xref: /openbmc/linux/drivers/s390/virtio/virtio_ccw.c (revision bb3982b4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ccw based virtio transport
4  *
5  * Copyright IBM Corp. 2012, 2014
6  *
7  *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
8  */
9 
10 #include <linux/kernel_stat.h>
11 #include <linux/init.h>
12 #include <linux/memblock.h>
13 #include <linux/err.h>
14 #include <linux/virtio.h>
15 #include <linux/virtio_config.h>
16 #include <linux/slab.h>
17 #include <linux/interrupt.h>
18 #include <linux/virtio_ring.h>
19 #include <linux/pfn.h>
20 #include <linux/async.h>
21 #include <linux/wait.h>
22 #include <linux/list.h>
23 #include <linux/bitops.h>
24 #include <linux/moduleparam.h>
25 #include <linux/io.h>
26 #include <linux/kvm_para.h>
27 #include <linux/notifier.h>
28 #include <asm/diag.h>
29 #include <asm/setup.h>
30 #include <asm/irq.h>
31 #include <asm/cio.h>
32 #include <asm/ccwdev.h>
33 #include <asm/virtio-ccw.h>
34 #include <asm/isc.h>
35 #include <asm/airq.h>
36 
37 /*
38  * virtio related functions
39  */
40 
41 struct vq_config_block {
42 	__u16 index;
43 	__u16 num;
44 } __packed;
45 
46 #define VIRTIO_CCW_CONFIG_SIZE 0x100
47 /* same as PCI config space size, should be enough for all drivers */
48 
49 struct virtio_ccw_device {
50 	struct virtio_device vdev;
51 	__u8 *status;
52 	__u8 config[VIRTIO_CCW_CONFIG_SIZE];
53 	struct ccw_device *cdev;
54 	__u32 curr_io;
55 	int err;
56 	unsigned int revision; /* Transport revision */
57 	wait_queue_head_t wait_q;
58 	spinlock_t lock;
59 	struct mutex io_lock; /* Serializes I/O requests */
60 	struct list_head virtqueues;
61 	unsigned long indicators;
62 	unsigned long indicators2;
63 	struct vq_config_block *config_block;
64 	bool is_thinint;
65 	bool going_away;
66 	bool device_lost;
67 	unsigned int config_ready;
68 	void *airq_info;
69 	u64 dma_mask;
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 	__le32 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 	union {
113 		struct vq_info_block s;
114 		struct vq_info_block_legacy l;
115 	} *info_block;
116 	int bit_nr;
117 	struct list_head node;
118 	long cookie;
119 };
120 
121 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
122 
123 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
124 #define MAX_AIRQ_AREAS 20
125 
126 static int virtio_ccw_use_airq = 1;
127 
128 struct airq_info {
129 	rwlock_t lock;
130 	u8 summary_indicator;
131 	struct airq_struct airq;
132 	struct airq_iv *aiv;
133 };
134 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
135 
136 #define CCW_CMD_SET_VQ 0x13
137 #define CCW_CMD_VDEV_RESET 0x33
138 #define CCW_CMD_SET_IND 0x43
139 #define CCW_CMD_SET_CONF_IND 0x53
140 #define CCW_CMD_READ_FEAT 0x12
141 #define CCW_CMD_WRITE_FEAT 0x11
142 #define CCW_CMD_READ_CONF 0x22
143 #define CCW_CMD_WRITE_CONF 0x21
144 #define CCW_CMD_WRITE_STATUS 0x31
145 #define CCW_CMD_READ_VQ_CONF 0x32
146 #define CCW_CMD_READ_STATUS 0x72
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_DOING_READ_STATUS 0x20000000
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, bool floating)
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 	if (!vcdev->airq_info)
276 		return;
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 	mutex_lock(&vcdev->io_lock);
303 	do {
304 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
305 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
306 		if (!ret) {
307 			if (!vcdev->curr_io)
308 				vcdev->err = 0;
309 			vcdev->curr_io |= flag;
310 		}
311 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
312 		cpu_relax();
313 	} while (ret == -EBUSY);
314 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
315 	ret = ret ? ret : vcdev->err;
316 	mutex_unlock(&vcdev->io_lock);
317 	return ret;
318 }
319 
320 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
321 				      struct ccw1 *ccw)
322 {
323 	int ret;
324 	unsigned long *indicatorp = NULL;
325 	struct virtio_thinint_area *thinint_area = NULL;
326 	struct airq_info *airq_info = vcdev->airq_info;
327 
328 	if (vcdev->is_thinint) {
329 		thinint_area = kzalloc(sizeof(*thinint_area),
330 				       GFP_DMA | GFP_KERNEL);
331 		if (!thinint_area)
332 			return;
333 		thinint_area->summary_indicator =
334 			(unsigned long) &airq_info->summary_indicator;
335 		thinint_area->isc = VIRTIO_AIRQ_ISC;
336 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
337 		ccw->count = sizeof(*thinint_area);
338 		ccw->cda = (__u32)(unsigned long) thinint_area;
339 	} else {
340 		/* payload is the address of the indicators */
341 		indicatorp = kmalloc(sizeof(&vcdev->indicators),
342 				     GFP_DMA | GFP_KERNEL);
343 		if (!indicatorp)
344 			return;
345 		*indicatorp = 0;
346 		ccw->cmd_code = CCW_CMD_SET_IND;
347 		ccw->count = sizeof(&vcdev->indicators);
348 		ccw->cda = (__u32)(unsigned long) indicatorp;
349 	}
350 	/* Deregister indicators from host. */
351 	vcdev->indicators = 0;
352 	ccw->flags = 0;
353 	ret = ccw_io_helper(vcdev, ccw,
354 			    vcdev->is_thinint ?
