xref: /kernel/linux/linux-5.10/drivers/block/sunvdc.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/* sunvdc.c: Sun LDOM Virtual Disk Client.
3 *
4 * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
5 */
6
7#include <linux/module.h>
8#include <linux/kernel.h>
9#include <linux/types.h>
10#include <linux/blk-mq.h>
11#include <linux/hdreg.h>
12#include <linux/genhd.h>
13#include <linux/cdrom.h>
14#include <linux/slab.h>
15#include <linux/spinlock.h>
16#include <linux/completion.h>
17#include <linux/delay.h>
18#include <linux/init.h>
19#include <linux/list.h>
20#include <linux/scatterlist.h>
21
22#include <asm/vio.h>
23#include <asm/ldc.h>
24
25#define DRV_MODULE_NAME		"sunvdc"
26#define PFX DRV_MODULE_NAME	": "
27#define DRV_MODULE_VERSION	"1.2"
28#define DRV_MODULE_RELDATE	"November 24, 2014"
29
30static char version[] =
31	DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
32MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
33MODULE_DESCRIPTION("Sun LDOM virtual disk client driver");
34MODULE_LICENSE("GPL");
35MODULE_VERSION(DRV_MODULE_VERSION);
36
37#define VDC_TX_RING_SIZE	512
38#define VDC_DEFAULT_BLK_SIZE	512
39
40#define MAX_XFER_BLKS		(128 * 1024)
41#define MAX_XFER_SIZE		(MAX_XFER_BLKS / VDC_DEFAULT_BLK_SIZE)
42#define MAX_RING_COOKIES	((MAX_XFER_BLKS / PAGE_SIZE) + 2)
43
44#define WAITING_FOR_LINK_UP	0x01
45#define WAITING_FOR_TX_SPACE	0x02
46#define WAITING_FOR_GEN_CMD	0x04
47#define WAITING_FOR_ANY		-1
48
49#define	VDC_MAX_RETRIES	10
50
51static struct workqueue_struct *sunvdc_wq;
52
53struct vdc_req_entry {
54	struct request		*req;
55};
56
57struct vdc_port {
58	struct vio_driver_state	vio;
59
60	struct gendisk		*disk;
61
62	struct vdc_completion	*cmp;
63
64	u64			req_id;
65	u64			seq;
66	struct vdc_req_entry	rq_arr[VDC_TX_RING_SIZE];
67
68	unsigned long		ring_cookies;
69
70	u64			max_xfer_size;
71	u32			vdisk_block_size;
72	u32			drain;
73
74	u64			ldc_timeout;
75	struct delayed_work	ldc_reset_timer_work;
76	struct work_struct	ldc_reset_work;
77
78	/* The server fills these in for us in the disk attribute
79	 * ACK packet.
80	 */
81	u64			operations;
82	u32			vdisk_size;
83	u8			vdisk_type;
84	u8			vdisk_mtype;
85	u32			vdisk_phys_blksz;
86
87	struct blk_mq_tag_set	tag_set;
88
89	char			disk_name[32];
90};
91
92static void vdc_ldc_reset(struct vdc_port *port);
93static void vdc_ldc_reset_work(struct work_struct *work);
94static void vdc_ldc_reset_timer_work(struct work_struct *work);
95
96static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
97{
98	return container_of(vio, struct vdc_port, vio);
99}
100
101/* Ordered from largest major to lowest */
102static struct vio_version vdc_versions[] = {
103	{ .major = 1, .minor = 2 },
104	{ .major = 1, .minor = 1 },
105	{ .major = 1, .minor = 0 },
106};
107
108static inline int vdc_version_supported(struct vdc_port *port,
109					u16 major, u16 minor)
110{
111	return port->vio.ver.major == major && port->vio.ver.minor >= minor;
112}
113
114#define VDCBLK_NAME	"vdisk"
115static int vdc_major;
116#define PARTITION_SHIFT	3
117
118static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
119{
120	return vio_dring_avail(dr, VDC_TX_RING_SIZE);
121}
122
123static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
124{
125	struct gendisk *disk = bdev->bd_disk;
126	sector_t nsect = get_capacity(disk);
127	sector_t cylinders = nsect;
128
129	geo->heads = 0xff;
130	geo->sectors = 0x3f;
131	sector_div(cylinders, geo->heads * geo->sectors);
132	geo->cylinders = cylinders;
133	if ((sector_t)(geo->cylinders + 1) * geo->heads * geo->sectors < nsect)
134		geo->cylinders = 0xffff;
135
136	return 0;
137}
138
139/* Add ioctl/CDROM_GET_CAPABILITY to support cdrom_id in udev
140 * when vdisk_mtype is VD_MEDIA_TYPE_CD or VD_MEDIA_TYPE_DVD.
141 * Needed to be able to install inside an ldom from an iso image.
