xref: /openbmc/linux/drivers/s390/virtio/virtio_ccw.c (revision 48cc39c3)
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 vcdev_dma_area {
50 	unsigned long indicators;
51 	unsigned long indicators2;
52 	struct vq_config_block config_block;
53 	__u8 status;
54 };
55 
56 struct virtio_ccw_device {
57 	struct virtio_device vdev;
58 	__u8 config[VIRTIO_CCW_CONFIG_SIZE];
59 	struct ccw_device *cdev;
60 	__u32 curr_io;
61 	int err;
62 	unsigned int revision; /* Transport revision */
63 	wait_queue_head_t wait_q;
64 	spinlock_t lock;
65 	struct mutex io_lock; /* Serializes I/O requests */
66 	struct list_head virtqueues;
67 	bool is_thinint;
68 	bool going_away;
69 	bool device_lost;
70 	unsigned int config_ready;
71 	void *airq_info;
72 	struct vcdev_dma_area *dma_area;
73 };
74 
75 static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
76 {
77 	return &vcdev->dma_area->indicators;
78 }
79 
80 static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev)
81 {
82 	return &vcdev->dma_area->indicators2;
83 }
84 
85 struct vq_info_block_legacy {
86 	__u64 queue;
87 	__u32 align;
88 	__u16 index;
89 	__u16 num;
90 } __packed;
91 
92 struct vq_info_block {
93 	__u64 desc;
94 	__u32 res0;
95 	__u16 index;
96 	__u16 num;
97 	__u64 avail;
98 	__u64 used;
99 } __packed;
100 
101 struct virtio_feature_desc {
102 	__le32 features;
103 	__u8 index;
104 } __packed;
105 
106 struct virtio_thinint_area {
107 	unsigned long summary_indicator;
108 	unsigned long indicator;
109 	u64 bit_nr;
110 	u8 isc;
111 } __packed;
112 
113 struct virtio_rev_info {
114 	__u16 revision;
115 	__u16 length;
116 	__u8 data[];
117 };
118 
119 /* the highest virtio-ccw revision we support */
120 #define VIRTIO_CCW_REV_MAX 2
121 
122 struct virtio_ccw_vq_info {
123 	struct virtqueue *vq;
124 	int num;
125 	union {
126 		struct vq_info_block s;
127 		struct vq_info_block_legacy l;
128 	} *info_block;
129 	int bit_nr;
130 	struct list_head node;
131 	long cookie;
132 };
133 
134 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
135 
136 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
137 #define MAX_AIRQ_AREAS 20
138 
139 static int virtio_ccw_use_airq = 1;
140 
141 struct airq_info {
142 	rwlock_t lock;
143 	u8 summary_indicator_idx;
144 	struct airq_struct airq;
145 	struct airq_iv *aiv;
146 };
147 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
148 static DEFINE_MUTEX(airq_areas_lock);
149 
150 static u8 *summary_indicators;
151 
152 static inline u8 *get_summary_indicator(struct airq_info *info)
153 {
154 	return summary_indicators + info->summary_indicator_idx;
155 }
156 
157 #define CCW_CMD_SET_VQ 0x13
158 #define CCW_CMD_VDEV_RESET 0x33
159 #define CCW_CMD_SET_IND 0x43
160 #define CCW_CMD_SET_CONF_IND 0x53
161 #define CCW_CMD_READ_FEAT 0x12
162 #define CCW_CMD_WRITE_FEAT 0x11
163 #define CCW_CMD_READ_CONF 0x22
164 #define CCW_CMD_WRITE_CONF 0x21
165 #define CCW_CMD_WRITE_STATUS 0x31
166 #define CCW_CMD_READ_VQ_CONF 0x32
167 #define CCW_CMD_READ_STATUS 0x72
168 #define CCW_CMD_SET_IND_ADAPTER 0x73
169 #define CCW_CMD_SET_VIRTIO_REV 0x83
170 
171 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
172 #define VIRTIO_CCW_DOING_RESET 0x00040000
173 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
174 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
175 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
176 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
177 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
178 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
179 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
180 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
181 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
182 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
183 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
184 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
185 
186 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
187 {
188 	return container_of(vdev, struct virtio_ccw_device, vdev);
189 }
190 
191 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
192 {
193 	unsigned long i, flags;
194 
195 	write_lock_irqsave(&info->lock, flags);
196 	for (i = 0; i < airq_iv_end(info->aiv); i++) {
197 		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
198 			airq_iv_free_bit(info->aiv, i);
199 			airq_iv_set_ptr(info->aiv, i, 0);
200 			break;
201 		}
202 	}
203 	write_unlock_irqrestore(&info->lock, flags);
204 }
205 
206 static void virtio_airq_handler(struct airq_struct *airq, bool floating)
207 {
208 	struct airq_info *info = container_of(airq, struct airq_info, airq);
209 	unsigned long ai;
210 
211 	inc_irq_stat(IRQIO_VAI);
212 	read_lock(&info->lock);
213 	/* Walk through indicators field, summary indicator active. */
214 	for (ai = 0;;) {
215 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
