xref: /openbmc/linux/drivers/block/sunvdc.c (revision cfbb9be8)
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 #define VDC_DEFAULT_BLK_SIZE	512
38 
39 #define WAITING_FOR_LINK_UP	0x01
40 #define WAITING_FOR_TX_SPACE	0x02
41 #define WAITING_FOR_GEN_CMD	0x04
42 #define WAITING_FOR_ANY		-1
43 
44 static struct workqueue_struct *sunvdc_wq;
45 
46 struct vdc_req_entry {
47 	struct request		*req;
48 };
49 
50 struct vdc_port {
51 	struct vio_driver_state	vio;
52 
53 	struct gendisk		*disk;
54 
55 	struct vdc_completion	*cmp;
56 
57 	u64			req_id;
58 	u64			seq;
59 	struct vdc_req_entry	rq_arr[VDC_TX_RING_SIZE];
60 
61 	unsigned long		ring_cookies;
62 
63 	u64			max_xfer_size;
64 	u32			vdisk_block_size;
65 
66 	u64			ldc_timeout;
67 	struct timer_list	ldc_reset_timer;
68 	struct work_struct	ldc_reset_work;
69 
70 	/* The server fills these in for us in the disk attribute
71 	 * ACK packet.
72 	 */
73 	u64			operations;
74 	u32			vdisk_size;
75 	u8			vdisk_type;
76 	u8			vdisk_mtype;
77 	u32			vdisk_phys_blksz;
78 
79 	char			disk_name[32];
80 };
81 
82 static void vdc_ldc_reset(struct vdc_port *port);
83 static void vdc_ldc_reset_work(struct work_struct *work);
84 static void vdc_ldc_reset_timer(struct timer_list *t);
85 
86 static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
87 {
88 	return container_of(vio, struct vdc_port, vio);
89 }
90 
91 /* Ordered from largest major to lowest */
92 static struct vio_version vdc_versions[] = {
93 	{ .major = 1, .minor = 2 },
94 	{ .major = 1, .minor = 1 },
95 	{ .major = 1, .minor = 0 },
96 };
97 
98 static inline int vdc_version_supported(struct vdc_port *port,
99 					u16 major, u16 minor)
100 {
101 	return port->vio.ver.major == major && port->vio.ver.minor >= minor;
102 }
103 
104 #define VDCBLK_NAME	"vdisk"
105 static int vdc_major;
106 #define PARTITION_SHIFT	3
107 
108 static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
109 {
110 	return vio_dring_avail(dr, VDC_TX_RING_SIZE);
111 }
112 
113 static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
114 {
115 	struct gendisk *disk = bdev->bd_disk;
116 	sector_t nsect = get_capacity(disk);
117 	sector_t cylinders = nsect;
118 
119 	geo->heads = 0xff;
120 	geo->sectors = 0x3f;
121 	sector_div(cylinders, geo->heads * geo->sectors);
122 	geo->cylinders = cylinders;
123 	if ((sector_t)(geo->cylinders + 1) * geo->heads * geo->sectors < nsect)
124 		geo->cylinders = 0xffff;
125 
126 	return 0;
127 }
128 
129 /* Add ioctl/CDROM_GET_CAPABILITY to support cdrom_id in udev
130  * when vdisk_mtype is VD_MEDIA_TYPE_CD or VD_MEDIA_TYPE_DVD.
131  * Needed to be able to install inside an ldom from an iso image.
132  */
133 static int vdc_ioctl(struct block_device *bdev, fmode_t mode,
134 		     unsigned command, unsigned long argument)
135 {
136 	int i;
137 	struct gendisk *disk;
138 
139 	switch (command) {
140 	case CDROMMULTISESSION:
141 		pr_debug(PFX "Multisession CDs not supported\n");
142 		for (i = 0; i < sizeof(struct cdrom_multisession); i++)
143 			if (put_user(0, (char __user *)(argument + i)))
144 				return -EFAULT;
145 		return 0;
146 
147 	case CDROM_GET_CAPABILITY:
148 		disk = bdev->bd_disk;
149 
150 		if (bdev->bd_disk && (disk->flags & GENHD_FL_CD))
151 			return 0;
152 		return -EINVAL;
153 
154 	default:
155 		pr_debug(PFX "ioctl %08x not supported\n", command);
156 		return -EINVAL;
157 	}
158 }
159 
160 static const struct block_device_operations vdc_fops = {
161 	.owner		= THIS_MODULE,
162 	.getgeo		= vdc_getgeo,
163 	.ioctl		= vdc_ioctl,
164 };
165 
166 static void vdc_blk_queue_start(struct vdc_port *port)
167 {
168 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
169 
170 	/* restart blk queue when ring is half emptied. also called after
171 	 * handshake completes, so check for initial handshake before we've
172 	 * allocated a disk.