355 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
356 			    VIRTIO_CCW_DOING_SET_IND);
357 	if (ret && (ret != -ENODEV))
358 		dev_info(&vcdev->cdev->dev,
359 			 "Failed to deregister indicators (%d)\n", ret);
360 	else if (vcdev->is_thinint)
361 		virtio_ccw_drop_indicators(vcdev);
362 	kfree(indicatorp);
363 	kfree(thinint_area);
364 }
365 
366 static inline long __do_kvm_notify(struct subchannel_id schid,
367 				   unsigned long queue_index,
368 				   long cookie)
369 {
370 	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
371 	register struct subchannel_id __schid asm("2") = schid;
372 	register unsigned long __index asm("3") = queue_index;
373 	register long __rc asm("2");
374 	register long __cookie asm("4") = cookie;
375 
376 	asm volatile ("diag 2,4,0x500\n"
377 		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
378 		      "d"(__cookie)
379 		      : "memory", "cc");
380 	return __rc;
381 }
382 
383 static inline long do_kvm_notify(struct subchannel_id schid,
384 				 unsigned long queue_index,
385 				 long cookie)
386 {
387 	diag_stat_inc(DIAG_STAT_X500);
388 	return __do_kvm_notify(schid, queue_index, cookie);
389 }
390 
391 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
392 {
393 	struct virtio_ccw_vq_info *info = vq->priv;
394 	struct virtio_ccw_device *vcdev;
395 	struct subchannel_id schid;
396 
397 	vcdev = to_vc_device(info->vq->vdev);
398 	ccw_device_get_schid(vcdev->cdev, &schid);
399 	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
400 	if (info->cookie < 0)
401 		return false;
402 	return true;
403 }
404 
405 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
406 				   struct ccw1 *ccw, int index)
407 {
408 	int ret;
409 
410 	vcdev->config_block->index = index;
411 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
412 	ccw->flags = 0;
413 	ccw->count = sizeof(struct vq_config_block);
414 	ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
415 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
416 	if (ret)
417 		return ret;
418 	return vcdev->config_block->num ?: -ENOENT;
419 }
420 
421 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
422 {
423 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
424 	struct virtio_ccw_vq_info *info = vq->priv;
425 	unsigned long flags;
426 	int ret;
427 	unsigned int index = vq->index;
428 
429 	/* Remove from our list. */
430 	spin_lock_irqsave(&vcdev->lock, flags);
431 	list_del(&info->node);
432 	spin_unlock_irqrestore(&vcdev->lock, flags);
433 
434 	/* Release from host. */
435 	if (vcdev->revision == 0) {
436 		info->info_block->l.queue = 0;
437 		info->info_block->l.align = 0;
438 		info->info_block->l.index = index;
439 		info->info_block->l.num = 0;
440 		ccw->count = sizeof(info->info_block->l);
441 	} else {
442 		info->info_block->s.desc = 0;
443 		info->info_block->s.index = index;
444 		info->info_block->s.num = 0;
445 		info->info_block->s.avail = 0;
446 		info->info_block->s.used = 0;
447 		ccw->count = sizeof(info->info_block->s);
448 	}
449 	ccw->cmd_code = CCW_CMD_SET_VQ;
450 	ccw->flags = 0;
451 	ccw->cda = (__u32)(unsigned long)(info->info_block);
452 	ret = ccw_io_helper(vcdev, ccw,
453 			    VIRTIO_CCW_DOING_SET_VQ | index);
454 	/*
455 	 * -ENODEV isn't considered an error: The device is gone anyway.
456 	 * This may happen on device detach.
