xref: /openbmc/linux/drivers/s390/virtio/virtio_ccw.c (revision 8e774e02)
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 1
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 u8 *summary_indicators;
149 
150 static inline u8 *get_summary_indicator(struct airq_info *info)
151 {
152 	return summary_indicators + info->summary_indicator_idx;
153 }
154 
155 #define CCW_CMD_SET_VQ 0x13
156 #define CCW_CMD_VDEV_RESET 0x33
157 #define CCW_CMD_SET_IND 0x43
158 #define CCW_CMD_SET_CONF_IND 0x53
159 #define CCW_CMD_READ_FEAT 0x12
160 #define CCW_CMD_WRITE_FEAT 0x11
161 #define CCW_CMD_READ_CONF 0x22
162 #define CCW_CMD_WRITE_CONF 0x21
163 #define CCW_CMD_WRITE_STATUS 0x31
164 #define CCW_CMD_READ_VQ_CONF 0x32
165 #define CCW_CMD_READ_STATUS 0x72
166 #define CCW_CMD_SET_IND_ADAPTER 0x73
167 #define CCW_CMD_SET_VIRTIO_REV 0x83
168 
169 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
170 #define VIRTIO_CCW_DOING_RESET 0x00040000
171 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
172 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
173 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
174 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
175 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
176 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
177 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
178 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
179 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
180 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
181 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
182 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
183 
184 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
185 {
186 	return container_of(vdev, struct virtio_ccw_device, vdev);
187 }
188 
189 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
190 {
191 	unsigned long i, flags;
192 
193 	write_lock_irqsave(&info->lock, flags);
194 	for (i = 0; i < airq_iv_end(info->aiv); i++) {
195 		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
196 			airq_iv_free_bit(info->aiv, i);
197 			airq_iv_set_ptr(info->aiv, i, 0);
198 			break;
199 		}
200 	}
201 	write_unlock_irqrestore(&info->lock, flags);
202 }
203 
204 static void virtio_airq_handler(struct airq_struct *airq, bool floating)
205 {
206 	struct airq_info *info = container_of(airq, struct airq_info, airq);
207 	unsigned long ai;
208 
209 	inc_irq_stat(IRQIO_VAI);
210 	read_lock(&info->lock);
211 	/* Walk through indicators field, summary indicator active. */
212 	for (ai = 0;;) {
213 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
214 		if (ai == -1UL)
215 			break;
216 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
217 	}
218 	*(get_summary_indicator(info)) = 0;
219 	smp_wmb();
220 	/* Walk through indicators field, summary indicator not active. */
221 	for (ai = 0;;) {
222 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
223 		if (ai == -1UL)
224 			break;
225 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
226 	}
227 	read_unlock(&info->lock);
228 }
229 
230 static struct airq_info *new_airq_info(int index)
231 {
232 	struct airq_info *info;
233 	int rc;
234 
235 	info = kzalloc(sizeof(*info), GFP_KERNEL);
236 	if (!info)
237 		return NULL;
238 	rwlock_init(&info->lock);
239 	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR
240 				   | AIRQ_IV_CACHELINE);
241 	if (!info->aiv) {
242 		kfree(info);
243 		return NULL;
244 	}
245 	info->airq.handler = virtio_airq_handler;
246 	info->summary_indicator_idx = index;
247 	info->airq.lsi_ptr = get_summary_indicator(info);
248 	info->airq.lsi_mask = 0xff;
249 	info->airq.isc = VIRTIO_AIRQ_ISC;
250 	rc = register_adapter_interrupt(&info->airq);
251 	if (rc) {
252 		airq_iv_release(info->aiv);
253 		kfree(info);
254 		return NULL;
255 	}
256 	return info;
257 }
258 
259 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
260 					u64 *first, void **airq_info)
261 {
262 	int i, j;
263 	struct airq_info *info;
264 	unsigned long indicator_addr = 0;
265 	unsigned long bit, flags;
266 
267 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
268 		if (!airq_areas[i])
269 			airq_areas[i] = new_airq_info(i);
270 		info = airq_areas[i];
271 		if (!info)
272 			return 0;
273 		write_lock_irqsave(&info->lock, flags);
274 		bit = airq_iv_alloc(info->aiv, nvqs);
275 		if (bit == -1UL) {
276 			/* Not enough vacancies. */
277 			write_unlock_irqrestore(&info->lock, flags);
278 			continue;
279 		}
280 		*first = bit;
281 		*airq_info = info;
282 		indicator_addr = (unsigned long)info->aiv->vector;
283 		for (j = 0; j < nvqs; j++) {
284 			airq_iv_set_ptr(info->aiv, bit + j,
285 					(unsigned long)vqs[j]);
286 		}
287 		write_unlock_irqrestore(&info->lock, flags);
288 	}
289 	return indicator_addr;
290 }
291 
292 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
293 {
294 	struct virtio_ccw_vq_info *info;
295 
296 	if (!vcdev->airq_info)
297 		return;
298 	list_for_each_entry(info, &vcdev->virtqueues, node)
299 		drop_airq_indicator(info->vq, vcdev->airq_info);
300 }
301 
302 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
303 {
304 	unsigned long flags;
305 	__u32 ret;
306 
307 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
308 	if (vcdev->err)
309 		ret = 0;
310 	else
311 		ret = vcdev->curr_io & flag;
312 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
313 	return ret;
314 }
315 
