xref: /openbmc/linux/drivers/s390/virtio/virtio_ccw.c (revision e2f1cf25)
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/setup.h>
32 #include <asm/irq.h>
33 #include <asm/cio.h>
34 #include <asm/ccwdev.h>
35 #include <asm/virtio-ccw.h>
36 #include <asm/isc.h>
37 #include <asm/airq.h>
38 
39 /*
40  * virtio related functions
41  */
42 
43 struct vq_config_block {
44 	__u16 index;
45 	__u16 num;
46 } __packed;
47 
48 #define VIRTIO_CCW_CONFIG_SIZE 0x100
49 /* same as PCI config space size, should be enough for all drivers */
50 
51 struct virtio_ccw_device {
52 	struct virtio_device vdev;
53 	__u8 *status;
54 	__u8 config[VIRTIO_CCW_CONFIG_SIZE];
55 	struct ccw_device *cdev;
56 	__u32 curr_io;
57 	int err;
58 	unsigned int revision; /* Transport revision */
59 	wait_queue_head_t wait_q;
60 	spinlock_t lock;
61 	struct list_head virtqueues;
62 	unsigned long indicators;
63 	unsigned long indicators2;
64 	struct vq_config_block *config_block;
65 	bool is_thinint;
66 	bool going_away;
67 	bool device_lost;
68 	unsigned int config_ready;
69 	void *airq_info;
70 };
71 
72 struct vq_info_block_legacy {
73 	__u64 queue;
74 	__u32 align;
75 	__u16 index;
76 	__u16 num;
77 } __packed;
78 
79 struct vq_info_block {
80 	__u64 desc;
81 	__u32 res0;
82 	__u16 index;
83 	__u16 num;
84 	__u64 avail;
85 	__u64 used;
86 } __packed;
87 
88 struct virtio_feature_desc {
89 	__u32 features;
90 	__u8 index;
91 } __packed;
92 
93 struct virtio_thinint_area {
94 	unsigned long summary_indicator;
95 	unsigned long indicator;
96 	u64 bit_nr;
97 	u8 isc;
98 } __packed;
99 
100 struct virtio_rev_info {
101 	__u16 revision;
102 	__u16 length;
103 	__u8 data[];
104 };
105 
106 /* the highest virtio-ccw revision we support */
107 #define VIRTIO_CCW_REV_MAX 1
108 
109 struct virtio_ccw_vq_info {
110 	struct virtqueue *vq;
111 	int num;
112 	void *queue;
113 	union {
114 		struct vq_info_block s;
115 		struct vq_info_block_legacy l;
116 	} *info_block;
117 	int bit_nr;
118 	struct list_head node;
119 	long cookie;
120 };
121 
122 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
123 
124 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
125 #define MAX_AIRQ_AREAS 20
126 
127 static int virtio_ccw_use_airq = 1;
128 
129 struct airq_info {
130 	rwlock_t lock;
131 	u8 summary_indicator;
132 	struct airq_struct airq;
133 	struct airq_iv *aiv;
134 };
135 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
136 
137 #define CCW_CMD_SET_VQ 0x13
138 #define CCW_CMD_VDEV_RESET 0x33
139 #define CCW_CMD_SET_IND 0x43
140 #define CCW_CMD_SET_CONF_IND 0x53
141 #define CCW_CMD_READ_FEAT 0x12
142 #define CCW_CMD_WRITE_FEAT 0x11
143 #define CCW_CMD_READ_CONF 0x22
144 #define CCW_CMD_WRITE_CONF 0x21
145 #define CCW_CMD_WRITE_STATUS 0x31
146 #define CCW_CMD_READ_VQ_CONF 0x32
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_INTPARM_MASK 0xffff0000
163 
164 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
165 {
166 	return container_of(vdev, struct virtio_ccw_device, vdev);
167 }
168 
169 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
170 {
171 	unsigned long i, flags;
172 
173 	write_lock_irqsave(&info->lock, flags);
174 	for (i = 0; i < airq_iv_end(info->aiv); i++) {
175 		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
176 			airq_iv_free_bit(info->aiv, i);
177 			airq_iv_set_ptr(info->aiv, i, 0);
178 			break;
179 		}
180 	}
181 	write_unlock_irqrestore(&info->lock, flags);
182 }
183 
184 static void virtio_airq_handler(struct airq_struct *airq)
185 {
186 	struct airq_info *info = container_of(airq, struct airq_info, airq);
187 	unsigned long ai;
188 
189 	inc_irq_stat(IRQIO_VAI);
190 	read_lock(&info->lock);
191 	/* Walk through indicators field, summary indicator active. */
192 	for (ai = 0;;) {
193 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
194 		if (ai == -1UL)
195 			break;
196 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
197 	}
198 	info->summary_indicator = 0;
199 	smp_wmb();
200 	/* Walk through indicators field, summary indicator not active. */
201 	for (ai = 0;;) {
202 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
203 		if (ai == -1UL)
204 			break;
205 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
206 	}
207 	read_unlock(&info->lock);
208 }
209 
