xref: /openbmc/linux/drivers/s390/virtio/virtio_ccw.c (revision 747f7a29)
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 #include <asm/tpi.h>
37 
38 /*
39  * virtio related functions
40  */
41 
42 struct vq_config_block {
43 	__u16 index;
44 	__u16 num;
45 } __packed;
46 
47 #define VIRTIO_CCW_CONFIG_SIZE 0x100
48 /* same as PCI config space size, should be enough for all drivers */
49 
50 struct vcdev_dma_area {
51 	unsigned long indicators;
52 	unsigned long indicators2;
53 	struct vq_config_block config_block;
54 	__u8 status;
55 };
56 
57 struct virtio_ccw_device {
58 	struct virtio_device vdev;
59 	__u8 config[VIRTIO_CCW_CONFIG_SIZE];
60 	struct ccw_device *cdev;
61 	__u32 curr_io;
62 	int err;
63 	unsigned int revision; /* Transport revision */
64 	wait_queue_head_t wait_q;
65 	spinlock_t lock;
66 	rwlock_t irq_lock;
67 	struct mutex io_lock; /* Serializes I/O requests */
68 	struct list_head virtqueues;
69 	bool is_thinint;
70 	bool going_away;
71 	bool device_lost;
72 	unsigned int config_ready;
73 	void *airq_info;
74 	struct vcdev_dma_area *dma_area;
75 };
76 
77 static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
78 {
79 	return &vcdev->dma_area->indicators;
80 }
81 
82 static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev)
83 {
84 	return &vcdev->dma_area->indicators2;
85 }
86 
87 struct vq_info_block_legacy {
88 	__u64 queue;
89 	__u32 align;
90 	__u16 index;
91 	__u16 num;
92 } __packed;
93 
94 struct vq_info_block {
95 	__u64 desc;
96 	__u32 res0;
97 	__u16 index;
98 	__u16 num;
99 	__u64 avail;
100 	__u64 used;
101 } __packed;
102 
103 struct virtio_feature_desc {
104 	__le32 features;
105 	__u8 index;
106 } __packed;
107 
108 struct virtio_thinint_area {
109 	unsigned long summary_indicator;
110 	unsigned long indicator;
111 	u64 bit_nr;
112 	u8 isc;
113 } __packed;
114 
115 struct virtio_rev_info {
116 	__u16 revision;
117 	__u16 length;
118 	__u8 data[];
119 };
120 
121 /* the highest virtio-ccw revision we support */
122 #define VIRTIO_CCW_REV_MAX 2
123 
124 struct virtio_ccw_vq_info {
125 	struct virtqueue *vq;
126 	int num;
127 	union {
128 		struct vq_info_block s;
129 		struct vq_info_block_legacy l;
130 	} *info_block;
131 	int bit_nr;
132 	struct list_head node;
133 	long cookie;
134 };
135 
136 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
137 
138 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
139 #define MAX_AIRQ_AREAS 20
140 
141 static int virtio_ccw_use_airq = 1;
142 
143 struct airq_info {
144 	rwlock_t lock;
145 	u8 summary_indicator_idx;
146 	struct airq_struct airq;
147 	struct airq_iv *aiv;
148 };
149 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
150 static DEFINE_MUTEX(airq_areas_lock);
151 
152 static u8 *summary_indicators;
153 
154 static inline u8 *get_summary_indicator(struct airq_info *info)
155 {
156 	return summary_indicators + info->summary_indicator_idx;
157 }
158 
159 #define CCW_CMD_SET_VQ 0x13
160 #define CCW_CMD_VDEV_RESET 0x33
161 #define CCW_CMD_SET_IND 0x43
162 #define CCW_CMD_SET_CONF_IND 0x53
163 #define CCW_CMD_READ_FEAT 0x12
164 #define CCW_CMD_WRITE_FEAT 0x11
165 #define CCW_CMD_READ_CONF 0x22
166 #define CCW_CMD_WRITE_CONF 0x21
167 #define CCW_CMD_WRITE_STATUS 0x31
168 #define CCW_CMD_READ_VQ_CONF 0x32
169 #define CCW_CMD_READ_STATUS 0x72
170 #define CCW_CMD_SET_IND_ADAPTER 0x73
171 #define CCW_CMD_SET_VIRTIO_REV 0x83
172 
173 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
174 #define VIRTIO_CCW_DOING_RESET 0x00040000
175 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
176 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
177 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
178 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
179 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
180 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
181 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
182 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
183 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
184 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
185 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
186 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
187 
188 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
189 {
190 	return container_of(vdev, struct virtio_ccw_device, vdev);
191 }
192 
193 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
194 {
195 	unsigned long i, flags;
196 
197 	write_lock_irqsave(&info->lock, flags);
198 	for (i = 0; i < airq_iv_end(info->aiv); i++) {
199 		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
200 			airq_iv_free_bit(info->aiv, i);
201 			airq_iv_set_ptr(info->aiv, i, 0);
202 			break;
203 		}
204 	}
205 	write_unlock_irqrestore(&info->lock, flags);
206 }
207 
208 static void virtio_airq_handler(struct airq_struct *airq,
209 				struct tpi_info *tpi_info)
210 {
211 	struct airq_info *info = container_of(airq, struct airq_info, airq);
212 	unsigned long ai;
213 
214 	inc_irq_stat(IRQIO_VAI);
215 	read_lock(&info->lock);