316 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
317 			 struct ccw1 *ccw, __u32 intparm)
318 {
319 	int ret;
320 	unsigned long flags;
321 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
322 
323 	mutex_lock(&vcdev->io_lock);
324 	do {
325 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
326 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
327 		if (!ret) {
328 			if (!vcdev->curr_io)
329 				vcdev->err = 0;
330 			vcdev->curr_io |= flag;
331 		}
332 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
333 		cpu_relax();
334 	} while (ret == -EBUSY);
335 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
336 	ret = ret ? ret : vcdev->err;
337 	mutex_unlock(&vcdev->io_lock);
338 	return ret;
339 }
340 
341 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
342 				      struct ccw1 *ccw)
343 {
344 	int ret;
345 	unsigned long *indicatorp = NULL;
346 	struct virtio_thinint_area *thinint_area = NULL;
347 	struct airq_info *airq_info = vcdev->airq_info;
348 
349 	if (vcdev->is_thinint) {
350 		thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
351 						     sizeof(*thinint_area));
352 		if (!thinint_area)
353 			return;
354 		thinint_area->summary_indicator =
355 			(unsigned long) get_summary_indicator(airq_info);
356 		thinint_area->isc = VIRTIO_AIRQ_ISC;
357 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
358 		ccw->count = sizeof(*thinint_area);
359 		ccw->cda = (__u32)(unsigned long) thinint_area;
360 	} else {
361 		/* payload is the address of the indicators */
362 		indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
363 						   sizeof(indicators(vcdev)));
364 		if (!indicatorp)
365 			return;
366 		*indicatorp = 0;
367 		ccw->cmd_code = CCW_CMD_SET_IND;
368 		ccw->count = sizeof(indicators(vcdev));
369 		ccw->cda = (__u32)(unsigned long) indicatorp;
370 	}
371 	/* Deregister indicators from host. */
372 	*indicators(vcdev) = 0;
373 	ccw->flags = 0;
374 	ret = ccw_io_helper(vcdev, ccw,
375 			    vcdev->is_thinint ?
376 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
377 			    VIRTIO_CCW_DOING_SET_IND);
378 	if (ret && (ret != -ENODEV))
379 		dev_info(&vcdev->cdev->dev,
380 			 "Failed to deregister indicators (%d)\n", ret);
381 	else if (vcdev->is_thinint)
382 		virtio_ccw_drop_indicators(vcdev);
383 	ccw_device_dma_free(vcdev->cdev, indicatorp, sizeof(indicators(vcdev)));
384 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
385 }
386 
387 static inline long __do_kvm_notify(struct subchannel_id schid,
388 				   unsigned long queue_index,
389 				   long cookie)
390 {
391 	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
392 	register struct subchannel_id __schid asm("2") = schid;
393 	register unsigned long __index asm("3") = queue_index;
394 	register long __rc asm("2");
395 	register long __cookie asm("4") = cookie;
396 
397 	asm volatile ("diag 2,4,0x500\n"
398 		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
399 		      "d"(__cookie)
400 		      : "memory", "cc");
401 	return __rc;
402 }
403 
404 static inline long do_kvm_notify(struct subchannel_id schid,
405 				 unsigned long queue_index,
406 				 long cookie)
407 {
408 	diag_stat_inc(DIAG_STAT_X500);
409 	return __do_kvm_notify(schid, queue_index, cookie);
410 }
411 
412 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
413 {
414 	struct virtio_ccw_vq_info *info = vq->priv;
415 	struct virtio_ccw_device *vcdev;
416 	struct subchannel_id schid;
417 
418 	vcdev = to_vc_device(info->vq->vdev);
419 	ccw_device_get_schid(vcdev->cdev, &schid);
420 	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
421 	if (info->cookie < 0)
422 		return false;
423 	return true;
424 }
425 
426 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
427 				   struct ccw1 *ccw, int index)
428 {
429 	int ret;
430 
431 	vcdev->dma_area->config_block.index = index;
432 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
433 	ccw->flags = 0;
434 	ccw->count = sizeof(struct vq_config_block);
435 	ccw->cda = (__u32)(unsigned long)(&vcdev->dma_area->config_block);
436 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
437 	if (ret)
438 		return ret;
439 	return vcdev->dma_area->config_block.num ?: -ENOENT;
440 }
441 
442 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
443 {
444 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
445 	struct virtio_ccw_vq_info *info = vq->priv;
446 	unsigned long flags;
447 	int ret;
448 	unsigned int index = vq->index;
449 
450 	/* Remove from our list. */
451 	spin_lock_irqsave(&vcdev->lock, flags);
452 	list_del(&info->node);
453 	spin_unlock_irqrestore(&vcdev->lock, flags);
454 
455 	/* Release from host. */
456 	if (vcdev->revision == 0) {
457 		info->info_block->l.queue = 0;
458 		info->info_block->l.align = 0;
459 		info->info_block->l.index = index;
460 		info->info_block->l.num = 0;
461 		ccw->count = sizeof(info->info_block->l);
462 	} else {
463 		info->info_block->s.desc = 0;
464 		info->info_block->s.index = index;
465 		info->info_block->s.num = 0;
466 		info->info_block->s.avail = 0;
467 		info->info_block->s.used = 0;
468 		ccw->count = sizeof(info->info_block->s);
469 	}
470 	ccw->cmd_code = CCW_CMD_SET_VQ;
471 	ccw->flags = 0;
472 	ccw->cda = (__u32)(unsigned long)(info->info_block);
473 	ret = ccw_io_helper(vcdev, ccw,
474 			    VIRTIO_CCW_DOING_SET_VQ | index);
475 	/*
476 	 * -ENODEV isn't considered an error: The device is gone anyway.