457 	 */
458 	if (ret && (ret != -ENODEV))
459 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
460 			 ret, index);
461 
462 	vring_del_virtqueue(vq);
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 	u64 queue;
495 	unsigned long flags;
496 	bool may_reduce;
497 
498 	/* Allocate queue. */
499 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
500 	if (!info) {
501 		dev_warn(&vcdev->cdev->dev, "no info\n");
502 		err = -ENOMEM;
503 		goto out_err;
504 	}
505 	info->info_block = kzalloc(sizeof(*info->info_block),
506 				   GFP_DMA | GFP_KERNEL);
507 	if (!info->info_block) {
508 		dev_warn(&vcdev->cdev->dev, "no info block\n");
509 		err = -ENOMEM;
510 		goto out_err;
511 	}
512 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
513 	if (info->num < 0) {
514 		err = info->num;
515 		goto out_err;
516 	}
517 	may_reduce = vcdev->revision > 0;
518 	vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
519 				    vdev, true, may_reduce, ctx,
520 				    virtio_ccw_kvm_notify, callback, name);
521 
522 	if (!vq) {
523 		/* For now, we fail if we can't get the requested size. */
524 		dev_warn(&vcdev->cdev->dev, "no vq\n");
525 		err = -ENOMEM;
526 		goto out_err;
527 	}
528 	/* it may have been reduced */
529 	info->num = virtqueue_get_vring_size(vq);
530 
531 	/* Register it with the host. */
532 	queue = virtqueue_get_desc_addr(vq);
533 	if (vcdev->revision == 0) {
534 		info->info_block->l.queue = 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 = 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_addr(vq);
544 		info->info_block->s.used = (__u64)virtqueue_get_used_addr(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 		kfree(info->info_block);
571 	}
572 	kfree(info);
573 	return ERR_PTR(err);
574 }
575 
576 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
577 					   struct virtqueue *vqs[], int nvqs,
578 					   struct ccw1 *ccw)
579 {
580 	int ret;
581 	struct virtio_thinint_area *thinint_area = NULL;
582 	struct airq_info *info;
583 
584 	thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
585 	if (!thinint_area) {
586 		ret = -ENOMEM;
587 		goto out;
588 	}
589 	/* Try to get an indicator. */
590 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
591 						     &thinint_area->bit_nr,
592 						     &vcdev->airq_info);
593 	if (!thinint_area->indicator) {
594 		ret = -ENOSPC;
595 		goto out;
596 	}
597 	info = vcdev->airq_info;
598 	thinint_area->summary_indicator =
599 		(unsigned long) &info->summary_indicator;
600 	thinint_area->isc = VIRTIO_AIRQ_ISC;
601 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
602 	ccw->flags = CCW_FLAG_SLI;
603 	ccw->count = sizeof(*thinint_area);
604 	ccw->cda = (__u32)(unsigned long)thinint_area;
605 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
606 	if (ret) {
607 		if (ret == -EOPNOTSUPP) {
608 			/*
609 			 * The host does not support adapter interrupts
610 			 * for virtio-ccw, stop trying.
611 			 */
612 			virtio_ccw_use_airq = 0;
613 			pr_info("Adapter interrupts unsupported on host\n");
614 		} else
615 			dev_warn(&vcdev->cdev->dev,
616 				 "enabling adapter interrupts = %d\n", ret);
617 		virtio_ccw_drop_indicators(vcdev);
618 	}
619 out:
620 	kfree(thinint_area);
621 	return ret;
622 }
623 
624 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
625 			       struct virtqueue *vqs[],
626 			       vq_callback_t *callbacks[],
627 			       const char * const names[],
628 			       const bool *ctx,
629 			       struct irq_affinity *desc)
630 {
631 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
632 	unsigned long *indicatorp = NULL;
633 	int ret, i, queue_idx = 0;
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 		if (!names[i]) {
642 			vqs[i] = NULL;
643 			continue;
644 		}
645 
646 		vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, callbacks[i],
647 					     names[i], ctx ? ctx[i] : false,
648 					     ccw);
649 		if (IS_ERR(vqs[i])) {
650 			ret = PTR_ERR(vqs[i]);
651 			vqs[i] = NULL;
652 			goto out;
653 		}
654 	}
655 	ret = -ENOMEM;
656 	/*
657 	 * We need a data area under 2G to communicate. Our payload is
658 	 * the address of the indicators.
