xref: /linux/drivers/s390/virtio/virtio_ccw.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 	int ret;
404 
405 	vcdev->config_block->index = index;
406 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
407 	ccw->flags = 0;
408 	ccw->count = sizeof(struct vq_config_block);
409 	ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
410 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
411 	if (ret)
412 		return ret;
413 	return vcdev->config_block->num;
414 }
415 
416 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
417 {
418 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
419 	struct virtio_ccw_vq_info *info = vq->priv;
420 	unsigned long flags;
421 	unsigned long size;
422 	int ret;
423 	unsigned int index = vq->index;
424 
425 	/* Remove from our list. */
426 	spin_lock_irqsave(&vcdev->lock, flags);
427 	list_del(&info->node);
428 	spin_unlock_irqrestore(&vcdev->lock, flags);
429 
430 	/* Release from host. */
431 	if (vcdev->revision == 0) {
432 		info->info_block->l.queue = 0;
433 		info->info_block->l.align = 0;
434 		info->info_block->l.index = index;
435 		info->info_block->l.num = 0;
436 		ccw->count = sizeof(info->info_block->l);
437 	} else {
438 		info->info_block->s.desc = 0;
439 		info->info_block->s.index = index;
440 		info->info_block->s.num = 0;
441 		info->info_block->s.avail = 0;
442 		info->info_block->s.used = 0;
443 		ccw->count = sizeof(info->info_block->s);
444 	}
445 	ccw->cmd_code = CCW_CMD_SET_VQ;
446 	ccw->flags = 0;
447 	ccw->cda = (__u32)(unsigned long)(info->info_block);
448 	ret = ccw_io_helper(vcdev, ccw,
449 			    VIRTIO_CCW_DOING_SET_VQ | index);
450 	/*
451 	 * -ENODEV isn't considered an error: The device is gone anyway.
452 	 * This may happen on device detach.
453 	 */
454 	if (ret && (ret != -ENODEV))
455 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d",
456 			 ret, index);
457 
458 	vring_del_virtqueue(vq);
459 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
460 	free_pages_exact(info->queue, size);
461 	kfree(info->info_block);
462 	kfree(info);
463 }
464 
465 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
466 {
467 	struct virtqueue *vq, *n;
468 	struct ccw1 *ccw;
469 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
470 
471 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
472 	if (!ccw)
473 		return;
474 
475 	virtio_ccw_drop_indicator(vcdev, ccw);
476 
477 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
478 		virtio_ccw_del_vq(vq, ccw);
479 
480 	kfree(ccw);
481 }
482 
483 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
484 					     int i, vq_callback_t *callback,
485 					     const char *name,
486 					     struct ccw1 *ccw)
487 {
488 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
489 	int err;
490 	struct virtqueue *vq = NULL;
491 	struct virtio_ccw_vq_info *info;
492 	unsigned long size = 0; /* silence the compiler */
493 	unsigned long flags;
494 
495 	/* Allocate queue. */
496 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
497 	if (!info) {
498 		dev_warn(&vcdev->cdev->dev, "no info\n");
499 		err = -ENOMEM;
500 		goto out_err;
501 	}
502 	info->info_block = kzalloc(sizeof(*info->info_block),
503 				   GFP_DMA | GFP_KERNEL);
504 	if (!info->info_block) {
505 		dev_warn(&vcdev->cdev->dev, "no info block\n");
506 		err = -ENOMEM;
507 		goto out_err;
508 	}
509 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
510 	if (info->num < 0) {
511 		err = info->num;
512 		goto out_err;
513 	}
514 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
515 	info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
516 	if (info->queue == NULL) {
517 		dev_warn(&vcdev->cdev->dev, "no queue\n");
518 		err = -ENOMEM;
519 		goto out_err;
520 	}
521 
522 	vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
523 				 true, info->queue, virtio_ccw_kvm_notify,
524 				 callback, name);
525 	if (!vq) {
526 		/* For now, we fail if we can't get the requested size. */
527 		dev_warn(&vcdev->cdev->dev, "no vq\n");
528 		err = -ENOMEM;
529 		goto out_err;
530 	}
531 
532 	/* Register it with the host. */
533 	if (vcdev->revision == 0) {