477 	 * This may happen on device detach.
478 	 */
479 	if (ret && (ret != -ENODEV))
480 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
481 			 ret, index);
482 
483 	vring_del_virtqueue(vq);
484 	ccw_device_dma_free(vcdev->cdev, info->info_block,
485 			    sizeof(*info->info_block));
486 	kfree(info);
487 }
488 
489 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
490 {
491 	struct virtqueue *vq, *n;
492 	struct ccw1 *ccw;
493 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
494 
495 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
496 	if (!ccw)
497 		return;
498 
499 	virtio_ccw_drop_indicator(vcdev, ccw);
500 
501 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
502 		virtio_ccw_del_vq(vq, ccw);
503 
504 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
505 }
506 
507 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
508 					     int i, vq_callback_t *callback,
509 					     const char *name, bool ctx,
510 					     struct ccw1 *ccw)
511 {
512 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
513 	int err;
514 	struct virtqueue *vq = NULL;
515 	struct virtio_ccw_vq_info *info;
516 	u64 queue;
517 	unsigned long flags;
518 	bool may_reduce;
519 
520 	/* Allocate queue. */
521 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
522 	if (!info) {
523 		dev_warn(&vcdev->cdev->dev, "no info\n");
524 		err = -ENOMEM;
525 		goto out_err;
526 	}
527 	info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
528 						 sizeof(*info->info_block));
529 	if (!info->info_block) {
530 		dev_warn(&vcdev->cdev->dev, "no info block\n");
531 		err = -ENOMEM;
532 		goto out_err;
533 	}
534 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
535 	if (info->num < 0) {
536 		err = info->num;
537 		goto out_err;
538 	}
539 	may_reduce = vcdev->revision > 0;
540 	vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
541 				    vdev, true, may_reduce, ctx,
542 				    virtio_ccw_kvm_notify, callback, name);
543 
544 	if (!vq) {
545 		/* For now, we fail if we can't get the requested size. */
546 		dev_warn(&vcdev->cdev->dev, "no vq\n");
547 		err = -ENOMEM;
548 		goto out_err;
549 	}
550 	/* it may have been reduced */
551 	info->num = virtqueue_get_vring_size(vq);
552 
553 	/* Register it with the host. */
554 	queue = virtqueue_get_desc_addr(vq);
555 	if (vcdev->revision == 0) {
556 		info->info_block->l.queue = queue;
557 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
558 		info->info_block->l.index = i;
559 		info->info_block->l.num = info->num;
560 		ccw->count = sizeof(info->info_block->l);
561 	} else {
562 		info->info_block->s.desc = queue;
563 		info->info_block->s.index = i;
564 		info->info_block->s.num = info->num;
565 		info->info_block->s.avail = (__u64)virtqueue_get_avail_addr(vq);
566 		info->info_block->s.used = (__u64)virtqueue_get_used_addr(vq);
567 		ccw->count = sizeof(info->info_block->s);
568 	}
569 	ccw->cmd_code = CCW_CMD_SET_VQ;
570 	ccw->flags = 0;
571 	ccw->cda = (__u32)(unsigned long)(info->info_block);
572 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
573 	if (err) {
574 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
575 		goto out_err;
576 	}
577 
578 	info->vq = vq;
579 	vq->priv = info;
580 
581 	/* Save it to our list. */
582 	spin_lock_irqsave(&vcdev->lock, flags);
583 	list_add(&info->node, &vcdev->virtqueues);
584 	spin_unlock_irqrestore(&vcdev->lock, flags);
585 
586 	return vq;
587 
588 out_err:
589 	if (vq)
590 		vring_del_virtqueue(vq);
591 	if (info) {
592 		ccw_device_dma_free(vcdev->cdev, info->info_block,
593 				    sizeof(*info->info_block));
594 	}
595 	kfree(info);
596 	return ERR_PTR(err);
597 }
598 
599 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
600 					   struct virtqueue *vqs[], int nvqs,
601 					   struct ccw1 *ccw)
602 {
603 	int ret;
604 	struct virtio_thinint_area *thinint_area = NULL;
605 	struct airq_info *info;
606 
607 	thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
608 					     sizeof(*thinint_area));
609 	if (!thinint_area) {
610 		ret = -ENOMEM;
611 		goto out;
612 	}
613 	/* Try to get an indicator. */
614 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
615 						     &thinint_area->bit_nr,
616 						     &vcdev->airq_info);
617 	if (!thinint_area->indicator) {
618 		ret = -ENOSPC;
619 		goto out;
620 	}
621 	info = vcdev->airq_info;
622 	thinint_area->summary_indicator =
623 		(unsigned long) get_summary_indicator(info);
624 	thinint_area->isc = VIRTIO_AIRQ_ISC;
625 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
626 	ccw->flags = CCW_FLAG_SLI;
627 	ccw->count = sizeof(*thinint_area);
628 	ccw->cda = (__u32)(unsigned long)thinint_area;
629 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
630 	if (ret) {
631 		if (ret == -EOPNOTSUPP) {
632 			/*
633 			 * The host does not support adapter interrupts
634 			 * for virtio-ccw, stop trying.
