xref: /openbmc/linux/drivers/s390/virtio/virtio_ccw.c (revision efe4a1ac)
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 	__le32 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_READ_STATUS 0x72
149 #define CCW_CMD_SET_IND_ADAPTER 0x73
150 #define CCW_CMD_SET_VIRTIO_REV 0x83
151 
152 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
153 #define VIRTIO_CCW_DOING_RESET 0x00040000
154 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
155 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
156 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
157 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
158 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
159 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
160 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
161 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
162 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
163 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
164 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
165 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
166 
167 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
168 {
169 	return container_of(vdev, struct virtio_ccw_device, vdev);
170 }
171 
172 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
173 {
174 	unsigned long i, flags;
175 
176 	write_lock_irqsave(&info->lock, flags);
177 	for (i = 0; i < airq_iv_end(info->aiv); i++) {
178 		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
179 			airq_iv_free_bit(info->aiv, i);
180 			airq_iv_set_ptr(info->aiv, i, 0);
181 			break;
182 		}
183 	}
184 	write_unlock_irqrestore(&info->lock, flags);
185 }
186 
187 static void virtio_airq_handler(struct airq_struct *airq)
188 {
189 	struct airq_info *info = container_of(airq, struct airq_info, airq);
190 	unsigned long ai;
191 
192 	inc_irq_stat(IRQIO_VAI);
193 	read_lock(&info->lock);
194 	/* Walk through indicators field, summary indicator active. */
195 	for (ai = 0;;) {
196 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
197 		if (ai == -1UL)
198 			break;
199 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
200 	}
201 	info->summary_indicator = 0;
202 	smp_wmb();
203 	/* Walk through indicators field, summary indicator not active. */
204 	for (ai = 0;;) {
205 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
206 		if (ai == -1UL)
207 			break;
208 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
209 	}
210 	read_unlock(&info->lock);
211 }
212 
213 static struct airq_info *new_airq_info(void)
214 {
215 	struct airq_info *info;
216 	int rc;
217 
218 	info = kzalloc(sizeof(*info), GFP_KERNEL);
219 	if (!info)
220 		return NULL;
221 	rwlock_init(&info->lock);
222 	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
223 	if (!info->aiv) {
224 		kfree(info);
225 		return NULL;
226 	}
227 	info->airq.handler = virtio_airq_handler;
228 	info->airq.lsi_ptr = &info->summary_indicator;
229 	info->airq.lsi_mask = 0xff;
230 	info->airq.isc = VIRTIO_AIRQ_ISC;
231 	rc = register_adapter_interrupt(&info->airq);
232 	if (rc) {
233 		airq_iv_release(info->aiv);
234 		kfree(info);
235 		return NULL;
236 	}
237 	return info;
238 }
239 
240 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
241 					u64 *first, void **airq_info)
242 {
243 	int i, j;
244 	struct airq_info *info;
245 	unsigned long indicator_addr = 0;
246 	unsigned long bit, flags;
247 
248 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
249 		if (!airq_areas[i])
250 			airq_areas[i] = new_airq_info();
251 		info = airq_areas[i];
252 		if (!info)
253 			return 0;
254 		write_lock_irqsave(&info->lock, flags);
255 		bit = airq_iv_alloc(info->aiv, nvqs);
256 		if (bit == -1UL) {
257 			/* Not enough vacancies. */
258 			write_unlock_irqrestore(&info->lock, flags);
259 			continue;
260 		}
261 		*first = bit;
262 		*airq_info = info;
263 		indicator_addr = (unsigned long)info->aiv->vector;
264 		for (j = 0; j < nvqs; j++) {
265 			airq_iv_set_ptr(info->aiv, bit + j,
266 					(unsigned long)vqs[j]);
267 		}
268 		write_unlock_irqrestore(&info->lock, flags);
269 	}
270 	return indicator_addr;
271 }
272 
273 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
274 {
275 	struct virtio_ccw_vq_info *info;
276 
277 	list_for_each_entry(info, &vcdev->virtqueues, node)
278 		drop_airq_indicator(info->vq, vcdev->airq_info);
279 }
280 
281 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
282 {
283 	unsigned long flags;
284 	__u32 ret;
285 
286 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
287 	if (vcdev->err)
288 		ret = 0;
289 	else
290 		ret = vcdev->curr_io & flag;
291 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
292 	return ret;
293 }
294 
295 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
296 			 struct ccw1 *ccw, __u32 intparm)
297 {
298 	int ret;
299 	unsigned long flags;
300 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
301 
302 	do {
303 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