173 	 */
174 	if (port->disk && blk_queue_stopped(port->disk->queue) &&
175 	    vdc_tx_dring_avail(dr) * 100 / VDC_TX_RING_SIZE >= 50) {
176 		blk_start_queue(port->disk->queue);
177 	}
178 
179 }
180 
181 static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
182 {
183 	if (vio->cmp &&
184 	    (waiting_for == -1 ||
185 	     vio->cmp->waiting_for == waiting_for)) {
186 		vio->cmp->err = err;
187 		complete(&vio->cmp->com);
188 		vio->cmp = NULL;
189 	}
190 }
191 
192 static void vdc_handshake_complete(struct vio_driver_state *vio)
193 {
194 	struct vdc_port *port = to_vdc_port(vio);
195 
196 	del_timer(&port->ldc_reset_timer);
197 	vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
198 	vdc_blk_queue_start(port);
199 }
200 
201 static int vdc_handle_unknown(struct vdc_port *port, void *arg)
202 {
203 	struct vio_msg_tag *pkt = arg;
204 
205 	printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
206 	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
207 	printk(KERN_ERR PFX "Resetting connection.\n");
208 
209 	ldc_disconnect(port->vio.lp);
210 
211 	return -ECONNRESET;
212 }
213 
214 static int vdc_send_attr(struct vio_driver_state *vio)
215 {
216 	struct vdc_port *port = to_vdc_port(vio);
217 	struct vio_disk_attr_info pkt;
218 
219 	memset(&pkt, 0, sizeof(pkt));
220 
221 	pkt.tag.type = VIO_TYPE_CTRL;
222 	pkt.tag.stype = VIO_SUBTYPE_INFO;
223 	pkt.tag.stype_env = VIO_ATTR_INFO;
224 	pkt.tag.sid = vio_send_sid(vio);
225 
226 	pkt.xfer_mode = VIO_DRING_MODE;
227 	pkt.vdisk_block_size = port->vdisk_block_size;
228 	pkt.max_xfer_size = port->max_xfer_size;
229 
230 	viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
231 	       pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);
232 
233 	return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
234 }
235 
236 static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
237 {
238 	struct vdc_port *port = to_vdc_port(vio);
239 	struct vio_disk_attr_info *pkt = arg;
240 
241 	viodbg(HS, "GOT ATTR stype[0x%x] ops[%llx] disk_size[%llu] disk_type[%x] "
242 	       "mtype[0x%x] xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
243 	       pkt->tag.stype, pkt->operations,
244 	       pkt->vdisk_size, pkt->vdisk_type, pkt->vdisk_mtype,
245 	       pkt->xfer_mode, pkt->vdisk_block_size,
246 	       pkt->max_xfer_size);
247 
248 	if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
249 		switch (pkt->vdisk_type) {
250 		case VD_DISK_TYPE_DISK:
251 		case VD_DISK_TYPE_SLICE:
252 			break;
253 
254 		default:
255 			printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n",
256 			       vio->name, pkt->vdisk_type);
257 			return -ECONNRESET;
258 		}
259 
260 		if (pkt->vdisk_block_size > port->vdisk_block_size) {
261 			printk(KERN_ERR PFX "%s: BLOCK size increased "
262 			       "%u --> %u\n",
263 			       vio->name,
264 			       port->vdisk_block_size, pkt->vdisk_block_size);
265 			return -ECONNRESET;
266 		}
267 
268 		port->operations = pkt->operations;
269 		port->vdisk_type = pkt->vdisk_type;
270 		if (vdc_version_supported(port, 1, 1)) {
271 			port->vdisk_size = pkt->vdisk_size;
272 			port->vdisk_mtype = pkt->vdisk_mtype;
273 		}
274 		if (pkt->max_xfer_size < port->max_xfer_size)
275 			port->max_xfer_size = pkt->max_xfer_size;
276 		port->vdisk_block_size = pkt->vdisk_block_size;
277 
278 		port->vdisk_phys_blksz = VDC_DEFAULT_BLK_SIZE;
279 		if (vdc_version_supported(port, 1, 2))
280 			port->vdisk_phys_blksz = pkt->phys_block_size;
281 
282 		return 0;
283 	} else {
284 		printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name);
285 
286 		return -ECONNRESET;
287 	}
288 }
289 
290 static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc)
291 {
292 	int err = desc->status;
293 
294 	vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
295 }
296 
297 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
298 			unsigned int index)
299 {
300 	struct vio_disk_desc *desc = vio_dring_entry(dr, index);
301 	struct vdc_req_entry *rqe = &port->rq_arr[index];
302 	struct request *req;
303 
304 	if (unlikely(desc->hdr.state != VIO_DESC_DONE))
305 		return;
306 
307 	ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
308 	desc->hdr.state = VIO_DESC_FREE;
309 	dr->cons = vio_dring_next(dr, index);
310 
311 	req = rqe->req;
312 	if (req == NULL) {
313 		vdc_end_special(port, desc);
314 		return;
315 	}
316 
317 	rqe->req = NULL;
318 
319 	__blk_end_request(req, (desc->status ? BLK_STS_IOERR : 0), desc->size);
320 
321 	vdc_blk_queue_start(port);
322 }
323 
324 static int vdc_ack(struct vdc_port *port, void *msgbuf)
325 {
326 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
327 	struct vio_dring_data *pkt = msgbuf;
