xref: /openbmc/linux/drivers/s390/virtio/virtio_ccw.c (revision 4f205687)
1 /*
2  * ccw based virtio transport
3  *
4  * Copyright IBM Corp. 2012, 2014
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License (version 2 only)
8  * as published by the Free Software Foundation.
9  *
10  *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
11  */
12 
13 #include <linux/kernel_stat.h>
14 #include <linux/init.h>
15 #include <linux/bootmem.h>
16 #include <linux/err.h>
17 #include <linux/virtio.h>
18 #include <linux/virtio_config.h>
19 #include <linux/slab.h>
20 #include <linux/interrupt.h>
21 #include <linux/virtio_ring.h>
22 #include <linux/pfn.h>
23 #include <linux/async.h>
24 #include <linux/wait.h>
25 #include <linux/list.h>
26 #include <linux/bitops.h>
27 #include <linux/module.h>
28 #include <linux/io.h>
29 #include <linux/kvm_para.h>
30 #include <linux/notifier.h>
31 #include <asm/diag.h>
32 #include <asm/setup.h>
33 #include <asm/irq.h>
34 #include <asm/cio.h>
35 #include <asm/ccwdev.h>
36 #include <asm/virtio-ccw.h>
37 #include <asm/isc.h>
38 #include <asm/airq.h>
39 
40 /*
41  * virtio related functions
42  */
43 
44 struct vq_config_block {
45 	__u16 index;
46 	__u16 num;
47 } __packed;
48 
49 #define VIRTIO_CCW_CONFIG_SIZE 0x100
50 /* same as PCI config space size, should be enough for all drivers */
51 
52 struct virtio_ccw_device {
53 	struct virtio_device vdev;
54 	__u8 *status;
55 	__u8 config[VIRTIO_CCW_CONFIG_SIZE];
56 	struct ccw_device *cdev;
57 	__u32 curr_io;
58 	int err;
59 	unsigned int revision; /* Transport revision */
60 	wait_queue_head_t wait_q;
61 	spinlock_t lock;
62 	struct list_head virtqueues;
63 	unsigned long indicators;
64 	unsigned long indicators2;
65 	struct vq_config_block *config_block;
66 	bool is_thinint;
67 	bool going_away;
68 	bool device_lost;
69 	unsigned int config_ready;
70 	void *airq_info;
71 };
72 
73 struct vq_info_block_legacy {
74 	__u64 queue;
75 	__u32 align;
76 	__u16 index;
77 	__u16 num;
78 } __packed;
79 
80 struct vq_info_block {
81 	__u64 desc;
82 	__u32 res0;
83 	__u16 index;
84 	__u16 num;
85 	__u64 avail;
86 	__u64 used;
87 } __packed;
88 
89 struct virtio_feature_desc {
90 	__u32 features;
91 	__u8 index;
92 } __packed;
93 
94 struct virtio_thinint_area {
95 	unsigned long summary_indicator;
96 	unsigned long indicator;
97 	u64 bit_nr;
98 	u8 isc;
99 } __packed;
100 
101 struct virtio_rev_info {
102 	__u16 revision;
103 	__u16 length;
104 	__u8 data[];
105 };
106 
107 /* the highest virtio-ccw revision we support */
108 #define VIRTIO_CCW_REV_MAX 1
109 
110 struct virtio_ccw_vq_info {
111 	struct virtqueue *vq;
112 	int num;
113 	void *queue;
114 	union {
115 		struct vq_info_block s;
116 		struct vq_info_block_legacy l;
117 	} *info_block;
118 	int bit_nr;
119 	struct list_head node;
120 	long cookie;
121 };
122 
123 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
124 
125 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
126 #define MAX_AIRQ_AREAS 20
127 
128 static int virtio_ccw_use_airq = 1;
129 
130 struct airq_info {
131 	rwlock_t lock;
132 	u8 summary_indicator;
133 	struct airq_struct airq;
134 	struct airq_iv *aiv;
135 };
136 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
137 
138 #define CCW_CMD_SET_VQ 0x13
139 #define CCW_CMD_VDEV_RESET 0x33
140 #define CCW_CMD_SET_IND 0x43
141 #define CCW_CMD_SET_CONF_IND 0x53
142 #define CCW_CMD_READ_FEAT 0x12
143 #define CCW_CMD_WRITE_FEAT 0x11
144 #define CCW_CMD_READ_CONF 0x22
145 #define CCW_CMD_WRITE_CONF 0x21
146 #define CCW_CMD_WRITE_STATUS 0x31
147 #define CCW_CMD_READ_VQ_CONF 0x32
148 #define CCW_CMD_SET_IND_ADAPTER 0x73
149 #define CCW_CMD_SET_VIRTIO_REV 0x83
150 
151 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
152 #define VIRTIO_CCW_DOING_RESET 0x00040000
153 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
154 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
155 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
156 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