210 static struct airq_info *new_airq_info(void)
211 {
212 	struct airq_info *info;
213 	int rc;
214 
215 	info = kzalloc(sizeof(*info), GFP_KERNEL);
216 	if (!info)
217 		return NULL;
218 	rwlock_init(&info->lock);
219 	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
220 	if (!info->aiv) {
221 		kfree(info);
222 		return NULL;
223 	}
224 	info->airq.handler = virtio_airq_handler;
225 	info->airq.lsi_ptr = &info->summary_indicator;
226 	info->airq.lsi_mask = 0xff;
227 	info->airq.isc = VIRTIO_AIRQ_ISC;
228 	rc = register_adapter_interrupt(&info->airq);
229 	if (rc) {
230 		airq_iv_release(info->aiv);
231 		kfree(info);
232 		return NULL;
233 	}
234 	return info;
235 }
236 
237 static void destroy_airq_info(struct airq_info *info)
238 {
239 	if (!info)
240 		return;
241 
242 	unregister_adapter_interrupt(&info->airq);
243 	airq_iv_release(info->aiv);
244 	kfree(info);
245 }
246 
247 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
248 					u64 *first, void **airq_info)
249 {
250 	int i, j;
251 	struct airq_info *info;
252 	unsigned long indicator_addr = 0;
253 	unsigned long bit, flags;
254 
255 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
256 		if (!airq_areas[i])
257 			airq_areas[i] = new_airq_info();
258 		info = airq_areas[i];
259 		if (!info)
260 			return 0;
261 		write_lock_irqsave(&info->lock, flags);
262 		bit = airq_iv_alloc(info->aiv, nvqs);
263 		if (bit == -1UL) {
264 			/* Not enough vacancies. */
265 			write_unlock_irqrestore(&info->lock, flags);
266 			continue;
267 		}
268 		*first = bit;
269 		*airq_info = info;
270 		indicator_addr = (unsigned long)info->aiv->vector;
271 		for (j = 0; j < nvqs; j++) {
272 			airq_iv_set_ptr(info->aiv, bit + j,
273 					(unsigned long)vqs[j]);
274 		}
275 		write_unlock_irqrestore(&info->lock, flags);
276 	}
277 	return indicator_addr;
278 }
279 
280 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
281 {
282 	struct virtio_ccw_vq_info *info;
283 
284 	list_for_each_entry(info, &vcdev->virtqueues, node)
285 		drop_airq_indicator(info->vq, vcdev->airq_info);
286 }
287 
288 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
289 {
290 	unsigned long flags;
291 	__u32 ret;
292 
293 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
294 	if (vcdev->err)
295 		ret = 0;
296 	else
297 		ret = vcdev->curr_io & flag;
298 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
299 	return ret;
300 }
301 
302 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
303 			 struct ccw1 *ccw, __u32 intparm)
304 {
305 	int ret;
306 	unsigned long flags;
307 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
308 
309 	do {
310 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
311 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
312 		if (!ret) {
313 			if (!vcdev->curr_io)
314 				vcdev->err = 0;
315 			vcdev->curr_io |= flag;
316 		}
317 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
318 		cpu_relax();
319 	} while (ret == -EBUSY);
320 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
321 	return ret ? ret : vcdev->err;
322 }
323 
324 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
325 				      struct ccw1 *ccw)
326 {
327 	int ret;
328 	unsigned long *indicatorp = NULL;
329 	struct virtio_thinint_area *thinint_area = NULL;
330 	struct airq_info *airq_info = vcdev->airq_info;
331 
332 	if (vcdev->is_thinint) {
333 		thinint_area = kzalloc(sizeof(*thinint_area),
334 				       GFP_DMA | GFP_KERNEL);
335 		if (!thinint_area)
336 			return;
337 		thinint_area->summary_indicator =
338 			(unsigned long) &airq_info->summary_indicator;
339 		thinint_area->isc = VIRTIO_AIRQ_ISC;
340 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
341 		ccw->count = sizeof(*thinint_area);
342 		ccw->cda = (__u32)(unsigned long) thinint_area;
343 	} else {
344 		indicatorp = kmalloc(sizeof(&vcdev->indicators),
345 				     GFP_DMA | GFP_KERNEL);
346 		if (!indicatorp)
347 			return;
348 		*indicatorp = 0;
349 		ccw->cmd_code = CCW_CMD_SET_IND;
350 		ccw->count = sizeof(vcdev->indicators);
351 		ccw->cda = (__u32)(unsigned long) indicatorp;
352 	}
353 	/* Deregister indicators from host. */
354 	vcdev->indicators = 0;
355 	ccw->flags = 0;
356 	ret = ccw_io_helper(vcdev, ccw,
357 			    vcdev->is_thinint ?