328 
329 	if (unlikely(pkt->dring_ident != dr->ident ||
330 		     pkt->start_idx != pkt->end_idx ||
331 		     pkt->start_idx >= VDC_TX_RING_SIZE))
332 		return 0;
333 
334 	vdc_end_one(port, dr, pkt->start_idx);
335 
336 	return 0;
337 }
338 
339 static int vdc_nack(struct vdc_port *port, void *msgbuf)
340 {
341 	/* XXX Implement me XXX */
342 	return 0;
343 }
344 
345 static void vdc_event(void *arg, int event)
346 {
347 	struct vdc_port *port = arg;
348 	struct vio_driver_state *vio = &port->vio;
349 	unsigned long flags;
350 	int err;
351 
352 	spin_lock_irqsave(&vio->lock, flags);
353 
354 	if (unlikely(event == LDC_EVENT_RESET)) {
355 		vio_link_state_change(vio, event);
356 		queue_work(sunvdc_wq, &port->ldc_reset_work);
357 		goto out;
358 	}
359 
360 	if (unlikely(event == LDC_EVENT_UP)) {
361 		vio_link_state_change(vio, event);
362 		goto out;
363 	}
364 
365 	if (unlikely(event != LDC_EVENT_DATA_READY)) {
366 		pr_warn(PFX "Unexpected LDC event %d\n", event);
367 		goto out;
368 	}
369 
370 	err = 0;
371 	while (1) {
372 		union {
373 			struct vio_msg_tag tag;
374 			u64 raw[8];
375 		} msgbuf;
376 
377 		err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
378 		if (unlikely(err < 0)) {
379 			if (err == -ECONNRESET)
380 				vio_conn_reset(vio);
381 			break;
382 		}
383 		if (err == 0)
384 			break;
385 		viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
386 		       msgbuf.tag.type,
387 		       msgbuf.tag.stype,
388 		       msgbuf.tag.stype_env,
389 		       msgbuf.tag.sid);
390 		err = vio_validate_sid(vio, &msgbuf.tag);
391 		if (err < 0)
392 			break;
393 
394 		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
395 			if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
396 				err = vdc_ack(port, &msgbuf);
397 			else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
398 				err = vdc_nack(port, &msgbuf);
399 			else
400 				err = vdc_handle_unknown(port, &msgbuf);
401 		} else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
402 			err = vio_control_pkt_engine(vio, &msgbuf);
403 		} else {
404 			err = vdc_handle_unknown(port, &msgbuf);
405 		}
406 		if (err < 0)
407 			break;
408 	}
409 	if (err < 0)
410 		vdc_finish(&port->vio, err, WAITING_FOR_ANY);
411 out:
412 	spin_unlock_irqrestore(&vio->lock, flags);
413 }
414 
415 static int __vdc_tx_trigger(struct vdc_port *port)
416 {
417 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
418 	struct vio_dring_data hdr = {
419 		.tag = {
420 			.type		= VIO_TYPE_DATA,
421 			.stype		= VIO_SUBTYPE_INFO,
422 			.stype_env	= VIO_DRING_DATA,
423 			.sid		= vio_send_sid(&port->vio),
424 		},
425 		.dring_ident		= dr->ident,
426 		.start_idx		= dr->prod,
427 		.end_idx		= dr->prod,
428 	};
429 	int err, delay;
430 
431 	hdr.seq = dr->snd_nxt;
432 	delay = 1;
433 	do {
434 		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
435 		if (err > 0) {
436 			dr->snd_nxt++;
437 			break;
438 		}
439 		udelay(delay);
440 		if ((delay <<= 1) > 128)
441 			delay = 128;
442 	} while (err == -EAGAIN);
443 
444 	if (err == -ENOTCONN)
445 		vdc_ldc_reset(port);
446 	return err;
447 }
448 
449 static int __send_request(struct request *req)
450 {
451 	struct vdc_port *port = req->rq_disk->private_data;
452 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
453 	struct scatterlist sg[port->ring_cookies];
454 	struct vdc_req_entry *rqe;
455 	struct vio_disk_desc *desc;
456 	unsigned int map_perm;
457 	int nsg, err, i;
458 	u64 len;
459 	u8 op;
460 
461 	map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
462 
463 	if (rq_data_dir(req) == READ) {
464 		map_perm |= LDC_MAP_W;
465 		op = VD_OP_BREAD;
466 	} else {
467 		map_perm |= LDC_MAP_R;
468 		op = VD_OP_BWRITE;
469 	}
470 
471 	sg_init_table(sg, port->ring_cookies);
472 	nsg = blk_rq_map_sg(req->q, req, sg);
473 
474 	len = 0;
475 	for (i = 0; i < nsg; i++)
476 		len += sg[i].length;
477 
478 	desc = vio_dring_cur(dr);
479 
480 	err = ldc_map_sg(port->vio.lp, sg, nsg,
481 			 desc->cookies, port->ring_cookies,
482 			 map_perm);
483 	if (err < 0) {
484 		printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
485 		return err;
486 	}
487 
488 	rqe = &port->rq_arr[dr->prod];
489 	rqe->req = req;
490 
491 	desc->hdr.ack = VIO_ACK_ENABLE;
492 	desc->req_id = port->req_id;
493 	desc->operation = op;
494 	if (port->vdisk_type == VD_DISK_TYPE_DISK) {
495 		desc->slice = 0xff;
496 	} else {
497 		desc->slice = 0;
498 	}
499 	desc->status = ~0;
500 	desc->offset = (blk_rq_pos(req) << 9) / port->vdisk_block_size;
501 	desc->size = len;
502 	desc->ncookies = err;
503 
504 	/* This has to be a non-SMP write barrier because we are writing
505 	 * to memory which is shared with the peer LDOM.