157 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
158 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
159 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
160 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
161 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
162 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
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 void destroy_airq_info(struct airq_info *info)
239 {
240 	if (!info)
241 		return;
242 
243 	unregister_adapter_interrupt(&info->airq);
244 	airq_iv_release(info->aiv);
245 	kfree(info);
246 }
247 
248 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
249 					u64 *first, void **airq_info)
250 {
251 	int i, j;
252 	struct airq_info *info;
253 	unsigned long indicator_addr = 0;
254 	unsigned long bit, flags;
255 
256 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
257 		if (!airq_areas[i])
258 			airq_areas[i] = new_airq_info();
259 		info = airq_areas[i];
260 		if (!info)
261 			return 0;
262 		write_lock_irqsave(&info->lock, flags);
263 		bit = airq_iv_alloc(info->aiv, nvqs);
264 		if (bit == -1UL) {
265 			/* Not enough vacancies. */
266 			write_unlock_irqrestore(&info->lock, flags);
267 			continue;
268 		}
269 		*first = bit;
270 		*airq_info = info;
271 		indicator_addr = (unsigned long)info->aiv->vector;
272 		for (j = 0; j < nvqs; j++) {
273 			airq_iv_set_ptr(info->aiv, bit + j,
274 					(unsigned long)vqs[j]);
275 		}
276 		write_unlock_irqrestore(&info->lock, flags);
277 	}
278 	return indicator_addr;
279 }
280 
281 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
282 {
283 	struct virtio_ccw_vq_info *info;
284 
285 	list_for_each_entry(info, &vcdev->virtqueues, node)
286 		drop_airq_indicator(info->vq, vcdev->airq_info);
287 }
288 
289 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
290 {
291 	unsigned long flags;
292 	__u32 ret;
293 
294 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
295 	if (vcdev->err)
296 		ret = 0;
297 	else
298 		ret = vcdev->curr_io & flag;
299 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
300 	return ret;
301 }
302 
303 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
304 			 struct ccw1 *ccw, __u32 intparm)
305 {
306 	int ret;
307 	unsigned long flags;
308 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
309 
310 	do {
311 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
312 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
313 		if (!ret) {
314 			if (!vcdev->curr_io)
315 				vcdev->err = 0;
316 			vcdev->curr_io |= flag;
317 		}
318 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
319 		cpu_relax();
320 	} while (ret == -EBUSY);
321 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
322 	return ret ? ret : vcdev->err;
323 }
324 
325 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
326 				      struct ccw1 *ccw)
327 {
328 	int ret;
329 	unsigned long *indicatorp = NULL;
330 	struct virtio_thinint_area *thinint_area = NULL;
331 	struct airq_info *airq_info = vcdev->airq_info;
332 
333 	if (vcdev->is_thinint) {
334 		thinint_area = kzalloc(sizeof(*thinint_area),
335 				       GFP_DMA | GFP_KERNEL);
336 		if (!thinint_area)
337 			return;
338 		thinint_area->summary_indicator =
339 			(unsigned long) &airq_info->summary_indicator;
340 		thinint_area->isc = VIRTIO_AIRQ_ISC;
341 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
342 		ccw->count = sizeof(*thinint_area);
343 		ccw->cda = (__u32)(unsigned long) thinint_area;
344 	} else {
345 		/* payload is the address of the indicators */
346 		indicatorp = kmalloc(sizeof(&vcdev->indicators),
347 				     GFP_DMA | GFP_KERNEL);
348 		if (!indicatorp)
349 			return;
350 		*indicatorp = 0;
351 		ccw->cmd_code = CCW_CMD_SET_IND;
352 		ccw->count = sizeof(&vcdev->indicators);
353 		ccw->cda = (__u32)(unsigned long) indicatorp;
354 	}
355 	/* Deregister indicators from host. */
356 	vcdev->indicators = 0;
357 	ccw->flags = 0;
358 	ret = ccw_io_helper(vcdev, ccw,
359 			    vcdev->is_thinint ?
