xref: /openbmc/linux/drivers/s390/virtio/virtio_ccw.c (revision 62e59c4e)
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 
41 struct 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 
49 struct virtio_ccw_device {
50 	struct virtio_device vdev;
51 	__u8 *status;
52 	__u8 config[VIRTIO_CCW_CONFIG_SIZE];
53 	struct ccw_device *cdev;
54 	__u32 curr_io;
55 	int err;
56 	unsigned int revision; /* Transport revision */
57 	wait_queue_head_t wait_q;
58 	spinlock_t lock;
59 	struct mutex io_lock; /* Serializes I/O requests */
60 	struct list_head virtqueues;
61 	unsigned long indicators;
62 	unsigned long indicators2;
63 	struct vq_config_block *config_block;
64 	bool is_thinint;
65 	bool going_away;
66 	bool device_lost;
67 	unsigned int config_ready;
68 	void *airq_info;
69 };
70 
71 struct vq_info_block_legacy {
72 	__u64 queue;
73 	__u32 align;
74 	__u16 index;
75 	__u16 num;
76 } __packed;
77 
78 struct vq_info_block {
79 	__u64 desc;
80 	__u32 res0;
81 	__u16 index;
82 	__u16 num;
83 	__u64 avail;
84 	__u64 used;
85 } __packed;
86 
87 struct virtio_feature_desc {
88 	__le32 features;
89 	__u8 index;
90 } __packed;
91 
92 struct virtio_thinint_area {
93 	unsigned long summary_indicator;
94 	unsigned long indicator;
95 	u64 bit_nr;
96 	u8 isc;
97 } __packed;
98 
99 struct virtio_rev_info {
100 	__u16 revision;
101 	__u16 length;
102 	__u8 data[];
103 };
104 
105 /* the highest virtio-ccw revision we support */
106 #define VIRTIO_CCW_REV_MAX 1
107 
108 struct virtio_ccw_vq_info {
109 	struct virtqueue *vq;
110 	int num;
111 	void *queue;
112 	union {
113 		struct vq_info_block s;
114 		struct vq_info_block_legacy l;
115 	} *info_block;
116 	int bit_nr;
117 	struct list_head node;
118 	long cookie;
119 };
120 
121 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
122 
123 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
124 #define MAX_AIRQ_AREAS 20
125 
126 static int virtio_ccw_use_airq = 1;
127 
128 struct airq_info {
129 	rwlock_t lock;
130 	u8 summary_indicator;
131 	struct airq_struct airq;
132 	struct airq_iv *aiv;
133 };
134 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
135 
136 #define CCW_CMD_SET_VQ 0x13
137 #define CCW_CMD_VDEV_RESET 0x33
138 #define CCW_CMD_SET_IND 0x43
139 #define CCW_CMD_SET_CONF_IND 0x53
140 #define CCW_CMD_READ_FEAT 0x12
141 #define CCW_CMD_WRITE_FEAT 0x11
142 #define CCW_CMD_READ_CONF 0x22
143 #define CCW_CMD_WRITE_CONF 0x21
144 #define CCW_CMD_WRITE_STATUS 0x31
145 #define CCW_CMD_READ_VQ_CONF 0x32
146 #define CCW_CMD_READ_STATUS 0x72
147 #define CCW_CMD_SET_IND_ADAPTER 0x73
148 #define CCW_CMD_SET_VIRTIO_REV 0x83
149 
150 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
151 #define VIRTIO_CCW_DOING_RESET 0x00040000
152 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
153 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
154 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
155 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
156 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
157 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
158 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
159 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
160 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
161 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
162 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
163 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
164 
165 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
166 {
167 	return container_of(vdev, struct virtio_ccw_device, vdev);
168 }
169 
170 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
171 {
172 	unsigned long i, flags;
173 
174 	write_lock_irqsave(&info->lock, flags);
175 	for (i = 0; i < airq_iv_end(info->aiv); i++) {
176 		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
177 			airq_iv_free_bit(info->aiv, i);
178 			airq_iv_set_ptr(info->aiv, i, 0);
179 			break;
180 		}
181 	}
182 	write_unlock_irqrestore(&info->lock, flags);
183 }
184 
185 static void virtio_airq_handler(struct airq_struct *airq)
186 {
187 	struct airq_info *info = container_of(airq, struct airq_info, airq);
188 	unsigned long ai;
189 
190 	inc_irq_stat(IRQIO_VAI);
191 	read_lock(&info->lock);
192 	/* Walk through indicators field, summary indicator active. */
193 	for (ai = 0;;) {
194 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
195 		if (ai == -1UL)
196 			break;
197 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
198 	}
199 	info->summary_indicator = 0;
200 	smp_wmb();