534 		info->info_block->l.queue = (__u64)info->queue;
535 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
536 		info->info_block->l.index = i;
537 		info->info_block->l.num = info->num;
538 		ccw->count = sizeof(info->info_block->l);
539 	} else {
540 		info->info_block->s.desc = (__u64)info->queue;
541 		info->info_block->s.index = i;
542 		info->info_block->s.num = info->num;
543 		info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
544 		info->info_block->s.used = (__u64)virtqueue_get_used(vq);
545 		ccw->count = sizeof(info->info_block->s);
546 	}
547 	ccw->cmd_code = CCW_CMD_SET_VQ;
548 	ccw->flags = 0;
549 	ccw->cda = (__u32)(unsigned long)(info->info_block);
550 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
551 	if (err) {
552 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
553 		goto out_err;
554 	}
555 
556 	info->vq = vq;
557 	vq->priv = info;
558 
559 	/* Save it to our list. */
560 	spin_lock_irqsave(&vcdev->lock, flags);
561 	list_add(&info->node, &vcdev->virtqueues);
562 	spin_unlock_irqrestore(&vcdev->lock, flags);
563 
564 	return vq;
565 
566 out_err:
567 	if (vq)
568 		vring_del_virtqueue(vq);
569 	if (info) {
570 		if (info->queue)
571 			free_pages_exact(info->queue, size);
572 		kfree(info->info_block);
573 	}
574 	kfree(info);
575 	return ERR_PTR(err);
576 }
577 
578 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
579 					   struct virtqueue *vqs[], int nvqs,
580 					   struct ccw1 *ccw)
581 {
582 	int ret;
583 	struct virtio_thinint_area *thinint_area = NULL;
584 	struct airq_info *info;
585 
586 	thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
587 	if (!thinint_area) {
588 		ret = -ENOMEM;
589 		goto out;
590 	}
591 	/* Try to get an indicator. */
592 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
593 						     &thinint_area->bit_nr,
594 						     &vcdev->airq_info);
595 	if (!thinint_area->indicator) {
596 		ret = -ENOSPC;
597 		goto out;
598 	}
599 	info = vcdev->airq_info;
600 	thinint_area->summary_indicator =
601 		(unsigned long) &info->summary_indicator;
602 	thinint_area->isc = VIRTIO_AIRQ_ISC;
603 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
604 	ccw->flags = CCW_FLAG_SLI;
605 	ccw->count = sizeof(*thinint_area);
606 	ccw->cda = (__u32)(unsigned long)thinint_area;
607 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
608 	if (ret) {
609 		if (ret == -EOPNOTSUPP) {
610 			/*
611 			 * The host does not support adapter interrupts
612 			 * for virtio-ccw, stop trying.
613 			 */
614 			virtio_ccw_use_airq = 0;
615 			pr_info("Adapter interrupts unsupported on host\n");
616 		} else
617 			dev_warn(&vcdev->cdev->dev,
618 				 "enabling adapter interrupts = %d\n", ret);
619 		virtio_ccw_drop_indicators(vcdev);
620 	}
621 out:
622 	kfree(thinint_area);
623 	return ret;
624 }
625 
626 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
627 			       struct virtqueue *vqs[],
628 			       vq_callback_t *callbacks[],
629 			       const char *names[])
630 {
631 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
632 	unsigned long *indicatorp = NULL;
633 	int ret, i;
634 	struct ccw1 *ccw;
635 
636 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
637 	if (!ccw)
638 		return -ENOMEM;
639 
640 	for (i = 0; i < nvqs; ++i) {
641 		vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
642 					     ccw);
643 		if (IS_ERR(vqs[i])) {
644 			ret = PTR_ERR(vqs[i]);
645 			vqs[i] = NULL;
646 			goto out;
647 		}
648 	}
649 	ret = -ENOMEM;
650 	/* We need a data area under 2G to communicate. */
651 	indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
652 	if (!indicatorp)
653 		goto out;
654 	*indicatorp = (unsigned long) &vcdev->indicators;
655 	if (vcdev->is_thinint) {
656 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
657 		if (ret)
658 			/* no error, just fall back to legacy interrupts */
659 			vcdev->is_thinint = 0;
660 	}
661 	if (!vcdev->is_thinint) {
662 		/* Register queue indicators with host. */
663 		vcdev->indicators = 0;
664 		ccw->cmd_code = CCW_CMD_SET_IND;
665 		ccw->flags = 0;
666 		ccw->count = sizeof(vcdev->indicators);