635 			 */
636 			virtio_ccw_use_airq = 0;
637 			pr_info("Adapter interrupts unsupported on host\n");
638 		} else
639 			dev_warn(&vcdev->cdev->dev,
640 				 "enabling adapter interrupts = %d\n", ret);
641 		virtio_ccw_drop_indicators(vcdev);
642 	}
643 out:
644 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
645 	return ret;
646 }
647 
648 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
649 			       struct virtqueue *vqs[],
650 			       vq_callback_t *callbacks[],
651 			       const char * const names[],
652 			       const bool *ctx,
653 			       struct irq_affinity *desc)
654 {
655 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
656 	unsigned long *indicatorp = NULL;
657 	int ret, i, queue_idx = 0;
658 	struct ccw1 *ccw;
659 
660 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
661 	if (!ccw)
662 		return -ENOMEM;
663 
664 	for (i = 0; i < nvqs; ++i) {
665 		if (!names[i]) {
666 			vqs[i] = NULL;
667 			continue;
668 		}
669 
670 		vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, callbacks[i],
671 					     names[i], ctx ? ctx[i] : false,
672 					     ccw);
673 		if (IS_ERR(vqs[i])) {
674 			ret = PTR_ERR(vqs[i]);
675 			vqs[i] = NULL;
676 			goto out;
677 		}
678 	}
679 	ret = -ENOMEM;
680 	/*
681 	 * We need a data area under 2G to communicate. Our payload is
682 	 * the address of the indicators.
683 	*/
684 	indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
685 					   sizeof(indicators(vcdev)));
686 	if (!indicatorp)
687 		goto out;
688 	*indicatorp = (unsigned long) indicators(vcdev);
689 	if (vcdev->is_thinint) {
690 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
691 		if (ret)
692 			/* no error, just fall back to legacy interrupts */
693 			vcdev->is_thinint = false;
694 	}
695 	if (!vcdev->is_thinint) {
696 		/* Register queue indicators with host. */
697 		*indicators(vcdev) = 0;
698 		ccw->cmd_code = CCW_CMD_SET_IND;
699 		ccw->flags = 0;
700 		ccw->count = sizeof(indicators(vcdev));
701 		ccw->cda = (__u32)(unsigned long) indicatorp;
702 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
703 		if (ret)
704 			goto out;
705 	}
706 	/* Register indicators2 with host for config changes */
707 	*indicatorp = (unsigned long) indicators2(vcdev);
708 	*indicators2(vcdev) = 0;
709 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
710 	ccw->flags = 0;
711 	ccw->count = sizeof(indicators2(vcdev));
712 	ccw->cda = (__u32)(unsigned long) indicatorp;
713 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
714 	if (ret)
715 		goto out;
716 
717 	if (indicatorp)
718 		ccw_device_dma_free(vcdev->cdev, indicatorp,
719 				    sizeof(indicators(vcdev)));
720 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
721 	return 0;
722 out:
723 	if (indicatorp)
724 		ccw_device_dma_free(vcdev->cdev, indicatorp,
725 				    sizeof(indicators(vcdev)));
726 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
727 	virtio_ccw_del_vqs(vdev);
728 	return ret;
729 }
730 
731 static void virtio_ccw_reset(struct virtio_device *vdev)
732 {
733 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
734 	struct ccw1 *ccw;
735 
736 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
737 	if (!ccw)
738 		return;
739 
740 	/* Zero status bits. */
741 	vcdev->dma_area->status = 0;
742 
743 	/* Send a reset ccw on device. */
744 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
745 	ccw->flags = 0;
746 	ccw->count = 0;
747 	ccw->cda = 0;
748 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
749 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
750 }
751 
752 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
753 {
754 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
755 	struct virtio_feature_desc *features;
756 	int ret;
757 	u64 rc;
758 	struct ccw1 *ccw;
759 
760 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
761 	if (!ccw)
762 		return 0;
763 
764 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
765 	if (!features) {
766 		rc = 0;
767 		goto out_free;
768 	}
769 	/* Read the feature bits from the host. */
770 	features->index = 0;
771 	ccw->cmd_code = CCW_CMD_READ_FEAT;
772 	ccw->flags = 0;
773 	ccw->count = sizeof(*features);
774 	ccw->cda = (__u32)(unsigned long)features;
775 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
776 	if (ret) {
777 		rc = 0;
778 		goto out_free;
779 	}
780 
781 	rc = le32_to_cpu(features->features);
782 
783 	if (vcdev->revision == 0)
784 		goto out_free;
785 
786 	/* Read second half of the feature bits from the host. */
787 	features->index = 1;
788 	ccw->cmd_code = CCW_CMD_READ_FEAT;
789 	ccw->flags = 0;
790 	ccw->count = sizeof(*features);
791 	ccw->cda = (__u32)(unsigned long)features;
792 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
793 	if (ret == 0)
794 		rc |= (u64)le32_to_cpu(features->features) << 32;
795 
796 out_free:
797 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
798 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
799 	return rc;
800 }
801 
802 static void ccw_transport_features(struct virtio_device *vdev)
803 {
804 	/*
805 	 * Currently nothing to do here.