360 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
361 			    VIRTIO_CCW_DOING_SET_IND);
362 	if (ret && (ret != -ENODEV))
363 		dev_info(&vcdev->cdev->dev,
364 			 "Failed to deregister indicators (%d)\n", ret);
365 	else if (vcdev->is_thinint)
366 		virtio_ccw_drop_indicators(vcdev);
367 	kfree(indicatorp);
368 	kfree(thinint_area);
369 }
370 
371 static inline long __do_kvm_notify(struct subchannel_id schid,
372 				   unsigned long queue_index,
373 				   long cookie)
374 {
375 	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
376 	register struct subchannel_id __schid asm("2") = schid;
377 	register unsigned long __index asm("3") = queue_index;
378 	register long __rc asm("2");
379 	register long __cookie asm("4") = cookie;
380 
381 	asm volatile ("diag 2,4,0x500\n"
382 		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
383 		      "d"(__cookie)
384 		      : "memory", "cc");
385 	return __rc;
386 }
387 
388 static inline long do_kvm_notify(struct subchannel_id schid,
389 				 unsigned long queue_index,
390 				 long cookie)
391 {
392 	diag_stat_inc(DIAG_STAT_X500);
393 	return __do_kvm_notify(schid, queue_index, cookie);
394 }
395 
396 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
397 {
398 	struct virtio_ccw_vq_info *info = vq->priv;
399 	struct virtio_ccw_device *vcdev;
400 	struct subchannel_id schid;
401 
402 	vcdev = to_vc_device(info->vq->vdev);
403 	ccw_device_get_schid(vcdev->cdev, &schid);
404 	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
405 	if (info->cookie < 0)
406 		return false;
407 	return true;
408 }
409 
410 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
411 				   struct ccw1 *ccw, int index)
412 {
413 	int ret;
414 
415 	vcdev->config_block->index = index;
416 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
417 	ccw->flags = 0;
418 	ccw->count = sizeof(struct vq_config_block);
419 	ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
420 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
421 	if (ret)
422 		return ret;
423 	return vcdev->config_block->num;
424 }
425 
426 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
427 {
428 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
429 	struct virtio_ccw_vq_info *info = vq->priv;
430 	unsigned long flags;
431 	unsigned long size;
432 	int ret;
433 	unsigned int index = vq->index;
434 
435 	/* Remove from our list. */
436 	spin_lock_irqsave(&vcdev->lock, flags);
437 	list_del(&info->node);
438 	spin_unlock_irqrestore(&vcdev->lock, flags);
439 
440 	/* Release from host. */
441 	if (vcdev->revision == 0) {
442 		info->info_block->l.queue = 0;
443 		info->info_block->l.align = 0;
444 		info->info_block->l.index = index;
445 		info->info_block->l.num = 0;
446 		ccw->count = sizeof(info->info_block->l);
447 	} else {
448 		info->info_block->s.desc = 0;
449 		info->info_block->s.index = index;
450 		info->info_block->s.num = 0;
451 		info->info_block->s.avail = 0;
452 		info->info_block->s.used = 0;
453 		ccw->count = sizeof(info->info_block->s);
454 	}
455 	ccw->cmd_code = CCW_CMD_SET_VQ;
456 	ccw->flags = 0;
457 	ccw->cda = (__u32)(unsigned long)(info->info_block);
458 	ret = ccw_io_helper(vcdev, ccw,
459 			    VIRTIO_CCW_DOING_SET_VQ | index);
460 	/*
461 	 * -ENODEV isn't considered an error: The device is gone anyway.
462 	 * This may happen on device detach.
463 	 */
464 	if (ret && (ret != -ENODEV))
465 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d",
466 			 ret, index);
467 
468 	vring_del_virtqueue(vq);
469 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
470 	free_pages_exact(info->queue, size);
471 	kfree(info->info_block);
472 	kfree(info);
473 }
474 
475 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
476 {
477 	struct virtqueue *vq, *n;
478 	struct ccw1 *ccw;
479 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
480 
481 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
482 	if (!ccw)
483 		return;
484 
485 	virtio_ccw_drop_indicator(vcdev, ccw);
486 
487 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
488 		virtio_ccw_del_vq(vq, ccw);
489 
490 	kfree(ccw);
491 }
492 
493 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
494 					     int i, vq_callback_t *callback,
495 					     const char *name,
496 					     struct ccw1 *ccw)
497 {
498 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
499 	int err;
500 	struct virtqueue *vq = NULL;
501 	struct virtio_ccw_vq_info *info;
502 	unsigned long size = 0; /* silence the compiler */
503 	unsigned long flags;
504 
505 	/* Allocate queue. */
506 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
507 	if (!info) {
508 		dev_warn(&vcdev->cdev->dev, "no info\n");
509 		err = -ENOMEM;
510 		goto out_err;
511 	}
512 	info->info_block = kzalloc(sizeof(*info->info_block),
513 				   GFP_DMA | GFP_KERNEL);
514 	if (!info->info_block) {
515 		dev_warn(&vcdev->cdev->dev, "no info block\n");
516 		err = -ENOMEM;
517 		goto out_err;
518 	}
519 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
520 	if (info->num < 0) {
521 		err = info->num;
522 		goto out_err;
523 	}
524 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
525 	info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
526 	if (info->queue == NULL) {
527 		dev_warn(&vcdev->cdev->dev, "no queue\n");
528 		err = -ENOMEM;
529 		goto out_err;
530 	}
531 
