xref: /linux/drivers/s390/virtio/virtio_ccw.c (revision 32786fdc9506aeba98278c1844d4bfb766863832)
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/moduleparam.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 unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
239 					u64 *first, void **airq_info)
240 {
241 	int i, j;
242 	struct airq_info *info;
243 	unsigned long indicator_addr = 0;
244 	unsigned long bit, flags;
245 
246 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
247 		if (!airq_areas[i])
248 			airq_areas[i] = new_airq_info();
249 		info = airq_areas[i];
250 		if (!info)
251 			return 0;
252 		write_lock_irqsave(&info->lock, flags);
253 		bit = airq_iv_alloc(info->aiv, nvqs);
254 		if (bit == -1UL) {
255 			/* Not enough vacancies. */
256 			write_unlock_irqrestore(&info->lock, flags);
257 			continue;
258 		}
259 		*first = bit;
260 		*airq_info = info;
261 		indicator_addr = (unsigned long)info->aiv->vector;
262 		for (j = 0; j < nvqs; j++) {
263 			airq_iv_set_ptr(info->aiv, bit + j,
264 					(unsigned long)vqs[j]);
265 		}
266 		write_unlock_irqrestore(&info->lock, flags);
267 	}
268 	return indicator_addr;
269 }
270 
271 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
272 {
273 	struct virtio_ccw_vq_info *info;
274 
275 	list_for_each_entry(info, &vcdev->virtqueues, node)
276 		drop_airq_indicator(info->vq, vcdev->airq_info);
277 }
278 
279 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
280 {
281 	unsigned long flags;
282 	__u32 ret;
283 
284 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
285 	if (vcdev->err)
286 		ret = 0;
287 	else
288 		ret = vcdev->curr_io & flag;
289 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
290 	return ret;
291 }
292 
293 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
294 			 struct ccw1 *ccw, __u32 intparm)
295 {
296 	int ret;
297 	unsigned long flags;
298 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
299 
300 	do {
301 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
302 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
303 		if (!ret) {
304 			if (!vcdev->curr_io)
305 				vcdev->err = 0;
306 			vcdev->curr_io |= flag;
307 		}
308 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
309 		cpu_relax();
310 	} while (ret == -EBUSY);
311 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
312 	return ret ? ret : vcdev->err;
313 }
314 
315 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
316 				      struct ccw1 *ccw)
317 {
318 	int ret;
319 	unsigned long *indicatorp = NULL;
320 	struct virtio_thinint_area *thinint_area = NULL;
321 	struct airq_info *airq_info = vcdev->airq_info;
322 
323 	if (vcdev->is_thinint) {
324 		thinint_area = kzalloc(sizeof(*thinint_area),
325 				       GFP_DMA | GFP_KERNEL);
326 		if (!thinint_area)
327 			return;
328 		thinint_area->summary_indicator =
329 			(unsigned long) &airq_info->summary_indicator;
330 		thinint_area->isc = VIRTIO_AIRQ_ISC;
331 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
332 		ccw->count = sizeof(*thinint_area);
333 		ccw->cda = (__u32)(unsigned long) thinint_area;
334 	} else {
335 		/* payload is the address of the indicators */
336 		indicatorp = kmalloc(sizeof(&vcdev->indicators),
337 				     GFP_DMA | GFP_KERNEL);
338 		if (!indicatorp)
339 			return;
340 		*indicatorp = 0;
341 		ccw->cmd_code = CCW_CMD_SET_IND;
342 		ccw->count = sizeof(&vcdev->indicators);
343 		ccw->cda = (__u32)(unsigned long) indicatorp;
344 	}
345 	/* Deregister indicators from host. */
346 	vcdev->indicators = 0;
347 	ccw->flags = 0;
348 	ret = ccw_io_helper(vcdev, ccw,
349 			    vcdev->is_thinint ?
