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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * ccw based virtio transport
   4 *
   5 * Copyright IBM Corp. 2012, 2014
   6 *
   7 *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
   8 */
   9
  10#include <linux/kernel_stat.h>
  11#include <linux/init.h>
  12#include <linux/memblock.h>
  13#include <linux/err.h>
  14#include <linux/virtio.h>
  15#include <linux/virtio_config.h>
  16#include <linux/slab.h>
  17#include <linux/interrupt.h>
  18#include <linux/virtio_ring.h>
  19#include <linux/pfn.h>
  20#include <linux/async.h>
  21#include <linux/wait.h>
  22#include <linux/list.h>
  23#include <linux/bitops.h>
  24#include <linux/moduleparam.h>
  25#include <linux/io.h>
  26#include <linux/kvm_para.h>
  27#include <linux/notifier.h>
  28#include <asm/diag.h>
  29#include <asm/setup.h>
  30#include <asm/irq.h>
  31#include <asm/cio.h>
  32#include <asm/ccwdev.h>
  33#include <asm/virtio-ccw.h>
  34#include <asm/isc.h>
  35#include <asm/airq.h>
  36
  37/*
  38 * virtio related functions
  39 */
  40
  41struct vq_config_block {
  42	__u16 index;
  43	__u16 num;
  44} __packed;
  45
  46#define VIRTIO_CCW_CONFIG_SIZE 0x100
  47/* same as PCI config space size, should be enough for all drivers */
  48
  49struct vcdev_dma_area {
  50	unsigned long indicators;
  51	unsigned long indicators2;
  52	struct vq_config_block config_block;
  53	__u8 status;
  54};
  55
  56struct virtio_ccw_device {
  57	struct virtio_device vdev;
  58	__u8 config[VIRTIO_CCW_CONFIG_SIZE];
  59	struct ccw_device *cdev;
  60	__u32 curr_io;
  61	int err;
  62	unsigned int revision; /* Transport revision */
  63	wait_queue_head_t wait_q;
  64	spinlock_t lock;
  65	struct mutex io_lock; /* Serializes I/O requests */
  66	struct list_head virtqueues;
  67	bool is_thinint;
  68	bool going_away;
  69	bool device_lost;
  70	unsigned int config_ready;
  71	void *airq_info;
  72	struct vcdev_dma_area *dma_area;
  73};
  74
  75static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
  76{
  77	return &vcdev->dma_area->indicators;
  78}
  79
  80static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev)
  81{
  82	return &vcdev->dma_area->indicators2;
  83}
  84
  85struct vq_info_block_legacy {
  86	__u64 queue;
  87	__u32 align;
  88	__u16 index;
  89	__u16 num;
  90} __packed;
  91
  92struct vq_info_block {
  93	__u64 desc;
  94	__u32 res0;
  95	__u16 index;
  96	__u16 num;
  97	__u64 avail;
  98	__u64 used;
  99} __packed;
 100
 101struct virtio_feature_desc {
 102	__le32 features;
 103	__u8 index;
 104} __packed;
 105
 106struct virtio_thinint_area {
 107	unsigned long summary_indicator;
 108	unsigned long indicator;
 109	u64 bit_nr;
 110	u8 isc;
 111} __packed;
 112
 113struct virtio_rev_info {
 114	__u16 revision;
 115	__u16 length;
 116	__u8 data[];
 117};
 118
 119/* the highest virtio-ccw revision we support */
 120#define VIRTIO_CCW_REV_MAX 1
 121
 122struct virtio_ccw_vq_info {
 123	struct virtqueue *vq;
 124	int num;
 125	union {
 126		struct vq_info_block s;
 127		struct vq_info_block_legacy l;
 128	} *info_block;
 129	int bit_nr;
 130	struct list_head node;
 131	long cookie;
 132};
 133
 134#define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
 135
 136#define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
 137#define MAX_AIRQ_AREAS 20
 138
 139static int virtio_ccw_use_airq = 1;
 140
 141struct airq_info {
 142	rwlock_t lock;
 143	u8 summary_indicator_idx;
 144	struct airq_struct airq;
 145	struct airq_iv *aiv;
 146};
 147static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
 148static DEFINE_MUTEX(airq_areas_lock);
 149
 150static u8 *summary_indicators;
 151
 152static inline u8 *get_summary_indicator(struct airq_info *info)
 153{
 154	return summary_indicators + info->summary_indicator_idx;
 155}
 156
 157#define CCW_CMD_SET_VQ 0x13
 158#define CCW_CMD_VDEV_RESET 0x33
 159#define CCW_CMD_SET_IND 0x43
 160#define CCW_CMD_SET_CONF_IND 0x53
 161#define CCW_CMD_READ_FEAT 0x12
 162#define CCW_CMD_WRITE_FEAT 0x11
 163#define CCW_CMD_READ_CONF 0x22
 164#define CCW_CMD_WRITE_CONF 0x21
 165#define CCW_CMD_WRITE_STATUS 0x31
 166#define CCW_CMD_READ_VQ_CONF 0x32
 167#define CCW_CMD_READ_STATUS 0x72
 168#define CCW_CMD_SET_IND_ADAPTER 0x73
 169#define CCW_CMD_SET_VIRTIO_REV 0x83
 170
 171#define VIRTIO_CCW_DOING_SET_VQ 0x00010000
 172#define VIRTIO_CCW_DOING_RESET 0x00040000
 173#define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
 174#define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
 175#define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
 176#define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
 177#define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
 178#define VIRTIO_CCW_DOING_SET_IND 0x01000000
 179#define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
 180#define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
 181#define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
 182#define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
 183#define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
 184#define VIRTIO_CCW_INTPARM_MASK 0xffff0000
 185
 186static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
 187{
 188	return container_of(vdev, struct virtio_ccw_device, vdev);
 189}
 190
 191static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
 192{
 193	unsigned long i, flags;
 194
 195	write_lock_irqsave(&info->lock, flags);
 196	for (i = 0; i < airq_iv_end(info->aiv); i++) {