659 	*/
660 	indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
661 	if (!indicatorp)
662 		goto out;
663 	*indicatorp = (unsigned long) &vcdev->indicators;
664 	if (vcdev->is_thinint) {
665 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
666 		if (ret)
667 			/* no error, just fall back to legacy interrupts */
668 			vcdev->is_thinint = false;
669 	}
670 	if (!vcdev->is_thinint) {
671 		/* Register queue indicators with host. */
672 		vcdev->indicators = 0;
673 		ccw->cmd_code = CCW_CMD_SET_IND;
674 		ccw->flags = 0;
675 		ccw->count = sizeof(&vcdev->indicators);
676 		ccw->cda = (__u32)(unsigned long) indicatorp;
677 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
678 		if (ret)
679 			goto out;
680 	}
681 	/* Register indicators2 with host for config changes */
682 	*indicatorp = (unsigned long) &vcdev->indicators2;
683 	vcdev->indicators2 = 0;
684 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
685 	ccw->flags = 0;
686 	ccw->count = sizeof(&vcdev->indicators2);
687 	ccw->cda = (__u32)(unsigned long) indicatorp;
688 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
689 	if (ret)
690 		goto out;
691 
692 	kfree(indicatorp);
693 	kfree(ccw);
694 	return 0;
695 out:
696 	kfree(indicatorp);
697 	kfree(ccw);
698 	virtio_ccw_del_vqs(vdev);
699 	return ret;
700 }
701 
702 static void virtio_ccw_reset(struct virtio_device *vdev)
703 {
704 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
705 	struct ccw1 *ccw;
706 
707 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
708 	if (!ccw)
709 		return;
710 
711 	/* Zero status bits. */
712 	*vcdev->status = 0;
713 
714 	/* Send a reset ccw on device. */
715 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
716 	ccw->flags = 0;
717 	ccw->count = 0;
718 	ccw->cda = 0;
719 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
720 	kfree(ccw);
721 }
722 
723 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
724 {
725 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
726 	struct virtio_feature_desc *features;
727 	int ret;
728 	u64 rc;
729 	struct ccw1 *ccw;
730 
731 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
732 	if (!ccw)
733 		return 0;
734 
735 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
736 	if (!features) {
737 		rc = 0;
738 		goto out_free;
739 	}
740 	/* Read the feature bits from the host. */
741 	features->index = 0;
742 	ccw->cmd_code = CCW_CMD_READ_FEAT;
743 	ccw->flags = 0;
744 	ccw->count = sizeof(*features);
745 	ccw->cda = (__u32)(unsigned long)features;
746 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
747 	if (ret) {
748 		rc = 0;
749 		goto out_free;
750 	}
751 
752 	rc = le32_to_cpu(features->features);
753 
754 	if (vcdev->revision == 0)
755 		goto out_free;
756 
757 	/* Read second half of the feature bits from the host. */
758 	features->index = 1;
759 	ccw->cmd_code = CCW_CMD_READ_FEAT;
760 	ccw->flags = 0;
761 	ccw->count = sizeof(*features);
762 	ccw->cda = (__u32)(unsigned long)features;
763 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
764 	if (ret == 0)
765 		rc |= (u64)le32_to_cpu(features->features) << 32;
766 
767 out_free:
768 	kfree(features);
769 	kfree(ccw);
770 	return rc;
771 }
772 
773 static void ccw_transport_features(struct virtio_device *vdev)
774 {
775 	/*
776 	 * Currently nothing to do here.
777 	 */
778 }
779 
780 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
781 {
782 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
783 	struct virtio_feature_desc *features;
784 	struct ccw1 *ccw;
785 	int ret;
786 
787 	if (vcdev->revision >= 1 &&
788 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
789 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
790 			"but does not have VIRTIO_F_VERSION_1\n");
791 		return -EINVAL;
792 	}
793 
794 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
795 	if (!ccw)
796 		return -ENOMEM;
797 
798 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
799 	if (!features) {
800 		ret = -ENOMEM;
801 		goto out_free;
802 	}
803 	/* Give virtio_ring a chance to accept features. */
804 	vring_transport_features(vdev);
805 
806 	/* Give virtio_ccw a chance to accept features. */
807 	ccw_transport_features(vdev);
808 
809 	features->index = 0;
810 	features->features = cpu_to_le32((u32)vdev->features);
811 	/* Write the first half of the feature bits to the host. */
812 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
813 	ccw->flags = 0;
814 	ccw->count = sizeof(*features);
815 	ccw->cda = (__u32)(unsigned long)features;
816 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
817 	if (ret)
818 		goto out_free;
819 
820 	if (vcdev->revision == 0)
821 		goto out_free;
822 
823 	features->index = 1;
824 	features->features = cpu_to_le32(vdev->features >> 32);