201 	/* Walk through indicators field, summary indicator not active. */
202 	for (ai = 0;;) {
203 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
204 		if (ai == -1UL)
205 			break;
206 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
207 	}
208 	read_unlock(&info->lock);
209 }
210 
211 static struct airq_info *new_airq_info(void)
212 {
213 	struct airq_info *info;
214 	int rc;
215 
216 	info = kzalloc(sizeof(*info), GFP_KERNEL);
217 	if (!info)
218 		return NULL;
219 	rwlock_init(&info->lock);
220 	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
221 	if (!info->aiv) {
222 		kfree(info);
223 		return NULL;
224 	}
225 	info->airq.handler = virtio_airq_handler;
226 	info->airq.lsi_ptr = &info->summary_indicator;
227 	info->airq.lsi_mask = 0xff;
228 	info->airq.isc = VIRTIO_AIRQ_ISC;
229 	rc = register_adapter_interrupt(&info->airq);
230 	if (rc) {
231 		airq_iv_release(info->aiv);
232 		kfree(info);
233 		return NULL;
234 	}
235 	return info;
236 }
237 
238 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
239 					u64 *first, void **airq_info)
240 {
241 	int i, j;
242 	struct airq_info *info;
243 	unsigned long indicator_addr = 0;
244 	unsigned long bit, flags;
245 
246 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
247 		if (!airq_areas[i])
248 			airq_areas[i] = new_airq_info();
249 		info = airq_areas[i];
250 		if (!info)
251 			return 0;
252 		write_lock_irqsave(&info->lock, flags);
253 		bit = airq_iv_alloc(info->aiv, nvqs);
254 		if (bit == -1UL) {
255 			/* Not enough vacancies. */
256 			write_unlock_irqrestore(&info->lock, flags);
257 			continue;
258 		}
259 		*first = bit;
260 		*airq_info = info;
261 		indicator_addr = (unsigned long)info->aiv->vector;
262 		for (j = 0; j < nvqs; j++) {
263 			airq_iv_set_ptr(info->aiv, bit + j,
264 					(unsigned long)vqs[j]);
265 		}
266 		write_unlock_irqrestore(&info->lock, flags);
267 	}
268 	return indicator_addr;
269 }
270 
271 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
272 {
273 	struct virtio_ccw_vq_info *info;
274 
275 	if (!vcdev->airq_info)
276 		return;
277 	list_for_each_entry(info, &vcdev->virtqueues, node)
278 		drop_airq_indicator(info->vq, vcdev->airq_info);
279 }
280 
281 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
282 {
283 	unsigned long flags;
284 	__u32 ret;
285 
286 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
287 	if (vcdev->err)
288 		ret = 0;
289 	else
290 		ret = vcdev->curr_io & flag;
291 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
292 	return ret;
293 }
294 
295 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
296 			 struct ccw1 *ccw, __u32 intparm)
297 {
298 	int ret;
299 	unsigned long flags;
300 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
301 
302 	mutex_lock(&vcdev->io_lock);
303 	do {
304 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
305 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
306 		if (!ret) {
307 			if (!vcdev->curr_io)
308 				vcdev->err = 0;
309 			vcdev->curr_io |= flag;
310 		}
311 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
312 		cpu_relax();
313 	} while (ret == -EBUSY);
314 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
315 	ret = ret ? ret : vcdev->err;
316 	mutex_unlock(&vcdev->io_lock);
317 	return ret;
318 }
319 
320 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
321 				      struct ccw1 *ccw)
322 {
323 	int ret;
324 	unsigned long *indicatorp = NULL;
325 	struct virtio_thinint_area *thinint_area = NULL;
326 	struct airq_info *airq_info = vcdev->airq_info;
327 
328 	if (vcdev->is_thinint) {
329 		thinint_area = kzalloc(sizeof(*thinint_area),
330 				       GFP_DMA | GFP_KERNEL);
331 		if (!thinint_area)
332 			return;
333 		thinint_area->summary_indicator =
334 			(unsigned long) &airq_info->summary_indicator;
335 		thinint_area->isc = VIRTIO_AIRQ_ISC;
336 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
337 		ccw->count = sizeof(*thinint_area);
338 		ccw->cda = (__u32)(unsigned long) thinint_area;
339 	} else {
340 		/* payload is the address of the indicators */
341 		indicatorp = kmalloc(sizeof(&vcdev->indicators),
342 				     GFP_DMA | GFP_KERNEL);
343 		if (!indicatorp)
344 			return;
345 		*indicatorp = 0;
346 		ccw->cmd_code = CCW_CMD_SET_IND;
347 		ccw->count = sizeof(&vcdev->indicators);
348 		ccw->cda = (__u32)(unsigned long) indicatorp;
349 	}
350 	/* Deregister indicators from host. */
351 	vcdev->indicators = 0;
352 	ccw->flags = 0;
353 	ret = ccw_io_helper(vcdev, ccw,
354 			    vcdev->is_thinint ?
