xref: /linux/drivers/s390/virtio/virtio_ccw.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 		indicatorp = kmalloc(sizeof(&vcdev->indicators),
346 				     GFP_DMA | GFP_KERNEL);
347 		if (!indicatorp)
348 			return;
349 		*indicatorp = 0;
350 		ccw->cmd_code = CCW_CMD_SET_IND;
351 		ccw->count = sizeof(vcdev->indicators);
352 		ccw->cda = (__u32)(unsigned long) indicatorp;
353 	}
354 	/* Deregister indicators from host. */
355 	vcdev->indicators = 0;
356 	ccw->flags = 0;
357 	ret = ccw_io_helper(vcdev, ccw,
358 			    vcdev->is_thinint ?
359 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
360 			    VIRTIO_CCW_DOING_SET_IND);
361 	if (ret && (ret != -ENODEV))
362 		dev_info(&vcdev->cdev->dev,
363 			 "Failed to deregister indicators (%d)\n", ret);
364 	else if (vcdev->is_thinint)
365 		virtio_ccw_drop_indicators(vcdev);
366 	kfree(indicatorp);
367 	kfree(thinint_area);
368 }
369 
370 static inline long __do_kvm_notify(struct subchannel_id schid,
371 				   unsigned long queue_index,
372 				   long cookie)
373 {
374 	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
375 	register struct subchannel_id __schid asm("2") = schid;
376 	register unsigned long __index asm("3") = queue_index;
377 	register long __rc asm("2");
378 	register long __cookie asm("4") = cookie;
379 
380 	asm volatile ("diag 2,4,0x500\n"
381 		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
382 		      "d"(__cookie)
383 		      : "memory", "cc");
384 	return __rc;
385 }
386 
387 static inline long do_kvm_notify(struct subchannel_id schid,
388 				 unsigned long queue_index,
389 				 long cookie)
390 {
391 	diag_stat_inc(DIAG_STAT_X500);
392 	return __do_kvm_notify(schid, queue_index, cookie);
393 }
394 
395 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
396 {
397 	struct virtio_ccw_vq_info *info = vq->priv;
398 	struct virtio_ccw_device *vcdev;
399 	struct subchannel_id schid;
400 
401 	vcdev = to_vc_device(info->vq->vdev);
402 	ccw_device_get_schid(vcdev->cdev, &schid);
403 	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
404 	if (info->cookie < 0)
405 		return false;
406 	return true;
407 }
408 
409 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
410 				   struct ccw1 *ccw, int index)
411 {
412 	int ret;
413 
414 	vcdev->config_block->index = index;
415 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
416 	ccw->flags = 0;
417 	ccw->count = sizeof(struct vq_config_block);
418 	ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
419 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
420 	if (ret)
421 		return ret;
422 	return vcdev->config_block->num;
423 }
424 
425 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
426 {
427 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
428 	struct virtio_ccw_vq_info *info = vq->priv;
429 	unsigned long flags;
430 	unsigned long size;
431 	int ret;
432 	unsigned int index = vq->index;
433 
434 	/* Remove from our list. */
435 	spin_lock_irqsave(&vcdev->lock, flags);
436 	list_del(&info->node);
437 	spin_unlock_irqrestore(&vcdev->lock, flags);
438 
439 	/* Release from host. */
440 	if (vcdev->revision == 0) {
441 		info->info_block->l.queue = 0;
442 		info->info_block->l.align = 0;
443 		info->info_block->l.index = index;
444 		info->info_block->l.num = 0;
445 		ccw->count = sizeof(info->info_block->l);
446 	} else {
447 		info->info_block->s.desc = 0;
448 		info->info_block->s.index = index;
449 		info->info_block->s.num = 0;
450 		info->info_block->s.avail = 0;
451 		info->info_block->s.used = 0;
452 		ccw->count = sizeof(info->info_block->s);
453 	}
454 	ccw->cmd_code = CCW_CMD_SET_VQ;
455 	ccw->flags = 0;
456 	ccw->cda = (__u32)(unsigned long)(info->info_block);
457 	ret = ccw_io_helper(vcdev, ccw,
458 			    VIRTIO_CCW_DOING_SET_VQ | index);
459 	/*
460 	 * -ENODEV isn't considered an error: The device is gone anyway.
