xref: /openbmc/linux/drivers/s390/virtio/virtio_ccw.c (revision 3dc4b6fb)
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 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 inline long __do_kvm_notify(struct subchannel_id schid,
392 				   unsigned long queue_index,
393 				   long cookie)
394 {
395 	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
396 	register struct subchannel_id __schid asm("2") = schid;
397 	register unsigned long __index asm("3") = queue_index;
398 	register long __rc asm("2");
399 	register long __cookie asm("4") = cookie;
400 
401 	asm volatile ("diag 2,4,0x500\n"
402 		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
403 		      "d"(__cookie)
404 		      : "memory", "cc");
405 	return __rc;
406 }
407 
408 static inline long do_kvm_notify(struct subchannel_id schid,
409 				 unsigned long queue_index,
410 				 long cookie)
411 {
412 	diag_stat_inc(DIAG_STAT_X500);
413 	return __do_kvm_notify(schid, queue_index, cookie);
414 }
415 
416 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
417 {
418 	struct virtio_ccw_vq_info *info = vq->priv;
419 	struct virtio_ccw_device *vcdev;
420 	struct subchannel_id schid;
421 
422 	vcdev = to_vc_device(info->vq->vdev);
423 	ccw_device_get_schid(vcdev->cdev, &schid);
424 	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
425 	if (info->cookie < 0)
426 		return false;
427 	return true;
428 }
429 
430 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
431 				   struct ccw1 *ccw, int index)
432 {
433 	int ret;
434 
435 	vcdev->dma_area->config_block.index = index;
436 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
437 	ccw->flags = 0;
438 	ccw->count = sizeof(struct vq_config_block);
439 	ccw->cda = (__u32)(unsigned long)(&vcdev->dma_area->config_block);
440 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
441 	if (ret)
442 		return ret;
443 	return vcdev->dma_area->config_block.num ?: -ENOENT;
444 }
445 
446 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
447 {
448 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
449 	struct virtio_ccw_vq_info *info = vq->priv;
450 	unsigned long flags;
451 	int ret;
452 	unsigned int index = vq->index;
453 
454 	/* Remove from our list. */
455 	spin_lock_irqsave(&vcdev->lock, flags);
456 	list_del(&info->node);
457 	spin_unlock_irqrestore(&vcdev->lock, flags);
458 
459 	/* Release from host. */
460 	if (vcdev->revision == 0) {
461 		info->info_block->l.queue = 0;
462 		info->info_block->l.align = 0;
463 		info->info_block->l.index = index;
464 		info->info_block->l.num = 0;
465 		ccw->count = sizeof(info->info_block->l);
466 	} else {
467 		info->info_block->s.desc = 0;
468 		info->info_block->s.index = index;
469 		info->info_block->s.num = 0;
470 		info->info_block->s.avail = 0;
471 		info->info_block->s.used = 0;
472 		ccw->count = sizeof(info->info_block->s);
473 	}
474 	ccw->cmd_code = CCW_CMD_SET_VQ;
475 	ccw->flags = 0;
476 	ccw->cda = (__u32)(unsigned long)(info->info_block);
477 	ret = ccw_io_helper(vcdev, ccw,
478 			    VIRTIO_CCW_DOING_SET_VQ | index);
479 	/*
480 	 * -ENODEV isn't considered an error: The device is gone anyway.
481 	 * This may happen on device detach.