358 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
359 			    VIRTIO_CCW_DOING_SET_IND);
360 	if (ret && (ret != -ENODEV))
361 		dev_info(&vcdev->cdev->dev,
362 			 "Failed to deregister indicators (%d)\n", ret);
363 	else if (vcdev->is_thinint)
364 		virtio_ccw_drop_indicators(vcdev);
365 	kfree(indicatorp);
366 	kfree(thinint_area);
367 }
368 
369 static inline long do_kvm_notify(struct subchannel_id schid,
370 				 unsigned long queue_index,
371 				 long cookie)
372 {
373 	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
374 	register struct subchannel_id __schid asm("2") = schid;
375 	register unsigned long __index asm("3") = queue_index;
376 	register long __rc asm("2");
377 	register long __cookie asm("4") = cookie;
378 
379 	asm volatile ("diag 2,4,0x500\n"
380 		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
381 		      "d"(__cookie)
382 		      : "memory", "cc");
383 	return __rc;
384 }
385 
386 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
387 {
388 	struct virtio_ccw_vq_info *info = vq->priv;
389 	struct virtio_ccw_device *vcdev;
390 	struct subchannel_id schid;
391 
392 	vcdev = to_vc_device(info->vq->vdev);
393 	ccw_device_get_schid(vcdev->cdev, &schid);
394 	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
395 	if (info->cookie < 0)
396 		return false;
397 	return true;
398 }
399 
400 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
401 				   struct ccw1 *ccw, int index)
402 {
403 	vcdev->config_block->index = index;
404 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
405 	ccw->flags = 0;
406 	ccw->count = sizeof(struct vq_config_block);
407 	ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
408 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
409 	return vcdev->config_block->num;
410 }
411 
412 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
413 {
414 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
415 	struct virtio_ccw_vq_info *info = vq->priv;
416 	unsigned long flags;
417 	unsigned long size;
418 	int ret;
419 	unsigned int index = vq->index;
420 
421 	/* Remove from our list. */
422 	spin_lock_irqsave(&vcdev->lock, flags);
423 	list_del(&info->node);
424 	spin_unlock_irqrestore(&vcdev->lock, flags);
425 
426 	/* Release from host. */
427 	if (vcdev->revision == 0) {
428 		info->info_block->l.queue = 0;
429 		info->info_block->l.align = 0;
430 		info->info_block->l.index = index;
431 		info->info_block->l.num = 0;
432 		ccw->count = sizeof(info->info_block->l);
433 	} else {
434 		info->info_block->s.desc = 0;
435 		info->info_block->s.index = index;
436 		info->info_block->s.num = 0;
437 		info->info_block->s.avail = 0;
438 		info->info_block->s.used = 0;
439 		ccw->count = sizeof(info->info_block->s);
440 	}
441 	ccw->cmd_code = CCW_CMD_SET_VQ;
442 	ccw->flags = 0;
443 	ccw->cda = (__u32)(unsigned long)(info->info_block);
444 	ret = ccw_io_helper(vcdev, ccw,
445 			    VIRTIO_CCW_DOING_SET_VQ | index);
446 	/*
447 	 * -ENODEV isn't considered an error: The device is gone anyway.
448 	 * This may happen on device detach.
449 	 */
450 	if (ret && (ret != -ENODEV))
451 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d",
452 			 ret, index);
453 
454 	vring_del_virtqueue(vq);
455 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
456 	free_pages_exact(info->queue, size);
457 	kfree(info->info_block);
458 	kfree(info);
459 }
460 
461 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
462 {
463 	struct virtqueue *vq, *n;
464 	struct ccw1 *ccw;
465 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
466 
467 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
468 	if (!ccw)
469 		return;
470 
471 	virtio_ccw_drop_indicator(vcdev, ccw);
472 
473 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
474 		virtio_ccw_del_vq(vq, ccw);
475 
476 	kfree(ccw);
477 }
478 
479 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
480 					     int i, vq_callback_t *callback,
481 					     const char *name,
482 					     struct ccw1 *ccw)
483 {
484 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
485 	int err;
486 	struct virtqueue *vq = NULL;
487 	struct virtio_ccw_vq_info *info;
488 	unsigned long size = 0; /* silence the compiler */
489 	unsigned long flags;
490 
491 	/* Allocate queue. */
492 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
493 	if (!info) {
494 		dev_warn(&vcdev->cdev->dev, "no info\n");
495 		err = -ENOMEM;
496 		goto out_err;
497 	}
498 	info->info_block = kzalloc(sizeof(*info->info_block),
499 				   GFP_DMA | GFP_KERNEL);
500 	if (!info->info_block) {
501 		dev_warn(&vcdev->cdev->dev, "no info block\n");
502 		err = -ENOMEM;
503 		goto out_err;
504 	}
505 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
506 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
507 	info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
508 	if (info->queue == NULL) {
509 		dev_warn(&vcdev->cdev->dev, "no queue\n");
510 		err = -ENOMEM;
511 		goto out_err;
512 	}
513 
514 	vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
515 				 true, info->queue, virtio_ccw_kvm_notify,
516 				 callback, name);
