xref: /openbmc/linux/drivers/block/sunvdc.c (revision 293d5b43)
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/cdrom.h>
13 #include <linux/slab.h>
14 #include <linux/spinlock.h>
15 #include <linux/completion.h>
16 #include <linux/delay.h>
17 #include <linux/init.h>
18 #include <linux/list.h>
19 #include <linux/scatterlist.h>
20 
21 #include <asm/vio.h>
22 #include <asm/ldc.h>
23 
24 #define DRV_MODULE_NAME		"sunvdc"
25 #define PFX DRV_MODULE_NAME	": "
26 #define DRV_MODULE_VERSION	"1.2"
27 #define DRV_MODULE_RELDATE	"November 24, 2014"
28 
29 static char version[] =
30 	DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
31 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
32 MODULE_DESCRIPTION("Sun LDOM virtual disk client driver");
33 MODULE_LICENSE("GPL");
34 MODULE_VERSION(DRV_MODULE_VERSION);
35 
36 #define VDC_TX_RING_SIZE	512
37 
38 #define WAITING_FOR_LINK_UP	0x01
39 #define WAITING_FOR_TX_SPACE	0x02
40 #define WAITING_FOR_GEN_CMD	0x04
41 #define WAITING_FOR_ANY		-1
42 
43 static struct workqueue_struct *sunvdc_wq;
44 
45 struct vdc_req_entry {
46 	struct request		*req;
47 };
48 
49 struct vdc_port {
50 	struct vio_driver_state	vio;
51 
52 	struct gendisk		*disk;
53 
54 	struct vdc_completion	*cmp;
55 
56 	u64			req_id;
57 	u64			seq;
58 	struct vdc_req_entry	rq_arr[VDC_TX_RING_SIZE];
59 
60 	unsigned long		ring_cookies;
61 
62 	u64			max_xfer_size;
63 	u32			vdisk_block_size;
64 
65 	u64			ldc_timeout;
66 	struct timer_list	ldc_reset_timer;
67 	struct work_struct	ldc_reset_work;
68 
69 	/* The server fills these in for us in the disk attribute
70 	 * ACK packet.
71 	 */
72 	u64			operations;
73 	u32			vdisk_size;
74 	u8			vdisk_type;
75 	u8			vdisk_mtype;
76 
77 	char			disk_name[32];
78 };
79 
80 static void vdc_ldc_reset(struct vdc_port *port);
81 static void vdc_ldc_reset_work(struct work_struct *work);
82 static void vdc_ldc_reset_timer(unsigned long _arg);
83 
84 static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
85 {
86 	return container_of(vio, struct vdc_port, vio);
87 }
88 
89 /* Ordered from largest major to lowest */
90 static struct vio_version vdc_versions[] = {
91 	{ .major = 1, .minor = 1 },
92 	{ .major = 1, .minor = 0 },
93 };
94 
95 static inline int vdc_version_supported(struct vdc_port *port,
96 					u16 major, u16 minor)
97 {
98 	return port->vio.ver.major == major && port->vio.ver.minor >= minor;
99 }
100 
101 #define VDCBLK_NAME	"vdisk"
102 static int vdc_major;
103 #define PARTITION_SHIFT	3
104 
105 static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
106 {
107 	return vio_dring_avail(dr, VDC_TX_RING_SIZE);
108 }
109 
110 static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
111 {
112 	struct gendisk *disk = bdev->bd_disk;
113 	sector_t nsect = get_capacity(disk);
114 	sector_t cylinders = nsect;
115 
116 	geo->heads = 0xff;
117 	geo->sectors = 0x3f;
118 	sector_div(cylinders, geo->heads * geo->sectors);
119 	geo->cylinders = cylinders;
120 	if ((sector_t)(geo->cylinders + 1) * geo->heads * geo->sectors < nsect)
121 		geo->cylinders = 0xffff;
122 
123 	return 0;
124 }
125 
126 /* Add ioctl/CDROM_GET_CAPABILITY to support cdrom_id in udev
127  * when vdisk_mtype is VD_MEDIA_TYPE_CD or VD_MEDIA_TYPE_DVD.
128  * Needed to be able to install inside an ldom from an iso image.