506 	 */
507 	wmb();
508 	desc->hdr.state = VIO_DESC_READY;
509 
510 	err = __vdc_tx_trigger(port);
511 	if (err < 0) {
512 		printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
513 	} else {
514 		port->req_id++;
515 		dr->prod = vio_dring_next(dr, dr->prod);
516 	}
517 
518 	return err;
519 }
520 
521 static void do_vdc_request(struct request_queue *rq)
522 {
523 	struct request *req;
524 
525 	while ((req = blk_peek_request(rq)) != NULL) {
526 		struct vdc_port *port;
527 		struct vio_dring_state *dr;
528 
529 		port = req->rq_disk->private_data;
530 		dr = &port->vio.drings[VIO_DRIVER_TX_RING];
531 		if (unlikely(vdc_tx_dring_avail(dr) < 1))
532 			goto wait;
533 
534 		blk_start_request(req);
535 
536 		if (__send_request(req) < 0) {
537 			blk_requeue_request(rq, req);
538 wait:
539 			/* Avoid pointless unplugs. */
540 			blk_stop_queue(rq);
541 			break;
542 		}
543 	}
544 }
545 
546 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
547 {
548 	struct vio_dring_state *dr;
549 	struct vio_completion comp;
550 	struct vio_disk_desc *desc;
551 	unsigned int map_perm;
552 	unsigned long flags;
553 	int op_len, err;
554 	void *req_buf;
555 
556 	if (!(((u64)1 << (u64)op) & port->operations))
557 		return -EOPNOTSUPP;
558 
559 	switch (op) {
560 	case VD_OP_BREAD:
561 	case VD_OP_BWRITE:
562 	default:
563 		return -EINVAL;
564 
565 	case VD_OP_FLUSH:
566 		op_len = 0;
567 		map_perm = 0;
568 		break;
569 
570 	case VD_OP_GET_WCE:
571 		op_len = sizeof(u32);
572 		map_perm = LDC_MAP_W;
573 		break;
574 
575 	case VD_OP_SET_WCE:
576 		op_len = sizeof(u32);
577 		map_perm = LDC_MAP_R;
578 		break;
579 
580 	case VD_OP_GET_VTOC:
581 		op_len = sizeof(struct vio_disk_vtoc);
582 		map_perm = LDC_MAP_W;
583 		break;
584 
585 	case VD_OP_SET_VTOC:
586 		op_len = sizeof(struct vio_disk_vtoc);
587 		map_perm = LDC_MAP_R;
588 		break;
589 
590 	case VD_OP_GET_DISKGEOM:
591 		op_len = sizeof(struct vio_disk_geom);
592 		map_perm = LDC_MAP_W;
593 		break;
594 
595 	case VD_OP_SET_DISKGEOM:
596 		op_len = sizeof(struct vio_disk_geom);
597 		map_perm = LDC_MAP_R;
598 		break;
599 
600 	case VD_OP_SCSICMD:
601 		op_len = 16;
602 		map_perm = LDC_MAP_RW;
603 		break;
604 
605 	case VD_OP_GET_DEVID:
606 		op_len = sizeof(struct vio_disk_devid);
607 		map_perm = LDC_MAP_W;
608 		break;
609 
610 	case VD_OP_GET_EFI:
611 	case VD_OP_SET_EFI:
612 		return -EOPNOTSUPP;
613 		break;
614 	};
615 
616 	map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
617 
618 	op_len = (op_len + 7) & ~7;
619 	req_buf = kzalloc(op_len, GFP_KERNEL);
620 	if (!req_buf)
621 		return -ENOMEM;
622 
623 	if (len > op_len)
624 		len = op_len;
625 
626 	if (map_perm & LDC_MAP_R)
627 		memcpy(req_buf, buf, len);
628 
629 	spin_lock_irqsave(&port->vio.lock, flags);
630 
631 	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
632 
633 	/* XXX If we want to use this code generically we have to
634 	 * XXX handle TX ring exhaustion etc.