461 	 * This may happen on device detach.
462 	 */
463 	if (ret && (ret != -ENODEV))
464 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d",
465 			 ret, index);
466 
467 	vring_del_virtqueue(vq);
468 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
469 	free_pages_exact(info->queue, size);
470 	kfree(info->info_block);
471 	kfree(info);
472 }
473 
474 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
475 {
476 	struct virtqueue *vq, *n;
477 	struct ccw1 *ccw;
478 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
479 
480 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
481 	if (!ccw)
482 		return;
483 
484 	virtio_ccw_drop_indicator(vcdev, ccw);
485 
486 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
487 		virtio_ccw_del_vq(vq, ccw);
488 
489 	kfree(ccw);
490 }
491 
492 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
493 					     int i, vq_callback_t *callback,
494 					     const char *name,
495 					     struct ccw1 *ccw)
496 {
497 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
498 	int err;
499 	struct virtqueue *vq = NULL;
500 	struct virtio_ccw_vq_info *info;
501 	unsigned long size = 0; /* silence the compiler */
502 	unsigned long flags;
503 
504 	/* Allocate queue. */
505 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
506 	if (!info) {
507 		dev_warn(&vcdev->cdev->dev, "no info\n");
508 		err = -ENOMEM;
509 		goto out_err;
510 	}
511 	info->info_block = kzalloc(sizeof(*info->info_block),
512 				   GFP_DMA | GFP_KERNEL);
513 	if (!info->info_block) {
514 		dev_warn(&vcdev->cdev->dev, "no info block\n");
515 		err = -ENOMEM;
516 		goto out_err;
517 	}
518 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
519 	if (info->num < 0) {
520 		err = info->num;
521 		goto out_err;
522 	}
523 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
524 	info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
525 	if (info->queue == NULL) {
526 		dev_warn(&vcdev->cdev->dev, "no queue\n");
527 		err = -ENOMEM;
528 		goto out_err;
529 	}
530 
531 	vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
532 				 true, info->queue, virtio_ccw_kvm_notify,
533 				 callback, name);
534 	if (!vq) {
535 		/* For now, we fail if we can't get the requested size. */
536 		dev_warn(&vcdev->cdev->dev, "no vq\n");
537 		err = -ENOMEM;
538 		goto out_err;
539 	}
540 
541 	/* Register it with the host. */
542 	if (vcdev->revision == 0) {
543 		info->info_block->l.queue = (__u64)info->queue;
544 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
545 		info->info_block->l.index = i;
546 		info->info_block->l.num = info->num;
547 		ccw->count = sizeof(info->info_block->l);
548 	} else {
549 		info->info_block->s.desc = (__u64)info->queue;
550 		info->info_block->s.index = i;
551 		info->info_block->s.num = info->num;
552 		info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
553 		info->info_block->s.used = (__u64)virtqueue_get_used(vq);
554 		ccw->count = sizeof(info->info_block->s);
555 	}
556 	ccw->cmd_code = CCW_CMD_SET_VQ;
557 	ccw->flags = 0;
558 	ccw->cda = (__u32)(unsigned long)(info->info_block);
559 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
560 	if (err) {
561 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
562 		goto out_err;
563 	}
564 
565 	info->vq = vq;
566 	vq->priv = info;
567 
568 	/* Save it to our list. */
569 	spin_lock_irqsave(&vcdev->lock, flags);
570 	list_add(&info->node, &vcdev->virtqueues);
571 	spin_unlock_irqrestore(&vcdev->lock, flags);
572 
573 	return vq;
574 
575 out_err:
576 	if (vq)
577 		vring_del_virtqueue(vq);
578 	if (info) {
579 		if (info->queue)
580 			free_pages_exact(info->queue, size);
581 		kfree(info->info_block);
582 	}
583 	kfree(info);
584 	return ERR_PTR(err);
585 }
586 
587 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
588 					   struct virtqueue *vqs[], int nvqs,
589 					   struct ccw1 *ccw)
590 {
591 	int ret;
592 	struct virtio_thinint_area *thinint_area = NULL;
593 	struct airq_info *info;
594 
595 	thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
596 	if (!thinint_area) {
597 		ret = -ENOMEM;
598 		goto out;
599 	}
600 	/* Try to get an indicator. */
601 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
602 						     &thinint_area->bit_nr,
603 						     &vcdev->airq_info);
604 	if (!thinint_area->indicator) {
605 		ret = -ENOSPC;
606 		goto out;
607 	}
608 	info = vcdev->airq_info;
609 	thinint_area->summary_indicator =
610 		(unsigned long) &info->summary_indicator;
611 	thinint_area->isc = VIRTIO_AIRQ_ISC;
612 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
613 	ccw->flags = CCW_FLAG_SLI;
614 	ccw->count = sizeof(*thinint_area);
615 	ccw->cda = (__u32)(unsigned long)thinint_area;
616 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
617 	if (ret) {
618 		if (ret == -EOPNOTSUPP) {
619 			/*
620 			 * The host does not support adapter interrupts
621 			 * for virtio-ccw, stop trying.