355 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
356 			    VIRTIO_CCW_DOING_SET_IND);
357 	if (ret && (ret != -ENODEV))
358 		dev_info(&vcdev->cdev->dev,
359 			 "Failed to deregister indicators (%d)\n", ret);
360 	else if (vcdev->is_thinint)
361 		virtio_ccw_drop_indicators(vcdev);
362 	kfree(indicatorp);
363 	kfree(thinint_area);
364 }
365 
366 static inline long __do_kvm_notify(struct subchannel_id schid,
367 				   unsigned long queue_index,
368 				   long cookie)
369 {
370 	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
371 	register struct subchannel_id __schid asm("2") = schid;
372 	register unsigned long __index asm("3") = queue_index;
373 	register long __rc asm("2");
374 	register long __cookie asm("4") = cookie;
375 
376 	asm volatile ("diag 2,4,0x500\n"
377 		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
378 		      "d"(__cookie)
379 		      : "memory", "cc");
380 	return __rc;
381 }
382 
383 static inline long do_kvm_notify(struct subchannel_id schid,
384 				 unsigned long queue_index,
385 				 long cookie)
386 {
387 	diag_stat_inc(DIAG_STAT_X500);
388 	return __do_kvm_notify(schid, queue_index, cookie);
389 }
390 
391 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
392 {
393 	struct virtio_ccw_vq_info *info = vq->priv;
394 	struct virtio_ccw_device *vcdev;
395 	struct subchannel_id schid;
396 
397 	vcdev = to_vc_device(info->vq->vdev);
398 	ccw_device_get_schid(vcdev->cdev, &schid);
399 	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
400 	if (info->cookie < 0)
401 		return false;
402 	return true;
403 }
404 
405 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
406 				   struct ccw1 *ccw, int index)
407 {
408 	int ret;
409 
410 	vcdev->config_block->index = index;
411 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
412 	ccw->flags = 0;
413 	ccw->count = sizeof(struct vq_config_block);
414 	ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
415 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
416 	if (ret)
417 		return ret;
418 	return vcdev->config_block->num ?: -ENOENT;
419 }
420 
421 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
422 {
423 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
424 	struct virtio_ccw_vq_info *info = vq->priv;
425 	unsigned long flags;
426 	unsigned long size;
427 	int ret;
428 	unsigned int index = vq->index;
429 
430 	/* Remove from our list. */
431 	spin_lock_irqsave(&vcdev->lock, flags);
432 	list_del(&info->node);
433 	spin_unlock_irqrestore(&vcdev->lock, flags);
434 
435 	/* Release from host. */
436 	if (vcdev->revision == 0) {
437 		info->info_block->l.queue = 0;
438 		info->info_block->l.align = 0;
439 		info->info_block->l.index = index;
440 		info->info_block->l.num = 0;
441 		ccw->count = sizeof(info->info_block->l);
442 	} else {
443 		info->info_block->s.desc = 0;
444 		info->info_block->s.index = index;
445 		info->info_block->s.num = 0;
446 		info->info_block->s.avail = 0;
447 		info->info_block->s.used = 0;
448 		ccw->count = sizeof(info->info_block->s);
449 	}
450 	ccw->cmd_code = CCW_CMD_SET_VQ;
451 	ccw->flags = 0;
452 	ccw->cda = (__u32)(unsigned long)(info->info_block);
453 	ret = ccw_io_helper(vcdev, ccw,
454 			    VIRTIO_CCW_DOING_SET_VQ | index);
455 	/*
456 	 * -ENODEV isn't considered an error: The device is gone anyway.
457 	 * This may happen on device detach.
458 	 */
459 	if (ret && (ret != -ENODEV))
460 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
461 			 ret, index);
462 
463 	vring_del_virtqueue(vq);
464 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
465 	free_pages_exact(info->queue, size);
466 	kfree(info->info_block);
467 	kfree(info);
468 }
469 
470 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
471 {
472 	struct virtqueue *vq, *n;
473 	struct ccw1 *ccw;
474 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
475 
476 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
477 	if (!ccw)
478 		return;
479 
480 	virtio_ccw_drop_indicator(vcdev, ccw);
481 
482 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
483 		virtio_ccw_del_vq(vq, ccw);
484 
485 	kfree(ccw);
486 }
487 
488 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
489 					     int i, vq_callback_t *callback,
490 					     const char *name, bool ctx,
491 					     struct ccw1 *ccw)
492 {
493 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
494 	int err;
495 	struct virtqueue *vq = NULL;
496 	struct virtio_ccw_vq_info *info;
497 	unsigned long size = 0; /* silence the compiler */
498 	unsigned long flags;
499 
500 	/* Allocate queue. */
501 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
502 	if (!info) {
503 		dev_warn(&vcdev->cdev->dev, "no info\n");
504 		err = -ENOMEM;
505 		goto out_err;
506 	}
507 	info->info_block = kzalloc(sizeof(*info->info_block),
508 				   GFP_DMA | GFP_KERNEL);
509 	if (!info->info_block) {
510 		dev_warn(&vcdev->cdev->dev, "no info block\n");
511 		err = -ENOMEM;
512 		goto out_err;
513 	}
514 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
515 	if (info->num < 0) {
516 		err = info->num;
517 		goto out_err;
518 	}
519 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
520 	info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
521 	if (info->queue == NULL) {
522 		dev_warn(&vcdev->cdev->dev, "no queue\n");
523 		err = -ENOMEM;
524 		goto out_err;
525 	}
526 
527 	vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
528 				 true, ctx, info->queue, virtio_ccw_kvm_notify,
529 				 callback, name);
530 	if (!vq) {
531 		/* For now, we fail if we can't get the requested size. */
532 		dev_warn(&vcdev->cdev->dev, "no vq\n");
533 		err = -ENOMEM;
534 		goto out_err;
535 	}
536 
537 	/* Register it with the host. */
538 	if (vcdev->revision == 0) {
539 		info->info_block->l.queue = (__u64)info->queue;
540 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
541 		info->info_block->l.index = i;
542 		info->info_block->l.num = info->num;
543 		ccw->count = sizeof(info->info_block->l);
544 	} else {
545 		info->info_block->s.desc = (__u64)info->queue;
546 		info->info_block->s.index = i;
547 		info->info_block->s.num = info->num;
548 		info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
549 		info->info_block->s.used = (__u64)virtqueue_get_used(vq);
550 		ccw->count = sizeof(info->info_block->s);
551 	}
552 	ccw->cmd_code = CCW_CMD_SET_VQ;
553 	ccw->flags = 0;
554 	ccw->cda = (__u32)(unsigned long)(info->info_block);
555 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
556 	if (err) {
557 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
558 		goto out_err;
559 	}
560 
561 	info->vq = vq;
562 	vq->priv = info;
563 
564 	/* Save it to our list. */
565 	spin_lock_irqsave(&vcdev->lock, flags);
566 	list_add(&info->node, &vcdev->virtqueues);
567 	spin_unlock_irqrestore(&vcdev->lock, flags);
568 
569 	return vq;
570 
571 out_err:
572 	if (vq)
573 		vring_del_virtqueue(vq);
574 	if (info) {
575 		if (info->queue)
576 			free_pages_exact(info->queue, size);
577 		kfree(info->info_block);
578 	}
579 	kfree(info);
580 	return ERR_PTR(err);
581 }
582 
583 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
584 					   struct virtqueue *vqs[], int nvqs,
585 					   struct ccw1 *ccw)
586 {
587 	int ret;
588 	struct virtio_thinint_area *thinint_area = NULL;
589 	struct airq_info *info;
590 
591 	thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
592 	if (!thinint_area) {
593 		ret = -ENOMEM;
594 		goto out;
595 	}
596 	/* Try to get an indicator. */
597 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
598 						     &thinint_area->bit_nr,
599 						     &vcdev->airq_info);
600 	if (!thinint_area->indicator) {
601 		ret = -ENOSPC;
602 		goto out;
603 	}
604 	info = vcdev->airq_info;
605 	thinint_area->summary_indicator =
606 		(unsigned long) &info->summary_indicator;
607 	thinint_area->isc = VIRTIO_AIRQ_ISC;
608 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
609 	ccw->flags = CCW_FLAG_SLI;
610 	ccw->count = sizeof(*thinint_area);
611 	ccw->cda = (__u32)(unsigned long)thinint_area;
612 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
613 	if (ret) {
614 		if (ret == -EOPNOTSUPP) {
615 			/*
616 			 * The host does not support adapter interrupts
617 			 * for virtio-ccw, stop trying.