142 */
143static int vdc_ioctl(struct block_device *bdev, fmode_t mode,
144		     unsigned command, unsigned long argument)
145{
146	int i;
147	struct gendisk *disk;
148
149	switch (command) {
150	case CDROMMULTISESSION:
151		pr_debug(PFX "Multisession CDs not supported\n");
152		for (i = 0; i < sizeof(struct cdrom_multisession); i++)
153			if (put_user(0, (char __user *)(argument + i)))
154				return -EFAULT;
155		return 0;
156
157	case CDROM_GET_CAPABILITY:
158		disk = bdev->bd_disk;
159
160		if (bdev->bd_disk && (disk->flags & GENHD_FL_CD))
161			return 0;
162		return -EINVAL;
163
164	default:
165		pr_debug(PFX "ioctl %08x not supported\n", command);
166		return -EINVAL;
167	}
168}
169
170static const struct block_device_operations vdc_fops = {
171	.owner		= THIS_MODULE,
172	.getgeo		= vdc_getgeo,
173	.ioctl		= vdc_ioctl,
174	.compat_ioctl	= blkdev_compat_ptr_ioctl,
175};
176
177static void vdc_blk_queue_start(struct vdc_port *port)
178{
179	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
180
181	/* restart blk queue when ring is half emptied. also called after
182	 * handshake completes, so check for initial handshake before we've
183	 * allocated a disk.
184	 */
185	if (port->disk && vdc_tx_dring_avail(dr) * 100 / VDC_TX_RING_SIZE >= 50)
186		blk_mq_start_stopped_hw_queues(port->disk->queue, true);
187}
188
189static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
190{
191	if (vio->cmp &&
192	    (waiting_for == -1 ||
193	     vio->cmp->waiting_for == waiting_for)) {
194		vio->cmp->err = err;
195		complete(&vio->cmp->com);
196		vio->cmp = NULL;
197	}
198}
199
200static void vdc_handshake_complete(struct vio_driver_state *vio)
201{
202	struct vdc_port *port = to_vdc_port(vio);
203
204	cancel_delayed_work(&port->ldc_reset_timer_work);
205	vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
206	vdc_blk_queue_start(port);
207}
208
209static int vdc_handle_unknown(struct vdc_port *port, void *arg)
210{
211	struct vio_msg_tag *pkt = arg;
212
213	printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
214	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
215	printk(KERN_ERR PFX "Resetting connection.\n");
216
217	ldc_disconnect(port->vio.lp);
218
219	return -ECONNRESET;
220}
221
222static int vdc_send_attr(struct vio_driver_state *vio)
223{
224	struct vdc_port *port = to_vdc_port(vio);
225	struct vio_disk_attr_info pkt;
226
227	memset(&pkt, 0, sizeof(pkt));
228
229	pkt.tag.type = VIO_TYPE_CTRL;
230	pkt.tag.stype = VIO_SUBTYPE_INFO;
231	pkt.tag.stype_env = VIO_ATTR_INFO;
232	pkt.tag.sid = vio_send_sid(vio);
233
234	pkt.xfer_mode = VIO_DRING_MODE;
235	pkt.vdisk_block_size = port->vdisk_block_size;
236	pkt.max_xfer_size = port->max_xfer_size;
237
238	viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
239	       pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);
240
241	return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
242}
243
244static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
245{
246	struct vdc_port *port = to_vdc_port(vio);
247	struct vio_disk_attr_info *pkt = arg;
248
249	viodbg(HS, "GOT ATTR stype[0x%x] ops[%llx] disk_size[%llu] disk_type[%x] "
250	       "mtype[0x%x] xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
251	       pkt->tag.stype, pkt->operations,
252	       pkt->vdisk_size, pkt->vdisk_type, pkt->vdisk_mtype,
253	       pkt->xfer_mode, pkt->vdisk_block_size,
254	       pkt->max_xfer_size);
255
256	if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
257		switch (pkt->vdisk_type) {
258		case VD_DISK_TYPE_DISK:
259		case VD_DISK_TYPE_SLICE:
260			break;
261
262		default:
263			printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n",
264			       vio->name, pkt->vdisk_type);
265			return -ECONNRESET;
266		}
267
268		if (pkt->vdisk_block_size > port->vdisk_block_size) {
269			printk(KERN_ERR PFX "%s: BLOCK size increased "
270			       "%u --> %u\n",
271			       vio->name,
272			       port->vdisk_block_size, pkt->vdisk_block_size);
273			return -ECONNRESET;
274		}
275
276		port->operations = pkt->operations;
277		port->vdisk_type = pkt->vdisk_type;
278		if (vdc_version_supported(port, 1, 1)) {
279			port->vdisk_size = pkt->vdisk_size;
280			port->vdisk_mtype = pkt->vdisk_mtype;
281		}
282		if (pkt->max_xfer_size < port->max_xfer_size)
283			port->max_xfer_size = pkt->max_xfer_size;
284		port->vdisk_block_size = pkt->vdisk_block_size;
285
286		port->vdisk_phys_blksz = VDC_DEFAULT_BLK_SIZE;
287		if (vdc_version_supported(port, 1, 2))
288			port->vdisk_phys_blksz = pkt->phys_block_size;
289
290		return 0;
291	} else {
292		printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name);
293
294		return -ECONNRESET;
295	}
296}
297
298static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc)
299{
300	int err = desc->status;
301
302	vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
303}
304
305static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
306			unsigned int index)
307{
308	struct vio_disk_desc *desc = vio_dring_entry(dr, index);
309	struct vdc_req_entry *rqe = &port->rq_arr[index];
310	struct request *req;
311
312	if (unlikely(desc->hdr.state != VIO_DESC_DONE))
313		return;
314