216 		if (ai == -1UL)
217 			break;
218 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
219 	}
220 	*(get_summary_indicator(info)) = 0;
221 	smp_wmb();
222 	/* Walk through indicators field, summary indicator not active. */
223 	for (ai = 0;;) {
224 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
225 		if (ai == -1UL)
226 			break;
227 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
228 	}
229 	read_unlock(&info->lock);
230 }
231 
232 static struct airq_info *new_airq_info(int index)
233 {
234 	struct airq_info *info;
235 	int rc;
236 
237 	info = kzalloc(sizeof(*info), GFP_KERNEL);
238 	if (!info)
239 		return NULL;
240 	rwlock_init(&info->lock);
241 	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR
242 				   | AIRQ_IV_CACHELINE);
243 	if (!info->aiv) {
244 		kfree(info);
245 		return NULL;
246 	}
247 	info->airq.handler = virtio_airq_handler;
248 	info->summary_indicator_idx = index;
249 	info->airq.lsi_ptr = get_summary_indicator(info);
250 	info->airq.lsi_mask = 0xff;
251 	info->airq.isc = VIRTIO_AIRQ_ISC;
252 	rc = register_adapter_interrupt(&info->airq);
253 	if (rc) {
254 		airq_iv_release(info->aiv);
255 		kfree(info);
256 		return NULL;
257 	}
258 	return info;
259 }
260 
261 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
262 					u64 *first, void **airq_info)
263 {
264 	int i, j;
265 	struct airq_info *info;
266 	unsigned long indicator_addr = 0;
267 	unsigned long bit, flags;
268 
269 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
270 		mutex_lock(&airq_areas_lock);
271 		if (!airq_areas[i])
272 			airq_areas[i] = new_airq_info(i);
273 		info = airq_areas[i];
274 		mutex_unlock(&airq_areas_lock);
275 		if (!info)
276 			return 0;
277 		write_lock_irqsave(&info->lock, flags);
278 		bit = airq_iv_alloc(info->aiv, nvqs);
279 		if (bit == -1UL) {
280 			/* Not enough vacancies. */
281 			write_unlock_irqrestore(&info->lock, flags);
282 			continue;
283 		}
284 		*first = bit;
285 		*airq_info = info;
286 		indicator_addr = (unsigned long)info->aiv->vector;
287 		for (j = 0; j < nvqs; j++) {
288 			airq_iv_set_ptr(info->aiv, bit + j,
289 					(unsigned long)vqs[j]);
290 		}
291 		write_unlock_irqrestore(&info->lock, flags);
292 	}
293 	return indicator_addr;
294 }
295 
296 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
297 {
298 	struct virtio_ccw_vq_info *info;
299 
300 	if (!vcdev->airq_info)
301 		return;
302 	list_for_each_entry(info, &vcdev->virtqueues, node)
303 		drop_airq_indicator(info->vq, vcdev->airq_info);
304 }
305 
306 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
307 {
308 	unsigned long flags;
309 	__u32 ret;
310 
311 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
312 	if (vcdev->err)
313 		ret = 0;
314 	else
315 		ret = vcdev->curr_io & flag;
316 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
317 	return ret;
318 }
319 
320 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
321 			 struct ccw1 *ccw, __u32 intparm)
322 {
323 	int ret;
324 	unsigned long flags;
325 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
326 
327 	mutex_lock(&vcdev->io_lock);
328 	do {
329 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
330 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
331 		if (!ret) {
332 			if (!vcdev->curr_io)
333 				vcdev->err = 0;
334 			vcdev->curr_io |= flag;
335 		}
336 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
337 		cpu_relax();
338 	} while (ret == -EBUSY);
339 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
340 	ret = ret ? ret : vcdev->err;
341 	mutex_unlock(&vcdev->io_lock);
342 	return ret;
343 }
344 
345 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
346 				      struct ccw1 *ccw)
347 {
348 	int ret;
349 	unsigned long *indicatorp = NULL;
350 	struct virtio_thinint_area *thinint_area = NULL;
351 	struct airq_info *airq_info = vcdev->airq_info;
352 
353 	if (vcdev->is_thinint) {
354 		thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
355 						     sizeof(*thinint_area));
356 		if (!thinint_area)
357 			return;
358 		thinint_area->summary_indicator =
359 			(unsigned long) get_summary_indicator(airq_info);
360 		thinint_area->isc = VIRTIO_AIRQ_ISC;
361 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
362 		ccw->count = sizeof(*thinint_area);
363 		ccw->cda = (__u32)(unsigned long) thinint_area;
364 	} else {
365 		/* payload is the address of the indicators */
366 		indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
367 						   sizeof(indicators(vcdev)));
368 		if (!indicatorp)
369 			return;
370 		*indicatorp = 0;
371 		ccw->cmd_code = CCW_CMD_SET_IND;
372 		ccw->count = sizeof(indicators(vcdev));
373 		ccw->cda = (__u32)(unsigned long) indicatorp;
374 	}
375 	/* Deregister indicators from host. */
376 	*indicators(vcdev) = 0;
377 	ccw->flags = 0;
378 	ret = ccw_io_helper(vcdev, ccw,
379 			    vcdev->is_thinint ?
