port->ring_cookies,
401 			 map_perm);
402 	if (err < 0) {
403 		printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
404 		return err;
405 	}
406 
407 	rqe = &port->rq_arr[dr->prod];
408 	rqe->req = req;
409 
410 	desc->hdr.ack = VIO_ACK_ENABLE;
411 	desc->req_id = port->req_id;
412 	desc->operation = op;
413 	if (port->vdisk_type == VD_DISK_TYPE_DISK) {
414 		desc->slice = 0xff;
415 	} else {
416 		desc->slice = 0;
417 	}
418 	desc->status = ~0;
419 	desc->offset = (blk_rq_pos(req) << 9) / port->vdisk_block_size;
420 	desc->size = len;
421 	desc->ncookies = err;
422 
423 	/* This has to be a non-SMP write barrier because we are writing
424 	 * to memory which is shared with the peer LDOM.
425 	 */
426 	wmb();
427 	desc->hdr.state = VIO_DESC_READY;
428 
429 	err = __vdc_tx_trigger(port);
430 	if (err < 0) {
431 		printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
432 	} else {
433 		port->req_id++;
434 		dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
435 	}
436 out:
437 
438 	return err;
439 }
440 
441 static void do_vdc_request(struct request_queue *q)
442 {
443 	while (1) {
444 		struct request *req = blk_fetch_request(q);
445 
446 		if (!req)
447 			break;
448 
449 		if (__send_request(req) < 0)
450 			__blk_end_request_all(req, -EIO);
451 	}
452 }
453 
454 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
455 {
456 	struct vio_dring_state *dr;
457 	struct vio_completion comp;
458 	struct vio_disk_desc *desc;
459 	unsigned int map_perm;
460 	unsigned long flags;
461 	int op_len, err;
462 	void *req_buf;
463 
464 	if (!(((u64)1 << ((u64)op - 1)) & port->operations))
465 		return -EOPNOTSUPP;
466 
467 	switch (op) {
468 	case VD_OP_BREAD:
469 	case VD_OP_BWRITE:
470 	default:
471 		return -EINVAL;
472 
473 	case VD_OP_FLUSH:
474 		op_len = 0;
475 		map_perm = 0;
476 		break;
477 
478 	case VD_OP_GET_WCE:
479 		op_len = sizeof(u32);
480 		map_perm = LDC_MAP_W;
481 		break;
482 
483 	case VD_OP_SET_WCE:
484 		op_len = sizeof(u32);
485 		map_perm = LDC_MAP_R;
486 		break;
487 
488 	case VD_OP_GET_VTOC:
489 		op_len = sizeof(struct vio_disk_vtoc);
490 		map_perm = LDC_MAP_W;
491 		break;
492 
493 	case VD_OP_SET_VTOC:
494 		op_len = sizeof(struct vio_disk_vtoc);
495 		map_perm = LDC_MAP_R;
496 		break;
497 
498 	case VD_OP_GET_DISKGEOM:
499 		op_len = sizeof(struct vio_disk_geom);
500 		map_perm = LDC_MAP_W;
501 		break;
502 
503 	case VD_OP_SET_DISKGEOM:
504 		op_len = sizeof(struct vio_disk_geom);
505 		map_perm = LDC_MAP_R;
506 		break;
507 
508 	case VD_OP_SCSICMD:
509 		op_len = 16;
510 		map_perm = LDC_MAP_RW;
511 		break;
512 
513 	case VD_OP_GET_DEVID:
514 		op_len = sizeof(struct vio_disk_devid);
515 		map_perm = LDC_MAP_W;
516 		break;
517 
518 	case VD_OP_GET_EFI:
519 	case VD_OP_SET_EFI:
520 		return -EOPNOTSUPP;
521 		break;
522 	};
523 
524 	map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
525 
526 	op_len = (op_len + 7) & ~7;
527 	req_buf = kzalloc(op_len, GFP_KERNEL);
528 	if (!req_buf)
529 		return -ENOMEM;
530 
531 	if (len > op_len)
532 		len = op_len;
533 
534 	if (map_perm & LDC_MAP_R)
535 		memcpy(req_buf, buf, len);
536 
537 	spin_lock_irqsave(&port->vio.lock, flags);
538 
539 	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
540 
541 	/* XXX If we want to use this code generically we have to
542 	 * XXX handle TX ring exhaustion etc.
543 	 */
544 	desc = vio_dring_cur(dr);
545 
546 	err = ldc_map_single(port->vio.lp, req_buf, op_len,
547 			     desc->cookies, port->ring_cookies,
548 			     map_perm);
549 	if (err < 0) {
550 		spin_unlock_irqrestore(&port->vio.lock, flags);
551 		kfree(req_buf);
552 		return err;
553 	}
554 
555 	init_completion(&comp.com);
556 	comp.waiting_for = WAITING_FOR_GEN_CMD;
557 	port->vio.cmp = &comp;
558 
559 	desc->hdr.ack = VIO_ACK_ENABLE;
560 	desc->req_id = port->req_id;
561 	desc->operation = op;
562 	desc->slice = 0;
563 	desc->status = ~0;
564 	desc->offset = 0;
565 	desc->size = op_len;
566 	desc->ncookies = err;
567 
568 	/* This has to be a non-SMP write barrier because we are writing
569 	 * to memory which is shared with the peer LDOM.