667 		ccw->cda = (__u32)(unsigned long) indicatorp;
668 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
669 		if (ret)
670 			goto out;
671 	}
672 	/* Register indicators2 with host for config changes */
673 	*indicatorp = (unsigned long) &vcdev->indicators2;
674 	vcdev->indicators2 = 0;
675 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
676 	ccw->flags = 0;
677 	ccw->count = sizeof(vcdev->indicators2);
678 	ccw->cda = (__u32)(unsigned long) indicatorp;
679 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
680 	if (ret)
681 		goto out;
682 
683 	kfree(indicatorp);
684 	kfree(ccw);
685 	return 0;
686 out:
687 	kfree(indicatorp);
688 	kfree(ccw);
689 	virtio_ccw_del_vqs(vdev);
690 	return ret;
691 }
692 
693 static void virtio_ccw_reset(struct virtio_device *vdev)
694 {
695 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
696 	struct ccw1 *ccw;
697 
698 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
699 	if (!ccw)
700 		return;
701 
702 	/* Zero status bits. */
703 	*vcdev->status = 0;
704 
705 	/* Send a reset ccw on device. */
706 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
707 	ccw->flags = 0;
708 	ccw->count = 0;
709 	ccw->cda = 0;
710 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
711 	kfree(ccw);
712 }
713 
714 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
715 {
716 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
717 	struct virtio_feature_desc *features;
718 	int ret;
719 	u64 rc;
720 	struct ccw1 *ccw;
721 
722 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
723 	if (!ccw)
724 		return 0;
725 
726 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
727 	if (!features) {
728 		rc = 0;
729 		goto out_free;
730 	}
731 	/* Read the feature bits from the host. */
732 	features->index = 0;
733 	ccw->cmd_code = CCW_CMD_READ_FEAT;
734 	ccw->flags = 0;
735 	ccw->count = sizeof(*features);
736 	ccw->cda = (__u32)(unsigned long)features;
737 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
738 	if (ret) {
739 		rc = 0;
740 		goto out_free;
741 	}
742 
743 	rc = le32_to_cpu(features->features);
744 
745 	if (vcdev->revision == 0)
746 		goto out_free;
747 
748 	/* Read second half of the feature bits from the host. */
749 	features->index = 1;
750 	ccw->cmd_code = CCW_CMD_READ_FEAT;
751 	ccw->flags = 0;
752 	ccw->count = sizeof(*features);
753 	ccw->cda = (__u32)(unsigned long)features;
754 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
755 	if (ret == 0)
756 		rc |= (u64)le32_to_cpu(features->features) << 32;
757 
758 out_free:
759 	kfree(features);
760 	kfree(ccw);
761 	return rc;
762 }
763 
764 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
765 {
766 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
767 	struct virtio_feature_desc *features;
768 	struct ccw1 *ccw;
769 	int ret;
770 
771 	if (vcdev->revision >= 1 &&
772 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
773 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
774 			"but does not have VIRTIO_F_VERSION_1\n");
775 		return -EINVAL;
776 	}
777 
778 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
779 	if (!ccw)
780 		return -ENOMEM;
781 
782 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
783 	if (!features) {
784 		ret = -ENOMEM;
785 		goto out_free;
786 	}
787 	/* Give virtio_ring a chance to accept features. */
788 	vring_transport_features(vdev);
789 
790 	features->index = 0;
791 	features->features = cpu_to_le32((u32)vdev->features);
792 	/* Write the first half of the feature bits to the host. */
793 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
794 	ccw->flags = 0;
795 	ccw->count = sizeof(*features);
796 	ccw->cda = (__u32)(unsigned long)features;
797 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
798 	if (ret)
799 		goto out_free;
800 
801 	if (vcdev->revision == 0)
802 		goto out_free;
803 
804 	features->index = 1;
805 	features->features = cpu_to_le32(vdev->features >> 32);
806 	/* Write the second half of the feature bits to the host. */
807 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
808 	ccw->flags = 0;
809 	ccw->count = sizeof(*features);