304 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
305 		if (!ret) {
306 			if (!vcdev->curr_io)
307 				vcdev->err = 0;
308 			vcdev->curr_io |= flag;
309 		}
310 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
311 		cpu_relax();
312 	} while (ret == -EBUSY);
313 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
314 	return ret ? ret : vcdev->err;
315 }
316 
317 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
318 				      struct ccw1 *ccw)
319 {
320 	int ret;
321 	unsigned long *indicatorp = NULL;
322 	struct virtio_thinint_area *thinint_area = NULL;
323 	struct airq_info *airq_info = vcdev->airq_info;
324 
325 	if (vcdev->is_thinint) {
326 		thinint_area = kzalloc(sizeof(*thinint_area),
327 				       GFP_DMA | GFP_KERNEL);
328 		if (!thinint_area)
329 			return;
330 		thinint_area->summary_indicator =
331 			(unsigned long) &airq_info->summary_indicator;
332 		thinint_area->isc = VIRTIO_AIRQ_ISC;
333 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
334 		ccw->count = sizeof(*thinint_area);
335 		ccw->cda = (__u32)(unsigned long) thinint_area;
336 	} else {
337 		/* payload is the address of the indicators */
338 		indicatorp = kmalloc(sizeof(&vcdev->indicators),
339 				     GFP_DMA | GFP_KERNEL);
340 		if (!indicatorp)
341 			return;
342 		*indicatorp = 0;
343 		ccw->cmd_code = CCW_CMD_SET_IND;
344 		ccw->count = sizeof(&vcdev->indicators);
345 		ccw->cda = (__u32)(unsigned long) indicatorp;
346 	}
347 	/* Deregister indicators from host. */
348 	vcdev->indicators = 0;
349 	ccw->flags = 0;
350 	ret = ccw_io_helper(vcdev, ccw,
351 			    vcdev->is_thinint ?
352 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
353 			    VIRTIO_CCW_DOING_SET_IND);
354 	if (ret && (ret != -ENODEV))
355 		dev_info(&vcdev->cdev->dev,
356 			 "Failed to deregister indicators (%d)\n", ret);
357 	else if (vcdev->is_thinint)
358 		virtio_ccw_drop_indicators(vcdev);
359 	kfree(indicatorp);
360 	kfree(thinint_area);
361 }
362 
363 static inline long __do_kvm_notify(struct subchannel_id schid,
364 				   unsigned long queue_index,
365 				   long cookie)
366 {
367 	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
368 	register struct subchannel_id __schid asm("2") = schid;
369 	register unsigned long __index asm("3") = queue_index;
370 	register long __rc asm("2");
371 	register long __cookie asm("4") = cookie;
372 
373 	asm volatile ("diag 2,4,0x500\n"
374 		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
375 		      "d"(__cookie)
376 		      : "memory", "cc");
377 	return __rc;
378 }
379 
380 static inline long do_kvm_notify(struct subchannel_id schid,
381 				 unsigned long queue_index,
382 				 long cookie)
383 {
384 	diag_stat_inc(DIAG_STAT_X500);
385 	return __do_kvm_notify(schid, queue_index, cookie);
386 }
387 
388 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
389 {
390 	struct virtio_ccw_vq_info *info = vq->priv;
391 	struct virtio_ccw_device *vcdev;
392 	struct subchannel_id schid;
393 
394 	vcdev = to_vc_device(info->vq->vdev);
395 	ccw_device_get_schid(vcdev->cdev, &schid);
396 	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
397 	if (info->cookie < 0)
398 		return false;
399 	return true;
400 }
401 
402 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
403 				   struct ccw1 *ccw, int index)
404 {
405 	int ret;
406 
407 	vcdev->config_block->index = index;
408 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
409 	ccw->flags = 0;
410 	ccw->count = sizeof(struct vq_config_block);
411 	ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
412 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
413 	if (ret)
414 		return ret;
415 	return vcdev->config_block->num;
416 }
417 
418 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
419 {
420 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
421 	struct virtio_ccw_vq_info *info = vq->priv;
422 	unsigned long flags;
423 	unsigned long size;
424 	int ret;
425 	unsigned int index = vq->index;
426 
427 	/* Remove from our list. */
428 	spin_lock_irqsave(&vcdev->lock, flags);
429 	list_del(&info->node);
430 	spin_unlock_irqrestore(&vcdev->lock, flags);
431 
432 	/* Release from host. */
433 	if (vcdev->revision == 0) {
434 		info->info_block->l.queue = 0;
435 		info->info_block->l.align = 0;
436 		info->info_block->l.index = index;
437 		info->info_block->l.num = 0;
438 		ccw->count = sizeof(info->info_block->l);
439 	} else {
440 		info->info_block->s.desc = 0;
441 		info->info_block->s.index = index;
442 		info->info_block->s.num = 0;
443 		info->info_block->s.avail = 0;
444 		info->info_block->s.used = 0;
445 		ccw->count = sizeof(info->info_block->s);
446 	}
447 	ccw->cmd_code = CCW_CMD_SET_VQ;
448 	ccw->flags = 0;
449 	ccw->cda = (__u32)(unsigned long)(info->info_block);
450 	ret = ccw_io_helper(vcdev, ccw,
451 			    VIRTIO_CCW_DOING_SET_VQ | index);
452 	/*
453 	 * -ENODEV isn't considered an error: The device is gone anyway.