482 	 */
483 	if (ret && (ret != -ENODEV))
484 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
485 			 ret, index);
486 
487 	vring_del_virtqueue(vq);
488 	ccw_device_dma_free(vcdev->cdev, info->info_block,
489 			    sizeof(*info->info_block));
490 	kfree(info);
491 }
492 
493 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
494 {
495 	struct virtqueue *vq, *n;
496 	struct ccw1 *ccw;
497 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
498 
499 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
500 	if (!ccw)
501 		return;
502 
503 	virtio_ccw_drop_indicator(vcdev, ccw);
504 
505 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
506 		virtio_ccw_del_vq(vq, ccw);
507 
508 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
509 }
510 
511 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
512 					     int i, vq_callback_t *callback,
513 					     const char *name, bool ctx,
514 					     struct ccw1 *ccw)
515 {
516 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
517 	int err;
518 	struct virtqueue *vq = NULL;
519 	struct virtio_ccw_vq_info *info;
520 	u64 queue;
521 	unsigned long flags;
522 	bool may_reduce;
523 
524 	/* Allocate queue. */
525 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
526 	if (!info) {
527 		dev_warn(&vcdev->cdev->dev, "no info\n");
528 		err = -ENOMEM;
529 		goto out_err;
530 	}
531 	info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
532 						 sizeof(*info->info_block));
533 	if (!info->info_block) {
534 		dev_warn(&vcdev->cdev->dev, "no info block\n");
535 		err = -ENOMEM;
536 		goto out_err;
537 	}
538 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
539 	if (info->num < 0) {
540 		err = info->num;
541 		goto out_err;
542 	}
543 	may_reduce = vcdev->revision > 0;
544 	vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
545 				    vdev, true, may_reduce, ctx,
546 				    virtio_ccw_kvm_notify, callback, name);
547 
548 	if (!vq) {
549 		/* For now, we fail if we can't get the requested size. */
550 		dev_warn(&vcdev->cdev->dev, "no vq\n");
551 		err = -ENOMEM;
552 		goto out_err;
553 	}
554 	/* it may have been reduced */
555 	info->num = virtqueue_get_vring_size(vq);
556 
557 	/* Register it with the host. */
558 	queue = virtqueue_get_desc_addr(vq);
559 	if (vcdev->revision == 0) {
560 		info->info_block->l.queue = queue;
561 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
562 		info->info_block->l.index = i;
563 		info->info_block->l.num = info->num;
564 		ccw->count = sizeof(info->info_block->l);
565 	} else {
566 		info->info_block->s.desc = queue;
567 		info->info_block->s.index = i;
568 		info->info_block->s.num = info->num;
569 		info->info_block->s.avail = (__u64)virtqueue_get_avail_addr(vq);
570 		info->info_block->s.used = (__u64)virtqueue_get_used_addr(vq);
571 		ccw->count = sizeof(info->info_block->s);
572 	}
573 	ccw->cmd_code = CCW_CMD_SET_VQ;
574 	ccw->flags = 0;
575 	ccw->cda = (__u32)(unsigned long)(info->info_block);
576 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
577 	if (err) {
578 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
579 		goto out_err;
580 	}
581 
582 	info->vq = vq;
583 	vq->priv = info;
584 
585 	/* Save it to our list. */
586 	spin_lock_irqsave(&vcdev->lock, flags);
587 	list_add(&info->node, &vcdev->virtqueues);
588 	spin_unlock_irqrestore(&vcdev->lock, flags);
589 
590 	return vq;
591 
592 out_err:
593 	if (vq)
594 		vring_del_virtqueue(vq);
595 	if (info) {
596 		ccw_device_dma_free(vcdev->cdev, info->info_block,
597 				    sizeof(*info->info_block));
598 	}
599 	kfree(info);
600 	return ERR_PTR(err);
601 }
602 
603 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
604 					   struct virtqueue *vqs[], int nvqs,
605 					   struct ccw1 *ccw)
606 {
607 	int ret;
608 	struct virtio_thinint_area *thinint_area = NULL;
609 	struct airq_info *info;
610 
611 	thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
612 					     sizeof(*thinint_area));
613 	if (!thinint_area) {
614 		ret = -ENOMEM;
615 		goto out;
616 	}
617 	/* Try to get an indicator. */
618 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
619 						     &thinint_area->bit_nr,
620 						     &vcdev->airq_info);
621 	if (!thinint_area->indicator) {
622 		ret = -ENOSPC;
623 		goto out;
624 	}
625 	info = vcdev->airq_info;
626 	thinint_area->summary_indicator =
627 		(unsigned long) get_summary_indicator(info);
628 	thinint_area->isc = VIRTIO_AIRQ_ISC;
629 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
630 	ccw->flags = CCW_FLAG_SLI;
631 	ccw->count = sizeof(*thinint_area);
632 	ccw->cda = (__u32)(unsigned long)thinint_area;
633 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
634 	if (ret) {
635 		if (ret == -EOPNOTSUPP) {
636 			/*
637 			 * The host does not support adapter interrupts
638 			 * for virtio-ccw, stop trying.