825 	/* Write the second half of the feature bits to the host. */
826 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
827 	ccw->flags = 0;
828 	ccw->count = sizeof(*features);
829 	ccw->cda = (__u32)(unsigned long)features;
830 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
831 
832 out_free:
833 	kfree(features);
834 	kfree(ccw);
835 
836 	return ret;
837 }
838 
839 static void virtio_ccw_get_config(struct virtio_device *vdev,
840 				  unsigned int offset, void *buf, unsigned len)
841 {
842 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
843 	int ret;
844 	struct ccw1 *ccw;
845 	void *config_area;
846 	unsigned long flags;
847 
848 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
849 	if (!ccw)
850 		return;
851 
852 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
853 	if (!config_area)
854 		goto out_free;
855 
856 	/* Read the config area from the host. */
857 	ccw->cmd_code = CCW_CMD_READ_CONF;
858 	ccw->flags = 0;
859 	ccw->count = offset + len;
860 	ccw->cda = (__u32)(unsigned long)config_area;
861 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
862 	if (ret)
863 		goto out_free;
864 
865 	spin_lock_irqsave(&vcdev->lock, flags);
866 	memcpy(vcdev->config, config_area, offset + len);
867 	if (vcdev->config_ready < offset + len)
868 		vcdev->config_ready = offset + len;
869 	spin_unlock_irqrestore(&vcdev->lock, flags);
870 	if (buf)
871 		memcpy(buf, config_area + offset, len);
872 
873 out_free:
874 	kfree(config_area);
875 	kfree(ccw);
876 }
877 
878 static void virtio_ccw_set_config(struct virtio_device *vdev,
879 				  unsigned int offset, const void *buf,
880 				  unsigned len)
881 {
882 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
883 	struct ccw1 *ccw;
884 	void *config_area;
885 	unsigned long flags;
886 
887 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
888 	if (!ccw)
889 		return;
890 
891 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
892 	if (!config_area)
893 		goto out_free;
894 
895 	/* Make sure we don't overwrite fields. */
896 	if (vcdev->config_ready < offset)
897 		virtio_ccw_get_config(vdev, 0, NULL, offset);
898 	spin_lock_irqsave(&vcdev->lock, flags);
899 	memcpy(&vcdev->config[offset], buf, len);
900 	/* Write the config area to the host. */
901 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
902 	spin_unlock_irqrestore(&vcdev->lock, flags);
903 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
904 	ccw->flags = 0;
905 	ccw->count = offset + len;
906 	ccw->cda = (__u32)(unsigned long)config_area;
907 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
908 
909 out_free:
910 	kfree(config_area);
911 	kfree(ccw);
912 }
913 
914 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
915 {
916 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
917 	u8 old_status = *vcdev->status;
918 	struct ccw1 *ccw;
919 
920 	if (vcdev->revision < 1)
921 		return *vcdev->status;
922 
923 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
924 	if (!ccw)
925 		return old_status;
926 
927 	ccw->cmd_code = CCW_CMD_READ_STATUS;
928 	ccw->flags = 0;
929 	ccw->count = sizeof(*vcdev->status);
930 	ccw->cda = (__u32)(unsigned long)vcdev->status;
931 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
932 /*
933  * If the channel program failed (should only happen if the device
934  * was hotunplugged, and then we clean up via the machine check
935  * handler anyway), vcdev->status was not overwritten and we just
936  * return the old status, which is fine.
937 */
938 	kfree(ccw);
939 
940 	return *vcdev->status;
941 }
942 
943 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
944 {
945 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
946 	u8 old_status = *vcdev->status;
947 	struct ccw1 *ccw;
948 	int ret;
949 
950 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
951 	if (!ccw)
952 		return;
953 
954 	/* Write the status to the host. */
955 	*vcdev->status = status;
956 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
957 	ccw->flags = 0;
958 	ccw->count = sizeof(status);
959 	ccw->cda = (__u32)(unsigned long)vcdev->status;
960 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
961 	/* Write failed? We assume status is unchanged. */
962 	if (ret)
963 		*vcdev->status = old_status;
964 	kfree(ccw);
965 }
966 
967 static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
968 {
969 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
970 
971 	return dev_name(&vcdev->cdev->dev);
972 }
973 
974 static const struct virtio_config_ops virtio_ccw_config_ops = {
975 	.get_features = virtio_ccw_get_features,
976 	.finalize_features = virtio_ccw_finalize_features,
977 	.get = virtio_ccw_get_config,
978 	.set = virtio_ccw_set_config,
979 	.get_status = virtio_ccw_get_status,