454 	 * This may happen on device detach.
455 	 */
456 	if (ret && (ret != -ENODEV))
457 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
458 			 ret, index);
459 
460 	vring_del_virtqueue(vq);
461 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
462 	free_pages_exact(info->queue, size);
463 	kfree(info->info_block);
464 	kfree(info);
465 }
466 
467 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
468 {
469 	struct virtqueue *vq, *n;
470 	struct ccw1 *ccw;
471 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
472 
473 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
474 	if (!ccw)
475 		return;
476 
477 	virtio_ccw_drop_indicator(vcdev, ccw);
478 
479 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
480 		virtio_ccw_del_vq(vq, ccw);
481 
482 	kfree(ccw);
483 }
484 
485 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
486 					     int i, vq_callback_t *callback,
487 					     const char *name, bool ctx,
488 					     struct ccw1 *ccw)
489 {
490 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
491 	int err;
492 	struct virtqueue *vq = NULL;
493 	struct virtio_ccw_vq_info *info;
494 	unsigned long size = 0; /* silence the compiler */
495 	unsigned long flags;
496 
497 	/* Allocate queue. */
498 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
499 	if (!info) {
500 		dev_warn(&vcdev->cdev->dev, "no info\n");
501 		err = -ENOMEM;
502 		goto out_err;
503 	}
504 	info->info_block = kzalloc(sizeof(*info->info_block),
505 				   GFP_DMA | GFP_KERNEL);
506 	if (!info->info_block) {
507 		dev_warn(&vcdev->cdev->dev, "no info block\n");
508 		err = -ENOMEM;
509 		goto out_err;
510 	}
511 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
512 	if (info->num < 0) {
513 		err = info->num;
514 		goto out_err;
515 	}
516 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
517 	info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
518 	if (info->queue == NULL) {
519 		dev_warn(&vcdev->cdev->dev, "no queue\n");
520 		err = -ENOMEM;
521 		goto out_err;
522 	}
523 
524 	vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
525 				 true, ctx, info->queue, virtio_ccw_kvm_notify,
526 				 callback, name);
527 	if (!vq) {
528 		/* For now, we fail if we can't get the requested size. */
529 		dev_warn(&vcdev->cdev->dev, "no vq\n");
530 		err = -ENOMEM;
531 		goto out_err;
532 	}
533 
534 	/* Register it with the host. */
535 	if (vcdev->revision == 0) {
536 		info->info_block->l.queue = (__u64)info->queue;
537 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
538 		info->info_block->l.index = i;
539 		info->info_block->l.num = info->num;
540 		ccw->count = sizeof(info->info_block->l);
541 	} else {
542 		info->info_block->s.desc = (__u64)info->queue;
543 		info->info_block->s.index = i;
544 		info->info_block->s.num = info->num;
545 		info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
546 		info->info_block->s.used = (__u64)virtqueue_get_used(vq);
547 		ccw->count = sizeof(info->info_block->s);
548 	}
549 	ccw->cmd_code = CCW_CMD_SET_VQ;
550 	ccw->flags = 0;
551 	ccw->cda = (__u32)(unsigned long)(info->info_block);
552 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
553 	if (err) {
554 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
555 		goto out_err;
556 	}
557 
558 	info->vq = vq;
559 	vq->priv = info;
560 
561 	/* Save it to our list. */
562 	spin_lock_irqsave(&vcdev->lock, flags);
563 	list_add(&info->node, &vcdev->virtqueues);
564 	spin_unlock_irqrestore(&vcdev->lock, flags);
565 
566 	return vq;
567 
568 out_err:
569 	if (vq)
570 		vring_del_virtqueue(vq);
571 	if (info) {
572 		if (info->queue)
573 			free_pages_exact(info->queue, size);
574 		kfree(info->info_block);
575 	}
576 	kfree(info);
577 	return ERR_PTR(err);
578 }
579 
580 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
581 					   struct virtqueue *vqs[], int nvqs,
582 					   struct ccw1 *ccw)
583 {
584 	int ret;
585 	struct virtio_thinint_area *thinint_area = NULL;
586 	struct airq_info *info;
587 
588 	thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
589 	if (!thinint_area) {
590 		ret = -ENOMEM;
591 		goto out;
592 	}
593 	/* Try to get an indicator. */
594 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
595 						     &thinint_area->bit_nr,
596 						     &vcdev->airq_info);
597 	if (!thinint_area->indicator) {
598 		ret = -ENOSPC;
599 		goto out;
600 	}
601 	info = vcdev->airq_info;
602 	thinint_area->summary_indicator =
603 		(unsigned long) &info->summary_indicator;
604 	thinint_area->isc = VIRTIO_AIRQ_ISC;
605 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
606 	ccw->flags = CCW_FLAG_SLI;
607 	ccw->count = sizeof(*thinint_area);
608 	ccw->cda = (__u32)(unsigned long)thinint_area;
609 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
610 	if (ret) {
611 		if (ret == -EOPNOTSUPP) {
612 			/*
613 			 * The host does not support adapter interrupts
614 			 * for virtio-ccw, stop trying.