129  */
130 static int vdc_ioctl(struct block_device *bdev, fmode_t mode,
131 		     unsigned command, unsigned long argument)
132 {
133 	int i;
134 	struct gendisk *disk;
135 
136 	switch (command) {
137 	case CDROMMULTISESSION:
138 		pr_debug(PFX "Multisession CDs not supported\n");
139 		for (i = 0; i < sizeof(struct cdrom_multisession); i++)
140 			if (put_user(0, (char __user *)(argument + i)))
141 				return -EFAULT;
142 		return 0;
143 
144 	case CDROM_GET_CAPABILITY:
145 		disk = bdev->bd_disk;
146 
147 		if (bdev->bd_disk && (disk->flags & GENHD_FL_CD))
148 			return 0;
149 		return -EINVAL;
150 
151 	default:
152 		pr_debug(PFX "ioctl %08x not supported\n", command);
153 		return -EINVAL;
154 	}
155 }
156 
157 static const struct block_device_operations vdc_fops = {
158 	.owner		= THIS_MODULE,
159 	.getgeo		= vdc_getgeo,
160 	.ioctl		= vdc_ioctl,
161 };
162 
163 static void vdc_blk_queue_start(struct vdc_port *port)
164 {
165 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
166 
167 	/* restart blk queue when ring is half emptied. also called after
168 	 * handshake completes, so check for initial handshake before we've
169 	 * allocated a disk.
170 	 */
171 	if (port->disk && blk_queue_stopped(port->disk->queue) &&
172 	    vdc_tx_dring_avail(dr) * 100 / VDC_TX_RING_SIZE >= 50) {
173 		blk_start_queue(port->disk->queue);
174 	}
175 
176 }
177 
178 static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
179 {
180 	if (vio->cmp &&
181 	    (waiting_for == -1 ||
182 	     vio->cmp->waiting_for == waiting_for)) {
183 		vio->cmp->err = err;
184 		complete(&vio->cmp->com);
185 		vio->cmp = NULL;
186 	}
187 }
188 
189 static void vdc_handshake_complete(struct vio_driver_state *vio)
190 {
191 	struct vdc_port *port = to_vdc_port(vio);
192 
193 	del_timer(&port->ldc_reset_timer);
194 	vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
195 	vdc_blk_queue_start(port);
196 }
197 
198 static int vdc_handle_unknown(struct vdc_port *port, void *arg)
199 {
200 	struct vio_msg_tag *pkt = arg;
201 
202 	printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
203 	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
204 	printk(KERN_ERR PFX "Resetting connection.\n");
205 
206 	ldc_disconnect(port->vio.lp);
207 
208 	return -ECONNRESET;
209 }
210 
211 static int vdc_send_attr(struct vio_driver_state *vio)
212 {
213 	struct vdc_port *port = to_vdc_port(vio);
214 	struct vio_disk_attr_info pkt;
215 
216 	memset(&pkt, 0, sizeof(pkt));
217 
218 	pkt.tag.type = VIO_TYPE_CTRL;
219 	pkt.tag.stype = VIO_SUBTYPE_INFO;
220 	pkt.tag.stype_env = VIO_ATTR_INFO;
221 	pkt.tag.sid = vio_send_sid(vio);
222 
223 	pkt.xfer_mode = VIO_DRING_MODE;
224 	pkt.vdisk_block_size = port->vdisk_block_size;
225 	pkt.max_xfer_size = port->max_xfer_size;
226 
227 	viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
228 	       pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);
229 
230 	return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
231 }
232 
233 static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
234 {
235 	struct vdc_port *port = to_vdc_port(vio);
236 	struct vio_disk_attr_info *pkt = arg;
237 
238 	viodbg(HS, "GOT ATTR stype[0x%x] ops[%llx] disk_size[%llu] disk_type[%x] "
239 	       "mtype[0x%x] xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
240 	       pkt->tag.stype, pkt->operations,
241 	       pkt->vdisk_size, pkt->vdisk_type, pkt->vdisk_mtype,
242 	       pkt->xfer_mode, pkt->vdisk_block_size,
243 	       pkt->max_xfer_size);
244 
245 	if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
246 		switch (pkt->vdisk_type) {
247 		case VD_DISK_TYPE_DISK:
248 		case VD_DISK_TYPE_SLICE:
249 			break;
250 
251 		default:
252 			printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n",
253 			       vio->name, pkt->vdisk_type);
254 			return -ECONNRESET;
255 		}
256 
257 		if (pkt->vdisk_block_size > port->vdisk_block_size) {
258 			printk(KERN_ERR PFX "%s: BLOCK size increased "
259 			       "%u --> %u\n",
260 			       vio->name,
261 			       port->vdisk_block_size, pkt->vdisk_block_size);
262 			return -ECONNRESET;
263 		}
264 
265 		port->operations = pkt->operations;
266 		port->vdisk_type = pkt->vdisk_type;
267 		if (vdc_version_supported(port, 1, 1)) {
268 			port->vdisk_size = pkt->vdisk_size;
269 			port->vdisk_mtype = pkt->vdisk_mtype;
270 		}
271 		if (pkt->max_xfer_size < port->max_xfer_size)
272 			port->max_xfer_size = pkt->max_xfer_size;