639 			 */
640 			virtio_ccw_use_airq = 0;
641 			pr_info("Adapter interrupts unsupported on host\n");
642 		} else
643 			dev_warn(&vcdev->cdev->dev,
644 				 "enabling adapter interrupts = %d\n", ret);
645 		virtio_ccw_drop_indicators(vcdev);
646 	}
647 out:
648 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
649 	return ret;
650 }
651 
652 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
653 			       struct virtqueue *vqs[],
654 			       vq_callback_t *callbacks[],
655 			       const char * const names[],
656 			       const bool *ctx,
657 			       struct irq_affinity *desc)
658 {
659 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
660 	unsigned long *indicatorp = NULL;
661 	int ret, i, queue_idx = 0;
662 	struct ccw1 *ccw;
663 
664 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
665 	if (!ccw)
666 		return -ENOMEM;
667 
668 	for (i = 0; i < nvqs; ++i) {
669 		if (!names[i]) {
670 			vqs[i] = NULL;
671 			continue;
672 		}
673 
674 		vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, callbacks[i],
675 					     names[i], ctx ? ctx[i] : false,
676 					     ccw);
677 		if (IS_ERR(vqs[i])) {
678 			ret = PTR_ERR(vqs[i]);
679 			vqs[i] = NULL;
680 			goto out;
681 		}
682 	}
683 	ret = -ENOMEM;
684 	/*
685 	 * We need a data area under 2G to communicate. Our payload is
686 	 * the address of the indicators.
687 	*/
688 	indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
689 					   sizeof(indicators(vcdev)));
690 	if (!indicatorp)
691 		goto out;
692 	*indicatorp = (unsigned long) indicators(vcdev);
693 	if (vcdev->is_thinint) {
694 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
695 		if (ret)
696 			/* no error, just fall back to legacy interrupts */
697 			vcdev->is_thinint = false;
698 	}
699 	if (!vcdev->is_thinint) {
700 		/* Register queue indicators with host. */
701 		*indicators(vcdev) = 0;
702 		ccw->cmd_code = CCW_CMD_SET_IND;
703 		ccw->flags = 0;
704 		ccw->count = sizeof(indicators(vcdev));
705 		ccw->cda = (__u32)(unsigned long) indicatorp;
706 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
707 		if (ret)
708 			goto out;
709 	}
710 	/* Register indicators2 with host for config changes */
711 	*indicatorp = (unsigned long) indicators2(vcdev);
712 	*indicators2(vcdev) = 0;
713 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
714 	ccw->flags = 0;
715 	ccw->count = sizeof(indicators2(vcdev));
716 	ccw->cda = (__u32)(unsigned long) indicatorp;
717 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
718 	if (ret)
719 		goto out;
720 
721 	if (indicatorp)
722 		ccw_device_dma_free(vcdev->cdev, indicatorp,
723 				    sizeof(indicators(vcdev)));
724 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
725 	return 0;
726 out:
727 	if (indicatorp)
728 		ccw_device_dma_free(vcdev->cdev, indicatorp,
729 				    sizeof(indicators(vcdev)));
730 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
731 	virtio_ccw_del_vqs(vdev);
732 	return ret;
733 }
734 
735 static void virtio_ccw_reset(struct virtio_device *vdev)
736 {
737 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
738 	struct ccw1 *ccw;
739 
740 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
741 	if (!ccw)
742 		return;
743 
744 	/* Zero status bits. */
745 	vcdev->dma_area->status = 0;
746 
747 	/* Send a reset ccw on device. */
748 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
749 	ccw->flags = 0;
750 	ccw->count = 0;
751 	ccw->cda = 0;
752 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
753 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
754 }
755 
756 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
757 {
758 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
759 	struct virtio_feature_desc *features;
760 	int ret;
761 	u64 rc;
762 	struct ccw1 *ccw;
763 
764 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
765 	if (!ccw)
766 		return 0;
767 
768 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
769 	if (!features) {
770 		rc = 0;
771 		goto out_free;
772 	}
773 	/* Read the feature bits from the host. */
774 	features->index = 0;
775 	ccw->cmd_code = CCW_CMD_READ_FEAT;
776 	ccw->flags = 0;
777 	ccw->count = sizeof(*features);
778 	ccw->cda = (__u32)(unsigned long)features;
779 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
780 	if (ret) {
781 		rc = 0;
782 		goto out_free;
783 	}
784 
785 	rc = le32_to_cpu(features->features);
786 
787 	if (vcdev->revision == 0)
788 		goto out_free;
789 
790 	/* Read second half of the feature bits from the host. */
791 	features->index = 1;
792 	ccw->cmd_code = CCW_CMD_READ_FEAT;
793 	ccw->flags = 0;
794 	ccw->count = sizeof(*features);
795 	ccw->cda = (__u32)(unsigned long)features;
796 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
797 	if (ret == 0)
798 		rc |= (u64)le32_to_cpu(features->features) << 32;
799 
800 out_free:
801 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
802 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
803 	return rc;
804 }
805 
806 static void ccw_transport_features(struct virtio_device *vdev)
807 {
808 	/*
809 	 * Currently nothing to do here.
