sunvdc.c

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