 197		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
 198			airq_iv_free_bit(info->aiv, i);
 199			airq_iv_set_ptr(info->aiv, i, 0);
 200			break;
 201		}
 202	}
 203	write_unlock_irqrestore(&info->lock, flags);
 204}
 205
 206static void virtio_airq_handler(struct airq_struct *airq, bool floating)
 207{
 208	struct airq_info *info = container_of(airq, struct airq_info, airq);
 209	unsigned long ai;
 210
 211	inc_irq_stat(IRQIO_VAI);
 212	read_lock(&info->lock);
 213	/* Walk through indicators field, summary indicator active. */
 214	for (ai = 0;;) {
 215		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 216		if (ai == -1UL)
 217			break;
 218		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 219	}
 220	*(get_summary_indicator(info)) = 0;
 221	smp_wmb();
 222	/* Walk through indicators field, summary indicator not active. */
 223	for (ai = 0;;) {
 224		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
 225		if (ai == -1UL)
 226			break;
 227		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
 228	}
 229	read_unlock(&info->lock);
 230}
 231
 232static struct airq_info *new_airq_info(int index)
 233{
 234	struct airq_info *info;
 235	int rc;
 236
 237	info = kzalloc(sizeof(*info), GFP_KERNEL);
 238	if (!info)
 239		return NULL;
 240	rwlock_init(&info->lock);
 241	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR
 242				   | AIRQ_IV_CACHELINE);
 243	if (!info->aiv) {
 244		kfree(info);
 245		return NULL;
 246	}
 247	info->airq.handler = virtio_airq_handler;
 248	info->summary_indicator_idx = index;
 249	info->airq.lsi_ptr = get_summary_indicator(info);
 250	info->airq.lsi_mask = 0xff;
 251	info->airq.isc = VIRTIO_AIRQ_ISC;
 252	rc = register_adapter_interrupt(&info->airq);
 253	if (rc) {
 254		airq_iv_release(info->aiv);
 255		kfree(info);
 256		return NULL;
 257	}
 258	return info;
 259}
 260
 261static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
 262					u64 *first, void **airq_info)
 263{
 264	int i, j;
 265	struct airq_info *info;
 266	unsigned long indicator_addr = 0;
 267	unsigned long bit, flags;
 268
 269	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
 270		mutex_lock(&airq_areas_lock);
 271		if (!airq_areas[i])
 272			airq_areas[i] = new_airq_info(i);
 273		info = airq_areas[i];
 274		mutex_unlock(&airq_areas_lock);
 275		if (!info)
 276			return 0;
 277		write_lock_irqsave(&info->lock, flags);
 278		bit = airq_iv_alloc(info->aiv, nvqs);
 279		if (bit == -1UL) {
 280			/* Not enough vacancies. */
 281			write_unlock_irqrestore(&info->lock, flags);
 282			continue;
 283		}
 284		*first = bit;
 285		*airq_info = info;
 286		indicator_addr = (unsigned long)info->aiv->vector;
 287		for (j = 0; j < nvqs; j++) {
 288			airq_iv_set_ptr(info->aiv, bit + j,
 289					(unsigned long)vqs[j]);
 290		}
 291		write_unlock_irqrestore(&info->lock, flags);
 292	}
 293	return indicator_addr;
 294}
 295
 296static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
 297{
 298	struct virtio_ccw_vq_info *info;
 299
 300	if (!vcdev->airq_info)
 301		return;
 302	list_for_each_entry(info, &vcdev->virtqueues, node)
 303		drop_airq_indicator(info->vq, vcdev->airq_info);
 304}
 305
 306static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
 307{
 308	unsigned long flags;
 309	__u32 ret;
 310
 311	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 312	if (vcdev->err)
 313		ret = 0;
 314	else
 315		ret = vcdev->curr_io & flag;
 316	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 317	return ret;
 318}
 319
 320static int ccw_io_helper(struct virtio_ccw_device *vcdev,
 321			 struct ccw1 *ccw, __u32 intparm)
 322{
 323	int ret;
 324	unsigned long flags;
 325	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
 326
 327	mutex_lock(&vcdev->io_lock);
 328	do {
 329		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
 330		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
 331		if (!ret) {
 332			if (!vcdev->curr_io)
 333				vcdev->err = 0;
 334			vcdev->curr_io |= flag;
 335		}
 336		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
 337		cpu_relax();
 338	} while (ret == -EBUSY);
 339	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
 340	ret = ret ? ret : vcdev->err;
 341	mutex_unlock(&vcdev->io_lock);
 342	return ret;
 343}
 344
 345static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
 346				      struct ccw1 *ccw)
 347{
 348	int ret;
 349	unsigned long *indicatorp = NULL;
 350	struct virtio_thinint_area *thinint_area = NULL;
 351	struct airq_info *airq_info = vcdev->airq_info;
 352
 353	if (vcdev->is_thinint) {
 354		thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
 355						     sizeof(*thinint_area));
 356		if (!thinint_area)
 357			return;
 358		thinint_area->summary_indicator =
 359			(unsigned long) get_summary_indicator(airq_info);
 360		thinint_area->isc = VIRTIO_AIRQ_ISC;
 361		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 362		ccw->count = sizeof(*thinint_area);
 363		ccw->cda = (__u32)(unsigned long) thinint_area;
 364	} else {
 365		/* payload is the address of the indicators */
 366		indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
 367						   sizeof(indicators(vcdev)));
 368		if (!indicatorp)
 369			return;
 370		*indicatorp = 0;
 371		ccw->cmd_code = CCW_CMD_SET_IND;
 372		ccw->count = sizeof(indicators(vcdev));
 373		ccw->cda = (__u32)(unsigned long) indicatorp;
 374	}
 375	/* Deregister indicators from host. */
 376	*indicators(vcdev) = 0;
 377	ccw->flags = 0;
 378	ret = ccw_io_helper(vcdev, ccw,
 379			    vcdev->is_thinint ?