532 	vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
533 				 true, info->queue, virtio_ccw_kvm_notify,
534 				 callback, name);
535 	if (!vq) {
536 		/* For now, we fail if we can't get the requested size. */
537 		dev_warn(&vcdev->cdev->dev, "no vq\n");
538 		err = -ENOMEM;
539 		goto out_err;
540 	}
541 
542 	/* Register it with the host. */
543 	if (vcdev->revision == 0) {
544 		info->info_block->l.queue = (__u64)info->queue;
545 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
546 		info->info_block->l.index = i;
547 		info->info_block->l.num = info->num;
548 		ccw->count = sizeof(info->info_block->l);
549 	} else {
550 		info->info_block->s.desc = (__u64)info->queue;
551 		info->info_block->s.index = i;
552 		info->info_block->s.num = info->num;
553 		info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
554 		info->info_block->s.used = (__u64)virtqueue_get_used(vq);
555 		ccw->count = sizeof(info->info_block->s);
556 	}
557 	ccw->cmd_code = CCW_CMD_SET_VQ;
558 	ccw->flags = 0;
559 	ccw->cda = (__u32)(unsigned long)(info->info_block);
560 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
561 	if (err) {
562 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
563 		goto out_err;
564 	}
565 
566 	info->vq = vq;
567 	vq->priv = info;
568 
569 	/* Save it to our list. */
570 	spin_lock_irqsave(&vcdev->lock, flags);
571 	list_add(&info->node, &vcdev->virtqueues);
572 	spin_unlock_irqrestore(&vcdev->lock, flags);
573 
574 	return vq;
575 
576 out_err:
577 	if (vq)
578 		vring_del_virtqueue(vq);
579 	if (info) {
580 		if (info->queue)
581 			free_pages_exact(info->queue, size);
582 		kfree(info->info_block);
583 	}
584 	kfree(info);
585 	return ERR_PTR(err);
586 }
587 
588 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
589 					   struct virtqueue *vqs[], int nvqs,
590 					   struct ccw1 *ccw)
591 {
592 	int ret;
593 	struct virtio_thinint_area *thinint_area = NULL;
594 	struct airq_info *info;
595 
596 	thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
597 	if (!thinint_area) {
598 		ret = -ENOMEM;
599 		goto out;
600 	}
601 	/* Try to get an indicator. */
602 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
603 						     &thinint_area->bit_nr,
604 						     &vcdev->airq_info);
605 	if (!thinint_area->indicator) {
606 		ret = -ENOSPC;
607 		goto out;
608 	}
609 	info = vcdev->airq_info;
610 	thinint_area->summary_indicator =
611 		(unsigned long) &info->summary_indicator;
612 	thinint_area->isc = VIRTIO_AIRQ_ISC;
613 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
614 	ccw->flags = CCW_FLAG_SLI;
615 	ccw->count = sizeof(*thinint_area);
616 	ccw->cda = (__u32)(unsigned long)thinint_area;
617 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
618 	if (ret) {
619 		if (ret == -EOPNOTSUPP) {
620 			/*
621 			 * The host does not support adapter interrupts
622 			 * for virtio-ccw, stop trying.
623 			 */
624 			virtio_ccw_use_airq = 0;
625 			pr_info("Adapter interrupts unsupported on host\n");
626 		} else
627 			dev_warn(&vcdev->cdev->dev,
628 				 "enabling adapter interrupts = %d\n", ret);
629 		virtio_ccw_drop_indicators(vcdev);
630 	}
631 out:
632 	kfree(thinint_area);
633 	return ret;
634 }
635 
636 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
637 			       struct virtqueue *vqs[],
638 			       vq_callback_t *callbacks[],
639 			       const char * const names[])
640 {
641 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
642 	unsigned long *indicatorp = NULL;
643 	int ret, i;
644 	struct ccw1 *ccw;
645 
646 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
647 	if (!ccw)
648 		return -ENOMEM;
649 
650 	for (i = 0; i < nvqs; ++i) {
651 		vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
652 					     ccw);
653 		if (IS_ERR(vqs[i])) {
654 			ret = PTR_ERR(vqs[i]);
655 			vqs[i] = NULL;
656 			goto out;
657 		}
658 	}
659 	ret = -ENOMEM;
660 	/*
661 	 * We need a data area under 2G to communicate. Our payload is
662 	 * the address of the indicators.
663 	*/
664 	indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
665 	if (!indicatorp)
666 		goto out;
667 	*indicatorp = (unsigned long) &vcdev->indicators;
668 	if (vcdev->is_thinint) {
669 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
670 		if (ret)
671 			/* no error, just fall back to legacy interrupts */
672 			vcdev->is_thinint = 0;
673 	}
674 	if (!vcdev->is_thinint) {
675 		/* Register queue indicators with host. */
676 		vcdev->indicators = 0;
677 		ccw->cmd_code = CCW_CMD_SET_IND;
678 		ccw->flags = 0;
679 		ccw->count = sizeof(&vcdev->indicators);
680 		ccw->cda = (__u32)(unsigned long) indicatorp;
681 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
682 		if (ret)
683 			goto out;
684 	}
685 	/* Register indicators2 with host for config changes */
686 	*indicatorp = (unsigned long) &vcdev->indicators2;
687 	vcdev->indicators2 = 0;
688 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
689 	ccw->flags = 0;
690 	ccw->count = sizeof(&vcdev->indicators2);
691 	ccw->cda = (__u32)(unsigned long) indicatorp;
692 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
693 	if (ret)
694 		goto out;
695 
696 	kfree(indicatorp);
697 	kfree(ccw);
698 	return 0;
699 out:
700 	kfree(indicatorp);
701 	kfree(ccw);
702 	virtio_ccw_del_vqs(vdev);
703 	return ret;
704 }
705 
706 static void virtio_ccw_reset(struct virtio_device *vdev)