618 			 */
619 			virtio_ccw_use_airq = 0;
620 			pr_info("Adapter interrupts unsupported on host\n");
621 		} else
622 			dev_warn(&vcdev->cdev->dev,
623 				 "enabling adapter interrupts = %d\n", ret);
624 		virtio_ccw_drop_indicators(vcdev);
625 	}
626 out:
627 	kfree(thinint_area);
628 	return ret;
629 }
630 
631 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
632 			       struct virtqueue *vqs[],
633 			       vq_callback_t *callbacks[],
634 			       const char * const names[],
635 			       const bool *ctx,
636 			       struct irq_affinity *desc)
637 {
638 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
639 	unsigned long *indicatorp = NULL;
640 	int ret, i, queue_idx = 0;
641 	struct ccw1 *ccw;
642 
643 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
644 	if (!ccw)
645 		return -ENOMEM;
646 
647 	for (i = 0; i < nvqs; ++i) {
648 		if (!names[i]) {
649 			vqs[i] = NULL;
650 			continue;
651 		}
652 
653 		vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, callbacks[i],
654 					     names[i], ctx ? ctx[i] : false,
655 					     ccw);
656 		if (IS_ERR(vqs[i])) {
657 			ret = PTR_ERR(vqs[i]);
658 			vqs[i] = NULL;
659 			goto out;
660 		}
661 	}
662 	ret = -ENOMEM;
663 	/*
664 	 * We need a data area under 2G to communicate. Our payload is
665 	 * the address of the indicators.
666 	*/
667 	indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
668 	if (!indicatorp)
669 		goto out;
670 	*indicatorp = (unsigned long) &vcdev->indicators;
671 	if (vcdev->is_thinint) {
672 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
673 		if (ret)
674 			/* no error, just fall back to legacy interrupts */
675 			vcdev->is_thinint = false;
676 	}
677 	if (!vcdev->is_thinint) {
678 		/* Register queue indicators with host. */
679 		vcdev->indicators = 0;
680 		ccw->cmd_code = CCW_CMD_SET_IND;
681 		ccw->flags = 0;
682 		ccw->count = sizeof(&vcdev->indicators);
683 		ccw->cda = (__u32)(unsigned long) indicatorp;
684 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
685 		if (ret)
686 			goto out;
687 	}
688 	/* Register indicators2 with host for config changes */
689 	*indicatorp = (unsigned long) &vcdev->indicators2;
690 	vcdev->indicators2 = 0;
691 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
692 	ccw->flags = 0;
693 	ccw->count = sizeof(&vcdev->indicators2);
694 	ccw->cda = (__u32)(unsigned long) indicatorp;
695 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
696 	if (ret)
697 		goto out;
698 
699 	kfree(indicatorp);
700 	kfree(ccw);
701 	return 0;
702 out:
703 	kfree(indicatorp);
704 	kfree(ccw);
705 	virtio_ccw_del_vqs(vdev);
706 	return ret;
707 }
708 
709 static void virtio_ccw_reset(struct virtio_device *vdev)
710 {
711 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
712 	struct ccw1 *ccw;
713 
714 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
715 	if (!ccw)
716 		return;
717 
718 	/* Zero status bits. */
719 	*vcdev->status = 0;
720 
721 	/* Send a reset ccw on device. */
722 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
723 	ccw->flags = 0;
724 	ccw->count = 0;
725 	ccw->cda = 0;
726 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
727 	kfree(ccw);
728 }
729 
730 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
731 {
732 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
733 	struct virtio_feature_desc *features;
734 	int ret;
735 	u64 rc;
736 	struct ccw1 *ccw;
737 
738 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
739 	if (!ccw)
740 		return 0;
741 
742 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
743 	if (!features) {
744 		rc = 0;
745 		goto out_free;
746 	}
747 	/* Read the feature bits from the host. */
748 	features->index = 0;
749 	ccw->cmd_code = CCW_CMD_READ_FEAT;
750 	ccw->flags = 0;
751 	ccw->count = sizeof(*features);
752 	ccw->cda = (__u32)(unsigned long)features;
753 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
754 	if (ret) {
755 		rc = 0;
756 		goto out_free;
757 	}
758 
759 	rc = le32_to_cpu(features->features);
760 
761 	if (vcdev->revision == 0)
762 		goto out_free;
763 
764 	/* Read second half of the feature bits from the host. */
765 	features->index = 1;
766 	ccw->cmd_code = CCW_CMD_READ_FEAT;
767 	ccw->flags = 0;
768 	ccw->count = sizeof(*features);
769 	ccw->cda = (__u32)(unsigned long)features;
770 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
771 	if (ret == 0)
772 		rc |= (u64)le32_to_cpu(features->features) << 32;
773 
774 out_free:
775 	kfree(features);
776 	kfree(ccw);
777 	return rc;
778 }
779 
780 static void ccw_transport_features(struct virtio_device *vdev)
781 {
782 	/*
783 	 * Packed ring isn't enabled on virtio_ccw for now,
784 	 * because virtio_ccw uses some legacy accessors,
785 	 * e.g. virtqueue_get_avail() and virtqueue_get_used()
786 	 * which aren't available in packed ring currently.