 380			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
 381			    VIRTIO_CCW_DOING_SET_IND);
 382	if (ret && (ret != -ENODEV))
 383		dev_info(&vcdev->cdev->dev,
 384			 "Failed to deregister indicators (%d)\n", ret);
 385	else if (vcdev->is_thinint)
 386		virtio_ccw_drop_indicators(vcdev);
 387	ccw_device_dma_free(vcdev->cdev, indicatorp, sizeof(indicators(vcdev)));
 388	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
 389}
 390
 391static inline long __do_kvm_notify(struct subchannel_id schid,
 392				   unsigned long queue_index,
 393				   long cookie)
 394{
 395	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
 396	register struct subchannel_id __schid asm("2") = schid;
 397	register unsigned long __index asm("3") = queue_index;
 398	register long __rc asm("2");
 399	register long __cookie asm("4") = cookie;
 400
 401	asm volatile ("diag 2,4,0x500\n"
 402		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
 403		      "d"(__cookie)
 404		      : "memory", "cc");
 405	return __rc;
 406}
 407
 408static inline long do_kvm_notify(struct subchannel_id schid,
 409				 unsigned long queue_index,
 410				 long cookie)
 411{
 412	diag_stat_inc(DIAG_STAT_X500);
 413	return __do_kvm_notify(schid, queue_index, cookie);
 414}
 415
 416static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
 417{
 418	struct virtio_ccw_vq_info *info = vq->priv;
 419	struct virtio_ccw_device *vcdev;
 420	struct subchannel_id schid;
 421
 422	vcdev = to_vc_device(info->vq->vdev);
 423	ccw_device_get_schid(vcdev->cdev, &schid);
 424	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
 425	if (info->cookie < 0)
 426		return false;
 427	return true;
 428}
 429
 430static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
 431				   struct ccw1 *ccw, int index)
 432{
 433	int ret;
 434
 435	vcdev->dma_area->config_block.index = index;
 436	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
 437	ccw->flags = 0;
 438	ccw->count = sizeof(struct vq_config_block);
 439	ccw->cda = (__u32)(unsigned long)(&vcdev->dma_area->config_block);
 440	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
 441	if (ret)
 442		return ret;
 443	return vcdev->dma_area->config_block.num ?: -ENOENT;
 444}
 445
 446static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
 447{
 448	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
 449	struct virtio_ccw_vq_info *info = vq->priv;
 450	unsigned long flags;
 451	int ret;
 452	unsigned int index = vq->index;
 453
 454	/* Remove from our list. */
 455	spin_lock_irqsave(&vcdev->lock, flags);
 456	list_del(&info->node);
 457	spin_unlock_irqrestore(&vcdev->lock, flags);
 458
 459	/* Release from host. */
 460	if (vcdev->revision == 0) {
 461		info->info_block->l.queue = 0;
 462		info->info_block->l.align = 0;
 463		info->info_block->l.index = index;
 464		info->info_block->l.num = 0;
 465		ccw->count = sizeof(info->info_block->l);
 466	} else {
 467		info->info_block->s.desc = 0;
 468		info->info_block->s.index = index;
 469		info->info_block->s.num = 0;
 470		info->info_block->s.avail = 0;
 471		info->info_block->s.used = 0;
 472		ccw->count = sizeof(info->info_block->s);
 473	}
 474	ccw->cmd_code = CCW_CMD_SET_VQ;
 475	ccw->flags = 0;
 476	ccw->cda = (__u32)(unsigned long)(info->info_block);
 477	ret = ccw_io_helper(vcdev, ccw,
 478			    VIRTIO_CCW_DOING_SET_VQ | index);
 479	/*
 480	 * -ENODEV isn't considered an error: The device is gone anyway.
 481	 * This may happen on device detach.