810 	ccw->cda = (__u32)(unsigned long)features;
811 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
812 
813 out_free:
814 	kfree(features);
815 	kfree(ccw);
816 
817 	return ret;
818 }
819 
820 static void virtio_ccw_get_config(struct virtio_device *vdev,
821 				  unsigned int offset, void *buf, unsigned len)
822 {
823 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
824 	int ret;
825 	struct ccw1 *ccw;
826 	void *config_area;
827 
828 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
829 	if (!ccw)
830 		return;
831 
832 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
833 	if (!config_area)
834 		goto out_free;
835 
836 	/* Read the config area from the host. */
837 	ccw->cmd_code = CCW_CMD_READ_CONF;
838 	ccw->flags = 0;
839 	ccw->count = offset + len;
840 	ccw->cda = (__u32)(unsigned long)config_area;
841 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
842 	if (ret)
843 		goto out_free;
844 
845 	memcpy(vcdev->config, config_area, offset + len);
846 	if (buf)
847 		memcpy(buf, &vcdev->config[offset], len);
848 	if (vcdev->config_ready < offset + len)
849 		vcdev->config_ready = offset + len;
850 
851 out_free:
852 	kfree(config_area);
853 	kfree(ccw);
854 }
855 
856 static void virtio_ccw_set_config(struct virtio_device *vdev,
857 				  unsigned int offset, const void *buf,
858 				  unsigned len)
859 {
860 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
861 	struct ccw1 *ccw;
862 	void *config_area;
863 
864 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
865 	if (!ccw)
866 		return;
867 
868 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
869 	if (!config_area)
870 		goto out_free;
871 
872 	/* Make sure we don't overwrite fields. */
873 	if (vcdev->config_ready < offset)
874 		virtio_ccw_get_config(vdev, 0, NULL, offset);
875 	memcpy(&vcdev->config[offset], buf, len);
876 	/* Write the config area to the host. */
877 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
878 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
879 	ccw->flags = 0;
880 	ccw->count = offset + len;
881 	ccw->cda = (__u32)(unsigned long)config_area;
882 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
883 
884 out_free:
885 	kfree(config_area);
886 	kfree(ccw);
887 }
888 
889 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
890 {
891 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
892 
893 	return *vcdev->status;
894 }
895 
896 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
897 {
898 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
899 	u8 old_status = *vcdev->status;
900 	struct ccw1 *ccw;
901 	int ret;
902 
903 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
904 	if (!ccw)
905 		return;
906 
907 	/* Write the status to the host. */
908 	*vcdev->status = status;
909 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
910 	ccw->flags = 0;
911 	ccw->count = sizeof(status);
912 	ccw->cda = (__u32)(unsigned long)vcdev->status;
913 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
914 	/* Write failed? We assume status is unchanged. */
915 	if (ret)
916 		*vcdev->status = old_status;
917 	kfree(ccw);
918 }
919 
920 static struct virtio_config_ops virtio_ccw_config_ops = {
921 	.get_features = virtio_ccw_get_features,
922 	.finalize_features = virtio_ccw_finalize_features,
923 	.get = virtio_ccw_get_config,
924 	.set = virtio_ccw_set_config,
925 	.get_status = virtio_ccw_get_status,
926 	.set_status = virtio_ccw_set_status,
927 	.reset = virtio_ccw_reset,
928 	.find_vqs = virtio_ccw_find_vqs,
929 	.del_vqs = virtio_ccw_del_vqs,
930 };
931 
932 
933 /*
934  * ccw bus driver related functions
935  */
936 
937 static void virtio_ccw_release_dev(struct device *_d)
938 {
939 	struct virtio_device *dev = container_of(_d, struct virtio_device,
940 						 dev);
941 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
942 
943 	kfree(vcdev->status);
944 	kfree(vcdev->config_block);
945 	kfree(vcdev);
946 }
947 
948 static int irb_is_error(struct irb *irb)
949 {
950 	if (scsw_cstat(&irb->scsw) != 0)
951 		return 1;
952 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