517 	if (!vq) {
518 		/* For now, we fail if we can't get the requested size. */
519 		dev_warn(&vcdev->cdev->dev, "no vq\n");
520 		err = -ENOMEM;
521 		goto out_err;
522 	}
523 
524 	/* Register it with the host. */
525 	if (vcdev->revision == 0) {
526 		info->info_block->l.queue = (__u64)info->queue;
527 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
528 		info->info_block->l.index = i;
529 		info->info_block->l.num = info->num;
530 		ccw->count = sizeof(info->info_block->l);
531 	} else {
532 		info->info_block->s.desc = (__u64)info->queue;
533 		info->info_block->s.index = i;
534 		info->info_block->s.num = info->num;
535 		info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
536 		info->info_block->s.used = (__u64)virtqueue_get_used(vq);
537 		ccw->count = sizeof(info->info_block->s);
538 	}
539 	ccw->cmd_code = CCW_CMD_SET_VQ;
540 	ccw->flags = 0;
541 	ccw->cda = (__u32)(unsigned long)(info->info_block);
542 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
543 	if (err) {
544 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
545 		goto out_err;
546 	}
547 
548 	info->vq = vq;
549 	vq->priv = info;
550 
551 	/* Save it to our list. */
552 	spin_lock_irqsave(&vcdev->lock, flags);
553 	list_add(&info->node, &vcdev->virtqueues);
554 	spin_unlock_irqrestore(&vcdev->lock, flags);
555 
556 	return vq;
557 
558 out_err:
559 	if (vq)
560 		vring_del_virtqueue(vq);
561 	if (info) {
562 		if (info->queue)
563 			free_pages_exact(info->queue, size);
564 		kfree(info->info_block);
565 	}
566 	kfree(info);
567 	return ERR_PTR(err);
568 }
569 
570 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
571 					   struct virtqueue *vqs[], int nvqs,
572 					   struct ccw1 *ccw)
573 {
574 	int ret;
575 	struct virtio_thinint_area *thinint_area = NULL;
576 	struct airq_info *info;
577 
578 	thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
579 	if (!thinint_area) {
580 		ret = -ENOMEM;
581 		goto out;
582 	}
583 	/* Try to get an indicator. */
584 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
585 						     &thinint_area->bit_nr,
586 						     &vcdev->airq_info);
587 	if (!thinint_area->indicator) {
588 		ret = -ENOSPC;
589 		goto out;
590 	}
591 	info = vcdev->airq_info;
592 	thinint_area->summary_indicator =
593 		(unsigned long) &info->summary_indicator;
594 	thinint_area->isc = VIRTIO_AIRQ_ISC;
595 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
596 	ccw->flags = CCW_FLAG_SLI;
597 	ccw->count = sizeof(*thinint_area);
598 	ccw->cda = (__u32)(unsigned long)thinint_area;
599 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
600 	if (ret) {
601 		if (ret == -EOPNOTSUPP) {
602 			/*
603 			 * The host does not support adapter interrupts
604 			 * for virtio-ccw, stop trying.
605 			 */
606 			virtio_ccw_use_airq = 0;
607 			pr_info("Adapter interrupts unsupported on host\n");
608 		} else
609 			dev_warn(&vcdev->cdev->dev,
610 				 "enabling adapter interrupts = %d\n", ret);
611 		virtio_ccw_drop_indicators(vcdev);
612 	}
613 out:
614 	kfree(thinint_area);
615 	return ret;
616 }
617 
618 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
619 			       struct virtqueue *vqs[],
620 			       vq_callback_t *callbacks[],
621 			       const char *names[])
622 {
623 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
624 	unsigned long *indicatorp = NULL;
625 	int ret, i;
626 	struct ccw1 *ccw;
627 
628 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
629 	if (!ccw)
630 		return -ENOMEM;
631 
632 	for (i = 0; i < nvqs; ++i) {
633 		vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
634 					     ccw);
635 		if (IS_ERR(vqs[i])) {
636 			ret = PTR_ERR(vqs[i]);
637 			vqs[i] = NULL;
638 			goto out;
639 		}
640 	}
641 	ret = -ENOMEM;
642 	/* We need a data area under 2G to communicate. */
643 	indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
644 	if (!indicatorp)
645 		goto out;
646 	*indicatorp = (unsigned long) &vcdev->indicators;
647 	if (vcdev->is_thinint) {
648 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
649 		if (ret)
650 			/* no error, just fall back to legacy interrupts */
651 			vcdev->is_thinint = 0;
652 	}
653 	if (!vcdev->is_thinint) {
654 		/* Register queue indicators with host. */
655 		vcdev->indicators = 0;
656 		ccw->cmd_code = CCW_CMD_SET_IND;
657 		ccw->flags = 0;
658 		ccw->count = sizeof(vcdev->indicators);
659 		ccw->cda = (__u32)(unsigned long) indicatorp;
660 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
661 		if (ret)
662 			goto out;
663 	}
664 	/* Register indicators2 with host for config changes */
665 	*indicatorp = (unsigned long) &vcdev->indicators2;
666 	vcdev->indicators2 = 0;
667 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
668 	ccw->flags = 0;
669 	ccw->count = sizeof(vcdev->indicators2);
670 	ccw->cda = (__u32)(unsigned long) indicatorp;
671 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
672 	if (ret)
673 		goto out;
674 
675 	kfree(indicatorp);
676 	kfree(ccw);
677 	return 0;
678 out:
679 	kfree(indicatorp);
680 	kfree(ccw);
681 	virtio_ccw_del_vqs(vdev);
682 	return ret;
683 }
684 