350 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
351 			    VIRTIO_CCW_DOING_SET_IND);
352 	if (ret && (ret != -ENODEV))
353 		dev_info(&vcdev->cdev->dev,
354 			 "Failed to deregister indicators (%d)\n", ret);
355 	else if (vcdev->is_thinint)
356 		virtio_ccw_drop_indicators(vcdev);
357 	kfree(indicatorp);
358 	kfree(thinint_area);
359 }
360 
361 static inline long __do_kvm_notify(struct subchannel_id schid,
362 				   unsigned long queue_index,
363 				   long cookie)
364 {
365 	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
366 	register struct subchannel_id __schid asm("2") = schid;
367 	register unsigned long __index asm("3") = queue_index;
368 	register long __rc asm("2");
369 	register long __cookie asm("4") = cookie;
370 
371 	asm volatile ("diag 2,4,0x500\n"
372 		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
373 		      "d"(__cookie)
374 		      : "memory", "cc");
375 	return __rc;
376 }
377 
378 static inline long do_kvm_notify(struct subchannel_id schid,
379 				 unsigned long queue_index,
380 				 long cookie)
381 {
382 	diag_stat_inc(DIAG_STAT_X500);
383 	return __do_kvm_notify(schid, queue_index, cookie);
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 * const 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 	/*
651 	 * We need a data area under 2G to communicate. Our payload is
652 	 * the address of the indicators.
653 	*/
654 	indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
655 	if (!indicatorp)
656 		goto out;
657 	*indicatorp = (unsigned long) &vcdev->indicators;
658 	if (vcdev->is_thinint) {
659 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
660 		if (ret)
661 			/* no error, just fall back to legacy interrupts */
662 			vcdev->is_thinint = 0;
663 	}
664 	if (!vcdev->is_thinint) {
665 		/* Register queue indicators with host. */
666 		vcdev->indicators = 0;
667 		ccw->cmd_code = CCW_CMD_SET_IND;
668 		ccw->flags = 0;
669 		ccw->count = sizeof(&vcdev->indicators);
670 		ccw->cda = (__u32)(unsigned long) indicatorp;
671 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
672 		if (ret)
673 			goto out;
674 	}
675 	/* Register indicators2 with host for config changes */
676 	*indicatorp = (unsigned long) &vcdev->indicators2;
677 	vcdev->indicators2 = 0;
678 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
679 	ccw->flags = 0;
680 	ccw->count = sizeof(&vcdev->indicators2);
681 	ccw->cda = (__u32)(unsigned long) indicatorp;
682 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
683 	if (ret)
684 		goto out;
685 
686 	kfree(indicatorp);
687 	kfree(ccw);
688 	return 0;
689 out:
690 	kfree(indicatorp);
691 	kfree(ccw);
692 	virtio_ccw_del_vqs(vdev);
693 	return ret;
694 }
695 
696 static void virtio_ccw_reset(struct virtio_device *vdev)
697 {
698 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
699 	struct ccw1 *ccw;
700 
701 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
702 	if (!ccw)
703 		return;
704 
705 	/* Zero status bits. */
706 	*vcdev->status = 0;
707 
708 	/* Send a reset ccw on device. */
709 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
710 	ccw->flags = 0;
711 	ccw->count = 0;
712 	ccw->cda = 0;
713 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
714 	kfree(ccw);
715 }
716 
717 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
718 {
719 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
720 	struct virtio_feature_desc *features;
721 	int ret;
722 	u64 rc;
723 	struct ccw1 *ccw;
724 
725 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
726 	if (!ccw)
727 		return 0;
728 
729 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
730 	if (!features) {
731 		rc = 0;
732 		goto out_free;
733 	}
734 	/* Read the feature bits from the host. */
735 	features->index = 0;