615 			 */
616 			virtio_ccw_use_airq = 0;
617 			pr_info("Adapter interrupts unsupported on host\n");
618 		} else
619 			dev_warn(&vcdev->cdev->dev,
620 				 "enabling adapter interrupts = %d\n", ret);
621 		virtio_ccw_drop_indicators(vcdev);
622 	}
623 out:
624 	kfree(thinint_area);
625 	return ret;
626 }
627 
628 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
629 			       struct virtqueue *vqs[],
630 			       vq_callback_t *callbacks[],
631 			       const char * const names[],
632 			       const bool *ctx,
633 			       struct irq_affinity *desc)
634 {
635 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
636 	unsigned long *indicatorp = NULL;
637 	int ret, i;
638 	struct ccw1 *ccw;
639 
640 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
641 	if (!ccw)
642 		return -ENOMEM;
643 
644 	for (i = 0; i < nvqs; ++i) {
645 		vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
646 					     ctx ? ctx[i] : false, ccw);
647 		if (IS_ERR(vqs[i])) {
648 			ret = PTR_ERR(vqs[i]);
649 			vqs[i] = NULL;
650 			goto out;
651 		}
652 	}
653 	ret = -ENOMEM;
654 	/*
655 	 * We need a data area under 2G to communicate. Our payload is
656 	 * the address of the indicators.
657 	*/
658 	indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
659 	if (!indicatorp)
660 		goto out;
661 	*indicatorp = (unsigned long) &vcdev->indicators;
662 	if (vcdev->is_thinint) {
663 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
664 		if (ret)
665 			/* no error, just fall back to legacy interrupts */
666 			vcdev->is_thinint = false;
667 	}
668 	if (!vcdev->is_thinint) {
669 		/* Register queue indicators with host. */
670 		vcdev->indicators = 0;
671 		ccw->cmd_code = CCW_CMD_SET_IND;
672 		ccw->flags = 0;
673 		ccw->count = sizeof(&vcdev->indicators);
674 		ccw->cda = (__u32)(unsigned long) indicatorp;
675 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
676 		if (ret)
677 			goto out;
678 	}
679 	/* Register indicators2 with host for config changes */
680 	*indicatorp = (unsigned long) &vcdev->indicators2;
681 	vcdev->indicators2 = 0;
682 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
683 	ccw->flags = 0;
684 	ccw->count = sizeof(&vcdev->indicators2);
685 	ccw->cda = (__u32)(unsigned long) indicatorp;
686 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
687 	if (ret)
688 		goto out;
689 
690 	kfree(indicatorp);
691 	kfree(ccw);
692 	return 0;
693 out:
694 	kfree(indicatorp);
695 	kfree(ccw);
696 	virtio_ccw_del_vqs(vdev);
697 	return ret;
698 }
699 
700 static void virtio_ccw_reset(struct virtio_device *vdev)
701 {
702 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
703 	struct ccw1 *ccw;
704 
705 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
706 	if (!ccw)
707 		return;
708 
709 	/* Zero status bits. */
710 	*vcdev->status = 0;
711 
712 	/* Send a reset ccw on device. */
713 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
714 	ccw->flags = 0;
715 	ccw->count = 0;
716 	ccw->cda = 0;
717 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
718 	kfree(ccw);
719 }
720 
721 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
722 {
723 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
724 	struct virtio_feature_desc *features;
725 	int ret;
726 	u64 rc;
727 	struct ccw1 *ccw;
728 
729 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
730 	if (!ccw)
731 		return 0;
732 
733 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
734 	if (!features) {
735 		rc = 0;
736 		goto out_free;
737 	}
738 	/* Read the feature bits from the host. */
739 	features->index = 0;
740 	ccw->cmd_code = CCW_CMD_READ_FEAT;
741 	ccw->flags = 0;
742 	ccw->count = sizeof(*features);
743 	ccw->cda = (__u32)(unsigned long)features;
744 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
745 	if (ret) {
746 		rc = 0;
747 		goto out_free;
748 	}
749 
750 	rc = le32_to_cpu(features->features);
751 
752 	if (vcdev->revision == 0)
753 		goto out_free;
754 
755 	/* Read second half of the feature bits from the host. */
756 	features->index = 1;
757 	ccw->cmd_code = CCW_CMD_READ_FEAT;
758 	ccw->flags = 0;
759 	ccw->count = sizeof(*features);
760 	ccw->cda = (__u32)(unsigned long)features;
761 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
762 	if (ret == 0)
763 		rc |= (u64)le32_to_cpu(features->features) << 32;
764 
765 out_free:
766 	kfree(features);
767 	kfree(ccw);
768 	return rc;
769 }
770 
771 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
772 {
773 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