273 		port->vdisk_block_size = pkt->vdisk_block_size;
274 		return 0;
275 	} else {
276 		printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name);
277 
278 		return -ECONNRESET;
279 	}
280 }
281 
282 static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc)
283 {
284 	int err = desc->status;
285 
286 	vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
287 }
288 
289 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
290 			unsigned int index)
291 {
292 	struct vio_disk_desc *desc = vio_dring_entry(dr, index);
293 	struct vdc_req_entry *rqe = &port->rq_arr[index];
294 	struct request *req;
295 
296 	if (unlikely(desc->hdr.state != VIO_DESC_DONE))
297 		return;
298 
299 	ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
300 	desc->hdr.state = VIO_DESC_FREE;
301 	dr->cons = vio_dring_next(dr, index);
302 
303 	req = rqe->req;
304 	if (req == NULL) {
305 		vdc_end_special(port, desc);
306 		return;
307 	}
308 
309 	rqe->req = NULL;
310 
311 	__blk_end_request(req, (desc->status ? -EIO : 0), desc->size);
312 
313 	vdc_blk_queue_start(port);
314 }
315 
316 static int vdc_ack(struct vdc_port *port, void *msgbuf)
317 {
318 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
319 	struct vio_dring_data *pkt = msgbuf;
320 
321 	if (unlikely(pkt->dring_ident != dr->ident ||
322 		     pkt->start_idx != pkt->end_idx ||
323 		     pkt->start_idx >= VDC_TX_RING_SIZE))
324 		return 0;
325 
326 	vdc_end_one(port, dr, pkt->start_idx);
327 
328 	return 0;
329 }
330 
331 static int vdc_nack(struct vdc_port *port, void *msgbuf)
332 {
333 	/* XXX Implement me XXX */
334 	return 0;
335 }
336 
337 static void vdc_event(void *arg, int event)
338 {
339 	struct vdc_port *port = arg;
340 	struct vio_driver_state *vio = &port->vio;
341 	unsigned long flags;
342 	int err;
343 
344 	spin_lock_irqsave(&vio->lock, flags);
345 
346 	if (unlikely(event == LDC_EVENT_RESET)) {
347 		vio_link_state_change(vio, event);
348 		queue_work(sunvdc_wq, &port->ldc_reset_work);
349 		goto out;
350 	}
351 
352 	if (unlikely(event == LDC_EVENT_UP)) {
353 		vio_link_state_change(vio, event);
354 		goto out;
355 	}
356 
357 	if (unlikely(event != LDC_EVENT_DATA_READY)) {
358 		pr_warn(PFX "Unexpected LDC event %d\n", event);
359 		goto out;
360 	}
361 
362 	err = 0;
363 	while (1) {
364 		union {
365 			struct vio_msg_tag tag;
366 			u64 raw[8];
367 		} msgbuf;
368 
369 		err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
370 		if (unlikely(err < 0)) {
371 			if (err == -ECONNRESET)
372 				vio_conn_reset(vio);
373 			break;
374 		}
375 		if (err == 0)
376 			break;
377 		viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
378 		       msgbuf.tag.type,
379 		       msgbuf.tag.stype,
380 		       msgbuf.tag.stype_env,
381 		       msgbuf.tag.sid);
382 		err = vio_validate_sid(vio, &msgbuf.tag);
383 		if (err < 0)
384 			break;
385 
386 		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
387 			if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
388 				err = vdc_ack(port, &msgbuf);
389 			else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
390 				err = vdc_nack(port, &msgbuf);
391 			else
392 				err = vdc_handle_unknown(port, &msgbuf);
393 		} else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
394 			err = vio_control_pkt_engine(vio, &msgbuf);
395 		} else {
396 			err = vdc_handle_unknown(port, &msgbuf);
397 		}
398 		if (err < 0)
399 			break;
400 	}
401 	if (err < 0)
402 		vdc_finish(&port->vio, err, WAITING_FOR_ANY);
403 out:
404 	spin_unlock_irqrestore(&vio->lock, flags);
405 }
406 
407 static int __vdc_tx_trigger(struct vdc_port *port)
408 {
409 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
410 	struct vio_dring_data hdr = {
411 		.tag = {
412 			.type		= VIO_TYPE_DATA,
413 			.stype		= VIO_SUBTYPE_INFO,
414 			.stype_env	= VIO_DRING_DATA,
415 			.sid		= vio_send_sid(&port->vio),
416 		},
417 		.dring_ident		= dr->ident,
418 		.start_idx		= dr->prod,
419 		.end_idx		= dr->prod,
420 	};
421 	int err, delay;
422 
423 	hdr.seq = dr->snd_nxt;
424 	delay = 1;
425 	do {
426 		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
427 		if (err > 0) {
428 			dr->snd_nxt++;
429 			break;
430 		}
431 		udelay(delay);
432 		if ((delay <<= 1) > 128)
433 			delay = 128;
434 	} while (err == -EAGAIN);
435 
436 	if (err == -ENOTCONN)
437 		vdc_ldc_reset(port);
438 	return err;
439 }
440 
441 static int __send_request(struct request *req)
442 {