707 {
708 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
709 	struct ccw1 *ccw;
710 
711 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
712 	if (!ccw)
713 		return;
714 
715 	/* Zero status bits. */
716 	*vcdev->status = 0;
717 
718 	/* Send a reset ccw on device. */
719 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
720 	ccw->flags = 0;
721 	ccw->count = 0;
722 	ccw->cda = 0;
723 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
724 	kfree(ccw);
725 }
726 
727 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
728 {
729 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
730 	struct virtio_feature_desc *features;
731 	int ret;
732 	u64 rc;
733 	struct ccw1 *ccw;
734 
735 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
736 	if (!ccw)
737 		return 0;
738 
739 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
740 	if (!features) {
741 		rc = 0;
742 		goto out_free;
743 	}
744 	/* Read the feature bits from the host. */
745 	features->index = 0;
746 	ccw->cmd_code = CCW_CMD_READ_FEAT;
747 	ccw->flags = 0;
748 	ccw->count = sizeof(*features);
749 	ccw->cda = (__u32)(unsigned long)features;
750 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
751 	if (ret) {
752 		rc = 0;
753 		goto out_free;
754 	}
755 
756 	rc = le32_to_cpu(features->features);
757 
758 	if (vcdev->revision == 0)
759 		goto out_free;
760 
761 	/* Read second half of the feature bits from the host. */
762 	features->index = 1;
763 	ccw->cmd_code = CCW_CMD_READ_FEAT;
764 	ccw->flags = 0;
765 	ccw->count = sizeof(*features);
766 	ccw->cda = (__u32)(unsigned long)features;
767 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
768 	if (ret == 0)
769 		rc |= (u64)le32_to_cpu(features->features) << 32;
770 
771 out_free:
772 	kfree(features);
773 	kfree(ccw);
774 	return rc;
775 }
776 
777 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
778 {
779 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
780 	struct virtio_feature_desc *features;
781 	struct ccw1 *ccw;
782 	int ret;
783 
784 	if (vcdev->revision >= 1 &&
785 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
786 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
787 			"but does not have VIRTIO_F_VERSION_1\n");
788 		return -EINVAL;
789 	}
790 
791 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
792 	if (!ccw)
793 		return -ENOMEM;
794 
795 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
796 	if (!features) {
797 		ret = -ENOMEM;
798 		goto out_free;
799 	}
800 	/* Give virtio_ring a chance to accept features. */
801 	vring_transport_features(vdev);
802 
803 	features->index = 0;
804 	features->features = cpu_to_le32((u32)vdev->features);
805 	/* Write the first half of the feature bits to the host. */
806 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
807 	ccw->flags = 0;
808 	ccw->count = sizeof(*features);
809 	ccw->cda = (__u32)(unsigned long)features;
810 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
811 	if (ret)
812 		goto out_free;
813 
814 	if (vcdev->revision == 0)
815 		goto out_free;
816 
817 	features->index = 1;
818 	features->features = cpu_to_le32(vdev->features >> 32);
819 	/* Write the second half of the feature bits to the host. */
820 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
821 	ccw->flags = 0;
822 	ccw->count = sizeof(*features);
823 	ccw->cda = (__u32)(unsigned long)features;
824 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
825 
826 out_free:
827 	kfree(features);
828 	kfree(ccw);
829 
830 	return ret;
831 }
832 
833 static void virtio_ccw_get_config(struct virtio_device *vdev,
834 				  unsigned int offset, void *buf, unsigned len)
835 {
836 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
837 	int ret;
838 	struct ccw1 *ccw;
839 	void *config_area;
840 
841 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
842 	if (!ccw)
843 		return;
844 
845 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
846 	if (!config_area)
847 		goto out_free;
848 
849 	/* Read the config area from the host. */
850 	ccw->cmd_code = CCW_CMD_READ_CONF;
851 	ccw->flags = 0;
852 	ccw->count = offset + len;
853 	ccw->cda = (__u32)(unsigned long)config_area;
854 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
855 	if (ret)
856 		goto out_free;
857 
858 	memcpy(vcdev->config, config_area, offset + len);
859 	if (buf)
860 		memcpy(buf, &vcdev->config[offset], len);
861 	if (vcdev->config_ready < offset + len)
862 		vcdev->config_ready = offset + len;
863 
864 out_free:
865 	kfree(config_area);
866 	kfree(ccw);
867 }
868 
869 static void virtio_ccw_set_config(struct virtio_device *vdev,
870 				  unsigned int offset, const void *buf,
871 				  unsigned len)
872 {
873 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
874 	struct ccw1 *ccw;
875 	void *config_area;
876 
877 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
878 	if (!ccw)
879 		return;
880 
881 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
882 	if (!config_area)
883 		goto out_free;
884 
885 	/* Make sure we don't overwrite fields. */
886 	if (vcdev->config_ready < offset)
887 		virtio_ccw_get_config(vdev, 0, NULL, offset);
888 	memcpy(&vcdev->config[offset], buf, len);
889 	/* Write the config area to the host. */
890 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
891 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