774 	struct virtio_feature_desc *features;
775 	struct ccw1 *ccw;
776 	int ret;
777 
778 	if (vcdev->revision >= 1 &&
779 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
780 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
781 			"but does not have VIRTIO_F_VERSION_1\n");
782 		return -EINVAL;
783 	}
784 
785 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
786 	if (!ccw)
787 		return -ENOMEM;
788 
789 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
790 	if (!features) {
791 		ret = -ENOMEM;
792 		goto out_free;
793 	}
794 	/* Give virtio_ring a chance to accept features. */
795 	vring_transport_features(vdev);
796 
797 	features->index = 0;
798 	features->features = cpu_to_le32((u32)vdev->features);
799 	/* Write the first half of the feature bits to the host. */
800 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
801 	ccw->flags = 0;
802 	ccw->count = sizeof(*features);
803 	ccw->cda = (__u32)(unsigned long)features;
804 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
805 	if (ret)
806 		goto out_free;
807 
808 	if (vcdev->revision == 0)
809 		goto out_free;
810 
811 	features->index = 1;
812 	features->features = cpu_to_le32(vdev->features >> 32);
813 	/* Write the second half of the feature bits to the host. */
814 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
815 	ccw->flags = 0;
816 	ccw->count = sizeof(*features);
817 	ccw->cda = (__u32)(unsigned long)features;
818 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
819 
820 out_free:
821 	kfree(features);
822 	kfree(ccw);
823 
824 	return ret;
825 }
826 
827 static void virtio_ccw_get_config(struct virtio_device *vdev,
828 				  unsigned int offset, void *buf, unsigned len)
829 {
830 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
831 	int ret;
832 	struct ccw1 *ccw;
833 	void *config_area;
834 
835 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
836 	if (!ccw)
837 		return;
838 
839 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
840 	if (!config_area)
841 		goto out_free;
842 
843 	/* Read the config area from the host. */
844 	ccw->cmd_code = CCW_CMD_READ_CONF;
845 	ccw->flags = 0;
846 	ccw->count = offset + len;
847 	ccw->cda = (__u32)(unsigned long)config_area;
848 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
849 	if (ret)
850 		goto out_free;
851 
852 	memcpy(vcdev->config, config_area, offset + len);
853 	if (buf)
854 		memcpy(buf, &vcdev->config[offset], len);
855 	if (vcdev->config_ready < offset + len)
856 		vcdev->config_ready = offset + len;
857 
858 out_free:
859 	kfree(config_area);
860 	kfree(ccw);
861 }
862 
863 static void virtio_ccw_set_config(struct virtio_device *vdev,
864 				  unsigned int offset, const void *buf,
865 				  unsigned len)
866 {
867 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
868 	struct ccw1 *ccw;
869 	void *config_area;
870 
871 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
872 	if (!ccw)
873 		return;
874 
875 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
876 	if (!config_area)
877 		goto out_free;
878 
879 	/* Make sure we don't overwrite fields. */
880 	if (vcdev->config_ready < offset)
881 		virtio_ccw_get_config(vdev, 0, NULL, offset);
882 	memcpy(&vcdev->config[offset], buf, len);
883 	/* Write the config area to the host. */
884 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
885 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
886 	ccw->flags = 0;
887 	ccw->count = offset + len;
888 	ccw->cda = (__u32)(unsigned long)config_area;
889 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
890 
891 out_free:
892 	kfree(config_area);
893 	kfree(ccw);
894 }
895 
896 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
897 {
898 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
899 	u8 old_status = *vcdev->status;
900 	struct ccw1 *ccw;
901 
902 	if (vcdev->revision < 1)
903 		return *vcdev->status;
904 
905 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
906 	if (!ccw)
907 		return old_status;
908 
909 	ccw->cmd_code = CCW_CMD_READ_STATUS;
910 	ccw->flags = 0;
911 	ccw->count = sizeof(*vcdev->status);
912 	ccw->cda = (__u32)(unsigned long)vcdev->status;
913 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
914 /*
915  * If the channel program failed (should only happen if the device
916  * was hotunplugged, and then we clean up via the machine check
917  * handler anyway), vcdev->status was not overwritten and we just
918  * return the old status, which is fine.