443 	struct vdc_port *port = req->rq_disk->private_data;
444 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
445 	struct scatterlist sg[port->ring_cookies];
446 	struct vdc_req_entry *rqe;
447 	struct vio_disk_desc *desc;
448 	unsigned int map_perm;
449 	int nsg, err, i;
450 	u64 len;
451 	u8 op;
452 
453 	map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
454 
455 	if (rq_data_dir(req) == READ) {
456 		map_perm |= LDC_MAP_W;
457 		op = VD_OP_BREAD;
458 	} else {
459 		map_perm |= LDC_MAP_R;
460 		op = VD_OP_BWRITE;
461 	}
462 
463 	sg_init_table(sg, port->ring_cookies);
464 	nsg = blk_rq_map_sg(req->q, req, sg);
465 
466 	len = 0;
467 	for (i = 0; i < nsg; i++)
468 		len += sg[i].length;
469 
470 	desc = vio_dring_cur(dr);
471 
472 	err = ldc_map_sg(port->vio.lp, sg, nsg,
473 			 desc->cookies, port->ring_cookies,
474 			 map_perm);
475 	if (err < 0) {
476 		printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
477 		return err;
478 	}
479 
480 	rqe = &port->rq_arr[dr->prod];
481 	rqe->req = req;
482 
483 	desc->hdr.ack = VIO_ACK_ENABLE;
484 	desc->req_id = port->req_id;
485 	desc->operation = op;
486 	if (port->vdisk_type == VD_DISK_TYPE_DISK) {
487 		desc->slice = 0xff;
488 	} else {
489 		desc->slice = 0;
490 	}
491 	desc->status = ~0;
492 	desc->offset = (blk_rq_pos(req) << 9) / port->vdisk_block_size;
493 	desc->size = len;
494 	desc->ncookies = err;
495 
496 	/* This has to be a non-SMP write barrier because we are writing
497 	 * to memory which is shared with the peer LDOM.
498 	 */
499 	wmb();
500 	desc->hdr.state = VIO_DESC_READY;
501 
502 	err = __vdc_tx_trigger(port);
503 	if (err < 0) {
504 		printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
505 	} else {
506 		port->req_id++;
507 		dr->prod = vio_dring_next(dr, dr->prod);
508 	}
509 
510 	return err;
511 }
512 
513 static void do_vdc_request(struct request_queue *rq)
514 {
515 	struct request *req;
516 
517 	while ((req = blk_peek_request(rq)) != NULL) {
518 		struct vdc_port *port;
519 		struct vio_dring_state *dr;
520 
521 		port = req->rq_disk->private_data;
522 		dr = &port->vio.drings[VIO_DRIVER_TX_RING];
523 		if (unlikely(vdc_tx_dring_avail(dr) < 1))
524 			goto wait;
525 
526 		blk_start_request(req);
527 
528 		if (__send_request(req) < 0) {
529 			blk_requeue_request(rq, req);
530 wait:
531 			/* Avoid pointless unplugs. */
532 			blk_stop_queue(rq);
533 			break;
534 		}
535 	}
536 }
537 
538 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
539 {
540 	struct vio_dring_state *dr;
541 	struct vio_completion comp;
542 	struct vio_disk_desc *desc;
543 	unsigned int map_perm;
544 	unsigned long flags;
545 	int op_len, err;
546 	void *req_buf;
547 
548 	if (!(((u64)1 << (u64)op) & port->operations))
549 		return -EOPNOTSUPP;
550 
551 	switch (op) {
552 	case VD_OP_BREAD:
553 	case VD_OP_BWRITE:
554 	default:
555 		return -EINVAL;
556 
557 	case VD_OP_FLUSH:
558 		op_len = 0;
559 		map_perm = 0;
560 		break;
561 
562 	case VD_OP_GET_WCE:
563 		op_len = sizeof(u32);
564 		map_perm = LDC_MAP_W;
565 		break;
566 
567 	case VD_OP_SET_WCE:
568 		op_len = sizeof(u32);
569 		map_perm = LDC_MAP_R;
570 		break;
571 
572 	case VD_OP_GET_VTOC:
573 		op_len = sizeof(struct vio_disk_vtoc);
574 		map_perm = LDC_MAP_W;
575 		break;
576 
577 	case VD_OP_SET_VTOC:
578 		op_len = sizeof(struct vio_disk_vtoc);
579 		map_perm = LDC_MAP_R;
580 		break;
581 
582 	case VD_OP_GET_DISKGEOM:
583 		op_len = sizeof(struct vio_disk_geom);
584 		map_perm = LDC_MAP_W;
585 		break;
586 
587 	case VD_OP_SET_DISKGEOM:
588 		op_len = sizeof(struct vio_disk_geom);
589 		map_perm = LDC_MAP_R;
590 		break;
591 
592 	case VD_OP_SCSICMD:
593 		op_len = 16;
594 		map_perm = LDC_MAP_RW;
595 		break;
596 
597 	case VD_OP_GET_DEVID:
598 		op_len = sizeof(struct vio_disk_devid);
599 		map_perm = LDC_MAP_W;
600 		break;
601 
602 	case VD_OP_GET_EFI:
603 	case VD_OP_SET_EFI:
604 		return -EOPNOTSUPP;
605 		break;
606 	};
607 
608 	map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
609 
610 	op_len = (op_len + 7) & ~7;
611 	req_buf = kzalloc(op_len, GFP_KERNEL);
612 	if (!req_buf)
613 		return -ENOMEM;
614 
615 	if (len > op_len)
616 		len = op_len;
617 
618 	if (map_perm & LDC_MAP_R)
619 		memcpy(req_buf, buf, len);
620 
621 	spin_lock_irqsave(&port->vio.lock, flags);
622 
623 	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
624 
625 	/* XXX If we want to use this code generically we have to
626 	 * XXX handle TX ring exhaustion etc.