570 	 */
571 	wmb();
572 	desc->hdr.state = VIO_DESC_READY;
573 
574 	err = __vdc_tx_trigger(port);
575 	if (err >= 0) {
576 		port->req_id++;
577 		dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
578 		spin_unlock_irqrestore(&port->vio.lock, flags);
579 
580 		wait_for_completion(&comp.com);
581 		err = comp.err;
582 	} else {
583 		port->vio.cmp = NULL;
584 		spin_unlock_irqrestore(&port->vio.lock, flags);
585 	}
586 
587 	if (map_perm & LDC_MAP_W)
588 		memcpy(buf, req_buf, len);
589 
590 	kfree(req_buf);
591 
592 	return err;
593 }
594 
595 static int __devinit vdc_alloc_tx_ring(struct vdc_port *port)
596 {
597 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
598 	unsigned long len, entry_size;
599 	int ncookies;
600 	void *dring;
601 
602 	entry_size = sizeof(struct vio_disk_desc) +
603 		(sizeof(struct ldc_trans_cookie) * port->ring_cookies);
604 	len = (VDC_TX_RING_SIZE * entry_size);
605 
606 	ncookies = VIO_MAX_RING_COOKIES;
607 	dring = ldc_alloc_exp_dring(port->vio.lp, len,
608 				    dr->cookies, &ncookies,
609 				    (LDC_MAP_SHADOW |
610 				     LDC_MAP_DIRECT |
611 				     LDC_MAP_RW));
612 	if (IS_ERR(dring))
613 		return PTR_ERR(dring);
614 
615 	dr->base = dring;
616 	dr->entry_size = entry_size;
617 	dr->num_entries = VDC_TX_RING_SIZE;
618 	dr->prod = dr->cons = 0;
619 	dr->pending = VDC_TX_RING_SIZE;
620 	dr->ncookies = ncookies;
621 
622 	return 0;
623 }
624 
625 static void vdc_free_tx_ring(struct vdc_port *port)
626 {
627 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
628 
629 	if (dr->base) {
630 		ldc_free_exp_dring(port->vio.lp, dr->base,
631 				   (dr->entry_size * dr->num_entries),
632 				   dr->cookies, dr->ncookies);
633 		dr->base = NULL;
634 		dr->entry_size = 0;
635 		dr->num_entries = 0;
636 		dr->pending = 0;
637 		dr->ncookies = 0;
638 	}
639 }
640 
641 static int probe_disk(struct vdc_port *port)
642 {
643 	struct vio_completion comp;
644 	struct request_queue *q;
645 	struct gendisk *g;
646 	int err;
647 
648 	init_completion(&comp.com);
649 	comp.err = 0;
650 	comp.waiting_for = WAITING_FOR_LINK_UP;
651 	port->vio.cmp = &comp;
652 
653 	vio_port_up(&port->vio);
654 
655 	wait_for_completion(&comp.com);
656 	if (comp.err)
657 		return comp.err;
658 
659 	err = generic_request(port, VD_OP_GET_VTOC,
660 			      &port->label, sizeof(port->label));
661 	if (err < 0) {
662 		printk(KERN_ERR PFX "VD_OP_GET_VTOC returns error %d\n", err);
663 		return err;
664 	}
665 
666 	err = generic_request(port, VD_OP_GET_DISKGEOM,
667 			      &port->geom, sizeof(port->geom));
668 	if (err < 0) {
669 		printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
670 		       "error %d\n", err);
671 		return err;
672 	}
673 
674 	port->vdisk_size = ((u64)port->geom.num_cyl *
675 			    (u64)port->geom.num_hd *
676 			    (u64)port->geom.num_sec);
677 
678 	q = blk_init_queue(do_vdc_request, &port->vio.lock);
679 	if (!q) {
680 		printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
681 		       port->vio.name);
682 		return -ENOMEM;
683 	}
684 	g = alloc_disk(1 << PARTITION_SHIFT);
685 	if (!g) {
686 		printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
687 		       port->vio.name);
688 		blk_cleanup_queue(q);
689 		return -ENOMEM;
690 	}
691 
692 	port->disk = g;
693 
694 	blk_queue_max_hw_segments(q, port->ring_cookies);
695 	blk_queue_max_phys_segments(q, port->ring_cookies);
696 	blk_queue_max_sectors(q, port->max_xfer_size);
697 	g->major = vdc_major;
698 	g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
699 	strcpy(g->disk_name, port->disk_name);
700 
701 	g->fops = &vdc_fops;
702 	g->queue = q;
703 	g->private_data = port;
704 	g->driverfs_dev = &port->vio.vdev->dev;
705 
706 	set_capacity(g, port->vdisk_size);
707 
708 	printk(KERN_INFO PFX "%s: %u sectors (%u MB)\n",
709 	       g->disk_name,
710 	       port->vdisk_size, (port->vdisk_size >> (20 - 9)));
711 
712 	add_disk(g);
713 
714 	return 0;