 482	 */
 483	if (ret && (ret != -ENODEV))
 484		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
 485			 ret, index);
 486
 487	vring_del_virtqueue(vq);
 488	ccw_device_dma_free(vcdev->cdev, info->info_block,
 489			    sizeof(*info->info_block));
 490	kfree(info);
 491}
 492
 493static void virtio_ccw_del_vqs(struct virtio_device *vdev)
 494{
 495	struct virtqueue *vq, *n;
 496	struct ccw1 *ccw;
 497	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 498
 499	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 500	if (!ccw)
 501		return;
 502
 503	virtio_ccw_drop_indicator(vcdev, ccw);
 504
 505	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
 506		virtio_ccw_del_vq(vq, ccw);
 507
 508	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 509}
 510
 511static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
 512					     int i, vq_callback_t *callback,
 513					     const char *name, bool ctx,
 514					     struct ccw1 *ccw)
 515{
 516	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 517	int err;
 518	struct virtqueue *vq = NULL;
 519	struct virtio_ccw_vq_info *info;
 520	u64 queue;
 521	unsigned long flags;
 522	bool may_reduce;
 523
 524	/* Allocate queue. */
 525	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
 526	if (!info) {
 527		dev_warn(&vcdev->cdev->dev, "no info\n");
 528		err = -ENOMEM;
 529		goto out_err;
 530	}
 531	info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
 532						 sizeof(*info->info_block));
 533	if (!info->info_block) {
 534		dev_warn(&vcdev->cdev->dev, "no info block\n");
 535		err = -ENOMEM;
 536		goto out_err;
 537	}
 538	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
 539	if (info->num < 0) {
 540		err = info->num;
 541		goto out_err;
 542	}
 543	may_reduce = vcdev->revision > 0;
 544	vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
 545				    vdev, true, may_reduce, ctx,
 546				    virtio_ccw_kvm_notify, callback, name);
 547
 548	if (!vq) {
 549		/* For now, we fail if we can't get the requested size. */
 550		dev_warn(&vcdev->cdev->dev, "no vq\n");
 551		err = -ENOMEM;
 552		goto out_err;
 553	}
 554	/* it may have been reduced */
 555	info->num = virtqueue_get_vring_size(vq);
 556
 557	/* Register it with the host. */
 558	queue = virtqueue_get_desc_addr(vq);
 559	if (vcdev->revision == 0) {
 560		info->info_block->l.queue = queue;
 561		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
 562		info->info_block->l.index = i;
 563		info->info_block->l.num = info->num;
 564		ccw->count = sizeof(info->info_block->l);
 565	} else {
 566		info->info_block->s.desc = queue;
 567		info->info_block->s.index = i;
 568		info->info_block->s.num = info->num;
 569		info->info_block->s.avail = (__u64)virtqueue_get_avail_addr(vq);
 570		info->info_block->s.used = (__u64)virtqueue_get_used_addr(vq);
 571		ccw->count = sizeof(info->info_block->s);
 572	}
 573	ccw->cmd_code = CCW_CMD_SET_VQ;
 574	ccw->flags = 0;
 575	ccw->cda = (__u32)(unsigned long)(info->info_block);
 576	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
 577	if (err) {
 578		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
 579		goto out_err;
 580	}
 581
 582	info->vq = vq;
 583	vq->priv = info;
 584
 585	/* Save it to our list. */
 586	spin_lock_irqsave(&vcdev->lock, flags);
 587	list_add(&info->node, &vcdev->virtqueues);
 588	spin_unlock_irqrestore(&vcdev->lock, flags);
 589
 590	return vq;
 591
 592out_err:
 593	if (vq)
 594		vring_del_virtqueue(vq);
 595	if (info) {
 596		ccw_device_dma_free(vcdev->cdev, info->info_block,
 597				    sizeof(*info->info_block));
 598	}
 599	kfree(info);
 600	return ERR_PTR(err);
 601}
 602
 603static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
 604					   struct virtqueue *vqs[], int nvqs,
 605					   struct ccw1 *ccw)
 606{
 607	int ret;
 608	struct virtio_thinint_area *thinint_area = NULL;
 609	struct airq_info *info;
 610
 611	thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
 612					     sizeof(*thinint_area));
 613	if (!thinint_area) {
 614		ret = -ENOMEM;
 615		goto out;
 616	}
 617	/* Try to get an indicator. */
 618	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
 619						     &thinint_area->bit_nr,
 620						     &vcdev->airq_info);
 621	if (!thinint_area->indicator) {
 622		ret = -ENOSPC;
 623		goto out;
 624	}
 625	info = vcdev->airq_info;
 626	thinint_area->summary_indicator =
 627		(unsigned long) get_summary_indicator(info);
 628	thinint_area->isc = VIRTIO_AIRQ_ISC;
 629	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 630	ccw->flags = CCW_FLAG_SLI;
 631	ccw->count = sizeof(*thinint_area);
 632	ccw->cda = (__u32)(unsigned long)thinint_area;
 633	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
 634	if (ret) {
 635		if (ret == -EOPNOTSUPP) {
 636			/*
 637			 * The host does not support adapter interrupts
 638			 * for virtio-ccw, stop trying.
 639			 */
 640			virtio_ccw_use_airq = 0;
 641			pr_info("Adapter interrupts unsupported on host\n");
 642		} else
 643			dev_warn(&vcdev->cdev->dev,
 644				 "enabling adapter interrupts = %d\n", ret);
 645		virtio_ccw_drop_indicators(vcdev);
 646	}
 647out:
 648	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
 649	return ret;
 650}
 651
 652static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 653			       struct virtqueue *vqs[],
 654			       vq_callback_t *callbacks[],
 655			       const char * const names[],
 656			       const bool *ctx,
 657			       struct irq_affinity *desc)
 658{
 659	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 660	unsigned long *indicatorp = NULL;
 661	int ret, i, queue_idx = 0;
 662	struct ccw1 *ccw;
 663
 664	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 665	if (!ccw)
 666		return -ENOMEM;
 667
 668	for (i = 0; i < nvqs; ++i) {
 669		if (!names[i]) {
 670			vqs[i] = NULL;
 671			continue;
 672		}
 673
 674		vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, callbacks[i],
 675					     names[i], ctx ? ctx[i] : false,
 676					     ccw);
 677		if (IS_ERR(vqs[i])) {
 678			ret = PTR_ERR(vqs[i]);
 679			vqs[i] = NULL;
 680			goto out;
 681		}
 682	}
 683	ret = -ENOMEM;
 684	/*
 685	 * We need a data area under 2G to communicate. Our payload is
 686	 * the address of the indicators.