980 	.set_status = virtio_ccw_set_status,
981 	.reset = virtio_ccw_reset,
982 	.find_vqs = virtio_ccw_find_vqs,
983 	.del_vqs = virtio_ccw_del_vqs,
984 	.bus_name = virtio_ccw_bus_name,
985 };
986 
987 
988 /*
989  * ccw bus driver related functions
990  */
991 
992 static void virtio_ccw_release_dev(struct device *_d)
993 {
994 	struct virtio_device *dev = dev_to_virtio(_d);
995 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
996 
997 	kfree(vcdev->status);
998 	kfree(vcdev->config_block);
999 	kfree(vcdev);
1000 }
1001 
1002 static int irb_is_error(struct irb *irb)
1003 {
1004 	if (scsw_cstat(&irb->scsw) != 0)
1005 		return 1;
1006 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1007 		return 1;
1008 	if (scsw_cc(&irb->scsw) != 0)
1009 		return 1;
1010 	return 0;
1011 }
1012 
1013 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1014 					      int index)
1015 {
1016 	struct virtio_ccw_vq_info *info;
1017 	unsigned long flags;
1018 	struct virtqueue *vq;
1019 
1020 	vq = NULL;
1021 	spin_lock_irqsave(&vcdev->lock, flags);
1022 	list_for_each_entry(info, &vcdev->virtqueues, node) {
1023 		if (info->vq->index == index) {
1024 			vq = info->vq;
1025 			break;
1026 		}
1027 	}
1028 	spin_unlock_irqrestore(&vcdev->lock, flags);
1029 	return vq;
1030 }
1031 
1032 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1033 				      __u32 activity)
1034 {
1035 	if (vcdev->curr_io & activity) {
1036 		switch (activity) {
1037 		case VIRTIO_CCW_DOING_READ_FEAT:
1038 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1039 		case VIRTIO_CCW_DOING_READ_CONFIG:
1040 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1041 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1042 		case VIRTIO_CCW_DOING_READ_STATUS:
1043 		case VIRTIO_CCW_DOING_SET_VQ:
1044 		case VIRTIO_CCW_DOING_SET_IND:
1045 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1046 		case VIRTIO_CCW_DOING_RESET:
1047 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1048 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1049 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1050 			vcdev->curr_io &= ~activity;
1051 			wake_up(&vcdev->wait_q);
1052 			break;
1053 		default:
1054 			/* don't know what to do... */
1055 			dev_warn(&vcdev->cdev->dev,
1056 				 "Suspicious activity '%08x'\n", activity);
1057 			WARN_ON(1);
1058 			break;
1059 		}
1060 	}
1061 }
1062 
1063 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1064 				   unsigned long intparm,
1065 				   struct irb *irb)
1066 {
1067 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1068 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1069 	int i;
1070 	struct virtqueue *vq;
1071 
1072 	if (!vcdev)
1073 		return;
1074 	if (IS_ERR(irb)) {
1075 		vcdev->err = PTR_ERR(irb);
1076 		virtio_ccw_check_activity(vcdev, activity);
1077 		/* Don't poke around indicators, something's wrong. */
1078 		return;
1079 	}
1080 	/* Check if it's a notification from the host. */
1081 	if ((intparm == 0) &&
1082 	    (scsw_stctl(&irb->scsw) ==
1083 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1084 		/* OK */
1085 	}
1086 	if (irb_is_error(irb)) {
1087 		/* Command reject? */
1088 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1089 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1090 			vcdev->err = -EOPNOTSUPP;
1091 		else
1092 			/* Map everything else to -EIO. */
1093 			vcdev->err = -EIO;
1094 	}
1095 	virtio_ccw_check_activity(vcdev, activity);
1096 	for_each_set_bit(i, &vcdev->indicators,
1097 			 sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1098 		/* The bit clear must happen before the vring kick. */
1099 		clear_bit(i, &vcdev->indicators);
1100 		barrier();
1101 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1102 		vring_interrupt(0, vq);
1103 	}
1104 	if (test_bit(0, &vcdev->indicators2)) {
1105 		virtio_config_changed(&vcdev->vdev);
1106 		clear_bit(0, &vcdev->indicators2);
1107 	}
1108 }
1109 
1110 /*
1111  * We usually want to autoonline all devices, but give the admin
1112  * a way to exempt devices from this.
1113  */
1114 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1115 		     (8*sizeof(long)))
1116 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1117 
1118 static char *no_auto = "";
1119 
1120 module_param(no_auto, charp, 0444);
1121 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1122 
1123 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1124 {
1125 	struct ccw_dev_id id;
1126 
1127 	ccw_device_get_id(cdev, &id);
1128 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1129 		return 0;
1130 	return 1;
1131 }
1132 
1133 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1134 {
1135 	struct ccw_device *cdev = data;
1136 	int ret;
1137 
1138 	ret = ccw_device_set_online(cdev);