919 */
920 	kfree(ccw);
921 
922 	return *vcdev->status;
923 }
924 
925 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
926 {
927 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
928 	u8 old_status = *vcdev->status;
929 	struct ccw1 *ccw;
930 	int ret;
931 
932 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
933 	if (!ccw)
934 		return;
935 
936 	/* Write the status to the host. */
937 	*vcdev->status = status;
938 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
939 	ccw->flags = 0;
940 	ccw->count = sizeof(status);
941 	ccw->cda = (__u32)(unsigned long)vcdev->status;
942 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
943 	/* Write failed? We assume status is unchanged. */
944 	if (ret)
945 		*vcdev->status = old_status;
946 	kfree(ccw);
947 }
948 
949 static const struct virtio_config_ops virtio_ccw_config_ops = {
950 	.get_features = virtio_ccw_get_features,
951 	.finalize_features = virtio_ccw_finalize_features,
952 	.get = virtio_ccw_get_config,
953 	.set = virtio_ccw_set_config,
954 	.get_status = virtio_ccw_get_status,
955 	.set_status = virtio_ccw_set_status,
956 	.reset = virtio_ccw_reset,
957 	.find_vqs = virtio_ccw_find_vqs,
958 	.del_vqs = virtio_ccw_del_vqs,
959 };
960 
961 
962 /*
963  * ccw bus driver related functions
964  */
965 
966 static void virtio_ccw_release_dev(struct device *_d)
967 {
968 	struct virtio_device *dev = dev_to_virtio(_d);
969 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
970 
971 	kfree(vcdev->status);
972 	kfree(vcdev->config_block);
973 	kfree(vcdev);
974 }
975 
976 static int irb_is_error(struct irb *irb)
977 {
978 	if (scsw_cstat(&irb->scsw) != 0)
979 		return 1;
980 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
981 		return 1;
982 	if (scsw_cc(&irb->scsw) != 0)
983 		return 1;
984 	return 0;
985 }
986 
987 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
988 					      int index)
989 {
990 	struct virtio_ccw_vq_info *info;
991 	unsigned long flags;
992 	struct virtqueue *vq;
993 
994 	vq = NULL;
995 	spin_lock_irqsave(&vcdev->lock, flags);
996 	list_for_each_entry(info, &vcdev->virtqueues, node) {
997 		if (info->vq->index == index) {
998 			vq = info->vq;
999 			break;
1000 		}
1001 	}
1002 	spin_unlock_irqrestore(&vcdev->lock, flags);
1003 	return vq;
1004 }
1005 
1006 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1007 				      __u32 activity)
1008 {
1009 	if (vcdev->curr_io & activity) {
1010 		switch (activity) {
1011 		case VIRTIO_CCW_DOING_READ_FEAT:
1012 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1013 		case VIRTIO_CCW_DOING_READ_CONFIG:
1014 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1015 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1016 		case VIRTIO_CCW_DOING_READ_STATUS:
1017 		case VIRTIO_CCW_DOING_SET_VQ:
1018 		case VIRTIO_CCW_DOING_SET_IND:
1019 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1020 		case VIRTIO_CCW_DOING_RESET:
1021 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1022 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1023 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1024 			vcdev->curr_io &= ~activity;
1025 			wake_up(&vcdev->wait_q);
1026 			break;
1027 		default:
1028 			/* don't know what to do... */
1029 			dev_warn(&vcdev->cdev->dev,
1030 				 "Suspicious activity '%08x'\n", activity);
1031 			WARN_ON(1);
1032 			break;
1033 		}
1034 	}
1035 }
1036 
1037 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1038 				   unsigned long intparm,
1039 				   struct irb *irb)
1040 {
1041 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1042 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1043 	int i;
1044 	struct virtqueue *vq;
1045 
1046 	if (!vcdev)
1047 		return;
1048 	if (IS_ERR(irb)) {
1049 		vcdev->err = PTR_ERR(irb);
1050 		virtio_ccw_check_activity(vcdev, activity);
1051 		/* Don't poke around indicators, something's wrong. */
1052 		return;
1053 	}
1054 	/* Check if it's a notification from the host. */
1055 	if ((intparm == 0) &&
1056 	    (scsw_stctl(&irb->scsw) ==
1057 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1058 		/* OK */
1059 	}
1060 	if (irb_is_error(irb)) {
1061 		/* Command reject? */
1062 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1063 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1064 			vcdev->err = -EOPNOTSUPP;
1065 		else
1066 			/* Map everything else to -EIO. */
1067 			vcdev->err = -EIO;
1068 	}
1069 	virtio_ccw_check_activity(vcdev, activity);
1070 	for_each_set_bit(i, &vcdev->indicators,
1071 			 sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1072 		/* The bit clear must happen before the vring kick. */
1073 		clear_bit(i, &vcdev->indicators);
1074 		barrier();
1075 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1076 		vring_interrupt(0, vq);
1077 	}
1078 	if (test_bit(0, &vcdev->indicators2)) {
1079 		virtio_config_changed(&vcdev->vdev);
1080 		clear_bit(0, &vcdev->indicators2);
1081 	}
1082 }
1083 
1084 /*
1085  * We usually want to autoonline all devices, but give the admin
1086  * a way to exempt devices from this.