622 			 */
623 			virtio_ccw_use_airq = 0;
624 			pr_info("Adapter interrupts unsupported on host\n");
625 		} else
626 			dev_warn(&vcdev->cdev->dev,
627 				 "enabling adapter interrupts = %d\n", ret);
628 		virtio_ccw_drop_indicators(vcdev);
629 	}
630 out:
631 	kfree(thinint_area);
632 	return ret;
633 }
634 
635 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
636 			       struct virtqueue *vqs[],
637 			       vq_callback_t *callbacks[],
638 			       const char * const names[])
639 {
640 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
641 	unsigned long *indicatorp = NULL;
642 	int ret, i;
643 	struct ccw1 *ccw;
644 
645 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
646 	if (!ccw)
647 		return -ENOMEM;
648 
649 	for (i = 0; i < nvqs; ++i) {
650 		vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
651 					     ccw);
652 		if (IS_ERR(vqs[i])) {
653 			ret = PTR_ERR(vqs[i]);
654 			vqs[i] = NULL;
655 			goto out;
656 		}
657 	}
658 	ret = -ENOMEM;
659 	/* We need a data area under 2G to communicate. */
660 	indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
661 	if (!indicatorp)
662 		goto out;
663 	*indicatorp = (unsigned long) &vcdev->indicators;
664 	if (vcdev->is_thinint) {
665 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
666 		if (ret)
667 			/* no error, just fall back to legacy interrupts */
668 			vcdev->is_thinint = 0;
669 	}
670 	if (!vcdev->is_thinint) {
671 		/* Register queue indicators with host. */
672 		vcdev->indicators = 0;
673 		ccw->cmd_code = CCW_CMD_SET_IND;
674 		ccw->flags = 0;
675 		ccw->count = sizeof(vcdev->indicators);
676 		ccw->cda = (__u32)(unsigned long) indicatorp;
677 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
678 		if (ret)
679 			goto out;
680 	}
681 	/* Register indicators2 with host for config changes */
682 	*indicatorp = (unsigned long) &vcdev->indicators2;
683 	vcdev->indicators2 = 0;
684 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
685 	ccw->flags = 0;
686 	ccw->count = sizeof(vcdev->indicators2);
687 	ccw->cda = (__u32)(unsigned long) indicatorp;
688 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
689 	if (ret)
690 		goto out;
691 
692 	kfree(indicatorp);
693 	kfree(ccw);
694 	return 0;
695 out:
696 	kfree(indicatorp);
697 	kfree(ccw);
698 	virtio_ccw_del_vqs(vdev);
699 	return ret;
700 }
701 
702 static void virtio_ccw_reset(struct virtio_device *vdev)
703 {
704 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
705 	struct ccw1 *ccw;
706 
707 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
708 	if (!ccw)
709 		return;
710 
711 	/* Zero status bits. */
712 	*vcdev->status = 0;
713 
714 	/* Send a reset ccw on device. */
715 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
716 	ccw->flags = 0;
717 	ccw->count = 0;
718 	ccw->cda = 0;
719 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
720 	kfree(ccw);
721 }
722 
723 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
724 {
725 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
726 	struct virtio_feature_desc *features;
727 	int ret;
728 	u64 rc;
729 	struct ccw1 *ccw;
730 
731 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
732 	if (!ccw)
733 		return 0;
734 
735 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
736 	if (!features) {
737 		rc = 0;
738 		goto out_free;
739 	}
740 	/* Read the feature bits from the host. */
741 	features->index = 0;
742 	ccw->cmd_code = CCW_CMD_READ_FEAT;
743 	ccw->flags = 0;
744 	ccw->count = sizeof(*features);
745 	ccw->cda = (__u32)(unsigned long)features;
746 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
747 	if (ret) {
748 		rc = 0;
749 		goto out_free;
750 	}
751 
752 	rc = le32_to_cpu(features->features);
753 
754 	if (vcdev->revision == 0)