787 	 */
788 	__virtio_clear_bit(vdev, VIRTIO_F_RING_PACKED);
789 }
790 
791 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
792 {
793 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
794 	struct virtio_feature_desc *features;
795 	struct ccw1 *ccw;
796 	int ret;
797 
798 	if (vcdev->revision >= 1 &&
799 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
800 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
801 			"but does not have VIRTIO_F_VERSION_1\n");
802 		return -EINVAL;
803 	}
804 
805 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
806 	if (!ccw)
807 		return -ENOMEM;
808 
809 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
810 	if (!features) {
811 		ret = -ENOMEM;
812 		goto out_free;
813 	}
814 	/* Give virtio_ring a chance to accept features. */
815 	vring_transport_features(vdev);
816 
817 	/* Give virtio_ccw a chance to accept features. */
818 	ccw_transport_features(vdev);
819 
820 	features->index = 0;
821 	features->features = cpu_to_le32((u32)vdev->features);
822 	/* Write the first half of the feature bits to the host. */
823 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
824 	ccw->flags = 0;
825 	ccw->count = sizeof(*features);
826 	ccw->cda = (__u32)(unsigned long)features;
827 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
828 	if (ret)
829 		goto out_free;
830 
831 	if (vcdev->revision == 0)
832 		goto out_free;
833 
834 	features->index = 1;
835 	features->features = cpu_to_le32(vdev->features >> 32);
836 	/* Write the second half of the feature bits to the host. */
837 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
838 	ccw->flags = 0;
839 	ccw->count = sizeof(*features);
840 	ccw->cda = (__u32)(unsigned long)features;
841 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
842 
843 out_free:
844 	kfree(features);
845 	kfree(ccw);
846 
847 	return ret;
848 }
849 
850 static void virtio_ccw_get_config(struct virtio_device *vdev,
851 				  unsigned int offset, void *buf, unsigned len)
852 {
853 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
854 	int ret;
855 	struct ccw1 *ccw;
856 	void *config_area;
857 	unsigned long flags;
858 
859 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
860 	if (!ccw)
861 		return;
862 
863 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
864 	if (!config_area)
865 		goto out_free;
866 
867 	/* Read the config area from the host. */
868 	ccw->cmd_code = CCW_CMD_READ_CONF;
869 	ccw->flags = 0;
870 	ccw->count = offset + len;
871 	ccw->cda = (__u32)(unsigned long)config_area;
872 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
873 	if (ret)
874 		goto out_free;
875 
876 	spin_lock_irqsave(&vcdev->lock, flags);
877 	memcpy(vcdev->config, config_area, offset + len);
878 	if (vcdev->config_ready < offset + len)
879 		vcdev->config_ready = offset + len;
880 	spin_unlock_irqrestore(&vcdev->lock, flags);
881 	if (buf)
882 		memcpy(buf, config_area + offset, len);
883 
884 out_free:
885 	kfree(config_area);
886 	kfree(ccw);
887 }
888 
889 static void virtio_ccw_set_config(struct virtio_device *vdev,
890 				  unsigned int offset, const void *buf,
891 				  unsigned len)
892 {
893 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
894 	struct ccw1 *ccw;
895 	void *config_area;
896 	unsigned long flags;
897 
898 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
899 	if (!ccw)
900 		return;
901 
902 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
903 	if (!config_area)
904 		goto out_free;
905 
906 	/* Make sure we don't overwrite fields. */
907 	if (vcdev->config_ready < offset)
908 		virtio_ccw_get_config(vdev, 0, NULL, offset);
909 	spin_lock_irqsave(&vcdev->lock, flags);
910 	memcpy(&vcdev->config[offset], buf, len);
911 	/* Write the config area to the host. */
912 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
913 	spin_unlock_irqrestore(&vcdev->lock, flags);
914 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
915 	ccw->flags = 0;
916 	ccw->count = offset + len;
917 	ccw->cda = (__u32)(unsigned long)config_area;
918 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
919 
920 out_free:
921 	kfree(config_area);
922 	kfree(ccw);
923 }
924 
925 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
926 {
927 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
928 	u8 old_status = *vcdev->status;
929 	struct ccw1 *ccw;
930 
931 	if (vcdev->revision < 1)
932 		return *vcdev->status;
933 
934 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
935 	if (!ccw)
936 		return old_status;
937 
938 	ccw->cmd_code = CCW_CMD_READ_STATUS;
939 	ccw->flags = 0;
940 	ccw->count = sizeof(*vcdev->status);
941 	ccw->cda = (__u32)(unsigned long)vcdev->status;
942 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
943 /*
944  * If the channel program failed (should only happen if the device
945  * was hotunplugged, and then we clean up via the machine check
946  * handler anyway), vcdev->status was not overwritten and we just
947  * return the old status, which is fine.