810 	 */
811 }
812 
813 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
814 {
815 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
816 	struct virtio_feature_desc *features;
817 	struct ccw1 *ccw;
818 	int ret;
819 
820 	if (vcdev->revision >= 1 &&
821 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
822 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
823 			"but does not have VIRTIO_F_VERSION_1\n");
824 		return -EINVAL;
825 	}
826 
827 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
828 	if (!ccw)
829 		return -ENOMEM;
830 
831 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
832 	if (!features) {
833 		ret = -ENOMEM;
834 		goto out_free;
835 	}
836 	/* Give virtio_ring a chance to accept features. */
837 	vring_transport_features(vdev);
838 
839 	/* Give virtio_ccw a chance to accept features. */
840 	ccw_transport_features(vdev);
841 
842 	features->index = 0;
843 	features->features = cpu_to_le32((u32)vdev->features);
844 	/* Write the first half of the feature bits to the host. */
845 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
846 	ccw->flags = 0;
847 	ccw->count = sizeof(*features);
848 	ccw->cda = (__u32)(unsigned long)features;
849 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
850 	if (ret)
851 		goto out_free;
852 
853 	if (vcdev->revision == 0)
854 		goto out_free;
855 
856 	features->index = 1;
857 	features->features = cpu_to_le32(vdev->features >> 32);
858 	/* Write the second half of the feature bits to the host. */
859 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
860 	ccw->flags = 0;
861 	ccw->count = sizeof(*features);
862 	ccw->cda = (__u32)(unsigned long)features;
863 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
864 
865 out_free:
866 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
867 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
868 
869 	return ret;
870 }
871 
872 static void virtio_ccw_get_config(struct virtio_device *vdev,
873 				  unsigned int offset, void *buf, unsigned len)
874 {
875 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
876 	int ret;
877 	struct ccw1 *ccw;
878 	void *config_area;
879 	unsigned long flags;
880 
881 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
882 	if (!ccw)
883 		return;
884 
885 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
886 					    VIRTIO_CCW_CONFIG_SIZE);
887 	if (!config_area)
888 		goto out_free;
889 
890 	/* Read the config area from the host. */
891 	ccw->cmd_code = CCW_CMD_READ_CONF;
892 	ccw->flags = 0;
893 	ccw->count = offset + len;
894 	ccw->cda = (__u32)(unsigned long)config_area;
895 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
896 	if (ret)
897 		goto out_free;
898 
899 	spin_lock_irqsave(&vcdev->lock, flags);
900 	memcpy(vcdev->config, config_area, offset + len);
901 	if (vcdev->config_ready < offset + len)
902 		vcdev->config_ready = offset + len;
903 	spin_unlock_irqrestore(&vcdev->lock, flags);
904 	if (buf)
905 		memcpy(buf, config_area + offset, len);
906 
907 out_free:
908 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
909 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
910 }
911 
912 static void virtio_ccw_set_config(struct virtio_device *vdev,
913 				  unsigned int offset, const void *buf,
914 				  unsigned len)
915 {
916 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
917 	struct ccw1 *ccw;
918 	void *config_area;
919 	unsigned long flags;
920 
921 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
922 	if (!ccw)
923 		return;
924 
925 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
926 					    VIRTIO_CCW_CONFIG_SIZE);
927 	if (!config_area)
928 		goto out_free;
929 
930 	/* Make sure we don't overwrite fields. */
931 	if (vcdev->config_ready < offset)
932 		virtio_ccw_get_config(vdev, 0, NULL, offset);
933 	spin_lock_irqsave(&vcdev->lock, flags);
934 	memcpy(&vcdev->config[offset], buf, len);
935 	/* Write the config area to the host. */
936 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
937 	spin_unlock_irqrestore(&vcdev->lock, flags);
938 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
939 	ccw->flags = 0;
940 	ccw->count = offset + len;
941 	ccw->cda = (__u32)(unsigned long)config_area;
942 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
943 
944 out_free:
945 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
946 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
947 }
948 
949 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
950 {
951 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
952 	u8 old_status = vcdev->dma_area->status;
953 	struct ccw1 *ccw;
954 
955 	if (vcdev->revision < 1)
956 		return vcdev->dma_area->status;
957 
958 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
959 	if (!ccw)
960 		return old_status;
961 
962 	ccw->cmd_code = CCW_CMD_READ_STATUS;
963 	ccw->flags = 0;
964 	ccw->count = sizeof(vcdev->dma_area->status);
965 	ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
966 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
967 /*
968  * If the channel program failed (should only happen if the device
969  * was hotunplugged, and then we clean up via the machine check
970  * handler anyway), vcdev->dma_area->status was not overwritten and we just
971  * return the old status, which is fine.