216 	/* Walk through indicators field, summary indicator active. */
217 	for (ai = 0;;) {
218 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
219 		if (ai == -1UL)
220 			break;
221 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
222 	}
223 	*(get_summary_indicator(info)) = 0;
224 	smp_wmb();
225 	/* Walk through indicators field, summary indicator not active. */
226 	for (ai = 0;;) {
227 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
228 		if (ai == -1UL)
229 			break;
230 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
231 	}
232 	read_unlock(&info->lock);
233 }
234 
235 static struct airq_info *new_airq_info(int index)
236 {
237 	struct airq_info *info;
238 	int rc;
239 
240 	info = kzalloc(sizeof(*info), GFP_KERNEL);
241 	if (!info)
242 		return NULL;
243 	rwlock_init(&info->lock);
244 	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR
245 				   | AIRQ_IV_CACHELINE, NULL);
246 	if (!info->aiv) {
247 		kfree(info);
248 		return NULL;
249 	}
250 	info->airq.handler = virtio_airq_handler;
251 	info->summary_indicator_idx = index;
252 	info->airq.lsi_ptr = get_summary_indicator(info);
253 	info->airq.lsi_mask = 0xff;
254 	info->airq.isc = VIRTIO_AIRQ_ISC;
255 	rc = register_adapter_interrupt(&info->airq);
256 	if (rc) {
257 		airq_iv_release(info->aiv);
258 		kfree(info);
259 		return NULL;
260 	}
261 	return info;
262 }
263 
264 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
265 					u64 *first, void **airq_info)
266 {
267 	int i, j;
268 	struct airq_info *info;
269 	unsigned long indicator_addr = 0;
270 	unsigned long bit, flags;
271 
272 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
273 		mutex_lock(&airq_areas_lock);
274 		if (!airq_areas[i])
275 			airq_areas[i] = new_airq_info(i);
276 		info = airq_areas[i];
277 		mutex_unlock(&airq_areas_lock);
278 		if (!info)
279 			return 0;
280 		write_lock_irqsave(&info->lock, flags);
281 		bit = airq_iv_alloc(info->aiv, nvqs);
282 		if (bit == -1UL) {
283 			/* Not enough vacancies. */
284 			write_unlock_irqrestore(&info->lock, flags);
285 			continue;
286 		}
287 		*first = bit;
288 		*airq_info = info;
289 		indicator_addr = (unsigned long)info->aiv->vector;
290 		for (j = 0; j < nvqs; j++) {
291 			airq_iv_set_ptr(info->aiv, bit + j,
292 					(unsigned long)vqs[j]);
293 		}
294 		write_unlock_irqrestore(&info->lock, flags);
295 	}
296 	return indicator_addr;
297 }
298 
299 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
300 {
301 	struct virtio_ccw_vq_info *info;
302 
303 	if (!vcdev->airq_info)
304 		return;
305 	list_for_each_entry(info, &vcdev->virtqueues, node)
306 		drop_airq_indicator(info->vq, vcdev->airq_info);
307 }
308 
309 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
310 {
311 	unsigned long flags;
312 	__u32 ret;
313 
314 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
315 	if (vcdev->err)
316 		ret = 0;
317 	else
318 		ret = vcdev->curr_io & flag;
319 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
320 	return ret;
321 }
322 
323 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
324 			 struct ccw1 *ccw, __u32 intparm)
325 {
326 	int ret;
327 	unsigned long flags;
328 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
329 
330 	mutex_lock(&vcdev->io_lock);
331 	do {
332 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
333 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
334 		if (!ret) {
335 			if (!vcdev->curr_io)
336 				vcdev->err = 0;
337 			vcdev->curr_io |= flag;
338 		}
339 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
340 		cpu_relax();
341 	} while (ret == -EBUSY);
342 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
343 	ret = ret ? ret : vcdev->err;
344 	mutex_unlock(&vcdev->io_lock);
345 	return ret;
346 }
347 
348 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
349 				      struct ccw1 *ccw)
350 {
351 	int ret;
352 	unsigned long *indicatorp = NULL;
353 	struct virtio_thinint_area *thinint_area = NULL;
354 	struct airq_info *airq_info = vcdev->airq_info;
355 
356 	if (vcdev->is_thinint) {
357 		thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
358 						     sizeof(*thinint_area));
359 		if (!thinint_area)
360 			return;
361 		thinint_area->summary_indicator =
362 			(unsigned long) get_summary_indicator(airq_info);
363 		thinint_area->isc = VIRTIO_AIRQ_ISC;
364 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
365 		ccw->count = sizeof(*thinint_area);
366 		ccw->cda = (__u32)(unsigned long) thinint_area;
367 	} else {
368 		/* payload is the address of the indicators */
369 		indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
370 						   sizeof(indicators(vcdev)));
371 		if (!indicatorp)
372 			return;
373 		*indicatorp = 0;
374 		ccw->cmd_code = CCW_CMD_SET_IND;
375 		ccw->count = sizeof(indicators(vcdev));
376 		ccw->cda = (__u32)(unsigned long) indicatorp;
377 	}
378 	/* Deregister indicators from host. */
379 	*indicators(vcdev) = 0;
380 	ccw->flags = 0;
381 	ret = ccw_io_helper(vcdev, ccw,
382 			    vcdev->is_thinint ?