892 	ccw->flags = 0;
893 	ccw->count = offset + len;
894 	ccw->cda = (__u32)(unsigned long)config_area;
895 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
896 
897 out_free:
898 	kfree(config_area);
899 	kfree(ccw);
900 }
901 
902 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
903 {
904 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
905 
906 	return *vcdev->status;
907 }
908 
909 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
910 {
911 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
912 	u8 old_status = *vcdev->status;
913 	struct ccw1 *ccw;
914 	int ret;
915 
916 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
917 	if (!ccw)
918 		return;
919 
920 	/* Write the status to the host. */
921 	*vcdev->status = status;
922 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
923 	ccw->flags = 0;
924 	ccw->count = sizeof(status);
925 	ccw->cda = (__u32)(unsigned long)vcdev->status;
926 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
927 	/* Write failed? We assume status is unchanged. */
928 	if (ret)
929 		*vcdev->status = old_status;
930 	kfree(ccw);
931 }
932 
933 static struct virtio_config_ops virtio_ccw_config_ops = {
934 	.get_features = virtio_ccw_get_features,
935 	.finalize_features = virtio_ccw_finalize_features,
936 	.get = virtio_ccw_get_config,
937 	.set = virtio_ccw_set_config,
938 	.get_status = virtio_ccw_get_status,
939 	.set_status = virtio_ccw_set_status,
940 	.reset = virtio_ccw_reset,
941 	.find_vqs = virtio_ccw_find_vqs,
942 	.del_vqs = virtio_ccw_del_vqs,
943 };
944 
945 
946 /*
947  * ccw bus driver related functions
948  */
949 
950 static void virtio_ccw_release_dev(struct device *_d)
951 {
952 	struct virtio_device *dev = dev_to_virtio(_d);
953 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
954 
955 	kfree(vcdev->status);
956 	kfree(vcdev->config_block);
957 	kfree(vcdev);
958 }
959 
960 static int irb_is_error(struct irb *irb)
961 {
962 	if (scsw_cstat(&irb->scsw) != 0)
963 		return 1;
964 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
965 		return 1;
966 	if (scsw_cc(&irb->scsw) != 0)
967 		return 1;
968 	return 0;
969 }
970 
971 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
972 					      int index)
973 {
974 	struct virtio_ccw_vq_info *info;
975 	unsigned long flags;
976 	struct virtqueue *vq;
977 
978 	vq = NULL;
979 	spin_lock_irqsave(&vcdev->lock, flags);
980 	list_for_each_entry(info, &vcdev->virtqueues, node) {
981 		if (info->vq->index == index) {
982 			vq = info->vq;
983 			break;
984 		}
985 	}
986 	spin_unlock_irqrestore(&vcdev->lock, flags);
987 	return vq;
988 }
989 
990 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
991 				      __u32 activity)
992 {
993 	if (vcdev->curr_io & activity) {
994 		switch (activity) {
995 		case VIRTIO_CCW_DOING_READ_FEAT:
996 		case VIRTIO_CCW_DOING_WRITE_FEAT:
997 		case VIRTIO_CCW_DOING_READ_CONFIG:
998 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
999 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1000 		case VIRTIO_CCW_DOING_SET_VQ:
1001 		case VIRTIO_CCW_DOING_SET_IND:
1002 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1003 		case VIRTIO_CCW_DOING_RESET:
1004 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1005 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1006 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1007 			vcdev->curr_io &= ~activity;
1008 			wake_up(&vcdev->wait_q);
1009 			break;
1010 		default:
1011 			/* don't know what to do... */
1012 			dev_warn(&vcdev->cdev->dev,
1013 				 "Suspicious activity '%08x'\n", activity);
1014 			WARN_ON(1);
1015 			break;
1016 		}
1017 	}
1018 }
1019 
1020 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1021 				   unsigned long intparm,
1022 				   struct irb *irb)
1023 {
1024 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1025 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1026 	int i;
1027 	struct virtqueue *vq;
1028 
1029 	if (!vcdev)
1030 		return;
1031 	if (IS_ERR(irb)) {
1032 		vcdev->err = PTR_ERR(irb);
1033 		virtio_ccw_check_activity(vcdev, activity);
1034 		/* Don't poke around indicators, something's wrong. */
1035 		return;
1036 	}
1037 	/* Check if it's a notification from the host. */
1038 	if ((intparm == 0) &&
1039 	    (scsw_stctl(&irb->scsw) ==
1040 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1041 		/* OK */
1042 	}
1043 	if (irb_is_error(irb)) {
1044 		/* Command reject? */
1045 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1046 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1047 			vcdev->err = -EOPNOTSUPP;
1048 		else
1049 			/* Map everything else to -EIO. */
1050 			vcdev->err = -EIO;
1051 	}
1052 	virtio_ccw_check_activity(vcdev, activity);
1053 	for_each_set_bit(i, &vcdev->indicators,
1054 			 sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1055 		/* The bit clear must happen before the vring kick. */
1056 		clear_bit(i, &vcdev->indicators);
1057 		barrier();
1058 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1059 		vring_interrupt(0, vq);
1060 	}
1061 	if (test_bit(0, &vcdev->indicators2)) {
1062 		virtio_config_changed(&vcdev->vdev);
1063 		clear_bit(0, &vcdev->indicators2);
1064 	}
1065 }
1066 
1067 /*
1068  * We usually want to autoonline all devices, but give the admin
1069  * a way to exempt devices from this.