380 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
381 			    VIRTIO_CCW_DOING_SET_IND);
382 	if (ret && (ret != -ENODEV))
383 		dev_info(&vcdev->cdev->dev,
384 			 "Failed to deregister indicators (%d)\n", ret);
385 	else if (vcdev->is_thinint)
386 		virtio_ccw_drop_indicators(vcdev);
387 	ccw_device_dma_free(vcdev->cdev, indicatorp, sizeof(indicators(vcdev)));
388 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
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 	BUILD_BUG_ON(sizeof(struct subchannel_id) != sizeof(unsigned int));
400 	info->cookie = kvm_hypercall3(KVM_S390_VIRTIO_CCW_NOTIFY,
401 				      *((unsigned int *)&schid),
402 				      vq->index, info->cookie);
403 	if (info->cookie < 0)
404 		return false;
405 	return true;
406 }
407 
408 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
409 				   struct ccw1 *ccw, int index)
410 {
411 	int ret;
412 
413 	vcdev->dma_area->config_block.index = index;
414 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
415 	ccw->flags = 0;
416 	ccw->count = sizeof(struct vq_config_block);
417 	ccw->cda = (__u32)(unsigned long)(&vcdev->dma_area->config_block);
418 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
419 	if (ret)
420 		return ret;
421 	return vcdev->dma_area->config_block.num ?: -ENOENT;
422 }
423 
424 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
425 {
426 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
427 	struct virtio_ccw_vq_info *info = vq->priv;
428 	unsigned long flags;
429 	int ret;
430 	unsigned int index = vq->index;
431 
432 	/* Remove from our list. */
433 	spin_lock_irqsave(&vcdev->lock, flags);
434 	list_del(&info->node);
435 	spin_unlock_irqrestore(&vcdev->lock, flags);
436 
437 	/* Release from host. */
438 	if (vcdev->revision == 0) {
439 		info->info_block->l.queue = 0;
440 		info->info_block->l.align = 0;
441 		info->info_block->l.index = index;
442 		info->info_block->l.num = 0;
443 		ccw->count = sizeof(info->info_block->l);
444 	} else {
445 		info->info_block->s.desc = 0;
446 		info->info_block->s.index = index;
447 		info->info_block->s.num = 0;
448 		info->info_block->s.avail = 0;
449 		info->info_block->s.used = 0;
450 		ccw->count = sizeof(info->info_block->s);
451 	}
452 	ccw->cmd_code = CCW_CMD_SET_VQ;
453 	ccw->flags = 0;
454 	ccw->cda = (__u32)(unsigned long)(info->info_block);
455 	ret = ccw_io_helper(vcdev, ccw,
456 			    VIRTIO_CCW_DOING_SET_VQ | index);
457 	/*
458 	 * -ENODEV isn't considered an error: The device is gone anyway.
459 	 * This may happen on device detach.
460 	 */
461 	if (ret && (ret != -ENODEV))
462 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
463 			 ret, index);
464 
465 	vring_del_virtqueue(vq);
466 	ccw_device_dma_free(vcdev->cdev, info->info_block,
467 			    sizeof(*info->info_block));
468 	kfree(info);
469 }
470 
471 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
472 {
473 	struct virtqueue *vq, *n;
474 	struct ccw1 *ccw;
475 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
476 
477 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
478 	if (!ccw)
479 		return;
480 
481 	virtio_ccw_drop_indicator(vcdev, ccw);
482 
483 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
484 		virtio_ccw_del_vq(vq, ccw);
485 
486 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
487 }
488 
489 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
490 					     int i, vq_callback_t *callback,
491 					     const char *name, bool ctx,
492 					     struct ccw1 *ccw)
493 {
494 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
495 	int err;
496 	struct virtqueue *vq = NULL;
497 	struct virtio_ccw_vq_info *info;
498 	u64 queue;
499 	unsigned long flags;
500 	bool may_reduce;
501 
502 	/* Allocate queue. */
503 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
504 	if (!info) {
505 		dev_warn(&vcdev->cdev->dev, "no info\n");
506 		err = -ENOMEM;
507 		goto out_err;
508 	}
509 	info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
510 						 sizeof(*info->info_block));
511 	if (!info->info_block) {
512 		dev_warn(&vcdev->cdev->dev, "no info block\n");
513 		err = -ENOMEM;
514 		goto out_err;
515 	}
516 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
517 	if (info->num < 0) {
518 		err = info->num;
519 		goto out_err;
520 	}
521 	may_reduce = vcdev->revision > 0;
522 	vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
523 				    vdev, true, may_reduce, ctx,
524 				    virtio_ccw_kvm_notify, callback, name);
525 
526 	if (!vq) {
527 		/* For now, we fail if we can't get the requested size. */
528 		dev_warn(&vcdev->cdev->dev, "no vq\n");
529 		err = -ENOMEM;
530 		goto out_err;
531 	}
532 	/* it may have been reduced */
533 	info->num = virtqueue_get_vring_size(vq);
534 
535 	/* Register it with the host. */
536 	queue = virtqueue_get_desc_addr(vq);
537 	if (vcdev->revision == 0) {
538 		info->info_block->l.queue = queue;
539 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
540 		info->info_block->l.index = i;
541 		info->info_block->l.num = info->num;
542 		ccw->count = sizeof(info->info_block->l);
543 	} else {
544 		info->info_block->s.desc = queue;
545 		info->info_block->s.index = i;
546 		info->info_block->s.num = info->num;
547 		info->info_block->s.avail = (__u64)virtqueue_get_avail_addr(vq);
548 		info->info_block->s.used = (__u64)virtqueue_get_used_addr(vq);
549 		ccw->count = sizeof(info->info_block->s);
550 	}
551 	ccw->cmd_code = CCW_CMD_SET_VQ;
552 	ccw->flags = 0;
553 	ccw->cda = (__u32)(unsigned long)(info->info_block);
554 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
555 	if (err) {
556 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
557 		goto out_err;
558 	}
559 
560 	info->vq = vq;
561 	vq->priv = info;
562 
563 	/* Save it to our list. */
564 	spin_lock_irqsave(&vcdev->lock, flags);
565 	list_add(&info->node, &vcdev->virtqueues);
566 	spin_unlock_irqrestore(&vcdev->lock, flags);
567 
568 	return vq;
569 
570 out_err:
571 	if (vq)
572 		vring_del_virtqueue(vq);
573 	if (info) {
574 		ccw_device_dma_free(vcdev->cdev, info->info_block,
575 				    sizeof(*info->info_block));
576 	}
577 	kfree(info);
578 	return ERR_PTR(err);