685 static void virtio_ccw_reset(struct virtio_device *vdev)
686 {
687 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
688 	struct ccw1 *ccw;
689 
690 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
691 	if (!ccw)
692 		return;
693 
694 	/* Zero status bits. */
695 	*vcdev->status = 0;
696 
697 	/* Send a reset ccw on device. */
698 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
699 	ccw->flags = 0;
700 	ccw->count = 0;
701 	ccw->cda = 0;
702 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
703 	kfree(ccw);
704 }
705 
706 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
707 {
708 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
709 	struct virtio_feature_desc *features;
710 	int ret;
711 	u64 rc;
712 	struct ccw1 *ccw;
713 
714 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
715 	if (!ccw)
716 		return 0;
717 
718 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
719 	if (!features) {
720 		rc = 0;
721 		goto out_free;
722 	}
723 	/* Read the feature bits from the host. */
724 	features->index = 0;
725 	ccw->cmd_code = CCW_CMD_READ_FEAT;
726 	ccw->flags = 0;
727 	ccw->count = sizeof(*features);
728 	ccw->cda = (__u32)(unsigned long)features;
729 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
730 	if (ret) {
731 		rc = 0;
732 		goto out_free;
733 	}
734 
735 	rc = le32_to_cpu(features->features);
736 
737 	if (vcdev->revision == 0)
738 		goto out_free;
739 
740 	/* Read second half of the feature bits from the host. */
741 	features->index = 1;
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 == 0)
748 		rc |= (u64)le32_to_cpu(features->features) << 32;
749 
750 out_free:
751 	kfree(features);
752 	kfree(ccw);
753 	return rc;
754 }
755 
756 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
757 {
758 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
759 	struct virtio_feature_desc *features;
760 	struct ccw1 *ccw;
761 	int ret;
762 
763 	if (vcdev->revision >= 1 &&
764 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
765 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
766 			"but does not have VIRTIO_F_VERSION_1\n");
767 		return -EINVAL;
768 	}
769 
770 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
771 	if (!ccw)
772 		return -ENOMEM;
773 
774 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
775 	if (!features) {
776 		ret = -ENOMEM;
777 		goto out_free;
778 	}
779 	/* Give virtio_ring a chance to accept features. */
780 	vring_transport_features(vdev);
781 
782 	features->index = 0;
783 	features->features = cpu_to_le32((u32)vdev->features);
784 	/* Write the first half of the feature bits to the host. */
785 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
786 	ccw->flags = 0;
787 	ccw->count = sizeof(*features);
788 	ccw->cda = (__u32)(unsigned long)features;
789 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
790 	if (ret)
791 		goto out_free;
792 
793 	if (vcdev->revision == 0)
794 		goto out_free;
795 
796 	features->index = 1;
797 	features->features = cpu_to_le32(vdev->features >> 32);
798 	/* Write the second half of the feature bits to the host. */
799 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
800 	ccw->flags = 0;
801 	ccw->count = sizeof(*features);
802 	ccw->cda = (__u32)(unsigned long)features;
803 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
804 
805 out_free:
806 	kfree(features);
807 	kfree(ccw);
808 
809 	return ret;
810 }
811 
812 static void virtio_ccw_get_config(struct virtio_device *vdev,
813 				  unsigned int offset, void *buf, unsigned len)
814 {
815 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
816 	int ret;
817 	struct ccw1 *ccw;
818 	void *config_area;
819 
820 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
821 	if (!ccw)
822 		return;
823 
824 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
825 	if (!config_area)
826 		goto out_free;
827 
828 	/* Read the config area from the host. */
829 	ccw->cmd_code = CCW_CMD_READ_CONF;
830 	ccw->flags = 0;
831 	ccw->count = offset + len;
832 	ccw->cda = (__u32)(unsigned long)config_area;
833 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
834 	if (ret)
835 		goto out_free;
836 
837 	memcpy(vcdev->config, config_area, offset + len);
838 	if (buf)
839 		memcpy(buf, &vcdev->config[offset], len);
840 	if (vcdev->config_ready < offset + len)
841 		vcdev->config_ready = offset + len;
842 
843 out_free:
844 	kfree(config_area);
845 	kfree(ccw);
846 }
847 
848 static void virtio_ccw_set_config(struct virtio_device *vdev,
849 				  unsigned int offset, const void *buf,
850 				  unsigned len)
851 {
852 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
853 	struct ccw1 *ccw;
854 	void *config_area;
855 
856 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
857 	if (!ccw)
858 		return;
859 
860 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
861 	if (!config_area)
862 		goto out_free;
863 
864 	/* Make sure we don't overwrite fields. */
865 	if (vcdev->config_ready < offset)
866 		virtio_ccw_get_config(vdev, 0, NULL, offset);
867 	memcpy(&vcdev->config[offset], buf, len);
868 	/* Write the config area to the host. */