1070  */
1071 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1072 		     (8*sizeof(long)))
1073 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1074 
1075 static char *no_auto = "";
1076 
1077 module_param(no_auto, charp, 0444);
1078 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1079 
1080 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1081 {
1082 	struct ccw_dev_id id;
1083 
1084 	ccw_device_get_id(cdev, &id);
1085 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1086 		return 0;
1087 	return 1;
1088 }
1089 
1090 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1091 {
1092 	struct ccw_device *cdev = data;
1093 	int ret;
1094 
1095 	ret = ccw_device_set_online(cdev);
1096 	if (ret)
1097 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1098 }
1099 
1100 static int virtio_ccw_probe(struct ccw_device *cdev)
1101 {
1102 	cdev->handler = virtio_ccw_int_handler;
1103 
1104 	if (virtio_ccw_check_autoonline(cdev))
1105 		async_schedule(virtio_ccw_auto_online, cdev);
1106 	return 0;
1107 }
1108 
1109 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1110 {
1111 	unsigned long flags;
1112 	struct virtio_ccw_device *vcdev;
1113 
1114 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1115 	vcdev = dev_get_drvdata(&cdev->dev);
1116 	if (!vcdev || vcdev->going_away) {
1117 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1118 		return NULL;
1119 	}
1120 	vcdev->going_away = true;
1121 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1122 	return vcdev;
1123 }
1124 
1125 static void virtio_ccw_remove(struct ccw_device *cdev)
1126 {
1127 	unsigned long flags;
1128 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1129 
1130 	if (vcdev && cdev->online) {
1131 		if (vcdev->device_lost)
1132 			virtio_break_device(&vcdev->vdev);
1133 		unregister_virtio_device(&vcdev->vdev);
1134 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1135 		dev_set_drvdata(&cdev->dev, NULL);
1136 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1137 	}
1138 	cdev->handler = NULL;
1139 }
1140 
1141 static int virtio_ccw_offline(struct ccw_device *cdev)
1142 {
1143 	unsigned long flags;
1144 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1145 
1146 	if (!vcdev)
1147 		return 0;
1148 	if (vcdev->device_lost)
1149 		virtio_break_device(&vcdev->vdev);
1150 	unregister_virtio_device(&vcdev->vdev);
1151 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1152 	dev_set_drvdata(&cdev->dev, NULL);
1153 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1154 	return 0;
1155 }
1156 
1157 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1158 {
1159 	struct virtio_rev_info *rev;
1160 	struct ccw1 *ccw;
1161 	int ret;
1162 
1163 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1164 	if (!ccw)
1165 		return -ENOMEM;
1166 	rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1167 	if (!rev) {
1168 		kfree(ccw);
1169 		return -ENOMEM;
1170 	}
1171 
1172 	/* Set transport revision */
1173 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1174 	ccw->flags = 0;
1175 	ccw->count = sizeof(*rev);
1176 	ccw->cda = (__u32)(unsigned long)rev;
1177 
1178 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1179 	do {
1180 		rev->revision = vcdev->revision;
1181 		/* none of our supported revisions carry payload */
1182 		rev->length = 0;
1183 		ret = ccw_io_helper(vcdev, ccw,
1184 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1185 		if (ret == -EOPNOTSUPP) {
1186 			if (vcdev->revision == 0)
1187 				/*
1188 				 * The host device does not support setting
1189 				 * the revision: let's operate it in legacy
1190 				 * mode.
1191 				 */
1192 				ret = 0;
1193 			else
1194 				vcdev->revision--;
1195 		}
1196 	} while (ret == -EOPNOTSUPP);
1197 
1198 	kfree(ccw);
1199 	kfree(rev);
1200 	return ret;
1201 }
1202 
1203 static int virtio_ccw_online(struct ccw_device *cdev)
1204 {
1205 	int ret;
1206 	struct virtio_ccw_device *vcdev;
1207 	unsigned long flags;
1208 
1209 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1210 	if (!vcdev) {
1211 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1212 		ret = -ENOMEM;
1213 		goto out_free;
1214 	}
1215 	vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1216 				   GFP_DMA | GFP_KERNEL);
1217 	if (!vcdev->config_block) {
1218 		ret = -ENOMEM;
1219 		goto out_free;
1220 	}
1221 	vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1222 	if (!vcdev->status) {
1223 		ret = -ENOMEM;
1224 		goto out_free;
1225 	}
1226 
1227 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1228 
1229 	vcdev->vdev.dev.parent = &cdev->dev;
1230 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1231 	vcdev->vdev.config = &virtio_ccw_config_ops;
1232 	vcdev->cdev = cdev;