579 }
580 
581 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
582 					   struct virtqueue *vqs[], int nvqs,
583 					   struct ccw1 *ccw)
584 {
585 	int ret;
586 	struct virtio_thinint_area *thinint_area = NULL;
587 	struct airq_info *info;
588 
589 	thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
590 					     sizeof(*thinint_area));
591 	if (!thinint_area) {
592 		ret = -ENOMEM;
593 		goto out;
594 	}
595 	/* Try to get an indicator. */
596 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
597 						     &thinint_area->bit_nr,
598 						     &vcdev->airq_info);
599 	if (!thinint_area->indicator) {
600 		ret = -ENOSPC;
601 		goto out;
602 	}
603 	info = vcdev->airq_info;
604 	thinint_area->summary_indicator =
605 		(unsigned long) get_summary_indicator(info);
606 	thinint_area->isc = VIRTIO_AIRQ_ISC;
607 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
608 	ccw->flags = CCW_FLAG_SLI;
609 	ccw->count = sizeof(*thinint_area);
610 	ccw->cda = (__u32)(unsigned long)thinint_area;
611 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
612 	if (ret) {
613 		if (ret == -EOPNOTSUPP) {
614 			/*
615 			 * The host does not support adapter interrupts
616 			 * for virtio-ccw, stop trying.
617 			 */
618 			virtio_ccw_use_airq = 0;
619 			pr_info("Adapter interrupts unsupported on host\n");
620 		} else
621 			dev_warn(&vcdev->cdev->dev,
622 				 "enabling adapter interrupts = %d\n", ret);
623 		virtio_ccw_drop_indicators(vcdev);
624 	}
625 out:
626 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
627 	return ret;
628 }
629 
630 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
631 			       struct virtqueue *vqs[],
632 			       vq_callback_t *callbacks[],
633 			       const char * const names[],
634 			       const bool *ctx,
635 			       struct irq_affinity *desc)
636 {
637 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
638 	unsigned long *indicatorp = NULL;
639 	int ret, i, queue_idx = 0;
640 	struct ccw1 *ccw;
641 
642 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
643 	if (!ccw)
644 		return -ENOMEM;
645 
646 	for (i = 0; i < nvqs; ++i) {
647 		if (!names[i]) {
648 			vqs[i] = NULL;
649 			continue;
650 		}
651 
652 		vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, callbacks[i],
653 					     names[i], ctx ? ctx[i] : false,
654 					     ccw);
655 		if (IS_ERR(vqs[i])) {
656 			ret = PTR_ERR(vqs[i]);
657 			vqs[i] = NULL;
658 			goto out;
659 		}
660 	}
661 	ret = -ENOMEM;
662 	/*
663 	 * We need a data area under 2G to communicate. Our payload is
664 	 * the address of the indicators.
665 	*/
666 	indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
667 					   sizeof(indicators(vcdev)));
668 	if (!indicatorp)
669 		goto out;
670 	*indicatorp = (unsigned long) indicators(vcdev);
671 	if (vcdev->is_thinint) {
672 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
673 		if (ret)
674 			/* no error, just fall back to legacy interrupts */
675 			vcdev->is_thinint = false;
676 	}
677 	if (!vcdev->is_thinint) {
678 		/* Register queue indicators with host. */
679 		*indicators(vcdev) = 0;
680 		ccw->cmd_code = CCW_CMD_SET_IND;
681 		ccw->flags = 0;
682 		ccw->count = sizeof(indicators(vcdev));
683 		ccw->cda = (__u32)(unsigned long) indicatorp;
684 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
685 		if (ret)
686 			goto out;
687 	}
688 	/* Register indicators2 with host for config changes */
689 	*indicatorp = (unsigned long) indicators2(vcdev);
690 	*indicators2(vcdev) = 0;
691 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
692 	ccw->flags = 0;
693 	ccw->count = sizeof(indicators2(vcdev));
694 	ccw->cda = (__u32)(unsigned long) indicatorp;
695 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
696 	if (ret)
697 		goto out;
698 
699 	if (indicatorp)
700 		ccw_device_dma_free(vcdev->cdev, indicatorp,
701 				    sizeof(indicators(vcdev)));
702 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
703 	return 0;
704 out:
705 	if (indicatorp)
706 		ccw_device_dma_free(vcdev->cdev, indicatorp,
707 				    sizeof(indicators(vcdev)));
708 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
709 	virtio_ccw_del_vqs(vdev);
710 	return ret;
711 }
712 
713 static void virtio_ccw_reset(struct virtio_device *vdev)
714 {
715 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
716 	struct ccw1 *ccw;
717 
718 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
719 	if (!ccw)
720 		return;
721 
722 	/* Zero status bits. */
723 	vcdev->dma_area->status = 0;
724 
725 	/* Send a reset ccw on device. */
726 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
727 	ccw->flags = 0;
728 	ccw->count = 0;
729 	ccw->cda = 0;
730 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
731 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
732 }
733 
734 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
735 {
736 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
737 	struct virtio_feature_desc *features;
738 	int ret;
739 	u64 rc;
740 	struct ccw1 *ccw;
741 
742 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
743 	if (!ccw)
744 		return 0;
745 
746 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
747 	if (!features) {
748 		rc = 0;
749 		goto out_free;
750 	}
751 	/* Read the feature bits from the host. */
752 	features->index = 0;
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) {
759 		rc = 0;
760 		goto out_free;
761 	}
762 
763 	rc = le32_to_cpu(features->features);
764 
765 	if (vcdev->revision == 0)
766 		goto out_free;
767 
768 	/* Read second half of the feature bits from the host. */
769 	features->index = 1;
770 	ccw->cmd_code = CCW_CMD_READ_FEAT;
771 	ccw->flags = 0;
772 	ccw->count = sizeof(*features);
773 	ccw->cda = (__u32)(unsigned long)features;
774 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
775 	if (ret == 0)
776 		rc |= (u64)le32_to_cpu(features->features) << 32;
777 
778 out_free:
779 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
780 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
781 	return rc;
782 }
783 
784 static void ccw_transport_features(struct virtio_device *vdev)
785 {
786 	/*
787 	 * Currently nothing to do here.