755 		goto out_free;
756 
757 	/* Read second half of the feature bits from the host. */
758 	features->index = 1;
759 	ccw->cmd_code = CCW_CMD_READ_FEAT;
760 	ccw->flags = 0;
761 	ccw->count = sizeof(*features);
762 	ccw->cda = (__u32)(unsigned long)features;
763 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
764 	if (ret == 0)
765 		rc |= (u64)le32_to_cpu(features->features) << 32;
766 
767 out_free:
768 	kfree(features);
769 	kfree(ccw);
770 	return rc;
771 }
772 
773 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
774 {
775 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
776 	struct virtio_feature_desc *features;
777 	struct ccw1 *ccw;
778 	int ret;
779 
780 	if (vcdev->revision >= 1 &&
781 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
782 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
783 			"but does not have VIRTIO_F_VERSION_1\n");
784 		return -EINVAL;
785 	}
786 
787 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
788 	if (!ccw)
789 		return -ENOMEM;
790 
791 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
792 	if (!features) {
793 		ret = -ENOMEM;
794 		goto out_free;
795 	}
796 	/* Give virtio_ring a chance to accept features. */
797 	vring_transport_features(vdev);
798 
799 	features->index = 0;
800 	features->features = cpu_to_le32((u32)vdev->features);
801 	/* Write the first half of the feature bits to the host. */
802 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
803 	ccw->flags = 0;
804 	ccw->count = sizeof(*features);
805 	ccw->cda = (__u32)(unsigned long)features;
806 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
807 	if (ret)
808 		goto out_free;
809 
810 	if (vcdev->revision == 0)
811 		goto out_free;
812 
813 	features->index = 1;
814 	features->features = cpu_to_le32(vdev->features >> 32);
815 	/* Write the second half of the feature bits to the host. */
816 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
817 	ccw->flags = 0;
818 	ccw->count = sizeof(*features);
819 	ccw->cda = (__u32)(unsigned long)features;
820 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
821 
822 out_free:
823 	kfree(features);
824 	kfree(ccw);
825 
826 	return ret;
827 }
828 
829 static void virtio_ccw_get_config(struct virtio_device *vdev,
830 				  unsigned int offset, void *buf, unsigned len)
831 {
832 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
833 	int ret;
834 	struct ccw1 *ccw;
835 	void *config_area;
836 
837 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
838 	if (!ccw)
839 		return;
840 
841 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
842 	if (!config_area)
843 		goto out_free;
844 
845 	/* Read the config area from the host. */
846 	ccw->cmd_code = CCW_CMD_READ_CONF;
847 	ccw->flags = 0;
848 	ccw->count = offset + len;
849 	ccw->cda = (__u32)(unsigned long)config_area;
850 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
851 	if (ret)
852 		goto out_free;
853 
854 	memcpy(vcdev->config, config_area, offset + len);
855 	if (buf)
856 		memcpy(buf, &vcdev->config[offset], len);
857 	if (vcdev->config_ready < offset + len)
858 		vcdev->config_ready = offset + len;
859 
860 out_free:
861 	kfree(config_area);
862 	kfree(ccw);
863 }
864 
865 static void virtio_ccw_set_config(struct virtio_device *vdev,
866 				  unsigned int offset, const void *buf,
867 				  unsigned len)
868 {
869 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
870 	struct ccw1 *ccw;
871 	void *config_area;
872 
873 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
874 	if (!ccw)
875 		return;
876 
877 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
878 	if (!config_area)
879 		goto out_free;
880 
881 	/* Make sure we don't overwrite fields. */
882 	if (vcdev->config_ready < offset)