1233 	init_waitqueue_head(&vcdev->wait_q);
1234 	INIT_LIST_HEAD(&vcdev->virtqueues);
1235 	spin_lock_init(&vcdev->lock);
1236 
1237 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1238 	dev_set_drvdata(&cdev->dev, vcdev);
1239 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1240 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1241 	vcdev->vdev.id.device = cdev->id.cu_model;
1242 
1243 	ret = virtio_ccw_set_transport_rev(vcdev);
1244 	if (ret)
1245 		goto out_free;
1246 
1247 	ret = register_virtio_device(&vcdev->vdev);
1248 	if (ret) {
1249 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1250 			 ret);
1251 		goto out_put;
1252 	}
1253 	return 0;
1254 out_put:
1255 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1256 	dev_set_drvdata(&cdev->dev, NULL);
1257 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1258 	put_device(&vcdev->vdev.dev);
1259 	return ret;
1260 out_free:
1261 	if (vcdev) {
1262 		kfree(vcdev->status);
1263 		kfree(vcdev->config_block);
1264 	}
1265 	kfree(vcdev);
1266 	return ret;
1267 }
1268 
1269 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1270 {
1271 	int rc;
1272 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1273 
1274 	/*
1275 	 * Make sure vcdev is set
1276 	 * i.e. set_offline/remove callback not already running
1277 	 */
1278 	if (!vcdev)
1279 		return NOTIFY_DONE;
1280 
1281 	switch (event) {
1282 	case CIO_GONE:
1283 		vcdev->device_lost = true;
1284 		rc = NOTIFY_DONE;
1285 		break;
1286 	default:
1287 		rc = NOTIFY_DONE;
1288 		break;
1289 	}
1290 	return rc;
1291 }
1292 
1293 static struct ccw_device_id virtio_ids[] = {
1294 	{ CCW_DEVICE(0x3832, 0) },
1295 	{},
1296 };
1297 MODULE_DEVICE_TABLE(ccw, virtio_ids);
1298 
1299 static struct ccw_driver virtio_ccw_driver = {
1300 	.driver = {
1301 		.owner = THIS_MODULE,
1302 		.name = "virtio_ccw",
1303 	},
1304 	.ids = virtio_ids,
1305 	.probe = virtio_ccw_probe,
1306 	.remove = virtio_ccw_remove,
1307 	.set_offline = virtio_ccw_offline,
1308 	.set_online = virtio_ccw_online,
1309 	.notify = virtio_ccw_cio_notify,
1310 	.int_class = IRQIO_VIR,
1311 };
1312 
1313 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1314 			   int max_digit, int max_val)
1315 {
1316 	int diff;
1317 
1318 	diff = 0;
1319 	*val = 0;
1320 
1321 	while (diff <= max_digit) {
1322 		int value = hex_to_bin(**cp);
1323 
1324 		if (value < 0)
1325 			break;
1326 		*val = *val * 16 + value;
1327 		(*cp)++;
1328 		diff++;
1329 	}
1330 
1331 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1332 		return 1;
1333 
1334 	return 0;
1335 }
1336 
1337 static int __init parse_busid(char *str, unsigned int *cssid,
1338 			      unsigned int *ssid, unsigned int *devno)
1339 {
1340 	char *str_work;
1341 	int rc, ret;
1342 
1343 	rc = 1;
1344 
1345 	if (*str == '\0')
1346 		goto out;
1347 
1348 	str_work = str;
1349 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1350 	if (ret || (str_work[0] != '.'))
1351 		goto out;
1352 	str_work++;
1353 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1354 	if (ret || (str_work[0] != '.'))
1355 		goto out;
1356 	str_work++;
1357 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1358 	if (ret || (str_work[0] != '\0'))
1359 		goto out;
1360 
1361 	rc = 0;
1362 out:
1363 	return rc;
1364 }
1365 
1366 static void __init no_auto_parse(void)
1367 {
1368 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1369 	char *parm, *str;
1370 	int rc;
1371 
1372 	str = no_auto;
1373 	while ((parm = strsep(&str, ","))) {
1374 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1375 				 &from_ssid, &from);
1376 		if (rc)
1377 			continue;
1378 		if (parm != NULL) {
1379 			rc = parse_busid(parm, &to_cssid,
1380 					 &to_ssid, &to);
1381 			if ((from_ssid > to_ssid) ||
1382 			    ((from_ssid == to_ssid) && (from > to)))
1383 				rc = -EINVAL;
1384 		} else {
1385 			to_cssid = from_cssid;
1386 			to_ssid = from_ssid;
1387 			to = from;
1388 		}
1389 		if (rc)
1390 			continue;
1391 		while ((from_ssid < to_ssid) ||
1392 		       ((from_ssid == to_ssid) && (from <= to))) {
1393 			set_bit(from, devs_no_auto[from_ssid]);
1394 			from++;
1395 			if (from > __MAX_SUBCHANNEL) {
1396 				from_ssid++;
1397 				from = 0;
1398 			}
1399 		}
1400 	}
1401 }
1402 
1403 static int __init virtio_ccw_init(void)
1404 {
1405 	/* parse no_auto string before we do anything further */
1406 	no_auto_parse();
1407 	return ccw_driver_register(&virtio_ccw_driver);
1408 }
1409 module_init(virtio_ccw_init);
1410 
1411 static void __exit virtio_ccw_exit(void)
1412 {
1413 	int i;
1414 
1415 	ccw_driver_unregister(&virtio_ccw_driver);
1416 	for (i = 0; i < MAX_AIRQ_AREAS; i++)
1417 		destroy_airq_info(airq_areas[i]);
1418 }
1419 module_exit(virtio_ccw_exit);
1420