715 }
716 
717 static struct ldc_channel_config vdc_ldc_cfg = {
718 	.event		= vdc_event,
719 	.mtu		= 64,
720 	.mode		= LDC_MODE_UNRELIABLE,
721 };
722 
723 static struct vio_driver_ops vdc_vio_ops = {
724 	.send_attr		= vdc_send_attr,
725 	.handle_attr		= vdc_handle_attr,
726 	.handshake_complete	= vdc_handshake_complete,
727 };
728 
729 static void __devinit print_version(void)
730 {
731 	static int version_printed;
732 
733 	if (version_printed++ == 0)
734 		printk(KERN_INFO "%s", version);
735 }
736 
737 static int __devinit vdc_port_probe(struct vio_dev *vdev,
738 				    const struct vio_device_id *id)
739 {
740 	struct mdesc_handle *hp;
741 	struct vdc_port *port;
742 	int err;
743 
744 	print_version();
745 
746 	hp = mdesc_grab();
747 
748 	err = -ENODEV;
749 	if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
750 		printk(KERN_ERR PFX "Port id [%llu] too large.\n",
751 		       vdev->dev_no);
752 		goto err_out_release_mdesc;
753 	}
754 
755 	port = kzalloc(sizeof(*port), GFP_KERNEL);
756 	err = -ENOMEM;
757 	if (!port) {
758 		printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
759 		goto err_out_release_mdesc;
760 	}
761 
762 	if (vdev->dev_no >= 26)
763 		snprintf(port->disk_name, sizeof(port->disk_name),
764 			 VDCBLK_NAME "%c%c",
765 			 'a' + ((int)vdev->dev_no / 26) - 1,
766 			 'a' + ((int)vdev->dev_no % 26));
767 	else
768 		snprintf(port->disk_name, sizeof(port->disk_name),
769 			 VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
770 
771 	err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
772 			      vdc_versions, ARRAY_SIZE(vdc_versions),
773 			      &vdc_vio_ops, port->disk_name);
774 	if (err)
775 		goto err_out_free_port;
776 
777 	port->vdisk_block_size = 512;
778 	port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size);
779 	port->ring_cookies = ((port->max_xfer_size *
780 			       port->vdisk_block_size) / PAGE_SIZE) + 2;
781 
782 	err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
783 	if (err)
784 		goto err_out_free_port;
785 
786 	err = vdc_alloc_tx_ring(port);
787 	if (err)
788 		goto err_out_free_ldc;
789 
790 	err = probe_disk(port);
791 	if (err)
792 		goto err_out_free_tx_ring;
793 
794 	dev_set_drvdata(&vdev->dev, port);
795 
796 	mdesc_release(hp);
797 
798 	return 0;
799 
800 err_out_free_tx_ring:
801 	vdc_free_tx_ring(port);
802 
803 err_out_free_ldc:
804 	vio_ldc_free(&port->vio);
805 
806 err_out_free_port:
807 	kfree(port);
808 
809 err_out_release_mdesc:
810 	mdesc_release(hp);
811 	return err;
812 }
813 
814 static int vdc_port_remove(struct vio_dev *vdev)
815 {
816 	struct vdc_port *port = dev_get_drvdata(&vdev->dev);
817 
818 	if (port) {
819 		del_timer_sync(&port->vio.timer);
820 
821 		vdc_free_tx_ring(port);
822 		vio_ldc_free(&port->vio);
823 
824 		dev_set_drvdata(&vdev->dev, NULL);
825 
826 		kfree(port);
827 	}
828 	return 0;
829 }
830 
831 static const struct vio_device_id vdc_port_match[] = {
832 	{
833 		.type = "vdc-port",
834 	},
835 	{},
836 };
837 MODULE_DEVICE_TABLE(vio, vdc_port_match);
838 
839 static struct vio_driver vdc_port_driver = {
840 	.id_table	= vdc_port_match,
841 	.probe		= vdc_port_probe,
842 	.remove		= vdc_port_remove,
843 	.driver		= {
844 		.name	= "vdc_port",
845 		.owner	= THIS_MODULE,
846 	}
847 };
848 
849 static int __init vdc_init(void)
850 {
851 	int err;
852 
853 	err = register_blkdev(0, VDCBLK_NAME);
854 	if (err < 0)
855 		goto out_err;
856 
857 	vdc_major = err;
858 
859 	err = vio_register_driver(&vdc_port_driver);
860 	if (err)
861 		goto out_unregister_blkdev;
862 
863 	return 0;
864 
865 out_unregister_blkdev:
866 	unregister_blkdev(vdc_major, VDCBLK_NAME);
867 	vdc_major = 0;
868 
869 out_err:
870 	return err;
871 }
872 
873 static void __exit vdc_exit(void)
874 {
875 	vio_unregister_driver(&vdc_port_driver);
876 	unregister_blkdev(vdc_major, VDCBLK_NAME);
877 }
878 
879 module_init(vdc_init);
880 module_exit(vdc_exit);
881