788 	 */
789 }
790 
791 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
792 {
793 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
794 	struct virtio_feature_desc *features;
795 	struct ccw1 *ccw;
796 	int ret;
797 
798 	if (vcdev->revision >= 1 &&
799 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
800 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
801 			"but does not have VIRTIO_F_VERSION_1\n");
802 		return -EINVAL;
803 	}
804 
805 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
806 	if (!ccw)
807 		return -ENOMEM;
808 
809 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
810 	if (!features) {
811 		ret = -ENOMEM;
812 		goto out_free;
813 	}
814 	/* Give virtio_ring a chance to accept features. */
815 	vring_transport_features(vdev);
816 
817 	/* Give virtio_ccw a chance to accept features. */
818 	ccw_transport_features(vdev);
819 
820 	features->index = 0;
821 	features->features = cpu_to_le32((u32)vdev->features);
822 	/* Write the first half of the feature bits to the host. */
823 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
824 	ccw->flags = 0;
825 	ccw->count = sizeof(*features);
826 	ccw->cda = (__u32)(unsigned long)features;
827 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
828 	if (ret)
829 		goto out_free;
830 
831 	if (vcdev->revision == 0)
832 		goto out_free;
833 
834 	features->index = 1;
835 	features->features = cpu_to_le32(vdev->features >> 32);
836 	/* Write the second half of the feature bits to the host. */
837 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
838 	ccw->flags = 0;
839 	ccw->count = sizeof(*features);
840 	ccw->cda = (__u32)(unsigned long)features;
841 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
842 
843 out_free:
844 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
845 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
846 
847 	return ret;
848 }
849 
850 static void virtio_ccw_get_config(struct virtio_device *vdev,
851 				  unsigned int offset, void *buf, unsigned len)
852 {
853 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
854 	int ret;
855 	struct ccw1 *ccw;
856 	void *config_area;
857 	unsigned long flags;
858 
859 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
860 	if (!ccw)
861 		return;
862 
863 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
864 					    VIRTIO_CCW_CONFIG_SIZE);
865 	if (!config_area)
866 		goto out_free;
867 
868 	/* Read the config area from the host. */
869 	ccw->cmd_code = CCW_CMD_READ_CONF;
870 	ccw->flags = 0;
871 	ccw->count = offset + len;
872 	ccw->cda = (__u32)(unsigned long)config_area;
873 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
874 	if (ret)
875 		goto out_free;
876 
877 	spin_lock_irqsave(&vcdev->lock, flags);
878 	memcpy(vcdev->config, config_area, offset + len);
879 	if (vcdev->config_ready < offset + len)
880 		vcdev->config_ready = offset + len;
881 	spin_unlock_irqrestore(&vcdev->lock, flags);
882 	if (buf)
883 		memcpy(buf, config_area + offset, len);
884 
885 out_free:
886 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
887 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
888 }
889 
890 static void virtio_ccw_set_config(struct virtio_device *vdev,
891 				  unsigned int offset, const void *buf,
892 				  unsigned len)
893 {
894 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
895 	struct ccw1 *ccw;
896 	void *config_area;
897 	unsigned long flags;
898 
899 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
900 	if (!ccw)
901 		return;
902 
903 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
904 					    VIRTIO_CCW_CONFIG_SIZE);
905 	if (!config_area)
906 		goto out_free;
907 
908 	/* Make sure we don't overwrite fields. */
909 	if (vcdev->config_ready < offset)
910 		virtio_ccw_get_config(vdev, 0, NULL, offset);
911 	spin_lock_irqsave(&vcdev->lock, flags);
912 	memcpy(&vcdev->config[offset], buf, len);
913 	/* Write the config area to the host. */
914 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
915 	spin_unlock_irqrestore(&vcdev->lock, flags);
916 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
917 	ccw->flags = 0;
918 	ccw->count = offset + len;
919 	ccw->cda = (__u32)(unsigned long)config_area;
920 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
921 
922 out_free:
923 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
924 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
925 }
926 
927 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
928 {
929 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
930 	u8 old_status = vcdev->dma_area->status;
931 	struct ccw1 *ccw;
932 
933 	if (vcdev->revision < 2)
934 		return vcdev->dma_area->status;
935 
936 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
937 	if (!ccw)
938 		return old_status;
939 
940 	ccw->cmd_code = CCW_CMD_READ_STATUS;
941 	ccw->flags = 0;
942 	ccw->count = sizeof(vcdev->dma_area->status);
943 	ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
944 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
945 /*
946  * If the channel program failed (should only happen if the device
947  * was hotunplugged, and then we clean up via the machine check
948  * handler anyway), vcdev->dma_area->status was not overwritten and we just
949  * return the old status, which is fine.