315	ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
316	desc->hdr.state = VIO_DESC_FREE;
317	dr->cons = vio_dring_next(dr, index);
318
319	req = rqe->req;
320	if (req == NULL) {
321		vdc_end_special(port, desc);
322		return;
323	}
324
325	rqe->req = NULL;
326
327	blk_mq_end_request(req, desc->status ? BLK_STS_IOERR : 0);
328
329	vdc_blk_queue_start(port);
330}
331
332static int vdc_ack(struct vdc_port *port, void *msgbuf)
333{
334	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
335	struct vio_dring_data *pkt = msgbuf;
336
337	if (unlikely(pkt->dring_ident != dr->ident ||
338		     pkt->start_idx != pkt->end_idx ||
339		     pkt->start_idx >= VDC_TX_RING_SIZE))
340		return 0;
341
342	vdc_end_one(port, dr, pkt->start_idx);
343
344	return 0;
345}
346
347static int vdc_nack(struct vdc_port *port, void *msgbuf)
348{
349	/* XXX Implement me XXX */
350	return 0;
351}
352
353static void vdc_event(void *arg, int event)
354{
355	struct vdc_port *port = arg;
356	struct vio_driver_state *vio = &port->vio;
357	unsigned long flags;
358	int err;
359
360	spin_lock_irqsave(&vio->lock, flags);
361
362	if (unlikely(event == LDC_EVENT_RESET)) {
363		vio_link_state_change(vio, event);
364		queue_work(sunvdc_wq, &port->ldc_reset_work);
365		goto out;
366	}
367
368	if (unlikely(event == LDC_EVENT_UP)) {
369		vio_link_state_change(vio, event);
370		goto out;
371	}
372
373	if (unlikely(event != LDC_EVENT_DATA_READY)) {
374		pr_warn(PFX "Unexpected LDC event %d\n", event);
375		goto out;
376	}
377
378	err = 0;
379	while (1) {
380		union {
381			struct vio_msg_tag tag;
382			u64 raw[8];
383		} msgbuf;
384
385		err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
386		if (unlikely(err < 0)) {
387			if (err == -ECONNRESET)
388				vio_conn_reset(vio);
389			break;
390		}
391		if (err == 0)
392			break;
393		viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
394		       msgbuf.tag.type,
395		       msgbuf.tag.stype,
396		       msgbuf.tag.stype_env,
397		       msgbuf.tag.sid);
398		err = vio_validate_sid(vio, &msgbuf.tag);
399		if (err < 0)
400			break;
401
402		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
403			if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
404				err = vdc_ack(port, &msgbuf);
405			else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
406				err = vdc_nack(port, &msgbuf);
407			else
408				err = vdc_handle_unknown(port, &msgbuf);
409		} else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
410			err = vio_control_pkt_engine(vio, &msgbuf);
411		} else {
412			err = vdc_handle_unknown(port, &msgbuf);
413		}
414		if (err < 0)
415			break;
416	}
417	if (err < 0)
418		vdc_finish(&port->vio, err, WAITING_FOR_ANY);
419out:
420	spin_unlock_irqrestore(&vio->lock, flags);
421}
422
423static int __vdc_tx_trigger(struct vdc_port *port)
424{
425	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
426	struct vio_dring_data hdr = {
427		.tag = {
428			.type		= VIO_TYPE_DATA,
429			.stype		= VIO_SUBTYPE_INFO,
430			.stype_env	= VIO_DRING_DATA,
431			.sid		= vio_send_sid(&port->vio),
432		},
433		.dring_ident		= dr->ident,
434		.start_idx		= dr->prod,
435		.end_idx		= dr->prod,
436	};
437	int err, delay;
438	int retries = 0;
439
440	hdr.seq = dr->snd_nxt;
441	delay = 1;
442	do {
443		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
444		if (err > 0) {
445			dr->snd_nxt++;
446			break;
447		}
448		udelay(delay);
449		if ((delay <<= 1) > 128)
450			delay = 128;
451		if (retries++ > VDC_MAX_RETRIES)
452			break;
453	} while (err == -EAGAIN);
454
455	if (err == -ENOTCONN)
456		vdc_ldc_reset(port);
457	return err;
458}
459
460static int __send_request(struct request *req)
461{
462	struct vdc_port *port = req->rq_disk->private_data;
463	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
464	struct scatterlist sg[MAX_RING_COOKIES];
465	struct vdc_req_entry *rqe;
466	struct vio_disk_desc *desc;
467	unsigned int map_perm;
468	int nsg, err, i;
469	u64 len;
470	u8 op;
471
472	if (WARN_ON(port->ring_cookies > MAX_RING_COOKIES))
473		return -EINVAL;
474
475	map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
476
477	if (rq_data_dir(req) == READ) {
478		map_perm |= LDC_MAP_W;
479		op = VD_OP_BREAD;
480	} else {
481		map_perm |= LDC_MAP_R;
482		op = VD_OP_BWRITE;
483	}
484
485	sg_init_table(sg, port->ring_cookies);
486	nsg = blk_rq_map_sg(req->q, req, sg);
487
488	len = 0;
489	for (i = 0; i < nsg; i++)
490		len += sg[i].length;
491
492	desc = vio_dring_cur(dr);
493
494	err = ldc_map_sg(port->vio.lp, sg, nsg,
495			 desc->cookies, port->ring_cookies,
496			 map_perm);
497	if (err < 0) {
498		printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
499		return err;
500	}
501
502	rqe = &port->rq_arr[dr->prod];
503	rqe->req = req;
504
505	desc->hdr.ack = VIO_ACK_ENABLE;
506	desc->req_id = port->req_id;
507	desc->operation = op;
508	if (port->vdisk_type == VD_DISK_TYPE_DISK) {
509		desc->slice = 0xff;
510	} else {
511		desc->slice = 0;
512	}
513	desc->status = ~0;
514	desc->offset = (blk_rq_pos(req) << 9) / port->vdisk_block_size;
515	desc->size = len;
516	desc->ncookies = err;
517
518	/* This has to be a non-SMP write barrier because we are writing
519	 * to memory which is shared with the peer LDOM.