883 		virtio_ccw_get_config(vdev, 0, NULL, offset);
884 	memcpy(&vcdev->config[offset], buf, len);
885 	/* Write the config area to the host. */
886 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
887 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
888 	ccw->flags = 0;
889 	ccw->count = offset + len;
890 	ccw->cda = (__u32)(unsigned long)config_area;
891 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
892 
893 out_free:
894 	kfree(config_area);
895 	kfree(ccw);
896 }
897 
898 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
899 {
900 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
901 
902 	return *vcdev->status;
903 }
904 
905 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
906 {
907 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
908 	u8 old_status = *vcdev->status;
909 	struct ccw1 *ccw;
910 	int ret;
911 
912 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
913 	if (!ccw)
914 		return;
915 
916 	/* Write the status to the host. */
917 	*vcdev->status = status;
918 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
919 	ccw->flags = 0;
920 	ccw->count = sizeof(status);
921 	ccw->cda = (__u32)(unsigned long)vcdev->status;
922 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
923 	/* Write failed? We assume status is unchanged. */
924 	if (ret)
925 		*vcdev->status = old_status;
926 	kfree(ccw);
927 }
928 
929 static struct virtio_config_ops virtio_ccw_config_ops = {
930 	.get_features = virtio_ccw_get_features,
931 	.finalize_features = virtio_ccw_finalize_features,
932 	.get = virtio_ccw_get_config,
933 	.set = virtio_ccw_set_config,
934 	.get_status = virtio_ccw_get_status,
935 	.set_status = virtio_ccw_set_status,
936 	.reset = virtio_ccw_reset,
937 	.find_vqs = virtio_ccw_find_vqs,
938 	.del_vqs = virtio_ccw_del_vqs,
939 };
940 
941 
942 /*
943  * ccw bus driver related functions
944  */
945 
946 static void virtio_ccw_release_dev(struct device *_d)
947 {
948 	struct virtio_device *dev = container_of(_d, struct virtio_device,
949 						 dev);
950 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
951 
952 	kfree(vcdev->status);
953 	kfree(vcdev->config_block);
954 	kfree(vcdev);
955 }
956 
957 static int irb_is_error(struct irb *irb)
958 {
959 	if (scsw_cstat(&irb->scsw) != 0)
960 		return 1;
961 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
962 		return 1;
963 	if (scsw_cc(&irb->scsw) != 0)
964 		return 1;
965 	return 0;
966 }
967 
968 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
969 					      int index)
970 {
971 	struct virtio_ccw_vq_info *info;
972 	unsigned long flags;
973 	struct virtqueue *vq;
974 
975 	vq = NULL;
976 	spin_lock_irqsave(&vcdev->lock, flags);
977 	list_for_each_entry(info, &vcdev->virtqueues, node) {
978 		if (info->vq->index == index) {
979 			vq = info->vq;
980 			break;
981 		}
982 	}
983 	spin_unlock_irqrestore(&vcdev->lock, flags);
984 	return vq;
985 }
986 
987 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
988 				      __u32 activity)
989 {
990 	if (vcdev->curr_io & activity) {
991 		switch (activity) {
992 		case VIRTIO_CCW_DOING_READ_FEAT:
993 		case VIRTIO_CCW_DOING_WRITE_FEAT:
994 		case VIRTIO_CCW_DOING_READ_CONFIG:
995 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
996 		case VIRTIO_CCW_DOING_WRITE_STATUS:
997 		case VIRTIO_CCW_DOING_SET_VQ:
998 		case VIRTIO_CCW_DOING_SET_IND:
999 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1000 		case VIRTIO_CCW_DOING_RESET:
1001 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1002 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1003 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1004 			vcdev->curr_io &= ~activity;
1005 			wake_up(&vcdev->wait_q);
1006 			break;
1007 		default:
1008 			/* don't know what to do... */