736 	ccw->cmd_code = CCW_CMD_READ_FEAT;
737 	ccw->flags = 0;
738 	ccw->count = sizeof(*features);
739 	ccw->cda = (__u32)(unsigned long)features;
740 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
741 	if (ret) {
742 		rc = 0;
743 		goto out_free;
744 	}
745 
746 	rc = le32_to_cpu(features->features);
747 
748 	if (vcdev->revision == 0)
749 		goto out_free;
750 
751 	/* Read second half of the feature bits from the host. */
752 	features->index = 1;
753 	ccw->cmd_code = CCW_CMD_READ_FEAT;
754 	ccw->flags = 0;
755 	ccw->count = sizeof(*features);
756 	ccw->cda = (__u32)(unsigned long)features;
757 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
758 	if (ret == 0)
759 		rc |= (u64)le32_to_cpu(features->features) << 32;
760 
761 out_free:
762 	kfree(features);
763 	kfree(ccw);
764 	return rc;
765 }
766 
767 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
768 {
769 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
770 	struct virtio_feature_desc *features;
771 	struct ccw1 *ccw;
772 	int ret;
773 
774 	if (vcdev->revision >= 1 &&
775 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
776 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
777 			"but does not have VIRTIO_F_VERSION_1\n");
778 		return -EINVAL;
779 	}
780 
781 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
782 	if (!ccw)
783 		return -ENOMEM;
784 
785 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
786 	if (!features) {
787 		ret = -ENOMEM;
788 		goto out_free;
789 	}
790 	/* Give virtio_ring a chance to accept features. */
791 	vring_transport_features(vdev);
792 
793 	features->index = 0;
794 	features->features = cpu_to_le32((u32)vdev->features);
795 	/* Write the first half of the feature bits to the host. */
796 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
797 	ccw->flags = 0;
798 	ccw->count = sizeof(*features);
799 	ccw->cda = (__u32)(unsigned long)features;
800 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
801 	if (ret)
802 		goto out_free;
803 
804 	if (vcdev->revision == 0)
805 		goto out_free;
806 
807 	features->index = 1;
808 	features->features = cpu_to_le32(vdev->features >> 32);
809 	/* Write the second half of the feature bits to the host. */
810 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
811 	ccw->flags = 0;
812 	ccw->count = sizeof(*features);
813 	ccw->cda = (__u32)(unsigned long)features;
814 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
815 
816 out_free:
817 	kfree(features);
818 	kfree(ccw);
819 
820 	return ret;
821 }
822 
823 static void virtio_ccw_get_config(struct virtio_device *vdev,
824 				  unsigned int offset, void *buf, unsigned len)
825 {
826 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
827 	int ret;
828 	struct ccw1 *ccw;
829 	void *config_area;
830 
831 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
832 	if (!ccw)
833 		return;
834 
835 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
836 	if (!config_area)
837 		goto out_free;
838 
839 	/* Read the config area from the host. */
840 	ccw->cmd_code = CCW_CMD_READ_CONF;
841 	ccw->flags = 0;
842 	ccw->count = offset + len;
843 	ccw->cda = (__u32)(unsigned long)config_area;
844 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
845 	if (ret)
846 		goto out_free;
847 
848 	memcpy(vcdev->config, config_area, offset + len);
849 	if (buf)
850 		memcpy(buf, &vcdev->config[offset], len);
851 	if (vcdev->config_ready < offset + len)
852 		vcdev->config_ready = offset + len;
853 
854 out_free:
855 	kfree(config_area);
856 	kfree(ccw);
857 }
858 
859 static void virtio_ccw_set_config(struct virtio_device *vdev,
860 				  unsigned int offset, const void *buf,
861 				  unsigned len)
862 {
863 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
864 	struct ccw1 *ccw;