635 	 */
636 	desc = vio_dring_cur(dr);
637 
638 	err = ldc_map_single(port->vio.lp, req_buf, op_len,
639 			     desc->cookies, port->ring_cookies,
640 			     map_perm);
641 	if (err < 0) {
642 		spin_unlock_irqrestore(&port->vio.lock, flags);
643 		kfree(req_buf);
644 		return err;
645 	}
646 
647 	init_completion(&comp.com);
648 	comp.waiting_for = WAITING_FOR_GEN_CMD;
649 	port->vio.cmp = &comp;
650 
651 	desc->hdr.ack = VIO_ACK_ENABLE;
652 	desc->req_id = port->req_id;
653 	desc->operation = op;
654 	desc->slice = 0;
655 	desc->status = ~0;
656 	desc->offset = 0;
657 	desc->size = op_len;
658 	desc->ncookies = err;
659 
660 	/* This has to be a non-SMP write barrier because we are writing
661 	 * to memory which is shared with the peer LDOM.
662 	 */
663 	wmb();
664 	desc->hdr.state = VIO_DESC_READY;
665 
666 	err = __vdc_tx_trigger(port);
667 	if (err >= 0) {
668 		port->req_id++;
669 		dr->prod = vio_dring_next(dr, dr->prod);
670 		spin_unlock_irqrestore(&port->vio.lock, flags);
671 
672 		wait_for_completion(&comp.com);
673 		err = comp.err;
674 	} else {
675 		port->vio.cmp = NULL;
676 		spin_unlock_irqrestore(&port->vio.lock, flags);
677 	}
678 
679 	if (map_perm & LDC_MAP_W)
680 		memcpy(buf, req_buf, len);
681 
682 	kfree(req_buf);
683 
684 	return err;
685 }
686 
687 static int vdc_alloc_tx_ring(struct vdc_port *port)
688 {
689 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
690 	unsigned long len, entry_size;
691 	int ncookies;
692 	void *dring;
693 
694 	entry_size = sizeof(struct vio_disk_desc) +
695 		(sizeof(struct ldc_trans_cookie) * port->ring_cookies);
696 	len = (VDC_TX_RING_SIZE * entry_size);
697 
698 	ncookies = VIO_MAX_RING_COOKIES;
699 	dring = ldc_alloc_exp_dring(port->vio.lp, len,
700 				    dr->cookies, &ncookies,
701 				    (LDC_MAP_SHADOW |
702 				     LDC_MAP_DIRECT |
703 				     LDC_MAP_RW));
704 	if (IS_ERR(dring))
705 		return PTR_ERR(dring);
706 
707 	dr->base = dring;
708 	dr->entry_size = entry_size;
709 	dr->num_entries = VDC_TX_RING_SIZE;
710 	dr->prod = dr->cons = 0;
711 	dr->pending = VDC_TX_RING_SIZE;
712 	dr->ncookies = ncookies;
713 
714 	return 0;
715 }
716 
717 static void vdc_free_tx_ring(struct vdc_port *port)
718 {
719 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
720 
721 	if (dr->base) {
722 		ldc_free_exp_dring(port->vio.lp, dr->base,
723 				   (dr->entry_size * dr->num_entries),
724 				   dr->cookies, dr->ncookies);
725 		dr->base = NULL;
726 		dr->entry_size = 0;
727 		dr->num_entries = 0;
728 		dr->pending = 0;
729 		dr->ncookies = 0;
730 	}
731 }
732 
733 static int vdc_port_up(struct vdc_port *port)
734 {
735 	struct vio_completion comp;
736 
737 	init_completion(&comp.com);
738 	comp.err = 0;
739 	comp.waiting_for = WAITING_FOR_LINK_UP;
740 	port->vio.cmp = &comp;
741 
742 	vio_port_up(&port->vio);
743 	wait_for_completion(&comp.com);
744 	return comp.err;
745 }
746 
747 static void vdc_port_down(struct vdc_port *port)
748 {
749 	ldc_disconnect(port->vio.lp);
750 	ldc_unbind(port->vio.lp);
751 	vdc_free_tx_ring(port);
752 	vio_ldc_free(&port->vio);
753 }
754 
755 static int probe_disk(struct vdc_port *port)
756 {
757 	struct request_queue *q;
758 	struct gendisk *g;
759 	int err;
760 
761 	err = vdc_port_up(port);
762 	if (err)
763 		return err;
764 
765 	/* Using version 1.2 means vdisk_phys_blksz should be set unless the
766 	 * disk is reserved by another system.