1009 			dev_warn(&vcdev->cdev->dev,
1010 				 "Suspicious activity '%08x'\n", activity);
1011 			WARN_ON(1);
1012 			break;
1013 		}
1014 	}
1015 }
1016 
1017 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1018 				   unsigned long intparm,
1019 				   struct irb *irb)
1020 {
1021 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1022 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1023 	int i;
1024 	struct virtqueue *vq;
1025 
1026 	if (!vcdev)
1027 		return;
1028 	if (IS_ERR(irb)) {
1029 		vcdev->err = PTR_ERR(irb);
1030 		virtio_ccw_check_activity(vcdev, activity);
1031 		/* Don't poke around indicators, something's wrong. */
1032 		return;
1033 	}
1034 	/* Check if it's a notification from the host. */
1035 	if ((intparm == 0) &&
1036 	    (scsw_stctl(&irb->scsw) ==
1037 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1038 		/* OK */
1039 	}
1040 	if (irb_is_error(irb)) {
1041 		/* Command reject? */
1042 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1043 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1044 			vcdev->err = -EOPNOTSUPP;
1045 		else
1046 			/* Map everything else to -EIO. */
1047 			vcdev->err = -EIO;
1048 	}
1049 	virtio_ccw_check_activity(vcdev, activity);
1050 	for_each_set_bit(i, &vcdev->indicators,
1051 			 sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1052 		/* The bit clear must happen before the vring kick. */
1053 		clear_bit(i, &vcdev->indicators);
1054 		barrier();
1055 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1056 		vring_interrupt(0, vq);
1057 	}
1058 	if (test_bit(0, &vcdev->indicators2)) {
1059 		virtio_config_changed(&vcdev->vdev);
1060 		clear_bit(0, &vcdev->indicators2);
1061 	}
1062 }
1063 
1064 /*
1065  * We usually want to autoonline all devices, but give the admin
1066  * a way to exempt devices from this.
1067  */
1068 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1069 		     (8*sizeof(long)))
1070 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1071 
1072 static char *no_auto = "";
1073 
1074 module_param(no_auto, charp, 0444);
1075 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1076 
1077 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1078 {
1079 	struct ccw_dev_id id;
1080 
1081 	ccw_device_get_id(cdev, &id);
1082 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1083 		return 0;
1084 	return 1;
1085 }
1086 
1087 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1088 {
1089 	struct ccw_device *cdev = data;
1090 	int ret;
1091 
1092 	ret = ccw_device_set_online(cdev);
1093 	if (ret)
1094 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1095 }
1096 
1097 static int virtio_ccw_probe(struct ccw_device *cdev)
1098 {
1099 	cdev->handler = virtio_ccw_int_handler;
1100 
1101 	if (virtio_ccw_check_autoonline(cdev))
1102 		async_schedule(virtio_ccw_auto_online, cdev);
1103 	return 0;
1104 }
1105 
1106 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1107 {
1108 	unsigned long flags;
1109 	struct virtio_ccw_device *vcdev;
1110 
1111 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1112 	vcdev = dev_get_drvdata(&cdev->dev);
1113 	if (!vcdev || vcdev->going_away) {
1114 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1115 		return NULL;
1116 	}
1117 	vcdev->going_away = true;
1118 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1119 	return vcdev;
1120 }
1121 
1122 static void virtio_ccw_remove(struct ccw_device *cdev)
1123 {
1124 	unsigned long flags;
1125 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1126 
1127 	if (vcdev && cdev->online) {
1128 		if (vcdev->device_lost)
1129 			virtio_break_device(&vcdev->vdev);
1130 		unregister_virtio_device(&vcdev->vdev);
1131 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1132 		dev_set_drvdata(&cdev->dev, NULL);