 687	*/
 688	indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
 689					   sizeof(indicators(vcdev)));
 690	if (!indicatorp)
 691		goto out;
 692	*indicatorp = (unsigned long) indicators(vcdev);
 693	if (vcdev->is_thinint) {
 694		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
 695		if (ret)
 696			/* no error, just fall back to legacy interrupts */
 697			vcdev->is_thinint = false;
 698	}
 699	if (!vcdev->is_thinint) {
 700		/* Register queue indicators with host. */
 701		*indicators(vcdev) = 0;
 702		ccw->cmd_code = CCW_CMD_SET_IND;
 703		ccw->flags = 0;
 704		ccw->count = sizeof(indicators(vcdev));
 705		ccw->cda = (__u32)(unsigned long) indicatorp;
 706		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
 707		if (ret)
 708			goto out;
 709	}
 710	/* Register indicators2 with host for config changes */
 711	*indicatorp = (unsigned long) indicators2(vcdev);
 712	*indicators2(vcdev) = 0;
 713	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
 714	ccw->flags = 0;
 715	ccw->count = sizeof(indicators2(vcdev));
 716	ccw->cda = (__u32)(unsigned long) indicatorp;
 717	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
 718	if (ret)
 719		goto out;
 720
 721	if (indicatorp)
 722		ccw_device_dma_free(vcdev->cdev, indicatorp,
 723				    sizeof(indicators(vcdev)));
 724	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 725	return 0;
 726out:
 727	if (indicatorp)
 728		ccw_device_dma_free(vcdev->cdev, indicatorp,
 729				    sizeof(indicators(vcdev)));
 730	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 731	virtio_ccw_del_vqs(vdev);
 732	return ret;
 733}
 734
 735static void virtio_ccw_reset(struct virtio_device *vdev)
 736{
 737	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 738	struct ccw1 *ccw;
 739
 740	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 741	if (!ccw)
 742		return;
 743
 744	/* Zero status bits. */
 745	vcdev->dma_area->status = 0;
 746
 747	/* Send a reset ccw on device. */
 748	ccw->cmd_code = CCW_CMD_VDEV_RESET;
 749	ccw->flags = 0;
 750	ccw->count = 0;
 751	ccw->cda = 0;
 752	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
 753	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 754}
 755
 756static u64 virtio_ccw_get_features(struct virtio_device *vdev)
 757{
 758	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 759	struct virtio_feature_desc *features;
 760	int ret;
 761	u64 rc;
 762	struct ccw1 *ccw;
 763
 764	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 765	if (!ccw)
 766		return 0;
 767
 768	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
 769	if (!features) {
 770		rc = 0;
 771		goto out_free;
 772	}
 773	/* Read the feature bits from the host. */
 774	features->index = 0;
 775	ccw->cmd_code = CCW_CMD_READ_FEAT;
 776	ccw->flags = 0;
 777	ccw->count = sizeof(*features);
 778	ccw->cda = (__u32)(unsigned long)features;
 779	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 780	if (ret) {
 781		rc = 0;
 782		goto out_free;
 783	}
 784
 785	rc = le32_to_cpu(features->features);
 786
 787	if (vcdev->revision == 0)
 788		goto out_free;
 789
 790	/* Read second half of the feature bits from the host. */
 791	features->index = 1;
 792	ccw->cmd_code = CCW_CMD_READ_FEAT;
 793	ccw->flags = 0;
 794	ccw->count = sizeof(*features);
 795	ccw->cda = (__u32)(unsigned long)features;
 796	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
 797	if (ret == 0)
 798		rc |= (u64)le32_to_cpu(features->features) << 32;
 799
 800out_free:
 801	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
 802	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 803	return rc;
 804}
 805
 806static void ccw_transport_features(struct virtio_device *vdev)
 807{
 808	/*
 809	 * Currently nothing to do here.
 810	 */
 811}
 812
 813static int virtio_ccw_finalize_features(struct virtio_device *vdev)
 814{
 815	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 816	struct virtio_feature_desc *features;
 817	struct ccw1 *ccw;
 818	int ret;
 819
 820	if (vcdev->revision >= 1 &&
 821	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
 822		dev_err(&vdev->dev, "virtio: device uses revision 1 "
 823			"but does not have VIRTIO_F_VERSION_1\n");
 824		return -EINVAL;
 825	}
 826
 827	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 828	if (!ccw)
 829		return -ENOMEM;
 830
 831	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
 832	if (!features) {
 833		ret = -ENOMEM;
 834		goto out_free;
 835	}
 836	/* Give virtio_ring a chance to accept features. */
 837	vring_transport_features(vdev);
 838
 839	/* Give virtio_ccw a chance to accept features. */
 840	ccw_transport_features(vdev);
 841
 842	features->index = 0;
 843	features->features = cpu_to_le32((u32)vdev->features);
 844	/* Write the first half of the feature bits to the host. */
 845	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 846	ccw->flags = 0;
 847	ccw->count = sizeof(*features);
 848	ccw->cda = (__u32)(unsigned long)features;
 849	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 850	if (ret)
 851		goto out_free;
 852
 853	if (vcdev->revision == 0)
 854		goto out_free;
 855
 856	features->index = 1;
 857	features->features = cpu_to_le32(vdev->features >> 32);
 858	/* Write the second half of the feature bits to the host. */
 859	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
 860	ccw->flags = 0;
 861	ccw->count = sizeof(*features);
 862	ccw->cda = (__u32)(unsigned long)features;
 863	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 864
 865out_free:
 866	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
 867	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 868
 869	return ret;
 870}
 871
 872static void virtio_ccw_get_config(struct virtio_device *vdev,
 873				  unsigned int offset, void *buf, unsigned len)
 874{
 875	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 876	int ret;
 877	struct ccw1 *ccw;
 878	void *config_area;
 879	unsigned long flags;
 880
 881	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 882	if (!ccw)