627 	 */
628 	desc = vio_dring_cur(dr);
629 
630 	err = ldc_map_single(port->vio.lp, req_buf, op_len,
631 			     desc->cookies, port->ring_cookies,
632 			     map_perm);
633 	if (err < 0) {
634 		spin_unlock_irqrestore(&port->vio.lock, flags);
635 		kfree(req_buf);
636 		return err;
637 	}
638 
639 	init_completion(&comp.com);
640 	comp.waiting_for = WAITING_FOR_GEN_CMD;
641 	port->vio.cmp = &comp;
642 
643 	desc->hdr.ack = VIO_ACK_ENABLE;
644 	desc->req_id = port->req_id;
645 	desc->operation = op;
646 	desc->slice = 0;
647 	desc->status = ~0;
648 	desc->offset = 0;
649 	desc->size = op_len;
650 	desc->ncookies = err;
651 
652 	/* This has to be a non-SMP write barrier because we are writing
653 	 * to memory which is shared with the peer LDOM.
654 	 */
655 	wmb();
656 	desc->hdr.state = VIO_DESC_READY;
657 
658 	err = __vdc_tx_trigger(port);
659 	if (err >= 0) {
660 		port->req_id++;
661 		dr->prod = vio_dring_next(dr, dr->prod);
662 		spin_unlock_irqrestore(&port->vio.lock, flags);
663 
664 		wait_for_completion(&comp.com);
665 		err = comp.err;
666 	} else {
667 		port->vio.cmp = NULL;
668 		spin_unlock_irqrestore(&port->vio.lock, flags);
669 	}
670 
671 	if (map_perm & LDC_MAP_W)
672 		memcpy(buf, req_buf, len);
673 
674 	kfree(req_buf);
675 
676 	return err;
677 }
678 
679 static int vdc_alloc_tx_ring(struct vdc_port *port)
680 {
681 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
682 	unsigned long len, entry_size;
683 	int ncookies;
684 	void *dring;
685 
686 	entry_size = sizeof(struct vio_disk_desc) +
687 		(sizeof(struct ldc_trans_cookie) * port->ring_cookies);
688 	len = (VDC_TX_RING_SIZE * entry_size);
689 
690 	ncookies = VIO_MAX_RING_COOKIES;
691 	dring = ldc_alloc_exp_dring(port->vio.lp, len,
692 				    dr->cookies, &ncookies,
693 				    (LDC_MAP_SHADOW |
694 				     LDC_MAP_DIRECT |
695 				     LDC_MAP_RW));
696 	if (IS_ERR(dring))
697 		return PTR_ERR(dring);
698 
699 	dr->base = dring;
700 	dr->entry_size = entry_size;
701 	dr->num_entries = VDC_TX_RING_SIZE;
702 	dr->prod = dr->cons = 0;
703 	dr->pending = VDC_TX_RING_SIZE;
704 	dr->ncookies = ncookies;
705 
706 	return 0;
707 }
708 
709 static void vdc_free_tx_ring(struct vdc_port *port)
710 {
711 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
712 
713 	if (dr->base) {
714 		ldc_free_exp_dring(port->vio.lp, dr->base,
715 				   (dr->entry_size * dr->num_entries),
716 				   dr->cookies, dr->ncookies);
717 		dr->base = NULL;
718 		dr->entry_size = 0;
719 		dr->num_entries = 0;
720 		dr->pending = 0;
721 		dr->ncookies = 0;
722 	}
723 }
724 
725 static int vdc_port_up(struct vdc_port *port)
726 {
727 	struct vio_completion comp;
728 
729 	init_completion(&comp.com);
730 	comp.err = 0;
731 	comp.waiting_for = WAITING_FOR_LINK_UP;
732 	port->vio.cmp = &comp;
733 
734 	vio_port_up(&port->vio);
735 	wait_for_completion(&comp.com);
736 	return comp.err;
737 }
738 
739 static void vdc_port_down(struct vdc_port *port)
740 {
741 	ldc_disconnect(port->vio.lp);
742 	ldc_unbind(port->vio.lp);
743 	vdc_free_tx_ring(port);
744 	vio_ldc_free(&port->vio);
745 }
746 
747 static int probe_disk(struct vdc_port *port)
748 {
749 	struct request_queue *q;
750 	struct gendisk *g;
751 	int err;
752 
753 	err = vdc_port_up(port);
754 	if (err)
755 		return err;
756 
757 	if (vdc_version_supported(port, 1, 1)) {
758 		/* vdisk_size should be set during the handshake, if it wasn't
759 		 * then the underlying disk is reserved by another system
760 		 */
761 		if (port->vdisk_size == -1)
762 			return -ENODEV;
763 	} else {
764 		struct vio_disk_geom geom;
765 
766 		err = generic_request(port, VD_OP_GET_DISKGEOM,
767 				      &geom, sizeof(geom));
768 		if (err < 0) {
769 			printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