1133 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1134 	}
1135 	cdev->handler = NULL;
1136 }
1137 
1138 static int virtio_ccw_offline(struct ccw_device *cdev)
1139 {
1140 	unsigned long flags;
1141 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1142 
1143 	if (!vcdev)
1144 		return 0;
1145 	if (vcdev->device_lost)
1146 		virtio_break_device(&vcdev->vdev);
1147 	unregister_virtio_device(&vcdev->vdev);
1148 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1149 	dev_set_drvdata(&cdev->dev, NULL);
1150 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1151 	return 0;
1152 }
1153 
1154 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1155 {
1156 	struct virtio_rev_info *rev;
1157 	struct ccw1 *ccw;
1158 	int ret;
1159 
1160 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1161 	if (!ccw)
1162 		return -ENOMEM;
1163 	rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1164 	if (!rev) {
1165 		kfree(ccw);
1166 		return -ENOMEM;
1167 	}
1168 
1169 	/* Set transport revision */
1170 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1171 	ccw->flags = 0;
1172 	ccw->count = sizeof(*rev);
1173 	ccw->cda = (__u32)(unsigned long)rev;
1174 
1175 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1176 	do {
1177 		rev->revision = vcdev->revision;
1178 		/* none of our supported revisions carry payload */
1179 		rev->length = 0;
1180 		ret = ccw_io_helper(vcdev, ccw,
1181 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1182 		if (ret == -EOPNOTSUPP) {
1183 			if (vcdev->revision == 0)
1184 				/*
1185 				 * The host device does not support setting
1186 				 * the revision: let's operate it in legacy
1187 				 * mode.
1188 				 */
1189 				ret = 0;
1190 			else
1191 				vcdev->revision--;
1192 		}
1193 	} while (ret == -EOPNOTSUPP);
1194 
1195 	kfree(ccw);
1196 	kfree(rev);
1197 	return ret;
1198 }
1199 
1200 static int virtio_ccw_online(struct ccw_device *cdev)
1201 {
1202 	int ret;
1203 	struct virtio_ccw_device *vcdev;
1204 	unsigned long flags;
1205 
1206 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1207 	if (!vcdev) {
1208 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1209 		ret = -ENOMEM;
1210 		goto out_free;
1211 	}
1212 	vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1213 				   GFP_DMA | GFP_KERNEL);
1214 	if (!vcdev->config_block) {
1215 		ret = -ENOMEM;
1216 		goto out_free;
1217 	}
1218 	vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1219 	if (!vcdev->status) {
1220 		ret = -ENOMEM;
1221 		goto out_free;
1222 	}
1223 
1224 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1225 
1226 	vcdev->vdev.dev.parent = &cdev->dev;
1227 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1228 	vcdev->vdev.config = &virtio_ccw_config_ops;
1229 	vcdev->cdev = cdev;
1230 	init_waitqueue_head(&vcdev->wait_q);
1231 	INIT_LIST_HEAD(&vcdev->virtqueues);
1232 	spin_lock_init(&vcdev->lock);
1233 
1234 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1235 	dev_set_drvdata(&cdev->dev, vcdev);
1236 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1237 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1238 	vcdev->vdev.id.device = cdev->id.cu_model;
1239 
1240 	ret = virtio_ccw_set_transport_rev(vcdev);
1241 	if (ret)
1242 		goto out_free;
1243 
1244 	ret = register_virtio_device(&vcdev->vdev);
1245 	if (ret) {
1246 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1247 			 ret);
1248 		goto out_put;
1249 	}
1250 	return 0;
1251 out_put:
1252 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1253 	dev_set_drvdata(&cdev->dev, NULL);
1254 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1255 	put_device(&vcdev->vdev.dev);
1256 	return ret;
1257 out_free:
1258 	if (vcdev) {
1259 		kfree(vcdev->status);
1260 		kfree(vcdev->config_block);