1139 	if (ret)
1140 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1141 }
1142 
1143 static int virtio_ccw_probe(struct ccw_device *cdev)
1144 {
1145 	cdev->handler = virtio_ccw_int_handler;
1146 
1147 	if (virtio_ccw_check_autoonline(cdev))
1148 		async_schedule(virtio_ccw_auto_online, cdev);
1149 	return 0;
1150 }
1151 
1152 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1153 {
1154 	unsigned long flags;
1155 	struct virtio_ccw_device *vcdev;
1156 
1157 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1158 	vcdev = dev_get_drvdata(&cdev->dev);
1159 	if (!vcdev || vcdev->going_away) {
1160 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1161 		return NULL;
1162 	}
1163 	vcdev->going_away = true;
1164 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1165 	return vcdev;
1166 }
1167 
1168 static void virtio_ccw_remove(struct ccw_device *cdev)
1169 {
1170 	unsigned long flags;
1171 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1172 
1173 	if (vcdev && cdev->online) {
1174 		if (vcdev->device_lost)
1175 			virtio_break_device(&vcdev->vdev);
1176 		unregister_virtio_device(&vcdev->vdev);
1177 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1178 		dev_set_drvdata(&cdev->dev, NULL);
1179 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1180 	}
1181 	cdev->handler = NULL;
1182 }
1183 
1184 static int virtio_ccw_offline(struct ccw_device *cdev)
1185 {
1186 	unsigned long flags;
1187 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1188 
1189 	if (!vcdev)
1190 		return 0;
1191 	if (vcdev->device_lost)
1192 		virtio_break_device(&vcdev->vdev);
1193 	unregister_virtio_device(&vcdev->vdev);
1194 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1195 	dev_set_drvdata(&cdev->dev, NULL);
1196 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1197 	return 0;
1198 }
1199 
1200 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1201 {
1202 	struct virtio_rev_info *rev;
1203 	struct ccw1 *ccw;
1204 	int ret;
1205 
1206 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1207 	if (!ccw)
1208 		return -ENOMEM;
1209 	rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1210 	if (!rev) {
1211 		kfree(ccw);
1212 		return -ENOMEM;
1213 	}
1214 
1215 	/* Set transport revision */
1216 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1217 	ccw->flags = 0;
1218 	ccw->count = sizeof(*rev);
1219 	ccw->cda = (__u32)(unsigned long)rev;
1220 
1221 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1222 	do {
1223 		rev->revision = vcdev->revision;
1224 		/* none of our supported revisions carry payload */
1225 		rev->length = 0;
1226 		ret = ccw_io_helper(vcdev, ccw,
1227 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1228 		if (ret == -EOPNOTSUPP) {
1229 			if (vcdev->revision == 0)
1230 				/*
1231 				 * The host device does not support setting
1232 				 * the revision: let's operate it in legacy
1233 				 * mode.
1234 				 */
1235 				ret = 0;
1236 			else
1237 				vcdev->revision--;
1238 		}
1239 	} while (ret == -EOPNOTSUPP);
1240 
1241 	kfree(ccw);
1242 	kfree(rev);
1243 	return ret;
1244 }
1245 
1246 static int virtio_ccw_online(struct ccw_device *cdev)
1247 {
1248 	int ret;
1249 	struct virtio_ccw_device *vcdev;
1250 	unsigned long flags;
1251 
1252 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1253 	if (!vcdev) {
1254 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1255 		ret = -ENOMEM;
1256 		goto out_free;
1257 	}
1258 
1259 	vcdev->vdev.dev.parent = &cdev->dev;
1260 	cdev->dev.dma_mask = &vcdev->dma_mask;
1261 	/* we are fine with common virtio infrastructure using 64 bit DMA */
1262 	ret = dma_set_mask_and_coherent(&cdev->dev, DMA_BIT_MASK(64));
1263 	if (ret) {
1264 		dev_warn(&cdev->dev, "Failed to enable 64-bit DMA.\n");
1265 		goto out_free;
1266 	}
1267 
1268 	vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1269 				   GFP_DMA | GFP_KERNEL);
1270 	if (!vcdev->config_block) {
1271 		ret = -ENOMEM;
1272 		goto out_free;
1273 	}
1274 	vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1275 	if (!vcdev->status) {
1276 		ret = -ENOMEM;
1277 		goto out_free;
1278 	}
1279 
1280 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1281 
1282 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1283 	vcdev->vdev.config = &virtio_ccw_config_ops;
1284 	vcdev->cdev = cdev;
1285 	init_waitqueue_head(&vcdev->wait_q);
1286 	INIT_LIST_HEAD(&vcdev->virtqueues);
1287 	spin_lock_init(&vcdev->lock);
1288 	mutex_init(&vcdev->io_lock);
1289 
1290 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1291 	dev_set_drvdata(&cdev->dev, vcdev);
1292 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1293 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1294 	vcdev->vdev.id.device = cdev->id.cu_model;
1295 