767 	 */
768 	if (vdc_version_supported(port, 1, 2) && !port->vdisk_phys_blksz)
769 		return -ENODEV;
770 
771 	if (vdc_version_supported(port, 1, 1)) {
772 		/* vdisk_size should be set during the handshake, if it wasn't
773 		 * then the underlying disk is reserved by another system
774 		 */
775 		if (port->vdisk_size == -1)
776 			return -ENODEV;
777 	} else {
778 		struct vio_disk_geom geom;
779 
780 		err = generic_request(port, VD_OP_GET_DISKGEOM,
781 				      &geom, sizeof(geom));
782 		if (err < 0) {
783 			printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
784 			       "error %d\n", err);
785 			return err;
786 		}
787 		port->vdisk_size = ((u64)geom.num_cyl *
788 				    (u64)geom.num_hd *
789 				    (u64)geom.num_sec);
790 	}
791 
792 	q = blk_init_queue(do_vdc_request, &port->vio.lock);
793 	if (!q) {
794 		printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
795 		       port->vio.name);
796 		return -ENOMEM;
797 	}
798 	g = alloc_disk(1 << PARTITION_SHIFT);
799 	if (!g) {
800 		printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
801 		       port->vio.name);
802 		blk_cleanup_queue(q);
803 		return -ENOMEM;
804 	}
805 
806 	port->disk = g;
807 
808 	/* Each segment in a request is up to an aligned page in size. */
809 	blk_queue_segment_boundary(q, PAGE_SIZE - 1);
810 	blk_queue_max_segment_size(q, PAGE_SIZE);
811 
812 	blk_queue_max_segments(q, port->ring_cookies);
813 	blk_queue_max_hw_sectors(q, port->max_xfer_size);
814 	g->major = vdc_major;
815 	g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
816 	strcpy(g->disk_name, port->disk_name);
817 
818 	g->fops = &vdc_fops;
819 	g->queue = q;
820 	g->private_data = port;
821 
822 	set_capacity(g, port->vdisk_size);
823 
824 	if (vdc_version_supported(port, 1, 1)) {
825 		switch (port->vdisk_mtype) {
826 		case VD_MEDIA_TYPE_CD:
827 			pr_info(PFX "Virtual CDROM %s\n", port->disk_name);
828 			g->flags |= GENHD_FL_CD;
829 			g->flags |= GENHD_FL_REMOVABLE;
830 			set_disk_ro(g, 1);
831 			break;
832 
833 		case VD_MEDIA_TYPE_DVD:
834 			pr_info(PFX "Virtual DVD %s\n", port->disk_name);
835 			g->flags |= GENHD_FL_CD;
836 			g->flags |= GENHD_FL_REMOVABLE;
837 			set_disk_ro(g, 1);
838 			break;
839 
840 		case VD_MEDIA_TYPE_FIXED:
841 			pr_info(PFX "Virtual Hard disk %s\n", port->disk_name);
842 			break;
843 		}
844 	}
845 
846 	blk_queue_physical_block_size(q, port->vdisk_phys_blksz);
847 
848 	pr_info(PFX "%s: %u sectors (%u MB) protocol %d.%d\n",
849 	       g->disk_name,
850 	       port->vdisk_size, (port->vdisk_size >> (20 - 9)),
851 	       port->vio.ver.major, port->vio.ver.minor);
852 
853 	device_add_disk(&port->vio.vdev->dev, g);
854 
855 	return 0;
856 }
857 
858 static struct ldc_channel_config vdc_ldc_cfg = {
859 	.event		= vdc_event,
860 	.mtu		= 64,
861 	.mode		= LDC_MODE_UNRELIABLE,
862 };
863 
864 static struct vio_driver_ops vdc_vio_ops = {
865 	.send_attr		= vdc_send_attr,
866 	.handle_attr		= vdc_handle_attr,
867 	.handshake_complete	= vdc_handshake_complete,
868 };
869 
870 static void print_version(void)
871 {
872 	static int version_printed;
873 
874 	if (version_printed++ == 0)
875 		printk(KERN_INFO "%s", version);
876 }
877 
878 struct vdc_check_port_data {
879 	int	dev_no;
880 	char	*type;
881 };
882 
883 static int vdc_device_probed(struct device *dev, void *arg)
884 {
885 	struct vio_dev *vdev = to_vio_dev(dev);
886 	struct vdc_check_port_data *port_data;
887 
888 	port_data = (struct vdc_check_port_data *)arg;
889 
890 	if ((vdev->dev_no == port_data->dev_no) &&
891 	    (!(strcmp((char *)&vdev->type, port_data->type))) &&
892 		dev_get_drvdata(dev)) {
893 		/* This device has already been configured
894 		 * by vdc_port_probe()
895 		 */
896 		return 1;
897 	} else {
898 		return 0;
899 	}
900 }
901 
902 /* Determine whether the VIO device is part of an mpgroup
903  * by locating all the virtual-device-port nodes associated
904  * with the parent virtual-device node for the VIO device
905  * and checking whether any of these nodes are vdc-ports
906  * which have already been configured.
907  *
908  * Returns true if this device is part of an mpgroup and has
909  * already been probed.