972 */
973 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
974 
975 	return vcdev->dma_area->status;
976 }
977 
978 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
979 {
980 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
981 	u8 old_status = vcdev->dma_area->status;
982 	struct ccw1 *ccw;
983 	int ret;
984 
985 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
986 	if (!ccw)
987 		return;
988 
989 	/* Write the status to the host. */
990 	vcdev->dma_area->status = status;
991 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
992 	ccw->flags = 0;
993 	ccw->count = sizeof(status);
994 	ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
995 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
996 	/* Write failed? We assume status is unchanged. */
997 	if (ret)
998 		vcdev->dma_area->status = old_status;
999 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1000 }
1001 
1002 static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
1003 {
1004 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1005 
1006 	return dev_name(&vcdev->cdev->dev);
1007 }
1008 
1009 static const struct virtio_config_ops virtio_ccw_config_ops = {
1010 	.get_features = virtio_ccw_get_features,
1011 	.finalize_features = virtio_ccw_finalize_features,
1012 	.get = virtio_ccw_get_config,
1013 	.set = virtio_ccw_set_config,
1014 	.get_status = virtio_ccw_get_status,
1015 	.set_status = virtio_ccw_set_status,
1016 	.reset = virtio_ccw_reset,
1017 	.find_vqs = virtio_ccw_find_vqs,
1018 	.del_vqs = virtio_ccw_del_vqs,
1019 	.bus_name = virtio_ccw_bus_name,
1020 };
1021 
1022 
1023 /*
1024  * ccw bus driver related functions
1025  */
1026 
1027 static void virtio_ccw_release_dev(struct device *_d)
1028 {
1029 	struct virtio_device *dev = dev_to_virtio(_d);
1030 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
1031 
1032 	ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1033 			    sizeof(*vcdev->dma_area));
1034 	kfree(vcdev);
1035 }
1036 
1037 static int irb_is_error(struct irb *irb)
1038 {
1039 	if (scsw_cstat(&irb->scsw) != 0)
1040 		return 1;
1041 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1042 		return 1;
1043 	if (scsw_cc(&irb->scsw) != 0)
1044 		return 1;
1045 	return 0;
1046 }
1047 
1048 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1049 					      int index)
1050 {
1051 	struct virtio_ccw_vq_info *info;
1052 	unsigned long flags;
1053 	struct virtqueue *vq;
1054 
1055 	vq = NULL;
1056 	spin_lock_irqsave(&vcdev->lock, flags);
1057 	list_for_each_entry(info, &vcdev->virtqueues, node) {
1058 		if (info->vq->index == index) {
1059 			vq = info->vq;
1060 			break;
1061 		}
1062 	}
1063 	spin_unlock_irqrestore(&vcdev->lock, flags);
1064 	return vq;
1065 }
1066 
1067 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1068 				      __u32 activity)
1069 {
1070 	if (vcdev->curr_io & activity) {
1071 		switch (activity) {
1072 		case VIRTIO_CCW_DOING_READ_FEAT:
1073 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1074 		case VIRTIO_CCW_DOING_READ_CONFIG:
1075 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1076 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1077 		case VIRTIO_CCW_DOING_READ_STATUS:
1078 		case VIRTIO_CCW_DOING_SET_VQ:
1079 		case VIRTIO_CCW_DOING_SET_IND:
1080 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1081 		case VIRTIO_CCW_DOING_RESET:
1082 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1083 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1084 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1085 			vcdev->curr_io &= ~activity;
1086 			wake_up(&vcdev->wait_q);
1087 			break;
1088 		default:
1089 			/* don't know what to do... */
1090 			dev_warn(&vcdev->cdev->dev,
1091 				 "Suspicious activity '%08x'\n", activity);
1092 			WARN_ON(1);
1093 			break;
1094 		}
1095 	}
1096 }
1097 
1098 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1099 				   unsigned long intparm,
1100 				   struct irb *irb)
1101 {
1102 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1103 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1104 	int i;
1105 	struct virtqueue *vq;
1106 
1107 	if (!vcdev)
1108 		return;
1109 	if (IS_ERR(irb)) {
1110 		vcdev->err = PTR_ERR(irb);
1111 		virtio_ccw_check_activity(vcdev, activity);
1112 		/* Don't poke around indicators, something's wrong. */
1113 		return;
1114 	}
1115 	/* Check if it's a notification from the host. */
1116 	if ((intparm == 0) &&
1117 	    (scsw_stctl(&irb->scsw) ==
1118 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1119 		/* OK */
1120 	}
1121 	if (irb_is_error(irb)) {