520	 */
521	wmb();
522	desc->hdr.state = VIO_DESC_READY;
523
524	err = __vdc_tx_trigger(port);
525	if (err < 0) {
526		printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
527	} else {
528		port->req_id++;
529		dr->prod = vio_dring_next(dr, dr->prod);
530	}
531
532	return err;
533}
534
535static blk_status_t vdc_queue_rq(struct blk_mq_hw_ctx *hctx,
536				 const struct blk_mq_queue_data *bd)
537{
538	struct vdc_port *port = hctx->queue->queuedata;
539	struct vio_dring_state *dr;
540	unsigned long flags;
541
542	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
543
544	blk_mq_start_request(bd->rq);
545
546	spin_lock_irqsave(&port->vio.lock, flags);
547
548	/*
549	 * Doing drain, just end the request in error
550	 */
551	if (unlikely(port->drain)) {
552		spin_unlock_irqrestore(&port->vio.lock, flags);
553		return BLK_STS_IOERR;
554	}
555
556	if (unlikely(vdc_tx_dring_avail(dr) < 1)) {
557		spin_unlock_irqrestore(&port->vio.lock, flags);
558		blk_mq_stop_hw_queue(hctx);
559		return BLK_STS_DEV_RESOURCE;
560	}
561
562	if (__send_request(bd->rq) < 0) {
563		spin_unlock_irqrestore(&port->vio.lock, flags);
564		return BLK_STS_IOERR;
565	}
566
567	spin_unlock_irqrestore(&port->vio.lock, flags);
568	return BLK_STS_OK;
569}
570
571static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
572{
573	struct vio_dring_state *dr;
574	struct vio_completion comp;
575	struct vio_disk_desc *desc;
576	unsigned int map_perm;
577	unsigned long flags;
578	int op_len, err;
579	void *req_buf;
580
581	if (!(((u64)1 << (u64)op) & port->operations))
582		return -EOPNOTSUPP;
583
584	switch (op) {
585	case VD_OP_BREAD:
586	case VD_OP_BWRITE:
587	default:
588		return -EINVAL;
589
590	case VD_OP_FLUSH:
591		op_len = 0;
592		map_perm = 0;
593		break;
594
595	case VD_OP_GET_WCE:
596		op_len = sizeof(u32);
597		map_perm = LDC_MAP_W;
598		break;
599
600	case VD_OP_SET_WCE:
601		op_len = sizeof(u32);
602		map_perm = LDC_MAP_R;
603		break;
604
605	case VD_OP_GET_VTOC:
606		op_len = sizeof(struct vio_disk_vtoc);
607		map_perm = LDC_MAP_W;
608		break;
609
610	case VD_OP_SET_VTOC:
611		op_len = sizeof(struct vio_disk_vtoc);
612		map_perm = LDC_MAP_R;
613		break;
614
615	case VD_OP_GET_DISKGEOM:
616		op_len = sizeof(struct vio_disk_geom);
617		map_perm = LDC_MAP_W;
618		break;
619
620	case VD_OP_SET_DISKGEOM:
621		op_len = sizeof(struct vio_disk_geom);
622		map_perm = LDC_MAP_R;
623		break;
624
625	case VD_OP_SCSICMD:
626		op_len = 16;
627		map_perm = LDC_MAP_RW;
628		break;
629
630	case VD_OP_GET_DEVID:
631		op_len = sizeof(struct vio_disk_devid);
632		map_perm = LDC_MAP_W;
633		break;
634
635	case VD_OP_GET_EFI:
636	case VD_OP_SET_EFI:
637		return -EOPNOTSUPP;
638	}
639
640	map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
641
642	op_len = (op_len + 7) & ~7;
643	req_buf = kzalloc(op_len, GFP_KERNEL);
644	if (!req_buf)
645		return -ENOMEM;
646
647	if (len > op_len)
648		len = op_len;
649
650	if (map_perm & LDC_MAP_R)
651		memcpy(req_buf, buf, len);
652
653	spin_lock_irqsave(&port->vio.lock, flags);
654
655	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
656
657	/* XXX If we want to use this code generically we have to
658	 * XXX handle TX ring exhaustion etc.