806 	 */
807 }
808 
809 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
810 {
811 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
812 	struct virtio_feature_desc *features;
813 	struct ccw1 *ccw;
814 	int ret;
815 
816 	if (vcdev->revision >= 1 &&
817 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
818 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
819 			"but does not have VIRTIO_F_VERSION_1\n");
820 		return -EINVAL;
821 	}
822 
823 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
824 	if (!ccw)
825 		return -ENOMEM;
826 
827 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
828 	if (!features) {
829 		ret = -ENOMEM;
830 		goto out_free;
831 	}
832 	/* Give virtio_ring a chance to accept features. */
833 	vring_transport_features(vdev);
834 
835 	/* Give virtio_ccw a chance to accept features. */
836 	ccw_transport_features(vdev);
837 
838 	features->index = 0;
839 	features->features = cpu_to_le32((u32)vdev->features);
840 	/* Write the first half of the feature bits to the host. */
841 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
842 	ccw->flags = 0;
843 	ccw->count = sizeof(*features);
844 	ccw->cda = (__u32)(unsigned long)features;
845 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
846 	if (ret)
847 		goto out_free;
848 
849 	if (vcdev->revision == 0)
850 		goto out_free;
851 
852 	features->index = 1;
853 	features->features = cpu_to_le32(vdev->features >> 32);
854 	/* Write the second half of the feature bits to the host. */
855 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
856 	ccw->flags = 0;
857 	ccw->count = sizeof(*features);
858 	ccw->cda = (__u32)(unsigned long)features;
859 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
860 
861 out_free:
862 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
863 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
864 
865 	return ret;
866 }
867 
868 static void virtio_ccw_get_config(struct virtio_device *vdev,
869 				  unsigned int offset, void *buf, unsigned len)
870 {
871 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
872 	int ret;
873 	struct ccw1 *ccw;
874 	void *config_area;
875 	unsigned long flags;
876 
877 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
878 	if (!ccw)
879 		return;
880 
881 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
882 					    VIRTIO_CCW_CONFIG_SIZE);
883 	if (!config_area)
884 		goto out_free;
885 
886 	/* Read the config area from the host. */
887 	ccw->cmd_code = CCW_CMD_READ_CONF;
888 	ccw->flags = 0;
889 	ccw->count = offset + len;
890 	ccw->cda = (__u32)(unsigned long)config_area;
891 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
892 	if (ret)
893 		goto out_free;
894 
895 	spin_lock_irqsave(&vcdev->lock, flags);
896 	memcpy(vcdev->config, config_area, offset + len);
897 	if (vcdev->config_ready < offset + len)
898 		vcdev->config_ready = offset + len;
899 	spin_unlock_irqrestore(&vcdev->lock, flags);
900 	if (buf)
901 		memcpy(buf, config_area + offset, len);
902 
903 out_free:
904 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
905 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
906 }
907 
908 static void virtio_ccw_set_config(struct virtio_device *vdev,
909 				  unsigned int offset, const void *buf,
910 				  unsigned len)
911 {
912 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
913 	struct ccw1 *ccw;
914 	void *config_area;
915 	unsigned long flags;
916 
917 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
918 	if (!ccw)
919 		return;
920 
921 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
922 					    VIRTIO_CCW_CONFIG_SIZE);
923 	if (!config_area)
924 		goto out_free;
925 
926 	/* Make sure we don't overwrite fields. */
927 	if (vcdev->config_ready < offset)
928 		virtio_ccw_get_config(vdev, 0, NULL, offset);
929 	spin_lock_irqsave(&vcdev->lock, flags);
930 	memcpy(&vcdev->config[offset], buf, len);
931 	/* Write the config area to the host. */
932 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
933 	spin_unlock_irqrestore(&vcdev->lock, flags);
934 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
935 	ccw->flags = 0;
936 	ccw->count = offset + len;
937 	ccw->cda = (__u32)(unsigned long)config_area;
938 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
939 
940 out_free:
941 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
942 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
943 }
944 
945 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
946 {
947 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
948 	u8 old_status = vcdev->dma_area->status;
949 	struct ccw1 *ccw;
950 
951 	if (vcdev->revision < 1)
952 		return vcdev->dma_area->status;
953 
954 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
955 	if (!ccw)
956 		return old_status;
957 
958 	ccw->cmd_code = CCW_CMD_READ_STATUS;
959 	ccw->flags = 0;
960 	ccw->count = sizeof(vcdev->dma_area->status);
961 	ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
962 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
963 /*
964  * If the channel program failed (should only happen if the device
965  * was hotunplugged, and then we clean up via the machine check
966  * handler anyway), vcdev->dma_area->status was not overwritten and we just
967  * return the old status, which is fine.