1122 		/* Command reject? */
1123 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1124 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1125 			vcdev->err = -EOPNOTSUPP;
1126 		else
1127 			/* Map everything else to -EIO. */
1128 			vcdev->err = -EIO;
1129 	}
1130 	virtio_ccw_check_activity(vcdev, activity);
1131 	for_each_set_bit(i, indicators(vcdev),
1132 			 sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {
1133 		/* The bit clear must happen before the vring kick. */
1134 		clear_bit(i, indicators(vcdev));
1135 		barrier();
1136 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1137 		vring_interrupt(0, vq);
1138 	}
1139 	if (test_bit(0, indicators2(vcdev))) {
1140 		virtio_config_changed(&vcdev->vdev);
1141 		clear_bit(0, indicators2(vcdev));
1142 	}
1143 }
1144 
1145 /*
1146  * We usually want to autoonline all devices, but give the admin
1147  * a way to exempt devices from this.
1148  */
1149 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1150 		     (8*sizeof(long)))
1151 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1152 
1153 static char *no_auto = "";
1154 
1155 module_param(no_auto, charp, 0444);
1156 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1157 
1158 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1159 {
1160 	struct ccw_dev_id id;
1161 
1162 	ccw_device_get_id(cdev, &id);
1163 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1164 		return 0;
1165 	return 1;
1166 }
1167 
1168 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1169 {
1170 	struct ccw_device *cdev = data;
1171 	int ret;
1172 
1173 	ret = ccw_device_set_online(cdev);
1174 	if (ret)
1175 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1176 }
1177 
1178 static int virtio_ccw_probe(struct ccw_device *cdev)
1179 {
1180 	cdev->handler = virtio_ccw_int_handler;
1181 
1182 	if (virtio_ccw_check_autoonline(cdev))
1183 		async_schedule(virtio_ccw_auto_online, cdev);
1184 	return 0;
1185 }
1186 
1187 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1188 {
1189 	unsigned long flags;
1190 	struct virtio_ccw_device *vcdev;
1191 
1192 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1193 	vcdev = dev_get_drvdata(&cdev->dev);
1194 	if (!vcdev || vcdev->going_away) {
1195 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1196 		return NULL;
1197 	}
1198 	vcdev->going_away = true;
1199 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1200 	return vcdev;
1201 }
1202 
1203 static void virtio_ccw_remove(struct ccw_device *cdev)
1204 {
1205 	unsigned long flags;
1206 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1207 
1208 	if (vcdev && cdev->online) {
1209 		if (vcdev->device_lost)
1210 			virtio_break_device(&vcdev->vdev);
1211 		unregister_virtio_device(&vcdev->vdev);
1212 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1213 		dev_set_drvdata(&cdev->dev, NULL);
1214 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1215 	}
1216 	cdev->handler = NULL;
1217 }
1218 
1219 static int virtio_ccw_offline(struct ccw_device *cdev)
1220 {
1221 	unsigned long flags;
1222 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1223 
1224 	if (!vcdev)
1225 		return 0;
1226 	if (vcdev->device_lost)
1227 		virtio_break_device(&vcdev->vdev);
1228 	unregister_virtio_device(&vcdev->vdev);
1229 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1230 	dev_set_drvdata(&cdev->dev, NULL);
1231 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1232 	return 0;
1233 }
1234 
1235 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1236 {
1237 	struct virtio_rev_info *rev;
1238 	struct ccw1 *ccw;
1239 	int ret;
1240 
1241 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
1242 	if (!ccw)
1243 		return -ENOMEM;
1244 	rev = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*rev));
1245 	if (!rev) {
1246 		ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1247 		return -ENOMEM;
1248 	}
1249 
1250 	/* Set transport revision */
1251 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1252 	ccw->flags = 0;
1253 	ccw->count = sizeof(*rev);
1254 	ccw->cda = (__u32)(unsigned long)rev;
1255 
1256 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1257 	do {
1258 		rev->revision = vcdev->revision;
1259 		/* none of our supported revisions carry payload */
1260 		rev->length = 0;
1261 		ret = ccw_io_helper(vcdev, ccw,
1262 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1263 		if (ret == -EOPNOTSUPP) {
1264 			if (vcdev->revision == 0)
1265 				/*
1266 				 * The host device does not support setting
1267 				 * the revision: let's operate it in legacy
1268 				 * mode.