865 	void *config_area;
866 
867 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
868 	if (!ccw)
869 		return;
870 
871 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
872 	if (!config_area)
873 		goto out_free;
874 
875 	/* Make sure we don't overwrite fields. */
876 	if (vcdev->config_ready < offset)
877 		virtio_ccw_get_config(vdev, 0, NULL, offset);
878 	memcpy(&vcdev->config[offset], buf, len);
879 	/* Write the config area to the host. */
880 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
881 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
882 	ccw->flags = 0;
883 	ccw->count = offset + len;
884 	ccw->cda = (__u32)(unsigned long)config_area;
885 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
886 
887 out_free:
888 	kfree(config_area);
889 	kfree(ccw);
890 }
891 
892 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
893 {
894 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
895 
896 	return *vcdev->status;
897 }
898 
899 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
900 {
901 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
902 	u8 old_status = *vcdev->status;
903 	struct ccw1 *ccw;
904 	int ret;
905 
906 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
907 	if (!ccw)
908 		return;
909 
910 	/* Write the status to the host. */
911 	*vcdev->status = status;
912 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
913 	ccw->flags = 0;
914 	ccw->count = sizeof(status);
915 	ccw->cda = (__u32)(unsigned long)vcdev->status;
916 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
917 	/* Write failed? We assume status is unchanged. */
918 	if (ret)
919 		*vcdev->status = old_status;
920 	kfree(ccw);
921 }
922 
923 static struct virtio_config_ops virtio_ccw_config_ops = {
924 	.get_features = virtio_ccw_get_features,
925 	.finalize_features = virtio_ccw_finalize_features,
926 	.get = virtio_ccw_get_config,
927 	.set = virtio_ccw_set_config,
928 	.get_status = virtio_ccw_get_status,
929 	.set_status = virtio_ccw_set_status,
930 	.reset = virtio_ccw_reset,
931 	.find_vqs = virtio_ccw_find_vqs,
932 	.del_vqs = virtio_ccw_del_vqs,
933 };
934 
935 
936 /*
937  * ccw bus driver related functions
938  */
939 
940 static void virtio_ccw_release_dev(struct device *_d)
941 {
942 	struct virtio_device *dev = dev_to_virtio(_d);
943 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
944 
945 	kfree(vcdev->status);
946 	kfree(vcdev->config_block);
947 	kfree(vcdev);
948 }
949 
950 static int irb_is_error(struct irb *irb)
951 {
952 	if (scsw_cstat(&irb->scsw) != 0)
953 		return 1;
954 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
955 		return 1;
956 	if (scsw_cc(&irb->scsw) != 0)
957 		return 1;
958 	return 0;
959 }
960 
961 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
962 					      int index)
963 {
964 	struct virtio_ccw_vq_info *info;
965 	unsigned long flags;
966 	struct virtqueue *vq;
967 
968 	vq = NULL;
969 	spin_lock_irqsave(&vcdev->lock, flags);
970 	list_for_each_entry(info, &vcdev->virtqueues, node) {
971 		if (info->vq->index == index) {
972 			vq = info->vq;
973 			break;
974 		}
975 	}
976 	spin_unlock_irqrestore(&vcdev->lock, flags);
977 	return vq;
978 }
979 
980 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
981 				      __u32 activity)
982 {
983 	if (vcdev->curr_io & activity) {
984 		switch (activity) {
985 		case VIRTIO_CCW_DOING_READ_FEAT:
986 		case VIRTIO_CCW_DOING_WRITE_FEAT:
987 		case VIRTIO_CCW_DOING_READ_CONFIG:
988 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
989 		case VIRTIO_CCW_DOING_WRITE_STATUS:
990 		case VIRTIO_CCW_DOING_SET_VQ:
991 		case VIRTIO_CCW_DOING_SET_IND:
992 		case VIRTIO_CCW_DOING_SET_CONF_IND:
993 		case VIRTIO_CCW_DOING_RESET:
994 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
995 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
996 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
997 			vcdev->curr_io &= ~activity;
998 			wake_up(&vcdev->wait_q);
999 			break;
1000 		default:
1001 			/* don't know what to do... */
1002 			dev_warn(&vcdev->cdev->dev,
1003 				 "Suspicious activity '%08x'\n", activity);
1004 			WARN_ON(1);
1005 			break;
1006 		}
1007 	}
1008 }
1009 
1010 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1011 				   unsigned long intparm,
1012 				   struct irb *irb)
1013 {
1014 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1015 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1016 	int i;
1017 	struct virtqueue *vq;
1018 
1019 	if (!vcdev)
1020 		return;
1021 	if (IS_ERR(irb)) {
1022 		vcdev->err = PTR_ERR(irb);
1023 		virtio_ccw_check_activity(vcdev, activity);
1024 		/* Don't poke around indicators, something's wrong. */
1025 		return;
1026 	}
1027 	/* Check if it's a notification from the host. */
1028 	if ((intparm == 0) &&
1029 	    (scsw_stctl(&irb->scsw) ==
1030 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1031 		/* OK */
1032 	}
1033 	if (irb_is_error(irb)) {
1034 		/* Command reject? */
1035 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1036 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1037 			vcdev->err = -EOPNOTSUPP;
1038 		else
1039 			/* Map everything else to -EIO. */
1040 			vcdev->err = -EIO;
1041 	}
1042 	virtio_ccw_check_activity(vcdev, activity);
1043 	for_each_set_bit(i, &vcdev->indicators,
1044 			 sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1045 		/* The bit clear must happen before the vring kick. */
1046 		clear_bit(i, &vcdev->indicators);
1047 		barrier();
1048 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1049 		vring_interrupt(0, vq);
1050 	}
1051 	if (test_bit(0, &vcdev->indicators2)) {
1052 		virtio_config_changed(&vcdev->vdev);
1053 		clear_bit(0, &vcdev->indicators2);
1054 	}
1055 }
1056 
1057 /*
1058  * We usually want to autoonline all devices, but give the admin
1059  * a way to exempt devices from this.
1060  */
1061 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1062 		     (8*sizeof(long)))
1063 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1064 
1065 static char *no_auto = "";
1066 
1067 module_param(no_auto, charp, 0444);
1068 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1069 
1070 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1071 {
1072 	struct ccw_dev_id id;
1073 
1074 	ccw_device_get_id(cdev, &id);
1075 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1076 		return 0;
1077 	return 1;
1078 }
1079 
1080 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1081 {
1082 	struct ccw_device *cdev = data;
1083 	int ret;
1084 
1085 	ret = ccw_device_set_online(cdev);
1086 	if (ret)
1087 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1088 }
1089 
1090 static int virtio_ccw_probe(struct ccw_device *cdev)
1091 {
1092 	cdev->handler = virtio_ccw_int_handler;
1093 
1094 	if (virtio_ccw_check_autoonline(cdev))
1095 		async_schedule(virtio_ccw_auto_online, cdev);
1096 	return 0;
1097 }
1098 
1099 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1100 {
1101 	unsigned long flags;
1102 	struct virtio_ccw_device *vcdev;
1103 
1104 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1105 	vcdev = dev_get_drvdata(&cdev->dev);
1106 	if (!vcdev || vcdev->going_away) {
1107 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1108 		return NULL;
1109 	}
1110 	vcdev->going_away = true;
1111 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1112 	return vcdev;
1113 }
1114 
1115 static void virtio_ccw_remove(struct ccw_device *cdev)
1116 {
1117 	unsigned long flags;