950 */
951 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
952 
953 	return vcdev->dma_area->status;
954 }
955 
956 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
957 {
958 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
959 	u8 old_status = vcdev->dma_area->status;
960 	struct ccw1 *ccw;
961 	int ret;
962 
963 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
964 	if (!ccw)
965 		return;
966 
967 	/* Write the status to the host. */
968 	vcdev->dma_area->status = status;
969 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
970 	ccw->flags = 0;
971 	ccw->count = sizeof(status);
972 	ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
973 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
974 	/* Write failed? We assume status is unchanged. */
975 	if (ret)
976 		vcdev->dma_area->status = old_status;
977 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
978 }
979 
980 static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
981 {
982 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
983 
984 	return dev_name(&vcdev->cdev->dev);
985 }
986 
987 static const struct virtio_config_ops virtio_ccw_config_ops = {
988 	.get_features = virtio_ccw_get_features,
989 	.finalize_features = virtio_ccw_finalize_features,
990 	.get = virtio_ccw_get_config,
991 	.set = virtio_ccw_set_config,
992 	.get_status = virtio_ccw_get_status,
993 	.set_status = virtio_ccw_set_status,
994 	.reset = virtio_ccw_reset,
995 	.find_vqs = virtio_ccw_find_vqs,
996 	.del_vqs = virtio_ccw_del_vqs,
997 	.bus_name = virtio_ccw_bus_name,
998 };
999 
1000 
1001 /*
1002  * ccw bus driver related functions
1003  */
1004 
1005 static void virtio_ccw_release_dev(struct device *_d)
1006 {
1007 	struct virtio_device *dev = dev_to_virtio(_d);
1008 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
1009 
1010 	ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1011 			    sizeof(*vcdev->dma_area));
1012 	kfree(vcdev);
1013 }
1014 
1015 static int irb_is_error(struct irb *irb)
1016 {
1017 	if (scsw_cstat(&irb->scsw) != 0)
1018 		return 1;
1019 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1020 		return 1;
1021 	if (scsw_cc(&irb->scsw) != 0)
1022 		return 1;
1023 	return 0;
1024 }
1025 
1026 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1027 					      int index)
1028 {
1029 	struct virtio_ccw_vq_info *info;
1030 	unsigned long flags;
1031 	struct virtqueue *vq;
1032 
1033 	vq = NULL;
1034 	spin_lock_irqsave(&vcdev->lock, flags);
1035 	list_for_each_entry(info, &vcdev->virtqueues, node) {
1036 		if (info->vq->index == index) {
1037 			vq = info->vq;
1038 			break;
1039 		}
1040 	}
1041 	spin_unlock_irqrestore(&vcdev->lock, flags);
1042 	return vq;
1043 }
1044 
1045 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1046 				      __u32 activity)
1047 {
1048 	if (vcdev->curr_io & activity) {
1049 		switch (activity) {
1050 		case VIRTIO_CCW_DOING_READ_FEAT:
1051 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1052 		case VIRTIO_CCW_DOING_READ_CONFIG:
1053 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1054 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1055 		case VIRTIO_CCW_DOING_READ_STATUS:
1056 		case VIRTIO_CCW_DOING_SET_VQ:
1057 		case VIRTIO_CCW_DOING_SET_IND:
1058 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1059 		case VIRTIO_CCW_DOING_RESET:
1060 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1061 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1062 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1063 			vcdev->curr_io &= ~activity;
1064 			wake_up(&vcdev->wait_q);
1065 			break;
1066 		default:
1067 			/* don't know what to do... */
1068 			dev_warn(&vcdev->cdev->dev,
1069 				 "Suspicious activity '%08x'\n", activity);
1070 			WARN_ON(1);
1071 			break;
1072 		}
1073 	}
1074 }
1075 
1076 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1077 				   unsigned long intparm,
1078 				   struct irb *irb)
1079 {
1080 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1081 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1082 	int i;
1083 	struct virtqueue *vq;
1084 
1085 	if (!vcdev)
1086 		return;
1087 	if (IS_ERR(irb)) {
1088 		vcdev->err = PTR_ERR(irb);
1089 		virtio_ccw_check_activity(vcdev, activity);
1090 		/* Don't poke around indicators, something's wrong. */
1091 		return;
1092 	}
1093 	/* Check if it's a notification from the host. */
1094 	if ((intparm == 0) &&
1095 	    (scsw_stctl(&irb->scsw) ==
1096 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1097 		/* OK */
1098 	}
1099 	if (irb_is_error(irb)) {
1100 		/* Command reject? */
1101 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1102 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1103 			vcdev->err = -EOPNOTSUPP;
1104 		else
1105 			/* Map everything else to -EIO. */
1106 			vcdev->err = -EIO;
1107 	}
1108 	virtio_ccw_check_activity(vcdev, activity);
1109 	for_each_set_bit(i, indicators(vcdev),
1110 			 sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {
1111 		/* The bit clear must happen before the vring kick. */
1112 		clear_bit(i, indicators(vcdev));
1113 		barrier();
1114 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1115 		vring_interrupt(0, vq);
1116 	}
1117 	if (test_bit(0, indicators2(vcdev))) {
1118 		virtio_config_changed(&vcdev->vdev);
1119 		clear_bit(0, indicators2(vcdev));
1120 	}
1121 }
1122 
1123 /*
1124  * We usually want to autoonline all devices, but give the admin
1125  * a way to exempt devices from this.