659	 */
660	desc = vio_dring_cur(dr);
661
662	err = ldc_map_single(port->vio.lp, req_buf, op_len,
663			     desc->cookies, port->ring_cookies,
664			     map_perm);
665	if (err < 0) {
666		spin_unlock_irqrestore(&port->vio.lock, flags);
667		kfree(req_buf);
668		return err;
669	}
670
671	init_completion(&comp.com);
672	comp.waiting_for = WAITING_FOR_GEN_CMD;
673	port->vio.cmp = &comp;
674
675	desc->hdr.ack = VIO_ACK_ENABLE;
676	desc->req_id = port->req_id;
677	desc->operation = op;
678	desc->slice = 0;
679	desc->status = ~0;
680	desc->offset = 0;
681	desc->size = op_len;
682	desc->ncookies = err;
683
684	/* This has to be a non-SMP write barrier because we are writing
685	 * to memory which is shared with the peer LDOM.
686	 */
687	wmb();
688	desc->hdr.state = VIO_DESC_READY;
689
690	err = __vdc_tx_trigger(port);
691	if (err >= 0) {
692		port->req_id++;
693		dr->prod = vio_dring_next(dr, dr->prod);
694		spin_unlock_irqrestore(&port->vio.lock, flags);
695
696		wait_for_completion(&comp.com);
697		err = comp.err;
698	} else {
699		port->vio.cmp = NULL;
700		spin_unlock_irqrestore(&port->vio.lock, flags);
701	}
702
703	if (map_perm & LDC_MAP_W)
704		memcpy(buf, req_buf, len);
705
706	kfree(req_buf);
707
708	return err;
709}
710
711static int vdc_alloc_tx_ring(struct vdc_port *port)
712{
713	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
714	unsigned long len, entry_size;
715	int ncookies;
716	void *dring;
717
718	entry_size = sizeof(struct vio_disk_desc) +
719		(sizeof(struct ldc_trans_cookie) * port->ring_cookies);
720	len = (VDC_TX_RING_SIZE * entry_size);
721
722	ncookies = VIO_MAX_RING_COOKIES;
723	dring = ldc_alloc_exp_dring(port->vio.lp, len,
724				    dr->cookies, &ncookies,
725				    (LDC_MAP_SHADOW |
726				     LDC_MAP_DIRECT |
727				     LDC_MAP_RW));
728	if (IS_ERR(dring))
729		return PTR_ERR(dring);
730
731	dr->base = dring;
732	dr->entry_size = entry_size;
733	dr->num_entries = VDC_TX_RING_SIZE;
734	dr->prod = dr->cons = 0;
735	dr->pending = VDC_TX_RING_SIZE;
736	dr->ncookies = ncookies;
737
738	return 0;
739}
740
741static void vdc_free_tx_ring(struct vdc_port *port)
742{
743	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
744
745	if (dr->base) {
746		ldc_free_exp_dring(port->vio.lp, dr->base,
747				   (dr->entry_size * dr->num_entries),
748				   dr->cookies, dr->ncookies);
749		dr->base = NULL;
750		dr->entry_size = 0;
751		dr->num_entries = 0;
752		dr->pending = 0;
753		dr->ncookies = 0;
754	}
755}
756
757static int vdc_port_up(struct vdc_port *port)
758{
759	struct vio_completion comp;
760
761	init_completion(&comp.com);
762	comp.err = 0;
763	comp.waiting_for = WAITING_FOR_LINK_UP;
764	port->vio.cmp = &comp;
765
766	vio_port_up(&port->vio);
767	wait_for_completion(&comp.com);
768	return comp.err;
769}
770
771static void vdc_port_down(struct vdc_port *port)
772{
773	ldc_disconnect(port->vio.lp);
774	ldc_unbind(port->vio.lp);
775	vdc_free_tx_ring(port);
776	vio_ldc_free(&port->vio);
777}
778
779static const struct blk_mq_ops vdc_mq_ops = {
780	.queue_rq	= vdc_queue_rq,
781};
782
783static void cleanup_queue(struct request_queue *q)
784{
785	struct vdc_port *port = q->queuedata;
786
787	blk_cleanup_queue(q);
788	blk_mq_free_tag_set(&port->tag_set);
789}
790
791static struct request_queue *init_queue(struct vdc_port *port)
792{
793	struct request_queue *q;
794
795	q = blk_mq_init_sq_queue(&port->tag_set, &vdc_mq_ops, VDC_TX_RING_SIZE,
796					BLK_MQ_F_SHOULD_MERGE);
797	if (IS_ERR(q))
798		return q;
799
800	q->queuedata = port;
801	return q;
802}
803
804static int probe_disk(struct vdc_port *port)
805{
806	struct request_queue *q;
807	struct gendisk *g;
808	int err;
809
810	err = vdc_port_up(port);
811	if (err)
812		return err;
813
814	/* Using version 1.2 means vdisk_phys_blksz should be set unless the
815	 * disk is reserved by another system.