1118 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1119 
1120 	if (vcdev && cdev->online) {
1121 		if (vcdev->device_lost)
1122 			virtio_break_device(&vcdev->vdev);
1123 		unregister_virtio_device(&vcdev->vdev);
1124 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1125 		dev_set_drvdata(&cdev->dev, NULL);
1126 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1127 	}
1128 	cdev->handler = NULL;
1129 }
1130 
1131 static int virtio_ccw_offline(struct ccw_device *cdev)
1132 {
1133 	unsigned long flags;
1134 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1135 
1136 	if (!vcdev)
1137 		return 0;
1138 	if (vcdev->device_lost)
1139 		virtio_break_device(&vcdev->vdev);
1140 	unregister_virtio_device(&vcdev->vdev);
1141 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1142 	dev_set_drvdata(&cdev->dev, NULL);
1143 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1144 	return 0;
1145 }
1146 
1147 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1148 {
1149 	struct virtio_rev_info *rev;
1150 	struct ccw1 *ccw;
1151 	int ret;
1152 
1153 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1154 	if (!ccw)
1155 		return -ENOMEM;
1156 	rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1157 	if (!rev) {
1158 		kfree(ccw);
1159 		return -ENOMEM;
1160 	}
1161 
1162 	/* Set transport revision */
1163 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1164 	ccw->flags = 0;
1165 	ccw->count = sizeof(*rev);
1166 	ccw->cda = (__u32)(unsigned long)rev;
1167 
1168 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1169 	do {
1170 		rev->revision = vcdev->revision;
1171 		/* none of our supported revisions carry payload */
1172 		rev->length = 0;
1173 		ret = ccw_io_helper(vcdev, ccw,
1174 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1175 		if (ret == -EOPNOTSUPP) {
1176 			if (vcdev->revision == 0)
1177 				/*
1178 				 * The host device does not support setting
1179 				 * the revision: let's operate it in legacy
1180 				 * mode.
1181 				 */
1182 				ret = 0;
1183 			else
1184 				vcdev->revision--;
1185 		}
1186 	} while (ret == -EOPNOTSUPP);
1187 
1188 	kfree(ccw);
1189 	kfree(rev);
1190 	return ret;
1191 }
1192 
1193 static int virtio_ccw_online(struct ccw_device *cdev)
1194 {
1195 	int ret;
1196 	struct virtio_ccw_device *vcdev;
1197 	unsigned long flags;
1198 
1199 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1200 	if (!vcdev) {
1201 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1202 		ret = -ENOMEM;
1203 		goto out_free;
1204 	}
1205 	vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1206 				   GFP_DMA | GFP_KERNEL);
1207 	if (!vcdev->config_block) {
1208 		ret = -ENOMEM;
1209 		goto out_free;
1210 	}
1211 	vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1212 	if (!vcdev->status) {
1213 		ret = -ENOMEM;
1214 		goto out_free;
1215 	}
1216 
1217 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1218 
1219 	vcdev->vdev.dev.parent = &cdev->dev;
1220 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1221 	vcdev->vdev.config = &virtio_ccw_config_ops;
1222 	vcdev->cdev = cdev;
1223 	init_waitqueue_head(&vcdev->wait_q);
1224 	INIT_LIST_HEAD(&vcdev->virtqueues);
1225 	spin_lock_init(&vcdev->lock);
1226 
1227 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1228 	dev_set_drvdata(&cdev->dev, vcdev);
1229 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1230 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1231 	vcdev->vdev.id.device = cdev->id.cu_model;
1232 
1233 	ret = virtio_ccw_set_transport_rev(vcdev);
1234 	if (ret)
1235 		goto out_free;
1236 
1237 	ret = register_virtio_device(&vcdev->vdev);
1238 	if (ret) {
1239 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1240 			 ret);
1241 		goto out_put;
1242 	}
1243 	return 0;
1244 out_put:
1245 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1246 	dev_set_drvdata(&cdev->dev, NULL);
1247 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1248 	put_device(&vcdev->vdev.dev);
1249 	return ret;
1250 out_free:
1251 	if (vcdev) {
1252 		kfree(vcdev->status);
1253 		kfree(vcdev->config_block);
1254 	}
1255 	kfree(vcdev);
1256 	return ret;
1257 }
1258 
1259 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1260 {
1261 	int rc;
1262 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1263 
1264 	/*
1265 	 * Make sure vcdev is set
1266 	 * i.e. set_offline/remove callback not already running
1267 	 */
1268 	if (!vcdev)
1269 		return NOTIFY_DONE;
1270 
1271 	switch (event) {
1272 	case CIO_GONE:
1273 		vcdev->device_lost = true;
1274 		rc = NOTIFY_DONE;
1275 		break;
1276 	default:
1277 		rc = NOTIFY_DONE;
1278 		break;
1279 	}
1280 	return rc;
1281 }
1282 
1283 static struct ccw_device_id virtio_ids[] = {
1284 	{ CCW_DEVICE(0x3832, 0) },
1285 	{},
1286 };
1287 
1288 static struct ccw_driver virtio_ccw_driver = {
1289 	.driver = {
1290 		.owner = THIS_MODULE,
1291 		.name = "virtio_ccw",
1292 	},
1293 	.ids = virtio_ids,
1294 	.probe = virtio_ccw_probe,
1295 	.remove = virtio_ccw_remove,
1296 	.set_offline = virtio_ccw_offline,
1297 	.set_online = virtio_ccw_online,
1298 	.notify = virtio_ccw_cio_notify,
1299 	.int_class = IRQIO_VIR,
1300 };
1301 
1302 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1303 			   int max_digit, int max_val)
1304 {
1305 	int diff;
1306 
1307 	diff = 0;
1308 	*val = 0;
1309 
1310 	while (diff <= max_digit) {
1311 		int value = hex_to_bin(**cp);
1312 
1313 		if (value < 0)
1314 			break;
1315 		*val = *val * 16 + value;
1316 		(*cp)++;
1317 		diff++;
1318 	}
1319 
1320 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1321 		return 1;
1322 
1323 	return 0;
1324 }
1325 
1326 static int __init parse_busid(char *str, unsigned int *cssid,
1327 			      unsigned int *ssid, unsigned int *devno)
1328 {
1329 	char *str_work;
1330 	int rc, ret;
1331 
1332 	rc = 1;
1333 
1334 	if (*str == '\0')
1335 		goto out;
1336 
1337 	str_work = str;
1338 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1339 	if (ret || (str_work[0] != '.'))
1340 		goto out;
1341 	str_work++;
1342 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1343 	if (ret || (str_work[0] != '.'))
1344 		goto out;
1345 	str_work++;
1346 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1347 	if (ret || (str_work[0] != '\0'))
1348 		goto out;
1349 
1350 	rc = 0;
1351 out:
1352 	return rc;
1353 }
1354 
1355 static void __init no_auto_parse(void)
1356 {
1357 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1358 	char *parm, *str;
1359 	int rc;
1360 
1361 	str = no_auto;
1362 	while ((parm = strsep(&str, ","))) {
1363 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1364 				 &from_ssid, &from);
1365 		if (rc)
1366 			continue;
1367 		if (parm != NULL) {
1368 			rc = parse_busid(parm, &to_cssid,
1369 					 &to_ssid, &to);
1370 			if ((from_ssid > to_ssid) ||
1371 			    ((from_ssid == to_ssid) && (from > to)))
1372 				rc = -EINVAL;
1373 		} else {
1374 			to_cssid = from_cssid;
1375 			to_ssid = from_ssid;
1376 			to = from;
1377 		}
1378 		if (rc)
1379 			continue;
1380 		while ((from_ssid < to_ssid) ||
1381 		       ((from_ssid == to_ssid) && (from <= to))) {
1382 			set_bit(from, devs_no_auto[from_ssid]);
1383 			from++;
1384 			if (from > __MAX_SUBCHANNEL) {
1385 				from_ssid++;
1386 				from = 0;
1387 			}
1388 		}
1389 	}
1390 }
1391 
1392 static int __init virtio_ccw_init(void)
1393 {
1394 	/* parse no_auto string before we do anything further */
1395 	no_auto_parse();
1396 	return ccw_driver_register(&virtio_ccw_driver);
1397 }
1398 device_initcall(virtio_ccw_init);
1399