1269 				 */
1270 				ret = 0;
1271 			else
1272 				vcdev->revision--;
1273 		}
1274 	} while (ret == -EOPNOTSUPP);
1275 
1276 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1277 	ccw_device_dma_free(vcdev->cdev, rev, sizeof(*rev));
1278 	return ret;
1279 }
1280 
1281 static int virtio_ccw_online(struct ccw_device *cdev)
1282 {
1283 	int ret;
1284 	struct virtio_ccw_device *vcdev;
1285 	unsigned long flags;
1286 
1287 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1288 	if (!vcdev) {
1289 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1290 		ret = -ENOMEM;
1291 		goto out_free;
1292 	}
1293 	vcdev->vdev.dev.parent = &cdev->dev;
1294 	vcdev->cdev = cdev;
1295 	vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,
1296 						sizeof(*vcdev->dma_area));
1297 	if (!vcdev->dma_area) {
1298 		ret = -ENOMEM;
1299 		goto out_free;
1300 	}
1301 
1302 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1303 
1304 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1305 	vcdev->vdev.config = &virtio_ccw_config_ops;
1306 	init_waitqueue_head(&vcdev->wait_q);
1307 	INIT_LIST_HEAD(&vcdev->virtqueues);
1308 	spin_lock_init(&vcdev->lock);
1309 	mutex_init(&vcdev->io_lock);
1310 
1311 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1312 	dev_set_drvdata(&cdev->dev, vcdev);
1313 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1314 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1315 	vcdev->vdev.id.device = cdev->id.cu_model;
1316 
1317 	ret = virtio_ccw_set_transport_rev(vcdev);
1318 	if (ret)
1319 		goto out_free;
1320 
1321 	ret = register_virtio_device(&vcdev->vdev);
1322 	if (ret) {
1323 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1324 			 ret);
1325 		goto out_put;
1326 	}
1327 	return 0;
1328 out_put:
1329 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1330 	dev_set_drvdata(&cdev->dev, NULL);
1331 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1332 	put_device(&vcdev->vdev.dev);
1333 	return ret;
1334 out_free:
1335 	if (vcdev) {
1336 		ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1337 				    sizeof(*vcdev->dma_area));
1338 	}
1339 	kfree(vcdev);
1340 	return ret;
1341 }
1342 
1343 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1344 {
1345 	int rc;
1346 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1347 
1348 	/*
1349 	 * Make sure vcdev is set
1350 	 * i.e. set_offline/remove callback not already running
1351 	 */
1352 	if (!vcdev)
1353 		return NOTIFY_DONE;
1354 
1355 	switch (event) {
1356 	case CIO_GONE:
1357 		vcdev->device_lost = true;
1358 		rc = NOTIFY_DONE;
1359 		break;
1360 	case CIO_OPER:
1361 		rc = NOTIFY_OK;
1362 		break;
1363 	default:
1364 		rc = NOTIFY_DONE;
1365 		break;
1366 	}
1367 	return rc;
1368 }
1369 
1370 static struct ccw_device_id virtio_ids[] = {
1371 	{ CCW_DEVICE(0x3832, 0) },
1372 	{},
1373 };
1374 
1375 #ifdef CONFIG_PM_SLEEP
1376 static int virtio_ccw_freeze(struct ccw_device *cdev)
1377 {
1378 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1379 
1380 	return virtio_device_freeze(&vcdev->vdev);
1381 }
1382 
1383 static int virtio_ccw_restore(struct ccw_device *cdev)
1384 {
1385 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1386 	int ret;
1387 
1388 	ret = virtio_ccw_set_transport_rev(vcdev);