1296 	ret = virtio_ccw_set_transport_rev(vcdev);
1297 	if (ret)
1298 		goto out_free;
1299 
1300 	ret = register_virtio_device(&vcdev->vdev);
1301 	if (ret) {
1302 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1303 			 ret);
1304 		goto out_put;
1305 	}
1306 	return 0;
1307 out_put:
1308 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1309 	dev_set_drvdata(&cdev->dev, NULL);
1310 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1311 	put_device(&vcdev->vdev.dev);
1312 	return ret;
1313 out_free:
1314 	if (vcdev) {
1315 		kfree(vcdev->status);
1316 		kfree(vcdev->config_block);
1317 	}
1318 	kfree(vcdev);
1319 	return ret;
1320 }
1321 
1322 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1323 {
1324 	int rc;
1325 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1326 
1327 	/*
1328 	 * Make sure vcdev is set
1329 	 * i.e. set_offline/remove callback not already running
1330 	 */
1331 	if (!vcdev)
1332 		return NOTIFY_DONE;
1333 
1334 	switch (event) {
1335 	case CIO_GONE:
1336 		vcdev->device_lost = true;
1337 		rc = NOTIFY_DONE;
1338 		break;
1339 	case CIO_OPER:
1340 		rc = NOTIFY_OK;
1341 		break;
1342 	default:
1343 		rc = NOTIFY_DONE;
1344 		break;
1345 	}
1346 	return rc;
1347 }
1348 
1349 static struct ccw_device_id virtio_ids[] = {
1350 	{ CCW_DEVICE(0x3832, 0) },
1351 	{},
1352 };
1353 
1354 #ifdef CONFIG_PM_SLEEP
1355 static int virtio_ccw_freeze(struct ccw_device *cdev)
1356 {
1357 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1358 
1359 	return virtio_device_freeze(&vcdev->vdev);
1360 }
1361 
1362 static int virtio_ccw_restore(struct ccw_device *cdev)
1363 {
1364 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1365 	int ret;
1366 
1367 	ret = virtio_ccw_set_transport_rev(vcdev);
1368 	if (ret)
1369 		return ret;
1370 
1371 	return virtio_device_restore(&vcdev->vdev);
1372 }
1373 #endif
1374 
1375 static struct ccw_driver virtio_ccw_driver = {
1376 	.driver = {
1377 		.owner = THIS_MODULE,
1378 		.name = "virtio_ccw",
1379 	},
1380 	.ids = virtio_ids,
1381 	.probe = virtio_ccw_probe,
1382 	.remove = virtio_ccw_remove,
1383 	.set_offline = virtio_ccw_offline,
1384 	.set_online = virtio_ccw_online,
1385 	.notify = virtio_ccw_cio_notify,
1386 	.int_class = IRQIO_VIR,
1387 #ifdef CONFIG_PM_SLEEP
1388 	.freeze = virtio_ccw_freeze,
1389 	.thaw = virtio_ccw_restore,
1390 	.restore = virtio_ccw_restore,
1391 #endif
1392 };
1393 
1394 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1395 			   int max_digit, int max_val)
1396 {
1397 	int diff;
1398 
1399 	diff = 0;
1400 	*val = 0;
1401 
1402 	while (diff <= max_digit) {
1403 		int value = hex_to_bin(**cp);
1404 
1405 		if (value < 0)
1406 			break;
1407 		*val = *val * 16 + value;
1408 		(*cp)++;
1409 		diff++;
1410 	}
1411 
1412 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1413 		return 1;
1414 
1415 	return 0;
1416 }
1417 
1418 static int __init parse_busid(char *str, unsigned int *cssid,
1419 			      unsigned int *ssid, unsigned int *devno)
1420 {
1421 	char *str_work;
1422 	int rc, ret;
1423 
1424 	rc = 1;
1425 
1426 	if (*str == '\0')
1427 		goto out;
1428 
1429 	str_work = str;
1430 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1431 	if (ret || (str_work[0] != '.'))
1432 		goto out;
1433 	str_work++;
1434 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1435 	if (ret || (str_work[0] != '.'))
1436 		goto out;
1437 	str_work++;
1438 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1439 	if (ret || (str_work[0] != '\0'))
1440 		goto out;
1441 
1442 	rc = 0;
1443 out:
1444 	return rc;
1445 }
1446 
1447 static void __init no_auto_parse(void)
1448 {
1449 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1450 	char *parm, *str;
1451 	int rc;
1452 
1453 	str = no_auto;
1454 	while ((parm = strsep(&str, ","))) {
1455 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1456 				 &from_ssid, &from);
1457 		if (rc)
1458 			continue;
1459 		if (parm != NULL) {
1460 			rc = parse_busid(parm, &to_cssid,
1461 					 &to_ssid, &to);
1462 			if ((from_ssid > to_ssid) ||
1463 			    ((from_ssid == to_ssid) && (from > to)))
1464 				rc = -EINVAL;
1465 		} else {
1466 			to_cssid = from_cssid;
1467 			to_ssid = from_ssid;
1468 			to = from;
1469 		}
1470 		if (rc)
1471 			continue;
1472 		while ((from_ssid < to_ssid) ||
1473 		       ((from_ssid == to_ssid) && (from <= to))) {
1474 			set_bit(from, devs_no_auto[from_ssid]);
1475 			from++;
1476 			if (from > __MAX_SUBCHANNEL) {
1477 				from_ssid++;
1478 				from = 0;
1479 			}
1480 		}
1481 	}
1482 }
1483 
1484 static int __init virtio_ccw_init(void)
1485 {
1486 	/* parse no_auto string before we do anything further */
1487 	no_auto_parse();
1488 	return ccw_driver_register(&virtio_ccw_driver);
1489 }
1490 device_initcall(virtio_ccw_init);
1491