869 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
870 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
871 	ccw->flags = 0;
872 	ccw->count = offset + len;
873 	ccw->cda = (__u32)(unsigned long)config_area;
874 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
875 
876 out_free:
877 	kfree(config_area);
878 	kfree(ccw);
879 }
880 
881 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
882 {
883 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
884 
885 	return *vcdev->status;
886 }
887 
888 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
889 {
890 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
891 	u8 old_status = *vcdev->status;
892 	struct ccw1 *ccw;
893 	int ret;
894 
895 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
896 	if (!ccw)
897 		return;
898 
899 	/* Write the status to the host. */
900 	*vcdev->status = status;
901 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
902 	ccw->flags = 0;
903 	ccw->count = sizeof(status);
904 	ccw->cda = (__u32)(unsigned long)vcdev->status;
905 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
906 	/* Write failed? We assume status is unchanged. */
907 	if (ret)
908 		*vcdev->status = old_status;
909 	kfree(ccw);
910 }
911 
912 static struct virtio_config_ops virtio_ccw_config_ops = {
913 	.get_features = virtio_ccw_get_features,
914 	.finalize_features = virtio_ccw_finalize_features,
915 	.get = virtio_ccw_get_config,
916 	.set = virtio_ccw_set_config,
917 	.get_status = virtio_ccw_get_status,
918 	.set_status = virtio_ccw_set_status,
919 	.reset = virtio_ccw_reset,
920 	.find_vqs = virtio_ccw_find_vqs,
921 	.del_vqs = virtio_ccw_del_vqs,
922 };
923 
924 
925 /*
926  * ccw bus driver related functions
927  */
928 
929 static void virtio_ccw_release_dev(struct device *_d)
930 {
931 	struct virtio_device *dev = container_of(_d, struct virtio_device,
932 						 dev);
933 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
934 
935 	kfree(vcdev->status);
936 	kfree(vcdev->config_block);
937 	kfree(vcdev);
938 }
939 
940 static int irb_is_error(struct irb *irb)
941 {
942 	if (scsw_cstat(&irb->scsw) != 0)
943 		return 1;
944 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
945 		return 1;
946 	if (scsw_cc(&irb->scsw) != 0)
947 		return 1;
948 	return 0;
949 }
950 
951 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
952 					      int index)
953 {
954 	struct virtio_ccw_vq_info *info;
955 	unsigned long flags;
956 	struct virtqueue *vq;
957 
958 	vq = NULL;
959 	spin_lock_irqsave(&vcdev->lock, flags);
960 	list_for_each_entry(info, &vcdev->virtqueues, node) {
961 		if (info->vq->index == index) {
962 			vq = info->vq;
963 			break;
964 		}
965 	}
966 	spin_unlock_irqrestore(&vcdev->lock, flags);
967 	return vq;
968 }
969 
970 static void virtio_ccw_int_handler(struct ccw_device *cdev,
971 				   unsigned long intparm,
972 				   struct irb *irb)
973 {
974 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
975 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
976 	int i;
977 	struct virtqueue *vq;
978 
979 	if (!vcdev)
980 		return;
981 	/* Check if it's a notification from the host. */
982 	if ((intparm == 0) &&
983 	    (scsw_stctl(&irb->scsw) ==
984 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
985 		/* OK */
986 	}
987 	if (irb_is_error(irb)) {
988 		/* Command reject? */
989 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
990 		    (irb->ecw[0] & SNS0_CMD_REJECT))
991 			vcdev->err = -EOPNOTSUPP;
992 		else
993 			/* Map everything else to -EIO. */
994 			vcdev->err = -EIO;
995 	}
996 	if (vcdev->curr_io & activity) {
997 		switch (activity) {
998 		case VIRTIO_CCW_DOING_READ_FEAT:
999 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1000 		case VIRTIO_CCW_DOING_READ_CONFIG:
1001 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1002 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1003 		case VIRTIO_CCW_DOING_SET_VQ:
1004 		case VIRTIO_CCW_DOING_SET_IND:
1005 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1006 		case VIRTIO_CCW_DOING_RESET:
1007 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1008 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1009 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1010 			vcdev->curr_io &= ~activity;
1011 			wake_up(&vcdev->wait_q);
1012 			break;
1013 		default:
1014 			/* don't know what to do... */
1015 			dev_warn(&cdev->dev, "Suspicious activity '%08x'\n",
1016 				 activity);
1017 			WARN_ON(1);
1018 			break;
1019 		}
1020 	}
1021 	for_each_set_bit(i, &vcdev->indicators,
1022 			 sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1023 		/* The bit clear must happen before the vring kick. */
1024 		clear_bit(i, &vcdev->indicators);
1025 		barrier();
1026 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1027 		vring_interrupt(0, vq);
1028 	}
1029 	if (test_bit(0, &vcdev->indicators2)) {
1030 		virtio_config_changed(&vcdev->vdev);
1031 		clear_bit(0, &vcdev->indicators2);
1032 	}
1033 }
1034 
1035 /*
1036  * We usually want to autoonline all devices, but give the admin
1037  * a way to exempt devices from this.