816	 */
817	if (vdc_version_supported(port, 1, 2) && !port->vdisk_phys_blksz)
818		return -ENODEV;
819
820	if (vdc_version_supported(port, 1, 1)) {
821		/* vdisk_size should be set during the handshake, if it wasn't
822		 * then the underlying disk is reserved by another system
823		 */
824		if (port->vdisk_size == -1)
825			return -ENODEV;
826	} else {
827		struct vio_disk_geom geom;
828
829		err = generic_request(port, VD_OP_GET_DISKGEOM,
830				      &geom, sizeof(geom));
831		if (err < 0) {
832			printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
833			       "error %d\n", err);
834			return err;
835		}
836		port->vdisk_size = ((u64)geom.num_cyl *
837				    (u64)geom.num_hd *
838				    (u64)geom.num_sec);
839	}
840
841	q = init_queue(port);
842	if (IS_ERR(q)) {
843		printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
844		       port->vio.name);
845		return PTR_ERR(q);
846	}
847	g = alloc_disk(1 << PARTITION_SHIFT);
848	if (!g) {
849		printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
850		       port->vio.name);
851		cleanup_queue(q);
852		return -ENOMEM;
853	}
854
855	port->disk = g;
856
857	/* Each segment in a request is up to an aligned page in size. */
858	blk_queue_segment_boundary(q, PAGE_SIZE - 1);
859	blk_queue_max_segment_size(q, PAGE_SIZE);
860
861	blk_queue_max_segments(q, port->ring_cookies);
862	blk_queue_max_hw_sectors(q, port->max_xfer_size);
863	g->major = vdc_major;
864	g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
865	strcpy(g->disk_name, port->disk_name);
866
867	g->fops = &vdc_fops;
868	g->queue = q;
869	g->private_data = port;
870
871	set_capacity(g, port->vdisk_size);
872
873	if (vdc_version_supported(port, 1, 1)) {
874		switch (port->vdisk_mtype) {
875		case VD_MEDIA_TYPE_CD:
876			pr_info(PFX "Virtual CDROM %s\n", port->disk_name);
877			g->flags |= GENHD_FL_CD;
878			g->flags |= GENHD_FL_REMOVABLE;
879			set_disk_ro(g, 1);
880			break;
881
882		case VD_MEDIA_TYPE_DVD:
883			pr_info(PFX "Virtual DVD %s\n", port->disk_name);
884			g->flags |= GENHD_FL_CD;
885			g->flags |= GENHD_FL_REMOVABLE;
886			set_disk_ro(g, 1);
887			break;
888
889		case VD_MEDIA_TYPE_FIXED:
890			pr_info(PFX "Virtual Hard disk %s\n", port->disk_name);
891			break;
892		}
893	}
894
895	blk_queue_physical_block_size(q, port->vdisk_phys_blksz);
896
897	pr_info(PFX "%s: %u sectors (%u MB) protocol %d.%d\n",
898	       g->disk_name,
899	       port->vdisk_size, (port->vdisk_size >> (20 - 9)),
900	       port->vio.ver.major, port->vio.ver.minor);
901
902	device_add_disk(&port->vio.vdev->dev, g, NULL);
903
904	return 0;
905}
906
907static struct ldc_channel_config vdc_ldc_cfg = {
908	.event		= vdc_event,
909	.mtu		= 64,
910	.mode		= LDC_MODE_UNRELIABLE,
911};
912
913static struct vio_driver_ops vdc_vio_ops = {
914	.send_attr		= vdc_send_attr,
915	.handle_attr		= vdc_handle_attr,
916	.handshake_complete	= vdc_handshake_complete,
917};
918
919static void print_version(void)
920{
921	static int version_printed;
922
923	if (version_printed++ == 0)
924		printk(KERN_INFO "%s", version);
925}
926
927struct vdc_check_port_data {
928	int	dev_no;
929	char	*type;
930};
931
932static int vdc_device_probed(struct device *dev, void *arg)
933{
934	struct vio_dev *vdev = to_vio_dev(dev);
935	struct vdc_check_port_data *port_data;
936
937	port_data = (struct vdc_check_port_data *)arg;
938
939	if ((vdev->dev_no == port_data->dev_no) &&
940	    (!(strcmp((char *)&vdev->type, port_data->type))) &&
941		dev_get_drvdata(dev)) {
942		/* This device has already been configured
943		 * by vdc_port_probe()
944		 */
945		return 1;
946	} else {
947		return 0;
948	}
949}
950
951/* Determine whether the VIO device is part of an mpgroup
952 * by locating all the virtual-device-port nodes associated
953 * with the parent virtual-device node for the VIO device
954 * and checking whether any of these nodes are vdc-ports
955 * which have already been configured.
956 *
957 * Returns true if this device is part of an mpgroup and has
958 * already been probed.