1087  */
1088 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1089 		     (8*sizeof(long)))
1090 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1091 
1092 static char *no_auto = "";
1093 
1094 module_param(no_auto, charp, 0444);
1095 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1096 
1097 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1098 {
1099 	struct ccw_dev_id id;
1100 
1101 	ccw_device_get_id(cdev, &id);
1102 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1103 		return 0;
1104 	return 1;
1105 }
1106 
1107 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1108 {
1109 	struct ccw_device *cdev = data;
1110 	int ret;
1111 
1112 	ret = ccw_device_set_online(cdev);
1113 	if (ret)
1114 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1115 }
1116 
1117 static int virtio_ccw_probe(struct ccw_device *cdev)
1118 {
1119 	cdev->handler = virtio_ccw_int_handler;
1120 
1121 	if (virtio_ccw_check_autoonline(cdev))
1122 		async_schedule(virtio_ccw_auto_online, cdev);
1123 	return 0;
1124 }
1125 
1126 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1127 {
1128 	unsigned long flags;
1129 	struct virtio_ccw_device *vcdev;
1130 
1131 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1132 	vcdev = dev_get_drvdata(&cdev->dev);
1133 	if (!vcdev || vcdev->going_away) {
1134 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1135 		return NULL;
1136 	}
1137 	vcdev->going_away = true;
1138 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1139 	return vcdev;
1140 }
1141 
1142 static void virtio_ccw_remove(struct ccw_device *cdev)
1143 {
1144 	unsigned long flags;
1145 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1146 
1147 	if (vcdev && cdev->online) {
1148 		if (vcdev->device_lost)
1149 			virtio_break_device(&vcdev->vdev);
1150 		unregister_virtio_device(&vcdev->vdev);
1151 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1152 		dev_set_drvdata(&cdev->dev, NULL);
1153 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1154 	}
1155 	cdev->handler = NULL;
1156 }
1157 
1158 static int virtio_ccw_offline(struct ccw_device *cdev)
1159 {
1160 	unsigned long flags;
1161 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1162 
1163 	if (!vcdev)
1164 		return 0;
1165 	if (vcdev->device_lost)
1166 		virtio_break_device(&vcdev->vdev);
1167 	unregister_virtio_device(&vcdev->vdev);
1168 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1169 	dev_set_drvdata(&cdev->dev, NULL);
1170 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1171 	return 0;
1172 }
1173 
1174 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1175 {
1176 	struct virtio_rev_info *rev;
1177 	struct ccw1 *ccw;
1178 	int ret;
1179 
1180 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1181 	if (!ccw)
1182 		return -ENOMEM;
1183 	rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1184 	if (!rev) {
1185 		kfree(ccw);
1186 		return -ENOMEM;
1187 	}
1188 
1189 	/* Set transport revision */
1190 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1191 	ccw->flags = 0;
1192 	ccw->count = sizeof(*rev);
1193 	ccw->cda = (__u32)(unsigned long)rev;
1194 
1195 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1196 	do {
1197 		rev->revision = vcdev->revision;
1198 		/* none of our supported revisions carry payload */
1199 		rev->length = 0;
1200 		ret = ccw_io_helper(vcdev, ccw,
1201 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1202 		if (ret == -EOPNOTSUPP) {
1203 			if (vcdev->revision == 0)
1204 				/*
1205 				 * The host device does not support setting
1206 				 * the revision: let's operate it in legacy
1207 				 * mode.
1208 				 */
1209 				ret = 0;
1210 			else
1211 				vcdev->revision--;
1212 		}
1213 	} while (ret == -EOPNOTSUPP);
1214 
1215 	kfree(ccw);
1216 	kfree(rev);
1217 	return ret;
1218 }
1219 
1220 static int virtio_ccw_online(struct ccw_device *cdev)
1221 {
1222 	int ret;
1223 	struct virtio_ccw_device *vcdev;
1224 	unsigned long flags;
1225 
1226 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1227 	if (!vcdev) {
1228 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1229 		ret = -ENOMEM;
1230 		goto out_free;
1231 	}
1232 	vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1233 				   GFP_DMA | GFP_KERNEL);
1234 	if (!vcdev->config_block) {
1235 		ret = -ENOMEM;
1236 		goto out_free;
1237 	}
1238 	vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1239 	if (!vcdev->status) {
1240 		ret = -ENOMEM;
1241 		goto out_free;
1242 	}
1243 
1244 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1245 
1246 	vcdev->vdev.dev.parent = &cdev->dev;