968 */
969 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
970 
971 	return vcdev->dma_area->status;
972 }
973 
974 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
975 {
976 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
977 	u8 old_status = vcdev->dma_area->status;
978 	struct ccw1 *ccw;
979 	int ret;
980 
981 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
982 	if (!ccw)
983 		return;
984 
985 	/* Write the status to the host. */
986 	vcdev->dma_area->status = status;
987 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
988 	ccw->flags = 0;
989 	ccw->count = sizeof(status);
990 	ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
991 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
992 	/* Write failed? We assume status is unchanged. */
993 	if (ret)
994 		vcdev->dma_area->status = old_status;
995 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
996 }
997 
998 static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
999 {
1000 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1001 
1002 	return dev_name(&vcdev->cdev->dev);
1003 }
1004 
1005 static const struct virtio_config_ops virtio_ccw_config_ops = {
1006 	.get_features = virtio_ccw_get_features,
1007 	.finalize_features = virtio_ccw_finalize_features,
1008 	.get = virtio_ccw_get_config,
1009 	.set = virtio_ccw_set_config,
1010 	.get_status = virtio_ccw_get_status,
1011 	.set_status = virtio_ccw_set_status,
1012 	.reset = virtio_ccw_reset,
1013 	.find_vqs = virtio_ccw_find_vqs,
1014 	.del_vqs = virtio_ccw_del_vqs,
1015 	.bus_name = virtio_ccw_bus_name,
1016 };
1017 
1018 
1019 /*
1020  * ccw bus driver related functions
1021  */
1022 
1023 static void virtio_ccw_release_dev(struct device *_d)
1024 {
1025 	struct virtio_device *dev = dev_to_virtio(_d);
1026 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
1027 
1028 	ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1029 			    sizeof(*vcdev->dma_area));
1030 	kfree(vcdev);
1031 }
1032 
1033 static int irb_is_error(struct irb *irb)
1034 {
1035 	if (scsw_cstat(&irb->scsw) != 0)
1036 		return 1;
1037 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1038 		return 1;
1039 	if (scsw_cc(&irb->scsw) != 0)
1040 		return 1;
1041 	return 0;
1042 }
1043 
1044 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1045 					      int index)
1046 {
1047 	struct virtio_ccw_vq_info *info;
1048 	unsigned long flags;
1049 	struct virtqueue *vq;
1050 
1051 	vq = NULL;
1052 	spin_lock_irqsave(&vcdev->lock, flags);
1053 	list_for_each_entry(info, &vcdev->virtqueues, node) {
1054 		if (info->vq->index == index) {
1055 			vq = info->vq;
1056 			break;
1057 		}
1058 	}
1059 	spin_unlock_irqrestore(&vcdev->lock, flags);
1060 	return vq;
1061 }
1062 
1063 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1064 				      __u32 activity)
1065 {
1066 	if (vcdev->curr_io & activity) {
1067 		switch (activity) {
1068 		case VIRTIO_CCW_DOING_READ_FEAT:
1069 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1070 		case VIRTIO_CCW_DOING_READ_CONFIG:
1071 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1072 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1073 		case VIRTIO_CCW_DOING_READ_STATUS:
1074 		case VIRTIO_CCW_DOING_SET_VQ:
1075 		case VIRTIO_CCW_DOING_SET_IND:
1076 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1077 		case VIRTIO_CCW_DOING_RESET:
1078 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1079 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1080 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1081 			vcdev->curr_io &= ~activity;
1082 			wake_up(&vcdev->wait_q);
1083 			break;
1084 		default:
1085 			/* don't know what to do... */
1086 			dev_warn(&vcdev->cdev->dev,
1087 				 "Suspicious activity '%08x'\n", activity);
1088 			WARN_ON(1);
1089 			break;
1090 		}
1091 	}
1092 }
1093 
1094 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1095 				   unsigned long intparm,
1096 				   struct irb *irb)
1097 {
1098 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1099 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1100 	int i;
1101 	struct virtqueue *vq;
1102 
1103 	if (!vcdev)
1104 		return;
1105 	if (IS_ERR(irb)) {
1106 		vcdev->err = PTR_ERR(irb);
1107 		virtio_ccw_check_activity(vcdev, activity);
1108 		/* Don't poke around indicators, something's wrong. */
1109 		return;
1110 	}
1111 	/* Check if it's a notification from the host. */
1112 	if ((intparm == 0) &&
1113 	    (scsw_stctl(&irb->scsw) ==
1114 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1115 		/* OK */
1116 	}
1117 	if (irb_is_error(irb)) {
1118 		/* Command reject? */
1119 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1120 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1121 			vcdev->err = -EOPNOTSUPP;
1122 		else
1123 			/* Map everything else to -EIO. */
1124 			vcdev->err = -EIO;
1125 	}
1126 	virtio_ccw_check_activity(vcdev, activity);
1127 	for_each_set_bit(i, indicators(vcdev),
1128 			 sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {
1129 		/* The bit clear must happen before the vring kick. */
1130 		clear_bit(i, indicators(vcdev));
1131 		barrier();
1132 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1133 		vring_interrupt(0, vq);
1134 	}
1135 	if (test_bit(0, indicators2(vcdev))) {
1136 		virtio_config_changed(&vcdev->vdev);
1137 		clear_bit(0, indicators2(vcdev));
1138 	}
1139 }
1140 
1141 /*
1142  * We usually want to autoonline all devices, but give the admin
1143  * a way to exempt devices from this.