948 */
949 	kfree(ccw);
950 
951 	return *vcdev->status;
952 }
953 
954 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
955 {
956 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
957 	u8 old_status = *vcdev->status;
958 	struct ccw1 *ccw;
959 	int ret;
960 
961 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
962 	if (!ccw)
963 		return;
964 
965 	/* Write the status to the host. */
966 	*vcdev->status = status;
967 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
968 	ccw->flags = 0;
969 	ccw->count = sizeof(status);
970 	ccw->cda = (__u32)(unsigned long)vcdev->status;
971 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
972 	/* Write failed? We assume status is unchanged. */
973 	if (ret)
974 		*vcdev->status = old_status;
975 	kfree(ccw);
976 }
977 
978 static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
979 {
980 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
981 
982 	return dev_name(&vcdev->cdev->dev);
983 }
984 
985 static const struct virtio_config_ops virtio_ccw_config_ops = {
986 	.get_features = virtio_ccw_get_features,
987 	.finalize_features = virtio_ccw_finalize_features,
988 	.get = virtio_ccw_get_config,
989 	.set = virtio_ccw_set_config,
990 	.get_status = virtio_ccw_get_status,
991 	.set_status = virtio_ccw_set_status,
992 	.reset = virtio_ccw_reset,
993 	.find_vqs = virtio_ccw_find_vqs,
994 	.del_vqs = virtio_ccw_del_vqs,
995 	.bus_name = virtio_ccw_bus_name,
996 };
997 
998 
999 /*
1000  * ccw bus driver related functions
1001  */
1002 
1003 static void virtio_ccw_release_dev(struct device *_d)
1004 {
1005 	struct virtio_device *dev = dev_to_virtio(_d);
1006 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
1007 
1008 	kfree(vcdev->status);
1009 	kfree(vcdev->config_block);
1010 	kfree(vcdev);
1011 }
1012 
1013 static int irb_is_error(struct irb *irb)
1014 {
1015 	if (scsw_cstat(&irb->scsw) != 0)
1016 		return 1;
1017 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1018 		return 1;
1019 	if (scsw_cc(&irb->scsw) != 0)
1020 		return 1;
1021 	return 0;
1022 }
1023 
1024 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1025 					      int index)
1026 {
1027 	struct virtio_ccw_vq_info *info;
1028 	unsigned long flags;
1029 	struct virtqueue *vq;
1030 
1031 	vq = NULL;
1032 	spin_lock_irqsave(&vcdev->lock, flags);
1033 	list_for_each_entry(info, &vcdev->virtqueues, node) {
1034 		if (info->vq->index == index) {
1035 			vq = info->vq;
1036 			break;
1037 		}
1038 	}
1039 	spin_unlock_irqrestore(&vcdev->lock, flags);
1040 	return vq;
1041 }
1042 
1043 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1044 				      __u32 activity)
1045 {
1046 	if (vcdev->curr_io & activity) {
1047 		switch (activity) {
1048 		case VIRTIO_CCW_DOING_READ_FEAT:
1049 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1050 		case VIRTIO_CCW_DOING_READ_CONFIG:
1051 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1052 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1053 		case VIRTIO_CCW_DOING_READ_STATUS:
1054 		case VIRTIO_CCW_DOING_SET_VQ:
1055 		case VIRTIO_CCW_DOING_SET_IND:
1056 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1057 		case VIRTIO_CCW_DOING_RESET:
1058 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1059 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1060 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1061 			vcdev->curr_io &= ~activity;
1062 			wake_up(&vcdev->wait_q);
1063 			break;
1064 		default:
1065 			/* don't know what to do... */
1066 			dev_warn(&vcdev->cdev->dev,
1067 				 "Suspicious activity '%08x'\n", activity);
1068 			WARN_ON(1);
1069 			break;
1070 		}
1071 	}
1072 }
1073 
1074 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1075 				   unsigned long intparm,
1076 				   struct irb *irb)
1077 {
1078 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1079 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1080 	int i;
1081 	struct virtqueue *vq;
1082 
1083 	if (!vcdev)
1084 		return;
1085 	if (IS_ERR(irb)) {
1086 		vcdev->err = PTR_ERR(irb);
1087 		virtio_ccw_check_activity(vcdev, activity);
1088 		/* Don't poke around indicators, something's wrong. */
1089 		return;
1090 	}
1091 	/* Check if it's a notification from the host. */
1092 	if ((intparm == 0) &&
1093 	    (scsw_stctl(&irb->scsw) ==
1094 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1095 		/* OK */
1096 	}
1097 	if (irb_is_error(irb)) {
1098 		/* Command reject? */
1099 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1100 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1101 			vcdev->err = -EOPNOTSUPP;
1102 		else
1103 			/* Map everything else to -EIO. */
1104 			vcdev->err = -EIO;
1105 	}
1106 	virtio_ccw_check_activity(vcdev, activity);
1107 	for_each_set_bit(i, &vcdev->indicators,
1108 			 sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1109 		/* The bit clear must happen before the vring kick. */
1110 		clear_bit(i, &vcdev->indicators);
1111 		barrier();
1112 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1113 		vring_interrupt(0, vq);
1114 	}
1115 	if (test_bit(0, &vcdev->indicators2)) {
1116 		virtio_config_changed(&vcdev->vdev);
1117 		clear_bit(0, &vcdev->indicators2);
1118 	}
1119 }
1120 
1121 /*
1122  * We usually want to autoonline all devices, but give the admin
1123  * a way to exempt devices from this.