1126  */
1127 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1128 		     (8*sizeof(long)))
1129 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1130 
1131 static char *no_auto = "";
1132 
1133 module_param(no_auto, charp, 0444);
1134 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1135 
1136 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1137 {
1138 	struct ccw_dev_id id;
1139 
1140 	ccw_device_get_id(cdev, &id);
1141 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1142 		return 0;
1143 	return 1;
1144 }
1145 
1146 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1147 {
1148 	struct ccw_device *cdev = data;
1149 	int ret;
1150 
1151 	ret = ccw_device_set_online(cdev);
1152 	if (ret)
1153 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1154 }
1155 
1156 static int virtio_ccw_probe(struct ccw_device *cdev)
1157 {
1158 	cdev->handler = virtio_ccw_int_handler;
1159 
1160 	if (virtio_ccw_check_autoonline(cdev))
1161 		async_schedule(virtio_ccw_auto_online, cdev);
1162 	return 0;
1163 }
1164 
1165 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1166 {
1167 	unsigned long flags;
1168 	struct virtio_ccw_device *vcdev;
1169 
1170 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1171 	vcdev = dev_get_drvdata(&cdev->dev);
1172 	if (!vcdev || vcdev->going_away) {
1173 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1174 		return NULL;
1175 	}
1176 	vcdev->going_away = true;
1177 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1178 	return vcdev;
1179 }
1180 
1181 static void virtio_ccw_remove(struct ccw_device *cdev)
1182 {
1183 	unsigned long flags;
1184 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1185 
1186 	if (vcdev && cdev->online) {
1187 		if (vcdev->device_lost)
1188 			virtio_break_device(&vcdev->vdev);
1189 		unregister_virtio_device(&vcdev->vdev);
1190 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1191 		dev_set_drvdata(&cdev->dev, NULL);
1192 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1193 	}
1194 	cdev->handler = NULL;
1195 }
1196 
1197 static int virtio_ccw_offline(struct ccw_device *cdev)
1198 {
1199 	unsigned long flags;
1200 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1201 
1202 	if (!vcdev)
1203 		return 0;
1204 	if (vcdev->device_lost)
1205 		virtio_break_device(&vcdev->vdev);
1206 	unregister_virtio_device(&vcdev->vdev);
1207 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1208 	dev_set_drvdata(&cdev->dev, NULL);
1209 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1210 	return 0;
1211 }
1212 
1213 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1214 {
1215 	struct virtio_rev_info *rev;
1216 	struct ccw1 *ccw;
1217 	int ret;
1218 
1219 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
1220 	if (!ccw)
1221 		return -ENOMEM;
1222 	rev = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*rev));
1223 	if (!rev) {
1224 		ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1225 		return -ENOMEM;
1226 	}
1227 
1228 	/* Set transport revision */
1229 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1230 	ccw->flags = 0;
1231 	ccw->count = sizeof(*rev);
1232 	ccw->cda = (__u32)(unsigned long)rev;
1233 
1234 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1235 	do {
1236 		rev->revision = vcdev->revision;
1237 		/* none of our supported revisions carry payload */
1238 		rev->length = 0;
1239 		ret = ccw_io_helper(vcdev, ccw,
1240 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1241 		if (ret == -EOPNOTSUPP) {
1242 			if (vcdev->revision == 0)
1243 				/*
1244 				 * The host device does not support setting
1245 				 * the revision: let's operate it in legacy
1246 				 * mode.