1144  */
1145 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1146 		     (8*sizeof(long)))
1147 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1148 
1149 static char *no_auto = "";
1150 
1151 module_param(no_auto, charp, 0444);
1152 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1153 
1154 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1155 {
1156 	struct ccw_dev_id id;
1157 
1158 	ccw_device_get_id(cdev, &id);
1159 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1160 		return 0;
1161 	return 1;
1162 }
1163 
1164 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1165 {
1166 	struct ccw_device *cdev = data;
1167 	int ret;
1168 
1169 	ret = ccw_device_set_online(cdev);
1170 	if (ret)
1171 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1172 }
1173 
1174 static int virtio_ccw_probe(struct ccw_device *cdev)
1175 {
1176 	cdev->handler = virtio_ccw_int_handler;
1177 
1178 	if (virtio_ccw_check_autoonline(cdev))
1179 		async_schedule(virtio_ccw_auto_online, cdev);
1180 	return 0;
1181 }
1182 
1183 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1184 {
1185 	unsigned long flags;
1186 	struct virtio_ccw_device *vcdev;
1187 
1188 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1189 	vcdev = dev_get_drvdata(&cdev->dev);
1190 	if (!vcdev || vcdev->going_away) {
1191 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1192 		return NULL;
1193 	}
1194 	vcdev->going_away = true;
1195 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1196 	return vcdev;
1197 }
1198 
1199 static void virtio_ccw_remove(struct ccw_device *cdev)
1200 {
1201 	unsigned long flags;
1202 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1203 
1204 	if (vcdev && cdev->online) {
1205 		if (vcdev->device_lost)
1206 			virtio_break_device(&vcdev->vdev);
1207 		unregister_virtio_device(&vcdev->vdev);
1208 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1209 		dev_set_drvdata(&cdev->dev, NULL);
1210 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1211 	}
1212 	cdev->handler = NULL;
1213 }
1214 
1215 static int virtio_ccw_offline(struct ccw_device *cdev)
1216 {
1217 	unsigned long flags;
1218 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1219 
1220 	if (!vcdev)
1221 		return 0;
1222 	if (vcdev->device_lost)
1223 		virtio_break_device(&vcdev->vdev);
1224 	unregister_virtio_device(&vcdev->vdev);
1225 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1226 	dev_set_drvdata(&cdev->dev, NULL);
1227 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1228 	return 0;
1229 }
1230 
1231 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1232 {
1233 	struct virtio_rev_info *rev;
1234 	struct ccw1 *ccw;
1235 	int ret;
1236 
1237 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
1238 	if (!ccw)
1239 		return -ENOMEM;
1240 	rev = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*rev));
1241 	if (!rev) {
1242 		ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1243 		return -ENOMEM;
1244 	}
1245 
1246 	/* Set transport revision */
1247 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1248 	ccw->flags = 0;
1249 	ccw->count = sizeof(*rev);
1250 	ccw->cda = (__u32)(unsigned long)rev;
1251 
1252 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1253 	do {
1254 		rev->revision = vcdev->revision;
1255 		/* none of our supported revisions carry payload */
1256 		rev->length = 0;
1257 		ret = ccw_io_helper(vcdev, ccw,
1258 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1259 		if (ret == -EOPNOTSUPP) {
1260 			if (vcdev->revision == 0)
1261 				/*
1262 				 * The host device does not support setting
1263 				 * the revision: let's operate it in legacy
1264 				 * mode.
1265 				 */
1266 				ret = 0;
1267 			else
1268 				vcdev->revision--;
1269 		}
1270 	} while (ret == -EOPNOTSUPP);
1271 
1272 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1273 	ccw_device_dma_free(vcdev->cdev, rev, sizeof(*rev));
1274 	return ret;
1275 }
1276 
1277 static int virtio_ccw_online(struct ccw_device *cdev)
1278 {
1279 	int ret;
1280 	struct virtio_ccw_device *vcdev;
1281 	unsigned long flags;
1282 
1283 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1284 	if (!vcdev) {
1285 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1286 		ret = -ENOMEM;
1287 		goto out_free;
1288 	}
1289 	vcdev->vdev.dev.parent = &cdev->dev;
1290 	vcdev->cdev = cdev;
1291 	vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,
1292 						sizeof(*vcdev->dma_area));
1293 	if (!vcdev->dma_area) {
1294 		ret = -ENOMEM;
1295 		goto out_free;
1296 	}
1297 
1298 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1299 
1300 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1301 	vcdev->vdev.config = &virtio_ccw_config_ops;
1302 	init_waitqueue_head(&vcdev->wait_q);
1303 	INIT_LIST_HEAD(&vcdev->virtqueues);
1304 	spin_lock_init(&vcdev->lock);
1305 	mutex_init(&vcdev->io_lock);
1306 
1307 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1308 	dev_set_drvdata(&cdev->dev, vcdev);
1309 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1310 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1311 	vcdev->vdev.id.device = cdev->id.cu_model;