1124  */
1125 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1126 		     (8*sizeof(long)))
1127 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1128 
1129 static char *no_auto = "";
1130 
1131 module_param(no_auto, charp, 0444);
1132 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1133 
1134 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1135 {
1136 	struct ccw_dev_id id;
1137 
1138 	ccw_device_get_id(cdev, &id);
1139 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1140 		return 0;
1141 	return 1;
1142 }
1143 
1144 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1145 {
1146 	struct ccw_device *cdev = data;
1147 	int ret;
1148 
1149 	ret = ccw_device_set_online(cdev);
1150 	if (ret)
1151 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1152 }
1153 
1154 static int virtio_ccw_probe(struct ccw_device *cdev)
1155 {
1156 	cdev->handler = virtio_ccw_int_handler;
1157 
1158 	if (virtio_ccw_check_autoonline(cdev))
1159 		async_schedule(virtio_ccw_auto_online, cdev);
1160 	return 0;
1161 }
1162 
1163 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1164 {
1165 	unsigned long flags;
1166 	struct virtio_ccw_device *vcdev;
1167 
1168 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1169 	vcdev = dev_get_drvdata(&cdev->dev);
1170 	if (!vcdev || vcdev->going_away) {
1171 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1172 		return NULL;
1173 	}
1174 	vcdev->going_away = true;
1175 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1176 	return vcdev;
1177 }
1178 
1179 static void virtio_ccw_remove(struct ccw_device *cdev)
1180 {
1181 	unsigned long flags;
1182 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1183 
1184 	if (vcdev && cdev->online) {
1185 		if (vcdev->device_lost)
1186 			virtio_break_device(&vcdev->vdev);
1187 		unregister_virtio_device(&vcdev->vdev);
1188 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1189 		dev_set_drvdata(&cdev->dev, NULL);
1190 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1191 	}
1192 	cdev->handler = NULL;
1193 }
1194 
1195 static int virtio_ccw_offline(struct ccw_device *cdev)
1196 {
1197 	unsigned long flags;
1198 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1199 
1200 	if (!vcdev)
1201 		return 0;
1202 	if (vcdev->device_lost)
1203 		virtio_break_device(&vcdev->vdev);
1204 	unregister_virtio_device(&vcdev->vdev);
1205 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1206 	dev_set_drvdata(&cdev->dev, NULL);
1207 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1208 	return 0;
1209 }
1210 
1211 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1212 {
1213 	struct virtio_rev_info *rev;
1214 	struct ccw1 *ccw;
1215 	int ret;
1216 
1217 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1218 	if (!ccw)
1219 		return -ENOMEM;
1220 	rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1221 	if (!rev) {
1222 		kfree(ccw);
1223 		return -ENOMEM;
1224 	}
1225 
1226 	/* Set transport revision */
1227 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1228 	ccw->flags = 0;
1229 	ccw->count = sizeof(*rev);
1230 	ccw->cda = (__u32)(unsigned long)rev;
1231 
1232 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1233 	do {
1234 		rev->revision = vcdev->revision;
1235 		/* none of our supported revisions carry payload */
1236 		rev->length = 0;
1237 		ret = ccw_io_helper(vcdev, ccw,
1238 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1239 		if (ret == -EOPNOTSUPP) {
1240 			if (vcdev->revision == 0)
1241 				/*
1242 				 * The host device does not support setting
1243 				 * the revision: let's operate it in legacy
1244 				 * mode.
1245 				 */
1246 				ret = 0;
1247 			else
1248 				vcdev->revision--;
1249 		}
1250 	} while (ret == -EOPNOTSUPP);
1251 
1252 	kfree(ccw);
1253 	kfree(rev);
1254 	return ret;
1255 }
1256 
1257 static int virtio_ccw_online(struct ccw_device *cdev)
1258 {
1259 	int ret;
1260 	struct virtio_ccw_device *vcdev;
1261 	unsigned long flags;
1262 
1263 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1264 	if (!vcdev) {
1265 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1266 		ret = -ENOMEM;
1267 		goto out_free;
1268 	}
1269 	vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1270 				   GFP_DMA | GFP_KERNEL);
1271 	if (!vcdev->config_block) {
1272 		ret = -ENOMEM;
1273 		goto out_free;
1274 	}
1275 	vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1276 	if (!vcdev->status) {
1277 		ret = -ENOMEM;
1278 		goto out_free;
1279 	}
1280 
1281 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1282 
1283 	vcdev->vdev.dev.parent = &cdev->dev;
1284 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1285 	vcdev->vdev.config = &virtio_ccw_config_ops;
1286 	vcdev->cdev = cdev;
1287 	init_waitqueue_head(&vcdev->wait_q);
1288 	INIT_LIST_HEAD(&vcdev->virtqueues);
1289 	spin_lock_init(&vcdev->lock);
1290 	mutex_init(&vcdev->io_lock);
1291 
1292 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1293 	dev_set_drvdata(&cdev->dev, vcdev);