953 		return 1;
954 	if (scsw_cc(&irb->scsw) != 0)
955 		return 1;
956 	return 0;
957 }
958 
959 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
960 					      int index)
961 {
962 	struct virtio_ccw_vq_info *info;
963 	unsigned long flags;
964 	struct virtqueue *vq;
965 
966 	vq = NULL;
967 	spin_lock_irqsave(&vcdev->lock, flags);
968 	list_for_each_entry(info, &vcdev->virtqueues, node) {
969 		if (info->vq->index == index) {
970 			vq = info->vq;
971 			break;
972 		}
973 	}
974 	spin_unlock_irqrestore(&vcdev->lock, flags);
975 	return vq;
976 }
977 
978 static void virtio_ccw_int_handler(struct ccw_device *cdev,
979 				   unsigned long intparm,
980 				   struct irb *irb)
981 {
982 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
983 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
984 	int i;
985 	struct virtqueue *vq;
986 
987 	if (!vcdev)
988 		return;
989 	/* Check if it's a notification from the host. */
990 	if ((intparm == 0) &&
991 	    (scsw_stctl(&irb->scsw) ==
992 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
993 		/* OK */
994 	}
995 	if (irb_is_error(irb)) {
996 		/* Command reject? */
997 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
998 		    (irb->ecw[0] & SNS0_CMD_REJECT))
999 			vcdev->err = -EOPNOTSUPP;
1000 		else
1001 			/* Map everything else to -EIO. */
1002 			vcdev->err = -EIO;
1003 	}
1004 	if (vcdev->curr_io & activity) {
1005 		switch (activity) {
1006 		case VIRTIO_CCW_DOING_READ_FEAT:
1007 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1008 		case VIRTIO_CCW_DOING_READ_CONFIG:
1009 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1010 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1011 		case VIRTIO_CCW_DOING_SET_VQ:
1012 		case VIRTIO_CCW_DOING_SET_IND:
1013 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1014 		case VIRTIO_CCW_DOING_RESET:
1015 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1016 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1017 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1018 			vcdev->curr_io &= ~activity;
1019 			wake_up(&vcdev->wait_q);
1020 			break;
1021 		default:
1022 			/* don't know what to do... */
1023 			dev_warn(&cdev->dev, "Suspicious activity '%08x'\n",
1024 				 activity);
1025 			WARN_ON(1);
1026 			break;
1027 		}
1028 	}
1029 	for_each_set_bit(i, &vcdev->indicators,
1030 			 sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1031 		/* The bit clear must happen before the vring kick. */
1032 		clear_bit(i, &vcdev->indicators);
1033 		barrier();
1034 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1035 		vring_interrupt(0, vq);
1036 	}
1037 	if (test_bit(0, &vcdev->indicators2)) {
1038 		virtio_config_changed(&vcdev->vdev);
1039 		clear_bit(0, &vcdev->indicators2);
1040 	}
1041 }
1042 
1043 /*
1044  * We usually want to autoonline all devices, but give the admin
1045  * a way to exempt devices from this.
1046  */
1047 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1048 		     (8*sizeof(long)))
1049 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1050 
1051 static char *no_auto = "";
1052 
1053 module_param(no_auto, charp, 0444);
1054 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1055 
1056 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1057 {
1058 	struct ccw_dev_id id;
1059 
1060 	ccw_device_get_id(cdev, &id);
1061 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1062 		return 0;
1063 	return 1;
1064 }
1065 
1066 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1067 {
1068 	struct ccw_device *cdev = data;
1069 	int ret;
1070 
1071 	ret = ccw_device_set_online(cdev);
1072 	if (ret)
1073 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1074 }
1075 
1076 static int virtio_ccw_probe(struct ccw_device *cdev)
1077 {
1078 	cdev->handler = virtio_ccw_int_handler;
1079 
1080 	if (virtio_ccw_check_autoonline(cdev))
1081 		async_schedule(virtio_ccw_auto_online, cdev);
1082 	return 0;
1083 }
1084 
1085 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1086 {
1087 	unsigned long flags;
1088 	struct virtio_ccw_device *vcdev;
1089 