1247 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1248 	vcdev->vdev.config = &virtio_ccw_config_ops;
1249 	vcdev->cdev = cdev;
1250 	init_waitqueue_head(&vcdev->wait_q);
1251 	INIT_LIST_HEAD(&vcdev->virtqueues);
1252 	spin_lock_init(&vcdev->lock);
1253 
1254 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1255 	dev_set_drvdata(&cdev->dev, vcdev);
1256 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1257 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1258 	vcdev->vdev.id.device = cdev->id.cu_model;
1259 
1260 	ret = virtio_ccw_set_transport_rev(vcdev);
1261 	if (ret)
1262 		goto out_free;
1263 
1264 	ret = register_virtio_device(&vcdev->vdev);
1265 	if (ret) {
1266 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1267 			 ret);
1268 		goto out_put;
1269 	}
1270 	return 0;
1271 out_put:
1272 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1273 	dev_set_drvdata(&cdev->dev, NULL);
1274 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1275 	put_device(&vcdev->vdev.dev);
1276 	return ret;
1277 out_free:
1278 	if (vcdev) {
1279 		kfree(vcdev->status);
1280 		kfree(vcdev->config_block);
1281 	}
1282 	kfree(vcdev);
1283 	return ret;
1284 }
1285 
1286 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1287 {
1288 	int rc;
1289 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1290 
1291 	/*
1292 	 * Make sure vcdev is set
1293 	 * i.e. set_offline/remove callback not already running
1294 	 */
1295 	if (!vcdev)
1296 		return NOTIFY_DONE;
1297 
1298 	switch (event) {
1299 	case CIO_GONE:
1300 		vcdev->device_lost = true;
1301 		rc = NOTIFY_DONE;
1302 		break;
1303 	default:
1304 		rc = NOTIFY_DONE;
1305 		break;
1306 	}
1307 	return rc;
1308 }
1309 
1310 static struct ccw_device_id virtio_ids[] = {
1311 	{ CCW_DEVICE(0x3832, 0) },
1312 	{},
1313 };
1314 
1315 static struct ccw_driver virtio_ccw_driver = {
1316 	.driver = {
1317 		.owner = THIS_MODULE,
1318 		.name = "virtio_ccw",
1319 	},
1320 	.ids = virtio_ids,
1321 	.probe = virtio_ccw_probe,
1322 	.remove = virtio_ccw_remove,
1323 	.set_offline = virtio_ccw_offline,
1324 	.set_online = virtio_ccw_online,
1325 	.notify = virtio_ccw_cio_notify,
1326 	.int_class = IRQIO_VIR,
1327 };
1328 
1329 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1330 			   int max_digit, int max_val)
1331 {
1332 	int diff;
1333 
1334 	diff = 0;
1335 	*val = 0;
1336 
1337 	while (diff <= max_digit) {
1338 		int value = hex_to_bin(**cp);
1339 
1340 		if (value < 0)
1341 			break;
1342 		*val = *val * 16 + value;
1343 		(*cp)++;
1344 		diff++;
1345 	}
1346 
1347 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1348 		return 1;
1349 
1350 	return 0;
1351 }
1352 
1353 static int __init parse_busid(char *str, unsigned int *cssid,
1354 			      unsigned int *ssid, unsigned int *devno)
1355 {
1356 	char *str_work;
1357 	int rc, ret;
1358 
1359 	rc = 1;
1360 
1361 	if (*str == '\0')
1362 		goto out;
1363 
1364 	str_work = str;
1365 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1366 	if (ret || (str_work[0] != '.'))
1367 		goto out;
1368 	str_work++;
1369 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1370 	if (ret || (str_work[0] != '.'))
1371 		goto out;
1372 	str_work++;
1373 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1374 	if (ret || (str_work[0] != '\0'))
1375 		goto out;
1376 
1377 	rc = 0;
1378 out:
1379 	return rc;
1380 }
1381 
1382 static void __init no_auto_parse(void)
1383 {
1384 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1385 	char *parm, *str;
1386 	int rc;
1387 
1388 	str = no_auto;
1389 	while ((parm = strsep(&str, ","))) {
1390 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1391 				 &from_ssid, &from);
1392 		if (rc)
1393 			continue;
1394 		if (parm != NULL) {
1395 			rc = parse_busid(parm, &to_cssid,
1396 					 &to_ssid, &to);
1397 			if ((from_ssid > to_ssid) ||
1398 			    ((from_ssid == to_ssid) && (from > to)))
1399 				rc = -EINVAL;
1400 		} else {
1401 			to_cssid = from_cssid;
1402 			to_ssid = from_ssid;
1403 			to = from;
1404 		}
1405 		if (rc)
1406 			continue;
1407 		while ((from_ssid < to_ssid) ||
1408 		       ((from_ssid == to_ssid) && (from <= to))) {
1409 			set_bit(from, devs_no_auto[from_ssid]);
1410 			from++;
1411 			if (from > __MAX_SUBCHANNEL) {
1412 				from_ssid++;
1413 				from = 0;
1414 			}
1415 		}
1416 	}
1417 }
1418 
1419 static int __init virtio_ccw_init(void)
1420 {
1421 	/* parse no_auto string before we do anything further */
1422 	no_auto_parse();
1423 	return ccw_driver_register(&virtio_ccw_driver);
1424 }
1425 device_initcall(virtio_ccw_init);
1426