 883		return;
 884
 885	config_area = ccw_device_dma_zalloc(vcdev->cdev,
 886					    VIRTIO_CCW_CONFIG_SIZE);
 887	if (!config_area)
 888		goto out_free;
 889
 890	/* Read the config area from the host. */
 891	ccw->cmd_code = CCW_CMD_READ_CONF;
 892	ccw->flags = 0;
 893	ccw->count = offset + len;
 894	ccw->cda = (__u32)(unsigned long)config_area;
 895	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
 896	if (ret)
 897		goto out_free;
 898
 899	spin_lock_irqsave(&vcdev->lock, flags);
 900	memcpy(vcdev->config, config_area, offset + len);
 901	if (vcdev->config_ready < offset + len)
 902		vcdev->config_ready = offset + len;
 903	spin_unlock_irqrestore(&vcdev->lock, flags);
 904	if (buf)
 905		memcpy(buf, config_area + offset, len);
 906
 907out_free:
 908	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
 909	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 910}
 911
 912static void virtio_ccw_set_config(struct virtio_device *vdev,
 913				  unsigned int offset, const void *buf,
 914				  unsigned len)
 915{
 916	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 917	struct ccw1 *ccw;
 918	void *config_area;
 919	unsigned long flags;
 920
 921	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 922	if (!ccw)
 923		return;
 924
 925	config_area = ccw_device_dma_zalloc(vcdev->cdev,
 926					    VIRTIO_CCW_CONFIG_SIZE);
 927	if (!config_area)
 928		goto out_free;
 929
 930	/* Make sure we don't overwrite fields. */
 931	if (vcdev->config_ready < offset)
 932		virtio_ccw_get_config(vdev, 0, NULL, offset);
 933	spin_lock_irqsave(&vcdev->lock, flags);
 934	memcpy(&vcdev->config[offset], buf, len);
 935	/* Write the config area to the host. */
 936	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
 937	spin_unlock_irqrestore(&vcdev->lock, flags);
 938	ccw->cmd_code = CCW_CMD_WRITE_CONF;
 939	ccw->flags = 0;
 940	ccw->count = offset + len;
 941	ccw->cda = (__u32)(unsigned long)config_area;
 942	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
 943
 944out_free:
 945	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
 946	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 947}
 948
 949static u8 virtio_ccw_get_status(struct virtio_device *vdev)
 950{
 951	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 952	u8 old_status = vcdev->dma_area->status;
 953	struct ccw1 *ccw;
 954
 955	if (vcdev->revision < 1)
 956		return vcdev->dma_area->status;
 957
 958	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 959	if (!ccw)
 960		return old_status;
 961
 962	ccw->cmd_code = CCW_CMD_READ_STATUS;
 963	ccw->flags = 0;
 964	ccw->count = sizeof(vcdev->dma_area->status);
 965	ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
 966	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
 967/*
 968 * If the channel program failed (should only happen if the device
 969 * was hotunplugged, and then we clean up via the machine check
 970 * handler anyway), vcdev->dma_area->status was not overwritten and we just
 971 * return the old status, which is fine.
 972*/
 973	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 974
 975	return vcdev->dma_area->status;
 976}
 977
 978static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
 979{
 980	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 981	u8 old_status = vcdev->dma_area->status;
 982	struct ccw1 *ccw;
 983	int ret;
 984
 985	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
 986	if (!ccw)
 987		return;
 988
 989	/* Write the status to the host. */
 990	vcdev->dma_area->status = status;
 991	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
 992	ccw->flags = 0;
 993	ccw->count = sizeof(status);
 994	ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
 995	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
 996	/* Write failed? We assume status is unchanged. */
 997	if (ret)
 998		vcdev->dma_area->status = old_status;
 999	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1000}
1001
1002static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
1003{
1004	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1005
1006	return dev_name(&vcdev->cdev->dev);
1007}
1008
1009static const struct virtio_config_ops virtio_ccw_config_ops = {
1010	.get_features = virtio_ccw_get_features,
1011	.finalize_features = virtio_ccw_finalize_features,
1012	.get = virtio_ccw_get_config,
1013	.set = virtio_ccw_set_config,
1014	.get_status = virtio_ccw_get_status,
1015	.set_status = virtio_ccw_set_status,
1016	.reset = virtio_ccw_reset,
1017	.find_vqs = virtio_ccw_find_vqs,
1018	.del_vqs = virtio_ccw_del_vqs,
1019	.bus_name = virtio_ccw_bus_name,
1020};
1021
1022
1023/*
1024 * ccw bus driver related functions
1025 */
1026
1027static void virtio_ccw_release_dev(struct device *_d)
1028{
1029	struct virtio_device *dev = dev_to_virtio(_d);
1030	struct virtio_ccw_device *vcdev = to_vc_device(dev);
1031
1032	ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1033			    sizeof(*vcdev->dma_area));
1034	kfree(vcdev);
1035}
1036
1037static int irb_is_error(struct irb *irb)
1038{
1039	if (scsw_cstat(&irb->scsw) != 0)
1040		return 1;
1041	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1042		return 1;
1043	if (scsw_cc(&irb->scsw) != 0)
1044		return 1;
1045	return 0;
1046}
1047
1048static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1049					      int index)
1050{
1051	struct virtio_ccw_vq_info *info;
1052	unsigned long flags;
1053	struct virtqueue *vq;
1054
1055	vq = NULL;
1056	spin_lock_irqsave(&vcdev->lock, flags);
1057	list_for_each_entry(info, &vcdev->virtqueues, node) {
1058		if (info->vq->index == index) {
1059			vq = info->vq;
1060			break;
1061		}
1062	}
1063	spin_unlock_irqrestore(&vcdev->lock, flags);
1064	return vq;
1065}
1066
1067static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1068				      __u32 activity)
1069{
1070	if (vcdev->curr_io & activity) {
1071		switch (activity) {
1072		case VIRTIO_CCW_DOING_READ_FEAT:
1073		case VIRTIO_CCW_DOING_WRITE_FEAT:
1074		case VIRTIO_CCW_DOING_READ_CONFIG:
1075		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1076		case VIRTIO_CCW_DOING_WRITE_STATUS:
1077		case VIRTIO_CCW_DOING_READ_STATUS:
1078		case VIRTIO_CCW_DOING_SET_VQ:
1079		case VIRTIO_CCW_DOING_SET_IND:
1080		case VIRTIO_CCW_DOING_SET_CONF_IND:
1081		case VIRTIO_CCW_DOING_RESET:
1082		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1083		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1084		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1085			vcdev->curr_io &= ~activity;
1086			wake_up(&vcdev->wait_q);
1087			break;
1088		default:
1089			/* don't know what to do... */
1090			dev_warn(&vcdev->cdev->dev,
1091				 "Suspicious activity '%08x'\n", activity);
1092			WARN_ON(1);
1093			break;
1094		}
1095	}
1096}
1097
1098static void virtio_ccw_int_handler(struct ccw_device *cdev,
1099				   unsigned long intparm,
1100				   struct irb *irb)
1101{
1102	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1103	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1104	int i;
1105	struct virtqueue *vq;
1106
1107	if (!vcdev)
1108		return;
1109	if (IS_ERR(irb)) {
1110		vcdev->err = PTR_ERR(irb);
1111		virtio_ccw_check_activity(vcdev, activity);
1112		/* Don't poke around indicators, something's wrong. */
1113		return;
1114	}
1115	/* Check if it's a notification from the host. */
1116	if ((intparm == 0) &&
1117	    (scsw_stctl(&irb->scsw) ==
1118	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1119		/* OK */
1120	}
1121	if (irb_is_error(irb)) {
1122		/* Command reject? */
1123		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1124		    (irb->ecw[0] & SNS0_CMD_REJECT))
1125			vcdev->err = -EOPNOTSUPP;
1126		else
1127			/* Map everything else to -EIO. */
1128			vcdev->err = -EIO;
1129	}
1130	virtio_ccw_check_activity(vcdev, activity);
1131	for_each_set_bit(i, indicators(vcdev),
1132			 sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {
1133		/* The bit clear must happen before the vring kick. */
1134		clear_bit(i, indicators(vcdev));
1135		barrier();
1136		vq = virtio_ccw_vq_by_ind(vcdev, i);
1137		vring_interrupt(0, vq);
1138	}
1139	if (test_bit(0, indicators2(vcdev))) {
1140		virtio_config_changed(&vcdev->vdev);
1141		clear_bit(0, indicators2(vcdev));
1142	}
1143}
1144
1145/*
1146 * We usually want to autoonline all devices, but give the admin
1147 * a way to exempt devices from this.
1148 */
1149#define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1150		     (8*sizeof(long)))
1151static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1152
1153static char *no_auto = "";
1154
1155module_param(no_auto, charp, 0444);
1156MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1157
1158static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1159{
1160	struct ccw_dev_id id;
1161
1162	ccw_device_get_id(cdev, &id);
1163	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1164		return 0;
1165	return 1;
1166}
1167
1168static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1169{
1170	struct ccw_device *cdev = data;
1171	int ret;
1172
1173	ret = ccw_device_set_online(cdev);
1174	if (ret)
1175		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1176}
1177
1178static int virtio_ccw_probe(struct ccw_device *cdev)
1179{
1180	cdev->handler = virtio_ccw_int_handler;
1181
1182	if (virtio_ccw_check_autoonline(cdev))
1183		async_schedule(virtio_ccw_auto_online, cdev);
1184	return 0;
1185}
1186
1187static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1188{
1189	unsigned long flags;
1190	struct virtio_ccw_device *vcdev;
1191
1192	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1193	vcdev = dev_get_drvdata(&cdev->dev);
1194	if (!vcdev || vcdev->going_away) {
1195		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1196		return NULL;
1197	}
1198	vcdev->going_away = true;
1199	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1200	return vcdev;
1201}
1202
1203static void virtio_ccw_remove(struct ccw_device *cdev)
1204{
1205	unsigned long flags;
1206	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1207
1208	if (vcdev && cdev->online) {
1209		if (vcdev->device_lost)
1210			virtio_break_device(&vcdev->vdev);
1211		unregister_virtio_device(&vcdev->vdev);
1212		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1213		dev_set_drvdata(&cdev->dev, NULL);
1214		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1215	}
1216	cdev->handler = NULL;
1217}
1218
1219static int virtio_ccw_offline(struct ccw_device *cdev)
1220{
1221	unsigned long flags;
1222	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1223
1224	if (!vcdev)
1225		return 0;
1226	if (vcdev->device_lost)
1227		virtio_break_device(&vcdev->vdev);
1228	unregister_virtio_device(&vcdev->vdev);
1229	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1230	dev_set_drvdata(&cdev->dev, NULL);
1231	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1232	return 0;
1233}
1234
1235static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1236{
1237	struct virtio_rev_info *rev;
1238	struct ccw1 *ccw;
1239	int ret;
1240
1241	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
1242	if (!ccw)
1243		return -ENOMEM;
1244	rev = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*rev));
1245	if (!rev) {
1246		ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1247		return -ENOMEM;
1248	}
1249
1250	/* Set transport revision */
1251	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1252	ccw->flags = 0;
1253	ccw->count = sizeof(*rev);
1254	ccw->cda = (__u32)(unsigned long)rev;
1255
1256	vcdev->revision = VIRTIO_CCW_REV_MAX;
1257	do {
1258		rev->revision = vcdev->revision;
1259		/* none of our supported revisions carry payload */
1260		rev->length = 0;
1261		ret = ccw_io_helper(vcdev, ccw,
1262				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1263		if (ret == -EOPNOTSUPP) {
1264			if (vcdev->revision == 0)
1265				/*
1266				 * The host device does not support setting
1267				 * the revision: let's operate it in legacy
1268				 * mode.