910  */
911 static bool vdc_port_mpgroup_check(struct vio_dev *vdev)
912 {
913 	struct vdc_check_port_data port_data;
914 	struct device *dev;
915 
916 	port_data.dev_no = vdev->dev_no;
917 	port_data.type = (char *)&vdev->type;
918 
919 	dev = device_find_child(vdev->dev.parent, &port_data,
920 				vdc_device_probed);
921 
922 	if (dev)
923 		return true;
924 
925 	return false;
926 }
927 
928 static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
929 {
930 	struct mdesc_handle *hp;
931 	struct vdc_port *port;
932 	int err;
933 	const u64 *ldc_timeout;
934 
935 	print_version();
936 
937 	hp = mdesc_grab();
938 
939 	err = -ENODEV;
940 	if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
941 		printk(KERN_ERR PFX "Port id [%llu] too large.\n",
942 		       vdev->dev_no);
943 		goto err_out_release_mdesc;
944 	}
945 
946 	/* Check if this device is part of an mpgroup */
947 	if (vdc_port_mpgroup_check(vdev)) {
948 		printk(KERN_WARNING
949 			"VIO: Ignoring extra vdisk port %s",
950 			dev_name(&vdev->dev));
951 		goto err_out_release_mdesc;
952 	}
953 
954 	port = kzalloc(sizeof(*port), GFP_KERNEL);
955 	err = -ENOMEM;
956 	if (!port) {
957 		printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
958 		goto err_out_release_mdesc;
959 	}
960 
961 	if (vdev->dev_no >= 26)
962 		snprintf(port->disk_name, sizeof(port->disk_name),
963 			 VDCBLK_NAME "%c%c",
964 			 'a' + ((int)vdev->dev_no / 26) - 1,
965 			 'a' + ((int)vdev->dev_no % 26));
966 	else
967 		snprintf(port->disk_name, sizeof(port->disk_name),
968 			 VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
969 	port->vdisk_size = -1;
970 
971 	/* Actual wall time may be double due to do_generic_file_read() doing
972 	 * a readahead I/O first, and once that fails it will try to read a
973 	 * single page.
974 	 */
975 	ldc_timeout = mdesc_get_property(hp, vdev->mp, "vdc-timeout", NULL);
976 	port->ldc_timeout = ldc_timeout ? *ldc_timeout : 0;
977 	timer_setup(&port->ldc_reset_timer, vdc_ldc_reset_timer, 0);
978 	INIT_WORK(&port->ldc_reset_work, vdc_ldc_reset_work);
979 
980 	err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
981 			      vdc_versions, ARRAY_SIZE(vdc_versions),
982 			      &vdc_vio_ops, port->disk_name);
983 	if (err)
984 		goto err_out_free_port;
985 
986 	port->vdisk_block_size = VDC_DEFAULT_BLK_SIZE;
987 	port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size);
988 	port->ring_cookies = ((port->max_xfer_size *
989 			       port->vdisk_block_size) / PAGE_SIZE) + 2;
990 
991 	err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
992 	if (err)
993 		goto err_out_free_port;
994 
995 	err = vdc_alloc_tx_ring(port);
996 	if (err)
997 		goto err_out_free_ldc;
998 
999 	err = probe_disk(port);
1000 	if (err)
1001 		goto err_out_free_tx_ring;
1002 
1003 	/* Note that the device driver_data is used to determine
1004 	 * whether the port has been probed.
1005 	 */
1006 	dev_set_drvdata(&vdev->dev, port);
1007 
1008 	mdesc_release(hp);
1009 
1010 	return 0;
1011 
1012 err_out_free_tx_ring:
1013 	vdc_free_tx_ring(port);
1014 
1015 err_out_free_ldc:
1016 	vio_ldc_free(&port->vio);
1017 
1018 err_out_free_port:
1019 	kfree(port);
1020 
1021 err_out_release_mdesc:
1022 	mdesc_release(hp);
1023 	return err;
1024 }
1025 
1026 static int vdc_port_remove(struct vio_dev *vdev)
1027 {
1028 	struct vdc_port *port = dev_get_drvdata(&vdev->dev);
1029 
1030 	if (port) {
1031 		unsigned long flags;
1032 
1033 		spin_lock_irqsave(&port->vio.lock, flags);
1034 		blk_stop_queue(port->disk->queue);
1035 		spin_unlock_irqrestore(&port->vio.lock, flags);
1036 
1037 		flush_work(&port->ldc_reset_work);
1038 		del_timer_sync(&port->ldc_reset_timer);
1039 		del_timer_sync(&port->vio.timer);
1040 
1041 		del_gendisk(port->disk);
1042 		blk_cleanup_queue(port->disk->queue);
1043 		put_disk(port->disk);
1044 		port->disk = NULL;
1045 
1046 		vdc_free_tx_ring(port);
1047 		vio_ldc_free(&port->vio);
1048 
1049 		dev_set_drvdata(&vdev->dev, NULL);
1050 
1051 		kfree(port);
1052 	}
1053 	return 0;
1054 }
1055 