1090 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1091 	vcdev = dev_get_drvdata(&cdev->dev);
1092 	if (!vcdev || vcdev->going_away) {
1093 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1094 		return NULL;
1095 	}
1096 	vcdev->going_away = true;
1097 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1098 	return vcdev;
1099 }
1100 
1101 static void virtio_ccw_remove(struct ccw_device *cdev)
1102 {
1103 	unsigned long flags;
1104 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1105 
1106 	if (vcdev && cdev->online) {
1107 		if (vcdev->device_lost)
1108 			virtio_break_device(&vcdev->vdev);
1109 		unregister_virtio_device(&vcdev->vdev);
1110 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1111 		dev_set_drvdata(&cdev->dev, NULL);
1112 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1113 	}
1114 	cdev->handler = NULL;
1115 }
1116 
1117 static int virtio_ccw_offline(struct ccw_device *cdev)
1118 {
1119 	unsigned long flags;
1120 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1121 
1122 	if (!vcdev)
1123 		return 0;
1124 	if (vcdev->device_lost)
1125 		virtio_break_device(&vcdev->vdev);
1126 	unregister_virtio_device(&vcdev->vdev);
1127 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1128 	dev_set_drvdata(&cdev->dev, NULL);
1129 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1130 	return 0;
1131 }
1132 
1133 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1134 {
1135 	struct virtio_rev_info *rev;
1136 	struct ccw1 *ccw;
1137 	int ret;
1138 
1139 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1140 	if (!ccw)
1141 		return -ENOMEM;
1142 	rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1143 	if (!rev) {
1144 		kfree(ccw);
1145 		return -ENOMEM;
1146 	}
1147 
1148 	/* Set transport revision */
1149 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1150 	ccw->flags = 0;
1151 	ccw->count = sizeof(*rev);
1152 	ccw->cda = (__u32)(unsigned long)rev;
1153 
1154 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1155 	do {
1156 		rev->revision = vcdev->revision;
1157 		/* none of our supported revisions carry payload */
1158 		rev->length = 0;
1159 		ret = ccw_io_helper(vcdev, ccw,
1160 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1161 		if (ret == -EOPNOTSUPP) {
1162 			if (vcdev->revision == 0)
1163 				/*
1164 				 * The host device does not support setting
1165 				 * the revision: let's operate it in legacy
1166 				 * mode.
1167 				 */
1168 				ret = 0;
1169 			else
1170 				vcdev->revision--;
1171 		}
1172 	} while (ret == -EOPNOTSUPP);
1173 
1174 	kfree(ccw);
1175 	kfree(rev);
1176 	return ret;
1177 }
1178 
1179 static int virtio_ccw_online(struct ccw_device *cdev)
1180 {
1181 	int ret;
1182 	struct virtio_ccw_device *vcdev;
1183 	unsigned long flags;
1184 
1185 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1186 	if (!vcdev) {
1187 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1188 		ret = -ENOMEM;
1189 		goto out_free;
1190 	}
1191 	vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1192 				   GFP_DMA | GFP_KERNEL);
1193 	if (!vcdev->config_block) {
1194 		ret = -ENOMEM;
1195 		goto out_free;
1196 	}
1197 	vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1198 	if (!vcdev->status) {
1199 		ret = -ENOMEM;
1200 		goto out_free;
1201 	}
1202 
1203 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1204 
1205 	vcdev->vdev.dev.parent = &cdev->dev;
1206 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1207 	vcdev->vdev.config = &virtio_ccw_config_ops;
1208 	vcdev->cdev = cdev;
1209 	init_waitqueue_head(&vcdev->wait_q);
1210 	INIT_LIST_HEAD(&vcdev->virtqueues);
1211 	spin_lock_init(&vcdev->lock);
1212 
1213 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1214 	dev_set_drvdata(&cdev->dev, vcdev);
1215 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1216 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1217 	vcdev->vdev.id.device = cdev->id.cu_model;
1218 
1219 	ret = virtio_ccw_set_transport_rev(vcdev);
1220 	if (ret)
1221 		goto out_free;
1222 
1223 	ret = register_virtio_device(&vcdev->vdev);
1224 	if (ret) {
1225 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1226 			 ret);