770 			       "error %d\n", err);
771 			return err;
772 		}
773 		port->vdisk_size = ((u64)geom.num_cyl *
774 				    (u64)geom.num_hd *
775 				    (u64)geom.num_sec);
776 	}
777 
778 	q = blk_init_queue(do_vdc_request, &port->vio.lock);
779 	if (!q) {
780 		printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
781 		       port->vio.name);
782 		return -ENOMEM;
783 	}
784 	g = alloc_disk(1 << PARTITION_SHIFT);
785 	if (!g) {
786 		printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
787 		       port->vio.name);
788 		blk_cleanup_queue(q);
789 		return -ENOMEM;
790 	}
791 
792 	port->disk = g;
793 
794 	/* Each segment in a request is up to an aligned page in size. */
795 	blk_queue_segment_boundary(q, PAGE_SIZE - 1);
796 	blk_queue_max_segment_size(q, PAGE_SIZE);
797 
798 	blk_queue_max_segments(q, port->ring_cookies);
799 	blk_queue_max_hw_sectors(q, port->max_xfer_size);
800 	g->major = vdc_major;
801 	g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
802 	strcpy(g->disk_name, port->disk_name);
803 
804 	g->fops = &vdc_fops;
805 	g->queue = q;
806 	g->private_data = port;
807 
808 	set_capacity(g, port->vdisk_size);
809 
810 	if (vdc_version_supported(port, 1, 1)) {
811 		switch (port->vdisk_mtype) {
812 		case VD_MEDIA_TYPE_CD:
813 			pr_info(PFX "Virtual CDROM %s\n", port->disk_name);
814 			g->flags |= GENHD_FL_CD;
815 			g->flags |= GENHD_FL_REMOVABLE;
816 			set_disk_ro(g, 1);
817 			break;
818 
819 		case VD_MEDIA_TYPE_DVD:
820 			pr_info(PFX "Virtual DVD %s\n", port->disk_name);
821 			g->flags |= GENHD_FL_CD;
822 			g->flags |= GENHD_FL_REMOVABLE;
823 			set_disk_ro(g, 1);
824 			break;
825 
826 		case VD_MEDIA_TYPE_FIXED:
827 			pr_info(PFX "Virtual Hard disk %s\n", port->disk_name);
828 			break;
829 		}
830 	}
831 
832 	pr_info(PFX "%s: %u sectors (%u MB) protocol %d.%d\n",
833 	       g->disk_name,
834 	       port->vdisk_size, (port->vdisk_size >> (20 - 9)),
835 	       port->vio.ver.major, port->vio.ver.minor);
836 
837 	device_add_disk(&port->vio.vdev->dev, g);
838 
839 	return 0;
840 }
841 
842 static struct ldc_channel_config vdc_ldc_cfg = {
843 	.event		= vdc_event,
844 	.mtu		= 64,
845 	.mode		= LDC_MODE_UNRELIABLE,
846 };
847 
848 static struct vio_driver_ops vdc_vio_ops = {
849 	.send_attr		= vdc_send_attr,
850 	.handle_attr		= vdc_handle_attr,
851 	.handshake_complete	= vdc_handshake_complete,
852 };
853 
854 static void print_version(void)
855 {
856 	static int version_printed;
857 
858 	if (version_printed++ == 0)
859 		printk(KERN_INFO "%s", version);
860 }
861 
862 static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
863 {
864 	struct mdesc_handle *hp;
865 	struct vdc_port *port;
866 	int err;
867 	const u64 *ldc_timeout;
868 
869 	print_version();
870 
871 	hp = mdesc_grab();
872 
873 	err = -ENODEV;
874 	if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
875 		printk(KERN_ERR PFX "Port id [%llu] too large.\n",
876 		       vdev->dev_no);
877 		goto err_out_release_mdesc;
878 	}
879 
880 	port = kzalloc(sizeof(*port), GFP_KERNEL);
881 	err = -ENOMEM;
882 	if (!port) {
883 		printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
884 		goto err_out_release_mdesc;
885 	}
886 
887 	if (vdev->dev_no >= 26)
888 		snprintf(port->disk_name, sizeof(port->disk_name),
889 			 VDCBLK_NAME "%c%c",
890 			 'a' + ((int)vdev->dev_no / 26) - 1,
891 			 'a' + ((int)vdev->dev_no % 26));
892 	else
893 		snprintf(port->disk_name, sizeof(port->disk_name),
894 			 VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
895 	port->vdisk_size = -1;
896 
897 	/* Actual wall time may be double due to do_generic_file_read() doing
898 	 * a readahead I/O first, and once that fails it will try to read a
899 	 * single page.