959 */
960static bool vdc_port_mpgroup_check(struct vio_dev *vdev)
961{
962	struct vdc_check_port_data port_data;
963	struct device *dev;
964
965	port_data.dev_no = vdev->dev_no;
966	port_data.type = (char *)&vdev->type;
967
968	dev = device_find_child(vdev->dev.parent, &port_data,
969				vdc_device_probed);
970
971	if (dev)
972		return true;
973
974	return false;
975}
976
977static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
978{
979	struct mdesc_handle *hp;
980	struct vdc_port *port;
981	int err;
982	const u64 *ldc_timeout;
983
984	print_version();
985
986	hp = mdesc_grab();
987	if (!hp)
988		return -ENODEV;
989
990	err = -ENODEV;
991	if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
992		printk(KERN_ERR PFX "Port id [%llu] too large.\n",
993		       vdev->dev_no);
994		goto err_out_release_mdesc;
995	}
996
997	/* Check if this device is part of an mpgroup */
998	if (vdc_port_mpgroup_check(vdev)) {
999		printk(KERN_WARNING
1000			"VIO: Ignoring extra vdisk port %s",
1001			dev_name(&vdev->dev));
1002		goto err_out_release_mdesc;
1003	}
1004
1005	port = kzalloc(sizeof(*port), GFP_KERNEL);
1006	err = -ENOMEM;
1007	if (!port) {
1008		printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
1009		goto err_out_release_mdesc;
1010	}
1011
1012	if (vdev->dev_no >= 26)
1013		snprintf(port->disk_name, sizeof(port->disk_name),
1014			 VDCBLK_NAME "%c%c",
1015			 'a' + ((int)vdev->dev_no / 26) - 1,
1016			 'a' + ((int)vdev->dev_no % 26));
1017	else
1018		snprintf(port->disk_name, sizeof(port->disk_name),
1019			 VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
1020	port->vdisk_size = -1;
1021
1022	/* Actual wall time may be double due to do_generic_file_read() doing
1023	 * a readahead I/O first, and once that fails it will try to read a
1024	 * single page.
1025	 */
1026	ldc_timeout = mdesc_get_property(hp, vdev->mp, "vdc-timeout", NULL);
1027	port->ldc_timeout = ldc_timeout ? *ldc_timeout : 0;
1028	INIT_DELAYED_WORK(&port->ldc_reset_timer_work, vdc_ldc_reset_timer_work);
1029	INIT_WORK(&port->ldc_reset_work, vdc_ldc_reset_work);
1030
1031	err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
1032			      vdc_versions, ARRAY_SIZE(vdc_versions),
1033			      &vdc_vio_ops, port->disk_name);
1034	if (err)
1035		goto err_out_free_port;
1036
1037	port->vdisk_block_size = VDC_DEFAULT_BLK_SIZE;
1038	port->max_xfer_size = MAX_XFER_SIZE;
1039	port->ring_cookies = MAX_RING_COOKIES;
1040
1041	err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
1042	if (err)
1043		goto err_out_free_port;
1044
1045	err = vdc_alloc_tx_ring(port);
1046	if (err)
1047		goto err_out_free_ldc;
1048
1049	err = probe_disk(port);
1050	if (err)
1051		goto err_out_free_tx_ring;
1052
1053	/* Note that the device driver_data is used to determine
1054	 * whether the port has been probed.
1055	 */
1056	dev_set_drvdata(&vdev->dev, port);
1057
1058	mdesc_release(hp);
1059
1060	return 0;
1061
1062err_out_free_tx_ring:
1063	vdc_free_tx_ring(port);
1064
1065err_out_free_ldc:
1066	vio_ldc_free(&port->vio);
1067
1068err_out_free_port:
1069	kfree(port);
1070
1071err_out_release_mdesc:
1072	mdesc_release(hp);
1073	return err;
1074}
1075
1076static int vdc_port_remove(struct vio_dev *vdev)
1077{
1078	struct vdc_port *port = dev_get_drvdata(&vdev->dev);
1079
1080	if (port) {
1081		blk_mq_stop_hw_queues(port->disk->queue);
1082
1083		flush_work(&port->ldc_reset_work);
1084		cancel_delayed_work_sync(&port->ldc_reset_timer_work);
1085		del_timer_sync(&port->vio.timer);
1086
1087		del_gendisk(port->disk);
1088		cleanup_queue(port->disk->queue);
1089		put_disk(port->disk);
1090		port->disk = NULL;
1091
1092		vdc_free_tx_ring(port);
1093		vio_ldc_free(&port->vio);
1094
1095		dev_set_drvdata(&vdev->dev, NULL);
1096
1097		kfree(port);
1098	}
1099	return 0;
1100}
1101
1102static void vdc_requeue_inflight(struct vdc_port *port)
1103{
1104	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1105	u32 idx;
1106
1107	for (idx = dr->cons; idx != dr->prod; idx = vio_dring_next(dr, idx)) {