1389 	if (ret)
1390 		return ret;
1391 
1392 	return virtio_device_restore(&vcdev->vdev);
1393 }
1394 #endif
1395 
1396 static struct ccw_driver virtio_ccw_driver = {
1397 	.driver = {
1398 		.owner = THIS_MODULE,
1399 		.name = "virtio_ccw",
1400 	},
1401 	.ids = virtio_ids,
1402 	.probe = virtio_ccw_probe,
1403 	.remove = virtio_ccw_remove,
1404 	.set_offline = virtio_ccw_offline,
1405 	.set_online = virtio_ccw_online,
1406 	.notify = virtio_ccw_cio_notify,
1407 	.int_class = IRQIO_VIR,
1408 #ifdef CONFIG_PM_SLEEP
1409 	.freeze = virtio_ccw_freeze,
1410 	.thaw = virtio_ccw_restore,
1411 	.restore = virtio_ccw_restore,
1412 #endif
1413 };
1414 
1415 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1416 			   int max_digit, int max_val)
1417 {
1418 	int diff;
1419 
1420 	diff = 0;
1421 	*val = 0;
1422 
1423 	while (diff <= max_digit) {
1424 		int value = hex_to_bin(**cp);
1425 
1426 		if (value < 0)
1427 			break;
1428 		*val = *val * 16 + value;
1429 		(*cp)++;
1430 		diff++;
1431 	}
1432 
1433 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1434 		return 1;
1435 
1436 	return 0;
1437 }
1438 
1439 static int __init parse_busid(char *str, unsigned int *cssid,
1440 			      unsigned int *ssid, unsigned int *devno)
1441 {
1442 	char *str_work;
1443 	int rc, ret;
1444 
1445 	rc = 1;
1446 
1447 	if (*str == '\0')
1448 		goto out;
1449 
1450 	str_work = str;
1451 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1452 	if (ret || (str_work[0] != '.'))
1453 		goto out;
1454 	str_work++;
1455 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1456 	if (ret || (str_work[0] != '.'))
1457 		goto out;
1458 	str_work++;
1459 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1460 	if (ret || (str_work[0] != '\0'))
1461 		goto out;
1462 
1463 	rc = 0;
1464 out:
1465 	return rc;
1466 }
1467 
1468 static void __init no_auto_parse(void)
1469 {
1470 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1471 	char *parm, *str;
1472 	int rc;
1473 
1474 	str = no_auto;
1475 	while ((parm = strsep(&str, ","))) {
1476 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1477 				 &from_ssid, &from);
1478 		if (rc)
1479 			continue;
1480 		if (parm != NULL) {
1481 			rc = parse_busid(parm, &to_cssid,
1482 					 &to_ssid, &to);
1483 			if ((from_ssid > to_ssid) ||
1484 			    ((from_ssid == to_ssid) && (from > to)))
1485 				rc = -EINVAL;
1486 		} else {
1487 			to_cssid = from_cssid;
1488 			to_ssid = from_ssid;
1489 			to = from;
1490 		}
1491 		if (rc)
1492 			continue;
1493 		while ((from_ssid < to_ssid) ||
1494 		       ((from_ssid == to_ssid) && (from <= to))) {
1495 			set_bit(from, devs_no_auto[from_ssid]);
1496 			from++;
1497 			if (from > __MAX_SUBCHANNEL) {
1498 				from_ssid++;
1499 				from = 0;
1500 			}
1501 		}
1502 	}
1503 }
1504 
1505 static int __init virtio_ccw_init(void)
1506 {
1507 	int rc;
1508 
1509 	/* parse no_auto string before we do anything further */
1510 	no_auto_parse();
1511 
1512 	summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS);
1513 	if (!summary_indicators)
1514 		return -ENOMEM;
1515 	rc = ccw_driver_register(&virtio_ccw_driver);
1516 	if (rc)
1517 		cio_dma_free(summary_indicators, MAX_AIRQ_AREAS);
1518 	return rc;
1519 }
1520 device_initcall(virtio_ccw_init);
1521