1038  */
1039 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1040 		     (8*sizeof(long)))
1041 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1042 
1043 static char *no_auto = "";
1044 
1045 module_param(no_auto, charp, 0444);
1046 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1047 
1048 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1049 {
1050 	struct ccw_dev_id id;
1051 
1052 	ccw_device_get_id(cdev, &id);
1053 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1054 		return 0;
1055 	return 1;
1056 }
1057 
1058 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1059 {
1060 	struct ccw_device *cdev = data;
1061 	int ret;
1062 
1063 	ret = ccw_device_set_online(cdev);
1064 	if (ret)
1065 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1066 }
1067 
1068 static int virtio_ccw_probe(struct ccw_device *cdev)
1069 {
1070 	cdev->handler = virtio_ccw_int_handler;
1071 
1072 	if (virtio_ccw_check_autoonline(cdev))
1073 		async_schedule(virtio_ccw_auto_online, cdev);
1074 	return 0;
1075 }
1076 
1077 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1078 {
1079 	unsigned long flags;
1080 	struct virtio_ccw_device *vcdev;
1081 
1082 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1083 	vcdev = dev_get_drvdata(&cdev->dev);
1084 	if (!vcdev || vcdev->going_away) {
1085 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1086 		return NULL;
1087 	}
1088 	vcdev->going_away = true;
1089 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1090 	return vcdev;
1091 }
1092 
1093 static void virtio_ccw_remove(struct ccw_device *cdev)
1094 {
1095 	unsigned long flags;
1096 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1097 
1098 	if (vcdev && cdev->online) {
1099 		if (vcdev->device_lost)
1100 			virtio_break_device(&vcdev->vdev);
1101 		unregister_virtio_device(&vcdev->vdev);
1102 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1103 		dev_set_drvdata(&cdev->dev, NULL);
1104 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1105 	}
1106 	cdev->handler = NULL;
1107 }
1108 
1109 static int virtio_ccw_offline(struct ccw_device *cdev)
1110 {
1111 	unsigned long flags;
1112 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1113 
1114 	if (!vcdev)
1115 		return 0;
1116 	if (vcdev->device_lost)
1117 		virtio_break_device(&vcdev->vdev);
1118 	unregister_virtio_device(&vcdev->vdev);
1119 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1120 	dev_set_drvdata(&cdev->dev, NULL);
1121 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1122 	return 0;
1123 }
1124 
1125 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1126 {
1127 	struct virtio_rev_info *rev;
1128 	struct ccw1 *ccw;
1129 	int ret;
1130 
1131 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1132 	if (!ccw)
1133 		return -ENOMEM;
1134 	rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1135 	if (!rev) {
1136 		kfree(ccw);
1137 		return -ENOMEM;
1138 	}
1139 
1140 	/* Set transport revision */
1141 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1142 	ccw->flags = 0;
1143 	ccw->count = sizeof(*rev);
1144 	ccw->cda = (__u32)(unsigned long)rev;
1145 
1146 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1147 	do {
1148 		rev->revision = vcdev->revision;
1149 		/* none of our supported revisions carry payload */
1150 		rev->length = 0;
1151 		ret = ccw_io_helper(vcdev, ccw,
1152 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1153 		if (ret == -EOPNOTSUPP) {
1154 			if (vcdev->revision == 0)
1155 				/*
1156 				 * The host device does not support setting
1157 				 * the revision: let's operate it in legacy
1158 				 * mode.
1159 				 */
1160 				ret = 0;
1161 			else
1162 				vcdev->revision--;
1163 		}
1164 	} while (ret == -EOPNOTSUPP);
1165 
1166 	kfree(ccw);
1167 	kfree(rev);
1168 	return ret;
1169 }
1170 
1171 static int virtio_ccw_online(struct ccw_device *cdev)
1172 {
1173 	int ret;
1174 	struct virtio_ccw_device *vcdev;
1175 	unsigned long flags;
1176 
1177 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1178 	if (!vcdev) {
1179 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1180 		ret = -ENOMEM;
1181 		goto out_free;
1182 	}
1183 	vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1184 				   GFP_DMA | GFP_KERNEL);
1185 	if (!vcdev->config_block) {
1186 		ret = -ENOMEM;
1187 		goto out_free;
1188 	}
1189 	vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1190 	if (!vcdev->status) {
1191 		ret = -ENOMEM;
1192 		goto out_free;
1193 	}
1194 
1195 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1196 
1197 	vcdev->vdev.dev.parent = &cdev->dev;
1198 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1199 	vcdev->vdev.config = &virtio_ccw_config_ops;
1200 	vcdev->cdev = cdev;