1108		struct vio_disk_desc *desc = vio_dring_entry(dr, idx);
1109		struct vdc_req_entry *rqe = &port->rq_arr[idx];
1110		struct request *req;
1111
1112		ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
1113		desc->hdr.state = VIO_DESC_FREE;
1114		dr->cons = vio_dring_next(dr, idx);
1115
1116		req = rqe->req;
1117		if (req == NULL) {
1118			vdc_end_special(port, desc);
1119			continue;
1120		}
1121
1122		rqe->req = NULL;
1123		blk_mq_requeue_request(req, false);
1124	}
1125}
1126
1127static void vdc_queue_drain(struct vdc_port *port)
1128{
1129	struct request_queue *q = port->disk->queue;
1130
1131	/*
1132	 * Mark the queue as draining, then freeze/quiesce to ensure
1133	 * that all existing requests are seen in ->queue_rq() and killed
1134	 */
1135	port->drain = 1;
1136	spin_unlock_irq(&port->vio.lock);
1137
1138	blk_mq_freeze_queue(q);
1139	blk_mq_quiesce_queue(q);
1140
1141	spin_lock_irq(&port->vio.lock);
1142	port->drain = 0;
1143	blk_mq_unquiesce_queue(q);
1144	blk_mq_unfreeze_queue(q);
1145}
1146
1147static void vdc_ldc_reset_timer_work(struct work_struct *work)
1148{
1149	struct vdc_port *port;
1150	struct vio_driver_state *vio;
1151
1152	port = container_of(work, struct vdc_port, ldc_reset_timer_work.work);
1153	vio = &port->vio;
1154
1155	spin_lock_irq(&vio->lock);
1156	if (!(port->vio.hs_state & VIO_HS_COMPLETE)) {
1157		pr_warn(PFX "%s ldc down %llu seconds, draining queue\n",
1158			port->disk_name, port->ldc_timeout);
1159		vdc_queue_drain(port);
1160		vdc_blk_queue_start(port);
1161	}
1162	spin_unlock_irq(&vio->lock);
1163}
1164
1165static void vdc_ldc_reset_work(struct work_struct *work)
1166{
1167	struct vdc_port *port;
1168	struct vio_driver_state *vio;
1169	unsigned long flags;
1170
1171	port = container_of(work, struct vdc_port, ldc_reset_work);
1172	vio = &port->vio;
1173
1174	spin_lock_irqsave(&vio->lock, flags);
1175	vdc_ldc_reset(port);
1176	spin_unlock_irqrestore(&vio->lock, flags);
1177}
1178
1179static void vdc_ldc_reset(struct vdc_port *port)
1180{
1181	int err;
1182
1183	assert_spin_locked(&port->vio.lock);
1184
1185	pr_warn(PFX "%s ldc link reset\n", port->disk_name);
1186	blk_mq_stop_hw_queues(port->disk->queue);
1187	vdc_requeue_inflight(port);
1188	vdc_port_down(port);
1189
1190	err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
1191	if (err) {
1192		pr_err(PFX "%s vio_ldc_alloc:%d\n", port->disk_name, err);
1193		return;
1194	}
1195
1196	err = vdc_alloc_tx_ring(port);
1197	if (err) {
1198		pr_err(PFX "%s vio_alloc_tx_ring:%d\n", port->disk_name, err);
1199		goto err_free_ldc;
1200	}
1201
1202	if (port->ldc_timeout)
1203		mod_delayed_work(system_wq, &port->ldc_reset_timer_work,
1204			  round_jiffies(jiffies + HZ * port->ldc_timeout));
1205	mod_timer(&port->vio.timer, round_jiffies(jiffies + HZ));
1206	return;
1207
1208err_free_ldc:
1209	vio_ldc_free(&port->vio);
1210}
1211
1212static const struct vio_device_id vdc_port_match[] = {
1213	{
1214		.type = "vdc-port",
1215	},
1216	{},
1217};
1218MODULE_DEVICE_TABLE(vio, vdc_port_match);
1219
1220static struct vio_driver vdc_port_driver = {
1221	.id_table	= vdc_port_match,
1222	.probe		= vdc_port_probe,
1223	.remove		= vdc_port_remove,
1224	.name		= "vdc_port",
1225};
1226
1227static int __init vdc_init(void)
1228{
1229	int err;
1230
1231	sunvdc_wq = alloc_workqueue("sunvdc", 0, 0);
1232	if (!sunvdc_wq)
1233		return -ENOMEM;
1234
1235	err = register_blkdev(0, VDCBLK_NAME);
1236	if (err < 0)
1237		goto out_free_wq;
1238
1239	vdc_major = err;
1240
1241	err = vio_register_driver(&vdc_port_driver);
1242	if (err)
1243		goto out_unregister_blkdev;
1244
1245	return 0;
1246
1247out_unregister_blkdev:
1248	unregister_blkdev(vdc_major, VDCBLK_NAME);
1249	vdc_major = 0;
1250
1251out_free_wq:
1252	destroy_workqueue(sunvdc_wq);
1253	return err;
1254}
1255
1256static void __exit vdc_exit(void)
1257{
1258	vio_unregister_driver(&vdc_port_driver);
1259	unregister_blkdev(vdc_major, VDCBLK_NAME);
1260	destroy_workqueue(sunvdc_wq);
1261}
1262
1263module_init(vdc_init);
1264module_exit(vdc_exit);
1265