900 	 */
901 	ldc_timeout = mdesc_get_property(hp, vdev->mp, "vdc-timeout", NULL);
902 	port->ldc_timeout = ldc_timeout ? *ldc_timeout : 0;
903 	setup_timer(&port->ldc_reset_timer, vdc_ldc_reset_timer,
904 		    (unsigned long)port);
905 	INIT_WORK(&port->ldc_reset_work, vdc_ldc_reset_work);
906 
907 	err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
908 			      vdc_versions, ARRAY_SIZE(vdc_versions),
909 			      &vdc_vio_ops, port->disk_name);
910 	if (err)
911 		goto err_out_free_port;
912 
913 	port->vdisk_block_size = 512;
914 	port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size);
915 	port->ring_cookies = ((port->max_xfer_size *
916 			       port->vdisk_block_size) / PAGE_SIZE) + 2;
917 
918 	err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
919 	if (err)
920 		goto err_out_free_port;
921 
922 	err = vdc_alloc_tx_ring(port);
923 	if (err)
924 		goto err_out_free_ldc;
925 
926 	err = probe_disk(port);
927 	if (err)
928 		goto err_out_free_tx_ring;
929 
930 	dev_set_drvdata(&vdev->dev, port);
931 
932 	mdesc_release(hp);
933 
934 	return 0;
935 
936 err_out_free_tx_ring:
937 	vdc_free_tx_ring(port);
938 
939 err_out_free_ldc:
940 	vio_ldc_free(&port->vio);
941 
942 err_out_free_port:
943 	kfree(port);
944 
945 err_out_release_mdesc:
946 	mdesc_release(hp);
947 	return err;
948 }
949 
950 static int vdc_port_remove(struct vio_dev *vdev)
951 {
952 	struct vdc_port *port = dev_get_drvdata(&vdev->dev);
953 
954 	if (port) {
955 		unsigned long flags;
956 
957 		spin_lock_irqsave(&port->vio.lock, flags);
958 		blk_stop_queue(port->disk->queue);
959 		spin_unlock_irqrestore(&port->vio.lock, flags);
960 
961 		flush_work(&port->ldc_reset_work);
962 		del_timer_sync(&port->ldc_reset_timer);
963 		del_timer_sync(&port->vio.timer);
964 
965 		del_gendisk(port->disk);
966 		blk_cleanup_queue(port->disk->queue);
967 		put_disk(port->disk);
968 		port->disk = NULL;
969 
970 		vdc_free_tx_ring(port);
971 		vio_ldc_free(&port->vio);
972 
973 		dev_set_drvdata(&vdev->dev, NULL);
974 
975 		kfree(port);
976 	}
977 	return 0;
978 }
979 
980 static void vdc_requeue_inflight(struct vdc_port *port)
981 {
982 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
983 	u32 idx;
984 
985 	for (idx = dr->cons; idx != dr->prod; idx = vio_dring_next(dr, idx)) {
986 		struct vio_disk_desc *desc = vio_dring_entry(dr, idx);
987 		struct vdc_req_entry *rqe = &port->rq_arr[idx];
988 		struct request *req;
989 
990 		ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
991 		desc->hdr.state = VIO_DESC_FREE;
992 		dr->cons = vio_dring_next(dr, idx);
993 
994 		req = rqe->req;
995 		if (req == NULL) {
996 			vdc_end_special(port, desc);
997 			continue;
998 		}
999 
1000 		rqe->req = NULL;
1001 		blk_requeue_request(port->disk->queue, req);
1002 	}
1003 }
1004 
1005 static void vdc_queue_drain(struct vdc_port *port)
1006 {
1007 	struct request *req;
1008 
1009 	while ((req = blk_fetch_request(port->disk->queue)) != NULL)
1010 		__blk_end_request_all(req, -EIO);
1011 }
1012 