1261 	}
1262 	kfree(vcdev);
1263 	return ret;
1264 }
1265 
1266 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1267 {
1268 	int rc;
1269 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1270 
1271 	/*
1272 	 * Make sure vcdev is set
1273 	 * i.e. set_offline/remove callback not already running
1274 	 */
1275 	if (!vcdev)
1276 		return NOTIFY_DONE;
1277 
1278 	switch (event) {
1279 	case CIO_GONE:
1280 		vcdev->device_lost = true;
1281 		rc = NOTIFY_DONE;
1282 		break;
1283 	default:
1284 		rc = NOTIFY_DONE;
1285 		break;
1286 	}
1287 	return rc;
1288 }
1289 
1290 static struct ccw_device_id virtio_ids[] = {
1291 	{ CCW_DEVICE(0x3832, 0) },
1292 	{},
1293 };
1294 MODULE_DEVICE_TABLE(ccw, virtio_ids);
1295 
1296 static struct ccw_driver virtio_ccw_driver = {
1297 	.driver = {
1298 		.owner = THIS_MODULE,
1299 		.name = "virtio_ccw",
1300 	},
1301 	.ids = virtio_ids,
1302 	.probe = virtio_ccw_probe,
1303 	.remove = virtio_ccw_remove,
1304 	.set_offline = virtio_ccw_offline,
1305 	.set_online = virtio_ccw_online,
1306 	.notify = virtio_ccw_cio_notify,
1307 	.int_class = IRQIO_VIR,
1308 };
1309 
1310 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1311 			   int max_digit, int max_val)
1312 {
1313 	int diff;
1314 
1315 	diff = 0;
1316 	*val = 0;
1317 
1318 	while (diff <= max_digit) {
1319 		int value = hex_to_bin(**cp);
1320 
1321 		if (value < 0)
1322 			break;
1323 		*val = *val * 16 + value;
1324 		(*cp)++;
1325 		diff++;
1326 	}
1327 
1328 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1329 		return 1;
1330 
1331 	return 0;
1332 }
1333 
1334 static int __init parse_busid(char *str, unsigned int *cssid,
1335 			      unsigned int *ssid, unsigned int *devno)
1336 {
1337 	char *str_work;
1338 	int rc, ret;
1339 
1340 	rc = 1;
1341 
1342 	if (*str == '\0')
1343 		goto out;
1344 
1345 	str_work = str;
1346 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1347 	if (ret || (str_work[0] != '.'))
1348 		goto out;
1349 	str_work++;
1350 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1351 	if (ret || (str_work[0] != '.'))
1352 		goto out;
1353 	str_work++;
1354 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1355 	if (ret || (str_work[0] != '\0'))
1356 		goto out;
1357 
1358 	rc = 0;
1359 out:
1360 	return rc;
1361 }
1362 
1363 static void __init no_auto_parse(void)
1364 {
1365 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1366 	char *parm, *str;
1367 	int rc;
1368 
1369 	str = no_auto;
1370 	while ((parm = strsep(&str, ","))) {
1371 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1372 				 &from_ssid, &from);
1373 		if (rc)
1374 			continue;
1375 		if (parm != NULL) {
1376 			rc = parse_busid(parm, &to_cssid,
1377 					 &to_ssid, &to);
1378 			if ((from_ssid > to_ssid) ||
1379 			    ((from_ssid == to_ssid) && (from > to)))
1380 				rc = -EINVAL;
1381 		} else {
1382 			to_cssid = from_cssid;
1383 			to_ssid = from_ssid;
1384 			to = from;
1385 		}
1386 		if (rc)
1387 			continue;
1388 		while ((from_ssid < to_ssid) ||
1389 		       ((from_ssid == to_ssid) && (from <= to))) {
1390 			set_bit(from, devs_no_auto[from_ssid]);
1391 			from++;
1392 			if (from > __MAX_SUBCHANNEL) {
1393 				from_ssid++;
1394 				from = 0;
1395 			}
1396 		}
1397 	}
1398 }
1399 
1400 static int __init virtio_ccw_init(void)
1401 {
1402 	/* parse no_auto string before we do anything further */
1403 	no_auto_parse();
1404 	return ccw_driver_register(&virtio_ccw_driver);
1405 }
1406 module_init(virtio_ccw_init);
1407 
1408 static void __exit virtio_ccw_exit(void)
1409 {
1410 	int i;
1411 
1412 	ccw_driver_unregister(&virtio_ccw_driver);
1413 	for (i = 0; i < MAX_AIRQ_AREAS; i++)
1414 		destroy_airq_info(airq_areas[i]);
1415 }
1416 module_exit(virtio_ccw_exit);
1417