1294 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1295 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1296 	vcdev->vdev.id.device = cdev->id.cu_model;
1297 
1298 	ret = virtio_ccw_set_transport_rev(vcdev);
1299 	if (ret)
1300 		goto out_free;
1301 
1302 	ret = register_virtio_device(&vcdev->vdev);
1303 	if (ret) {
1304 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1305 			 ret);
1306 		goto out_put;
1307 	}
1308 	return 0;
1309 out_put:
1310 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1311 	dev_set_drvdata(&cdev->dev, NULL);
1312 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1313 	put_device(&vcdev->vdev.dev);
1314 	return ret;
1315 out_free:
1316 	if (vcdev) {
1317 		kfree(vcdev->status);
1318 		kfree(vcdev->config_block);
1319 	}
1320 	kfree(vcdev);
1321 	return ret;
1322 }
1323 
1324 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1325 {
1326 	int rc;
1327 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1328 
1329 	/*
1330 	 * Make sure vcdev is set
1331 	 * i.e. set_offline/remove callback not already running
1332 	 */
1333 	if (!vcdev)
1334 		return NOTIFY_DONE;
1335 
1336 	switch (event) {
1337 	case CIO_GONE:
1338 		vcdev->device_lost = true;
1339 		rc = NOTIFY_DONE;
1340 		break;
1341 	case CIO_OPER:
1342 		rc = NOTIFY_OK;
1343 		break;
1344 	default:
1345 		rc = NOTIFY_DONE;
1346 		break;
1347 	}
1348 	return rc;
1349 }
1350 
1351 static struct ccw_device_id virtio_ids[] = {
1352 	{ CCW_DEVICE(0x3832, 0) },
1353 	{},
1354 };
1355 
1356 #ifdef CONFIG_PM_SLEEP
1357 static int virtio_ccw_freeze(struct ccw_device *cdev)
1358 {
1359 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1360 
1361 	return virtio_device_freeze(&vcdev->vdev);
1362 }
1363 
1364 static int virtio_ccw_restore(struct ccw_device *cdev)
1365 {
1366 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1367 	int ret;
1368 
1369 	ret = virtio_ccw_set_transport_rev(vcdev);
1370 	if (ret)
1371 		return ret;
1372 
1373 	return virtio_device_restore(&vcdev->vdev);
1374 }
1375 #endif
1376 
1377 static struct ccw_driver virtio_ccw_driver = {
1378 	.driver = {
1379 		.owner = THIS_MODULE,
1380 		.name = "virtio_ccw",
1381 	},
1382 	.ids = virtio_ids,
1383 	.probe = virtio_ccw_probe,
1384 	.remove = virtio_ccw_remove,
1385 	.set_offline = virtio_ccw_offline,
1386 	.set_online = virtio_ccw_online,
1387 	.notify = virtio_ccw_cio_notify,
1388 	.int_class = IRQIO_VIR,
1389 #ifdef CONFIG_PM_SLEEP
1390 	.freeze = virtio_ccw_freeze,
1391 	.thaw = virtio_ccw_restore,
1392 	.restore = virtio_ccw_restore,
1393 #endif
1394 };
1395 
1396 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1397 			   int max_digit, int max_val)
1398 {
1399 	int diff;
1400 
1401 	diff = 0;
1402 	*val = 0;
1403 
1404 	while (diff <= max_digit) {
1405 		int value = hex_to_bin(**cp);
1406 
1407 		if (value < 0)
1408 			break;
1409 		*val = *val * 16 + value;
1410 		(*cp)++;
1411 		diff++;
1412 	}
1413 
1414 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1415 		return 1;
1416 
1417 	return 0;
1418 }
1419 
1420 static int __init parse_busid(char *str, unsigned int *cssid,
1421 			      unsigned int *ssid, unsigned int *devno)
1422 {
1423 	char *str_work;
1424 	int rc, ret;
1425 
1426 	rc = 1;
1427 
1428 	if (*str == '\0')
1429 		goto out;
1430 
1431 	str_work = str;
1432 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1433 	if (ret || (str_work[0] != '.'))
1434 		goto out;
1435 	str_work++;
1436 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1437 	if (ret || (str_work[0] != '.'))
1438 		goto out;
1439 	str_work++;
1440 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1441 	if (ret || (str_work[0] != '\0'))
1442 		goto out;
1443 
1444 	rc = 0;
1445 out:
1446 	return rc;
1447 }
1448 
1449 static void __init no_auto_parse(void)
1450 {
1451 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1452 	char *parm, *str;
1453 	int rc;
1454 
1455 	str = no_auto;
1456 	while ((parm = strsep(&str, ","))) {
1457 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1458 				 &from_ssid, &from);
1459 		if (rc)
1460 			continue;
1461 		if (parm != NULL) {
1462 			rc = parse_busid(parm, &to_cssid,
1463 					 &to_ssid, &to);
1464 			if ((from_ssid > to_ssid) ||
1465 			    ((from_ssid == to_ssid) && (from > to)))
1466 				rc = -EINVAL;
1467 		} else {
1468 			to_cssid = from_cssid;
1469 			to_ssid = from_ssid;
1470 			to = from;
1471 		}
1472 		if (rc)
1473 			continue;
1474 		while ((from_ssid < to_ssid) ||
1475 		       ((from_ssid == to_ssid) && (from <= to))) {
1476 			set_bit(from, devs_no_auto[from_ssid]);
1477 			from++;
1478 			if (from > __MAX_SUBCHANNEL) {
1479 				from_ssid++;
1480 				from = 0;
1481 			}
1482 		}
1483 	}
1484 }
1485 
1486 static int __init virtio_ccw_init(void)
1487 {
1488 	/* parse no_auto string before we do anything further */
1489 	no_auto_parse();
1490 	return ccw_driver_register(&virtio_ccw_driver);
1491 }
1492 device_initcall(virtio_ccw_init);
1493