1013 static void vdc_ldc_reset_timer(unsigned long _arg)
1014 {
1015 	struct vdc_port *port = (struct vdc_port *) _arg;
1016 	struct vio_driver_state *vio = &port->vio;
1017 	unsigned long flags;
1018 
1019 	spin_lock_irqsave(&vio->lock, flags);
1020 	if (!(port->vio.hs_state & VIO_HS_COMPLETE)) {
1021 		pr_warn(PFX "%s ldc down %llu seconds, draining queue\n",
1022 			port->disk_name, port->ldc_timeout);
1023 		vdc_queue_drain(port);
1024 		vdc_blk_queue_start(port);
1025 	}
1026 	spin_unlock_irqrestore(&vio->lock, flags);
1027 }
1028 
1029 static void vdc_ldc_reset_work(struct work_struct *work)
1030 {
1031 	struct vdc_port *port;
1032 	struct vio_driver_state *vio;
1033 	unsigned long flags;
1034 
1035 	port = container_of(work, struct vdc_port, ldc_reset_work);
1036 	vio = &port->vio;
1037 
1038 	spin_lock_irqsave(&vio->lock, flags);
1039 	vdc_ldc_reset(port);
1040 	spin_unlock_irqrestore(&vio->lock, flags);
1041 }
1042 
1043 static void vdc_ldc_reset(struct vdc_port *port)
1044 {
1045 	int err;
1046 
1047 	assert_spin_locked(&port->vio.lock);
1048 
1049 	pr_warn(PFX "%s ldc link reset\n", port->disk_name);
1050 	blk_stop_queue(port->disk->queue);
1051 	vdc_requeue_inflight(port);
1052 	vdc_port_down(port);
1053 
1054 	err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
1055 	if (err) {
1056 		pr_err(PFX "%s vio_ldc_alloc:%d\n", port->disk_name, err);
1057 		return;
1058 	}
1059 
1060 	err = vdc_alloc_tx_ring(port);
1061 	if (err) {
1062 		pr_err(PFX "%s vio_alloc_tx_ring:%d\n", port->disk_name, err);
1063 		goto err_free_ldc;
1064 	}
1065 
1066 	if (port->ldc_timeout)
1067 		mod_timer(&port->ldc_reset_timer,
1068 			  round_jiffies(jiffies + HZ * port->ldc_timeout));
1069 	mod_timer(&port->vio.timer, round_jiffies(jiffies + HZ));
1070 	return;
1071 
1072 err_free_ldc:
1073 	vio_ldc_free(&port->vio);
1074 }
1075 
1076 static const struct vio_device_id vdc_port_match[] = {
1077 	{
1078 		.type = "vdc-port",
1079 	},
1080 	{},
1081 };
1082 MODULE_DEVICE_TABLE(vio, vdc_port_match);
1083 
1084 static struct vio_driver vdc_port_driver = {
1085 	.id_table	= vdc_port_match,
1086 	.probe		= vdc_port_probe,
1087 	.remove		= vdc_port_remove,
1088 	.name		= "vdc_port",
1089 };
1090 
1091 static int __init vdc_init(void)
1092 {
1093 	int err;
1094 
1095 	sunvdc_wq = alloc_workqueue("sunvdc", 0, 0);
1096 	if (!sunvdc_wq)
1097 		return -ENOMEM;
1098 
1099 	err = register_blkdev(0, VDCBLK_NAME);
1100 	if (err < 0)
1101 		goto out_free_wq;
1102 
1103 	vdc_major = err;
1104 
1105 	err = vio_register_driver(&vdc_port_driver);
1106 	if (err)
1107 		goto out_unregister_blkdev;
1108 
1109 	return 0;
1110 
1111 out_unregister_blkdev:
1112 	unregister_blkdev(vdc_major, VDCBLK_NAME);
1113 	vdc_major = 0;
1114 
1115 out_free_wq:
1116 	destroy_workqueue(sunvdc_wq);
1117 	return err;
1118 }
1119 
1120 static void __exit vdc_exit(void)
1121 {
1122 	vio_unregister_driver(&vdc_port_driver);
1123 	unregister_blkdev(vdc_major, VDCBLK_NAME);
1124 	destroy_workqueue(sunvdc_wq);
1125 }
1126 
1127 module_init(vdc_init);
1128 module_exit(vdc_exit);
1129