1247 				 */
1248 				ret = 0;
1249 			else
1250 				vcdev->revision--;
1251 		}
1252 	} while (ret == -EOPNOTSUPP);
1253 
1254 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1255 	ccw_device_dma_free(vcdev->cdev, rev, sizeof(*rev));
1256 	return ret;
1257 }
1258 
1259 static int virtio_ccw_online(struct ccw_device *cdev)
1260 {
1261 	int ret;
1262 	struct virtio_ccw_device *vcdev;
1263 	unsigned long flags;
1264 
1265 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1266 	if (!vcdev) {
1267 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1268 		ret = -ENOMEM;
1269 		goto out_free;
1270 	}
1271 	vcdev->vdev.dev.parent = &cdev->dev;
1272 	vcdev->cdev = cdev;
1273 	vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,
1274 						sizeof(*vcdev->dma_area));
1275 	if (!vcdev->dma_area) {
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 	init_waitqueue_head(&vcdev->wait_q);
1285 	INIT_LIST_HEAD(&vcdev->virtqueues);
1286 	spin_lock_init(&vcdev->lock);
1287 	mutex_init(&vcdev->io_lock);
1288 
1289 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1290 	dev_set_drvdata(&cdev->dev, vcdev);
1291 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1292 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1293 	vcdev->vdev.id.device = cdev->id.cu_model;
1294 
1295 	ret = virtio_ccw_set_transport_rev(vcdev);
1296 	if (ret)
1297 		goto out_free;
1298 
1299 	ret = register_virtio_device(&vcdev->vdev);
1300 	if (ret) {
1301 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1302 			 ret);
1303 		goto out_put;
1304 	}
1305 	return 0;
1306 out_put:
1307 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1308 	dev_set_drvdata(&cdev->dev, NULL);
1309 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1310 	put_device(&vcdev->vdev.dev);
1311 	return ret;
1312 out_free:
1313 	if (vcdev) {
1314 		ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1315 				    sizeof(*vcdev->dma_area));
1316 	}
1317 	kfree(vcdev);
1318 	return ret;
1319 }
1320 
1321 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1322 {
1323 	int rc;
1324 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1325 
1326 	/*
1327 	 * Make sure vcdev is set
1328 	 * i.e. set_offline/remove callback not already running
1329 	 */
1330 	if (!vcdev)
1331 		return NOTIFY_DONE;
1332 
1333 	switch (event) {
1334 	case CIO_GONE:
1335 		vcdev->device_lost = true;
1336 		rc = NOTIFY_DONE;
1337 		break;
1338 	case CIO_OPER:
1339 		rc = NOTIFY_OK;
1340 		break;
1341 	default:
1342 		rc = NOTIFY_DONE;
1343 		break;
1344 	}
1345 	return rc;
1346 }
1347 
1348 static struct ccw_device_id virtio_ids[] = {
1349 	{ CCW_DEVICE(0x3832, 0) },
1350 	{},
1351 };
1352 
1353 static struct ccw_driver virtio_ccw_driver = {
1354 	.driver = {
1355 		.owner = THIS_MODULE,
1356 		.name = "virtio_ccw",
1357 	},
1358 	.ids = virtio_ids,
1359 	.probe = virtio_ccw_probe,
1360 	.remove = virtio_ccw_remove,
1361 	.set_offline = virtio_ccw_offline,
1362 	.set_online = virtio_ccw_online,
1363 	.notify = virtio_ccw_cio_notify,
1364 	.int_class = IRQIO_VIR,
1365 };
1366 
1367 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1368 			   int max_digit, int max_val)
1369 {
1370 	int diff;
1371 
1372 	diff = 0;
1373 	*val = 0;
1374 
1375 	while (diff <= max_digit) {
1376 		int value = hex_to_bin(**cp);
1377 
1378 		if (value < 0)
1379 			break;
1380 		*val = *val * 16 + value;
1381 		(*cp)++;
1382 		diff++;
1383 	}
1384 
1385 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1386 		return 1;
1387 
1388 	return 0;
1389 }
1390 
1391 static int __init parse_busid(char *str, unsigned int *cssid,
1392 			      unsigned int *ssid, unsigned int *devno)
1393 {
1394 	char *str_work;
1395 	int rc, ret;
1396 
1397 	rc = 1;
1398 
1399 	if (*str == '\0')
1400 		goto out;
1401 
1402 	str_work = str;
1403 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1404 	if (ret || (str_work[0] != '.'))
1405 		goto out;
1406 	str_work++;
1407 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1408 	if (ret || (str_work[0] != '.'))
1409 		goto out;
1410 	str_work++;
1411 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1412 	if (ret || (str_work[0] != '\0'))
1413 		goto out;
1414 
1415 	rc = 0;
1416 out:
1417 	return rc;
1418 }
1419 
1420 static void __init no_auto_parse(void)
1421 {
1422 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1423 	char *parm, *str;
1424 	int rc;
1425 
1426 	str = no_auto;
1427 	while ((parm = strsep(&str, ","))) {
1428 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1429 				 &from_ssid, &from);
1430 		if (rc)
1431 			continue;
1432 		if (parm != NULL) {
1433 			rc = parse_busid(parm, &to_cssid,
1434 					 &to_ssid, &to);
1435 			if ((from_ssid > to_ssid) ||
1436 			    ((from_ssid == to_ssid) && (from > to)))
1437 				rc = -EINVAL;
1438 		} else {
1439 			to_cssid = from_cssid;
1440 			to_ssid = from_ssid;
1441 			to = from;
1442 		}
1443 		if (rc)
1444 			continue;
1445 		while ((from_ssid < to_ssid) ||
1446 		       ((from_ssid == to_ssid) && (from <= to))) {
1447 			set_bit(from, devs_no_auto[from_ssid]);
1448 			from++;
1449 			if (from > __MAX_SUBCHANNEL) {
1450 				from_ssid++;
1451 				from = 0;
1452 			}
1453 		}
1454 	}
1455 }
1456 
1457 static int __init virtio_ccw_init(void)
1458 {
1459 	int rc;
1460 
1461 	/* parse no_auto string before we do anything further */
1462 	no_auto_parse();
1463 
1464 	summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS);
1465 	if (!summary_indicators)
1466 		return -ENOMEM;
1467 	rc = ccw_driver_register(&virtio_ccw_driver);
1468 	if (rc)
1469 		cio_dma_free(summary_indicators, MAX_AIRQ_AREAS);
1470 	return rc;
1471 }
1472 device_initcall(virtio_ccw_init);
1473