1269				 */
1270				ret = 0;
1271			else
1272				vcdev->revision--;
1273		}
1274	} while (ret == -EOPNOTSUPP);
1275
1276	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1277	ccw_device_dma_free(vcdev->cdev, rev, sizeof(*rev));
1278	return ret;
1279}
1280
1281static int virtio_ccw_online(struct ccw_device *cdev)
1282{
1283	int ret;
1284	struct virtio_ccw_device *vcdev;
1285	unsigned long flags;
1286
1287	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1288	if (!vcdev) {
1289		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1290		ret = -ENOMEM;
1291		goto out_free;
1292	}
1293	vcdev->vdev.dev.parent = &cdev->dev;
1294	vcdev->cdev = cdev;
1295	vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,
1296						sizeof(*vcdev->dma_area));
1297	if (!vcdev->dma_area) {
1298		ret = -ENOMEM;
1299		goto out_free;
1300	}
1301
1302	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1303
1304	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1305	vcdev->vdev.config = &virtio_ccw_config_ops;
1306	init_waitqueue_head(&vcdev->wait_q);
1307	INIT_LIST_HEAD(&vcdev->virtqueues);
1308	spin_lock_init(&vcdev->lock);
1309	mutex_init(&vcdev->io_lock);
1310
1311	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1312	dev_set_drvdata(&cdev->dev, vcdev);
1313	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1314	vcdev->vdev.id.vendor = cdev->id.cu_type;
1315	vcdev->vdev.id.device = cdev->id.cu_model;
1316
1317	ret = virtio_ccw_set_transport_rev(vcdev);
1318	if (ret)
1319		goto out_free;
1320
1321	ret = register_virtio_device(&vcdev->vdev);
1322	if (ret) {
1323		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1324			 ret);
1325		goto out_put;
1326	}
1327	return 0;
1328out_put:
1329	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1330	dev_set_drvdata(&cdev->dev, NULL);
1331	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1332	put_device(&vcdev->vdev.dev);
1333	return ret;
1334out_free:
1335	if (vcdev) {
1336		ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1337				    sizeof(*vcdev->dma_area));
1338	}
1339	kfree(vcdev);
1340	return ret;
1341}
1342
1343static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1344{
1345	int rc;
1346	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1347
1348	/*
1349	 * Make sure vcdev is set
1350	 * i.e. set_offline/remove callback not already running
1351	 */
1352	if (!vcdev)
1353		return NOTIFY_DONE;
1354
1355	switch (event) {
1356	case CIO_GONE:
1357		vcdev->device_lost = true;
1358		rc = NOTIFY_DONE;
1359		break;
1360	case CIO_OPER:
1361		rc = NOTIFY_OK;
1362		break;
1363	default:
1364		rc = NOTIFY_DONE;
1365		break;
1366	}
1367	return rc;
1368}
1369
1370static struct ccw_device_id virtio_ids[] = {
1371	{ CCW_DEVICE(0x3832, 0) },
1372	{},
1373};
1374
1375static struct ccw_driver virtio_ccw_driver = {
1376	.driver = {
1377		.owner = THIS_MODULE,
1378		.name = "virtio_ccw",
1379	},
1380	.ids = virtio_ids,
1381	.probe = virtio_ccw_probe,
1382	.remove = virtio_ccw_remove,
1383	.set_offline = virtio_ccw_offline,
1384	.set_online = virtio_ccw_online,
1385	.notify = virtio_ccw_cio_notify,
1386	.int_class = IRQIO_VIR,
1387};
1388
1389static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1390			   int max_digit, int max_val)
1391{
1392	int diff;
1393
1394	diff = 0;
1395	*val = 0;
1396
1397	while (diff <= max_digit) {
1398		int value = hex_to_bin(**cp);
1399
1400		if (value < 0)
1401			break;
1402		*val = *val * 16 + value;
1403		(*cp)++;
1404		diff++;
1405	}
1406
1407	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1408		return 1;
1409
1410	return 0;
1411}
1412
1413static int __init parse_busid(char *str, unsigned int *cssid,
1414			      unsigned int *ssid, unsigned int *devno)
1415{
1416	char *str_work;
1417	int rc, ret;
1418
1419	rc = 1;
1420
1421	if (*str == '\0')
1422		goto out;
1423
1424	str_work = str;
1425	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1426	if (ret || (str_work[0] != '.'))
1427		goto out;
1428	str_work++;
1429	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1430	if (ret || (str_work[0] != '.'))
1431		goto out;
1432	str_work++;
1433	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1434	if (ret || (str_work[0] != '\0'))
1435		goto out;
1436
1437	rc = 0;
1438out:
1439	return rc;
1440}
1441
1442static void __init no_auto_parse(void)
1443{
1444	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1445	char *parm, *str;
1446	int rc;
1447
1448	str = no_auto;
1449	while ((parm = strsep(&str, ","))) {
1450		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1451				 &from_ssid, &from);
1452		if (rc)
1453			continue;
1454		if (parm != NULL) {
1455			rc = parse_busid(parm, &to_cssid,
1456					 &to_ssid, &to);
1457			if ((from_ssid > to_ssid) ||
1458			    ((from_ssid == to_ssid) && (from > to)))
1459				rc = -EINVAL;
1460		} else {
1461			to_cssid = from_cssid;
1462			to_ssid = from_ssid;
1463			to = from;
1464		}
1465		if (rc)
1466			continue;
1467		while ((from_ssid < to_ssid) ||
1468		       ((from_ssid == to_ssid) && (from <= to))) {
1469			set_bit(from, devs_no_auto[from_ssid]);
1470			from++;
1471			if (from > __MAX_SUBCHANNEL) {
1472				from_ssid++;
1473				from = 0;
1474			}
1475		}
1476	}
1477}
1478
1479static int __init virtio_ccw_init(void)
1480{
1481	int rc;
1482
1483	/* parse no_auto string before we do anything further */
1484	no_auto_parse();
1485
1486	summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS);
1487	if (!summary_indicators)
1488		return -ENOMEM;
1489	rc = ccw_driver_register(&virtio_ccw_driver);
1490	if (rc)
1491		cio_dma_free(summary_indicators, MAX_AIRQ_AREAS);
1492	return rc;
1493}
1494device_initcall(virtio_ccw_init);