1056 static void vdc_requeue_inflight(struct vdc_port *port)
1057 {
1058 	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1059 	u32 idx;
1060 
1061 	for (idx = dr->cons; idx != dr->prod; idx = vio_dring_next(dr, idx)) {
1062 		struct vio_disk_desc *desc = vio_dring_entry(dr, idx);
1063 		struct vdc_req_entry *rqe = &port->rq_arr[idx];
1064 		struct request *req;
1065 
1066 		ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
1067 		desc->hdr.state = VIO_DESC_FREE;
1068 		dr->cons = vio_dring_next(dr, idx);
1069 
1070 		req = rqe->req;
1071 		if (req == NULL) {
1072 			vdc_end_special(port, desc);
1073 			continue;
1074 		}
1075 
1076 		rqe->req = NULL;
1077 		blk_requeue_request(port->disk->queue, req);
1078 	}
1079 }
1080 
1081 static void vdc_queue_drain(struct vdc_port *port)
1082 {
1083 	struct request *req;
1084 
1085 	while ((req = blk_fetch_request(port->disk->queue)) != NULL)
1086 		__blk_end_request_all(req, BLK_STS_IOERR);
1087 }
1088 
1089 static void vdc_ldc_reset_timer(struct timer_list *t)
1090 {
1091 	struct vdc_port *port = from_timer(port, t, ldc_reset_timer);
1092 	struct vio_driver_state *vio = &port->vio;
1093 	unsigned long flags;
1094 
1095 	spin_lock_irqsave(&vio->lock, flags);
1096 	if (!(port->vio.hs_state & VIO_HS_COMPLETE)) {
1097 		pr_warn(PFX "%s ldc down %llu seconds, draining queue\n",
1098 			port->disk_name, port->ldc_timeout);
1099 		vdc_queue_drain(port);
1100 		vdc_blk_queue_start(port);
1101 	}
1102 	spin_unlock_irqrestore(&vio->lock, flags);
1103 }
1104 
1105 static void vdc_ldc_reset_work(struct work_struct *work)
1106 {
1107 	struct vdc_port *port;
1108 	struct vio_driver_state *vio;
1109 	unsigned long flags;
1110 
1111 	port = container_of(work, struct vdc_port, ldc_reset_work);
1112 	vio = &port->vio;
1113 
1114 	spin_lock_irqsave(&vio->lock, flags);
1115 	vdc_ldc_reset(port);
1116 	spin_unlock_irqrestore(&vio->lock, flags);
1117 }
1118 
1119 static void vdc_ldc_reset(struct vdc_port *port)
1120 {
1121 	int err;
1122 
1123 	assert_spin_locked(&port->vio.lock);
1124 
1125 	pr_warn(PFX "%s ldc link reset\n", port->disk_name);
1126 	blk_stop_queue(port->disk->queue);
1127 	vdc_requeue_inflight(port);
1128 	vdc_port_down(port);
1129 
1130 	err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
1131 	if (err) {
1132 		pr_err(PFX "%s vio_ldc_alloc:%d\n", port->disk_name, err);
1133 		return;
1134 	}
1135 
1136 	err = vdc_alloc_tx_ring(port);
1137 	if (err) {
1138 		pr_err(PFX "%s vio_alloc_tx_ring:%d\n", port->disk_name, err);
1139 		goto err_free_ldc;
1140 	}
1141 
1142 	if (port->ldc_timeout)
1143 		mod_timer(&port->ldc_reset_timer,
1144 			  round_jiffies(jiffies + HZ * port->ldc_timeout));
1145 	mod_timer(&port->vio.timer, round_jiffies(jiffies + HZ));
1146 	return;
1147 
1148 err_free_ldc:
1149 	vio_ldc_free(&port->vio);
1150 }
1151 
1152 static const struct vio_device_id vdc_port_match[] = {
1153 	{
1154 		.type = "vdc-port",
1155 	},
1156 	{},
1157 };
1158 MODULE_DEVICE_TABLE(vio, vdc_port_match);
1159 
1160 static struct vio_driver vdc_port_driver = {
1161 	.id_table	= vdc_port_match,
1162 	.probe		= vdc_port_probe,
1163 	.remove		= vdc_port_remove,
1164 	.name		= "vdc_port",
1165 };
1166 
1167 static int __init vdc_init(void)
1168 {
1169 	int err;
1170 
1171 	sunvdc_wq = alloc_workqueue("sunvdc", 0, 0);
1172 	if (!sunvdc_wq)
1173 		return -ENOMEM;
1174 
1175 	err = register_blkdev(0, VDCBLK_NAME);
1176 	if (err < 0)
1177 		goto out_free_wq;
1178 
1179 	vdc_major = err;
1180 
1181 	err = vio_register_driver(&vdc_port_driver);
1182 	if (err)
1183 		goto out_unregister_blkdev;
1184 
1185 	return 0;
1186 
1187 out_unregister_blkdev:
1188 	unregister_blkdev(vdc_major, VDCBLK_NAME);
1189 	vdc_major = 0;
1190 
1191 out_free_wq:
1192 	destroy_workqueue(sunvdc_wq);
1193 	return err;
1194 }
1195 
1196 static void __exit vdc_exit(void)
1197 {
1198 	vio_unregister_driver(&vdc_port_driver);
1199 	unregister_blkdev(vdc_major, VDCBLK_NAME);
1200 	destroy_workqueue(sunvdc_wq);
1201 }
1202 
1203 module_init(vdc_init);
1204 module_exit(vdc_exit);
1205