1227 		goto out_put;
1228 	}
1229 	return 0;
1230 out_put:
1231 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1232 	dev_set_drvdata(&cdev->dev, NULL);
1233 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1234 	put_device(&vcdev->vdev.dev);
1235 	return ret;
1236 out_free:
1237 	if (vcdev) {
1238 		kfree(vcdev->status);
1239 		kfree(vcdev->config_block);
1240 	}
1241 	kfree(vcdev);
1242 	return ret;
1243 }
1244 
1245 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1246 {
1247 	int rc;
1248 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1249 
1250 	/*
1251 	 * Make sure vcdev is set
1252 	 * i.e. set_offline/remove callback not already running
1253 	 */
1254 	if (!vcdev)
1255 		return NOTIFY_DONE;
1256 
1257 	switch (event) {
1258 	case CIO_GONE:
1259 		vcdev->device_lost = true;
1260 		rc = NOTIFY_DONE;
1261 		break;
1262 	default:
1263 		rc = NOTIFY_DONE;
1264 		break;
1265 	}
1266 	return rc;
1267 }
1268 
1269 static struct ccw_device_id virtio_ids[] = {
1270 	{ CCW_DEVICE(0x3832, 0) },
1271 	{},
1272 };
1273 MODULE_DEVICE_TABLE(ccw, virtio_ids);
1274 
1275 static struct ccw_driver virtio_ccw_driver = {
1276 	.driver = {
1277 		.owner = THIS_MODULE,
1278 		.name = "virtio_ccw",
1279 	},
1280 	.ids = virtio_ids,
1281 	.probe = virtio_ccw_probe,
1282 	.remove = virtio_ccw_remove,
1283 	.set_offline = virtio_ccw_offline,
1284 	.set_online = virtio_ccw_online,
1285 	.notify = virtio_ccw_cio_notify,
1286 	.int_class = IRQIO_VIR,
1287 };
1288 
1289 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1290 			   int max_digit, int max_val)
1291 {
1292 	int diff;
1293 
1294 	diff = 0;
1295 	*val = 0;
1296 
1297 	while (diff <= max_digit) {
1298 		int value = hex_to_bin(**cp);
1299 
1300 		if (value < 0)
1301 			break;
1302 		*val = *val * 16 + value;
1303 		(*cp)++;
1304 		diff++;
1305 	}
1306 
1307 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1308 		return 1;
1309 
1310 	return 0;
1311 }
1312 
1313 static int __init parse_busid(char *str, unsigned int *cssid,
1314 			      unsigned int *ssid, unsigned int *devno)
1315 {
1316 	char *str_work;
1317 	int rc, ret;
1318 
1319 	rc = 1;
1320 
1321 	if (*str == '\0')
1322 		goto out;
1323 
1324 	str_work = str;
1325 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1326 	if (ret || (str_work[0] != '.'))
1327 		goto out;
1328 	str_work++;
1329 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1330 	if (ret || (str_work[0] != '.'))
1331 		goto out;
1332 	str_work++;
1333 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1334 	if (ret || (str_work[0] != '\0'))
1335 		goto out;
1336 
1337 	rc = 0;
1338 out:
1339 	return rc;
1340 }
1341 
1342 static void __init no_auto_parse(void)
1343 {
1344 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1345 	char *parm, *str;
1346 	int rc;
1347 
1348 	str = no_auto;
1349 	while ((parm = strsep(&str, ","))) {
1350 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1351 				 &from_ssid, &from);
1352 		if (rc)
1353 			continue;
1354 		if (parm != NULL) {
1355 			rc = parse_busid(parm, &to_cssid,
1356 					 &to_ssid, &to);
1357 			if ((from_ssid > to_ssid) ||
1358 			    ((from_ssid == to_ssid) && (from > to)))
1359 				rc = -EINVAL;
1360 		} else {
1361 			to_cssid = from_cssid;
1362 			to_ssid = from_ssid;
1363 			to = from;
1364 		}
1365 		if (rc)
1366 			continue;
1367 		while ((from_ssid < to_ssid) ||
1368 		       ((from_ssid == to_ssid) && (from <= to))) {
1369 			set_bit(from, devs_no_auto[from_ssid]);
1370 			from++;
1371 			if (from > __MAX_SUBCHANNEL) {
1372 				from_ssid++;
1373 				from = 0;
1374 			}
1375 		}
1376 	}
1377 }
1378 
1379 static int __init virtio_ccw_init(void)
1380 {
1381 	/* parse no_auto string before we do anything further */
1382 	no_auto_parse();
1383 	return ccw_driver_register(&virtio_ccw_driver);
1384 }
1385 module_init(virtio_ccw_init);
1386 
1387 static void __exit virtio_ccw_exit(void)
1388 {
1389 	int i;
1390 
1391 	ccw_driver_unregister(&virtio_ccw_driver);
1392 	for (i = 0; i < MAX_AIRQ_AREAS; i++)
1393 		destroy_airq_info(airq_areas[i]);
1394 }
1395 module_exit(virtio_ccw_exit);
1396