1312 
1313 	ret = virtio_ccw_set_transport_rev(vcdev);
1314 	if (ret)
1315 		goto out_free;
1316 
1317 	ret = register_virtio_device(&vcdev->vdev);
1318 	if (ret) {
1319 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1320 			 ret);
1321 		goto out_put;
1322 	}
1323 	return 0;
1324 out_put:
1325 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1326 	dev_set_drvdata(&cdev->dev, NULL);
1327 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1328 	put_device(&vcdev->vdev.dev);
1329 	return ret;
1330 out_free:
1331 	if (vcdev) {
1332 		ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1333 				    sizeof(*vcdev->dma_area));
1334 	}
1335 	kfree(vcdev);
1336 	return ret;
1337 }
1338 
1339 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1340 {
1341 	int rc;
1342 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1343 
1344 	/*
1345 	 * Make sure vcdev is set
1346 	 * i.e. set_offline/remove callback not already running
1347 	 */
1348 	if (!vcdev)
1349 		return NOTIFY_DONE;
1350 
1351 	switch (event) {
1352 	case CIO_GONE:
1353 		vcdev->device_lost = true;
1354 		rc = NOTIFY_DONE;
1355 		break;
1356 	case CIO_OPER:
1357 		rc = NOTIFY_OK;
1358 		break;
1359 	default:
1360 		rc = NOTIFY_DONE;
1361 		break;
1362 	}
1363 	return rc;
1364 }
1365 
1366 static struct ccw_device_id virtio_ids[] = {
1367 	{ CCW_DEVICE(0x3832, 0) },
1368 	{},
1369 };
1370 
1371 #ifdef CONFIG_PM_SLEEP
1372 static int virtio_ccw_freeze(struct ccw_device *cdev)
1373 {
1374 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1375 
1376 	return virtio_device_freeze(&vcdev->vdev);
1377 }
1378 
1379 static int virtio_ccw_restore(struct ccw_device *cdev)
1380 {
1381 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1382 	int ret;
1383 
1384 	ret = virtio_ccw_set_transport_rev(vcdev);
1385 	if (ret)
1386 		return ret;
1387 
1388 	return virtio_device_restore(&vcdev->vdev);
1389 }
1390 #endif
1391 
1392 static struct ccw_driver virtio_ccw_driver = {
1393 	.driver = {
1394 		.owner = THIS_MODULE,
1395 		.name = "virtio_ccw",
1396 	},
1397 	.ids = virtio_ids,
1398 	.probe = virtio_ccw_probe,
1399 	.remove = virtio_ccw_remove,
1400 	.set_offline = virtio_ccw_offline,
1401 	.set_online = virtio_ccw_online,
1402 	.notify = virtio_ccw_cio_notify,
1403 	.int_class = IRQIO_VIR,
1404 #ifdef CONFIG_PM_SLEEP
1405 	.freeze = virtio_ccw_freeze,
1406 	.thaw = virtio_ccw_restore,
1407 	.restore = virtio_ccw_restore,
1408 #endif
1409 };
1410 
1411 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1412 			   int max_digit, int max_val)
1413 {
1414 	int diff;
1415 
1416 	diff = 0;
1417 	*val = 0;
1418 
1419 	while (diff <= max_digit) {
1420 		int value = hex_to_bin(**cp);
1421 
1422 		if (value < 0)
1423 			break;
1424 		*val = *val * 16 + value;
1425 		(*cp)++;
1426 		diff++;
1427 	}
1428 
1429 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1430 		return 1;
1431 
1432 	return 0;
1433 }
1434 
1435 static int __init parse_busid(char *str, unsigned int *cssid,
1436 			      unsigned int *ssid, unsigned int *devno)
1437 {
1438 	char *str_work;
1439 	int rc, ret;
1440 
1441 	rc = 1;
1442 
1443 	if (*str == '\0')
1444 		goto out;
1445 
1446 	str_work = str;
1447 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1448 	if (ret || (str_work[0] != '.'))
1449 		goto out;
1450 	str_work++;
1451 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1452 	if (ret || (str_work[0] != '.'))
1453 		goto out;
1454 	str_work++;
1455 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1456 	if (ret || (str_work[0] != '\0'))
1457 		goto out;
1458 
1459 	rc = 0;
1460 out:
1461 	return rc;
1462 }
1463 
1464 static void __init no_auto_parse(void)
1465 {
1466 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1467 	char *parm, *str;
1468 	int rc;
1469 
1470 	str = no_auto;
1471 	while ((parm = strsep(&str, ","))) {
1472 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1473 				 &from_ssid, &from);
1474 		if (rc)
1475 			continue;
1476 		if (parm != NULL) {
1477 			rc = parse_busid(parm, &to_cssid,
1478 					 &to_ssid, &to);
1479 			if ((from_ssid > to_ssid) ||
1480 			    ((from_ssid == to_ssid) && (from > to)))
1481 				rc = -EINVAL;
1482 		} else {
1483 			to_cssid = from_cssid;
1484 			to_ssid = from_ssid;
1485 			to = from;
1486 		}
1487 		if (rc)
1488 			continue;
1489 		while ((from_ssid < to_ssid) ||
1490 		       ((from_ssid == to_ssid) && (from <= to))) {
1491 			set_bit(from, devs_no_auto[from_ssid]);
1492 			from++;
1493 			if (from > __MAX_SUBCHANNEL) {
1494 				from_ssid++;
1495 				from = 0;
1496 			}
1497 		}
1498 	}
1499 }
1500 
1501 static int __init virtio_ccw_init(void)
1502 {
1503 	int rc;
1504 
1505 	/* parse no_auto string before we do anything further */
1506 	no_auto_parse();
1507 
1508 	summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS);
1509 	if (!summary_indicators)
1510 		return -ENOMEM;
1511 	rc = ccw_driver_register(&virtio_ccw_driver);
1512 	if (rc)
1513 		cio_dma_free(summary_indicators, MAX_AIRQ_AREAS);
1514 	return rc;
1515 }
1516 device_initcall(virtio_ccw_init);
1517