1201 	init_waitqueue_head(&vcdev->wait_q);
1202 	INIT_LIST_HEAD(&vcdev->virtqueues);
1203 	spin_lock_init(&vcdev->lock);
1204 
1205 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1206 	dev_set_drvdata(&cdev->dev, vcdev);
1207 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1208 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1209 	vcdev->vdev.id.device = cdev->id.cu_model;
1210 
1211 	ret = virtio_ccw_set_transport_rev(vcdev);
1212 	if (ret)
1213 		goto out_free;
1214 
1215 	ret = register_virtio_device(&vcdev->vdev);
1216 	if (ret) {
1217 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1218 			 ret);
1219 		goto out_put;
1220 	}
1221 	return 0;
1222 out_put:
1223 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1224 	dev_set_drvdata(&cdev->dev, NULL);
1225 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1226 	put_device(&vcdev->vdev.dev);
1227 	return ret;
1228 out_free:
1229 	if (vcdev) {
1230 		kfree(vcdev->status);
1231 		kfree(vcdev->config_block);
1232 	}
1233 	kfree(vcdev);
1234 	return ret;
1235 }
1236 
1237 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1238 {
1239 	int rc;
1240 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1241 
1242 	/*
1243 	 * Make sure vcdev is set
1244 	 * i.e. set_offline/remove callback not already running
1245 	 */
1246 	if (!vcdev)
1247 		return NOTIFY_DONE;
1248 
1249 	switch (event) {
1250 	case CIO_GONE:
1251 		vcdev->device_lost = true;
1252 		rc = NOTIFY_DONE;
1253 		break;
1254 	default:
1255 		rc = NOTIFY_DONE;
1256 		break;
1257 	}
1258 	return rc;
1259 }
1260 
1261 static struct ccw_device_id virtio_ids[] = {
1262 	{ CCW_DEVICE(0x3832, 0) },
1263 	{},
1264 };
1265 MODULE_DEVICE_TABLE(ccw, virtio_ids);
1266 
1267 static struct ccw_driver virtio_ccw_driver = {
1268 	.driver = {
1269 		.owner = THIS_MODULE,
1270 		.name = "virtio_ccw",
1271 	},
1272 	.ids = virtio_ids,
1273 	.probe = virtio_ccw_probe,
1274 	.remove = virtio_ccw_remove,
1275 	.set_offline = virtio_ccw_offline,
1276 	.set_online = virtio_ccw_online,
1277 	.notify = virtio_ccw_cio_notify,
1278 	.int_class = IRQIO_VIR,
1279 };
1280 
1281 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1282 			   int max_digit, int max_val)
1283 {
1284 	int diff;
1285 
1286 	diff = 0;
1287 	*val = 0;
1288 
1289 	while (diff <= max_digit) {
1290 		int value = hex_to_bin(**cp);
1291 
1292 		if (value < 0)
1293 			break;
1294 		*val = *val * 16 + value;
1295 		(*cp)++;
1296 		diff++;
1297 	}
1298 
1299 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1300 		return 1;
1301 
1302 	return 0;
1303 }
1304 
1305 static int __init parse_busid(char *str, unsigned int *cssid,
1306 			      unsigned int *ssid, unsigned int *devno)
1307 {
1308 	char *str_work;
1309 	int rc, ret;
1310 
1311 	rc = 1;
1312 
1313 	if (*str == '\0')
1314 		goto out;
1315 
1316 	str_work = str;
1317 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1318 	if (ret || (str_work[0] != '.'))
1319 		goto out;
1320 	str_work++;
1321 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1322 	if (ret || (str_work[0] != '.'))
1323 		goto out;
1324 	str_work++;
1325 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1326 	if (ret || (str_work[0] != '\0'))
1327 		goto out;
1328 
1329 	rc = 0;
1330 out:
1331 	return rc;
1332 }
1333 
1334 static void __init no_auto_parse(void)
1335 {
1336 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1337 	char *parm, *str;
1338 	int rc;
1339 
1340 	str = no_auto;
1341 	while ((parm = strsep(&str, ","))) {
1342 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1343 				 &from_ssid, &from);
1344 		if (rc)
1345 			continue;
1346 		if (parm != NULL) {
1347 			rc = parse_busid(parm, &to_cssid,
1348 					 &to_ssid, &to);
1349 			if ((from_ssid > to_ssid) ||
1350 			    ((from_ssid == to_ssid) && (from > to)))
1351 				rc = -EINVAL;
1352 		} else {
1353 			to_cssid = from_cssid;
1354 			to_ssid = from_ssid;
1355 			to = from;
1356 		}
1357 		if (rc)
1358 			continue;
1359 		while ((from_ssid < to_ssid) ||
1360 		       ((from_ssid == to_ssid) && (from <= to))) {
1361 			set_bit(from, devs_no_auto[from_ssid]);
1362 			from++;
1363 			if (from > __MAX_SUBCHANNEL) {
1364 				from_ssid++;
1365 				from = 0;
1366 			}
1367 		}
1368 	}
1369 }
1370 
1371 static int __init virtio_ccw_init(void)
1372 {
1373 	/* parse no_auto string before we do anything further */
1374 	no_auto_parse();
1375 	return ccw_driver_register(&virtio_ccw_driver);
1376 }
1377 module_init(virtio_ccw_init);
1378 
1379 static void __exit virtio_ccw_exit(void)
1380 {
1381 	int i;
1382 
1383 	ccw_driver_unregister(&virtio_ccw_driver);
1384 	for (i = 0; i < MAX_AIRQ_AREAS; i++)
1385 		destroy_airq_info(airq_areas[i]);
1386 }
1387 module_exit(virtio_ccw_exit);
1388