383 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
384 			    VIRTIO_CCW_DOING_SET_IND);
385 	if (ret && (ret != -ENODEV))
386 		dev_info(&vcdev->cdev->dev,
387 			 "Failed to deregister indicators (%d)\n", ret);
388 	else if (vcdev->is_thinint)
389 		virtio_ccw_drop_indicators(vcdev);
390 	ccw_device_dma_free(vcdev->cdev, indicatorp, sizeof(indicators(vcdev)));
391 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
392 }
393 
394 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
395 {
396 	struct virtio_ccw_vq_info *info = vq->priv;
397 	struct virtio_ccw_device *vcdev;
398 	struct subchannel_id schid;
399 
400 	vcdev = to_vc_device(info->vq->vdev);
401 	ccw_device_get_schid(vcdev->cdev, &schid);
402 	BUILD_BUG_ON(sizeof(struct subchannel_id) != sizeof(unsigned int));
403 	info->cookie = kvm_hypercall3(KVM_S390_VIRTIO_CCW_NOTIFY,
404 				      *((unsigned int *)&schid),
405 				      vq->index, info->cookie);
406 	if (info->cookie < 0)
407 		return false;
408 	return true;
409 }
410 
411 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
412 				   struct ccw1 *ccw, int index)
413 {
414 	int ret;
415 
416 	vcdev->dma_area->config_block.index = index;
417 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
418 	ccw->flags = 0;
419 	ccw->count = sizeof(struct vq_config_block);
420 	ccw->cda = (__u32)(unsigned long)(&vcdev->dma_area->config_block);
421 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
422 	if (ret)
423 		return ret;
424 	return vcdev->dma_area->config_block.num ?: -ENOENT;
425 }
426 
427 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
428 {
429 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
430 	struct virtio_ccw_vq_info *info = vq->priv;
431 	unsigned long flags;
432 	int ret;
433 	unsigned int index = vq->index;
434 
435 	/* Remove from our list. */
436 	spin_lock_irqsave(&vcdev->lock, flags);
437 	list_del(&info->node);
438 	spin_unlock_irqrestore(&vcdev->lock, flags);
439 
440 	/* Release from host. */
441 	if (vcdev->revision == 0) {
442 		info->info_block->l.queue = 0;
443 		info->info_block->l.align = 0;
444 		info->info_block->l.index = index;
445 		info->info_block->l.num = 0;
446 		ccw->count = sizeof(info->info_block->l);
447 	} else {
448 		info->info_block->s.desc = 0;
449 		info->info_block->s.index = index;
450 		info->info_block->s.num = 0;
451 		info->info_block->s.avail = 0;
452 		info->info_block->s.used = 0;
453 		ccw->count = sizeof(info->info_block->s);
454 	}
455 	ccw->cmd_code = CCW_CMD_SET_VQ;
456 	ccw->flags = 0;
457 	ccw->cda = (__u32)(unsigned long)(info->info_block);
458 	ret = ccw_io_helper(vcdev, ccw,
459 			    VIRTIO_CCW_DOING_SET_VQ | index);
460 	/*
461 	 * -ENODEV isn't considered an error: The device is gone anyway.
462 	 * This may happen on device detach.
463 	 */
464 	if (ret && (ret != -ENODEV))
465 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
466 			 ret, index);
467 
468 	vring_del_virtqueue(vq);
469 	ccw_device_dma_free(vcdev->cdev, info->info_block,
470 			    sizeof(*info->info_block));
471 	kfree(info);
472 }
473 
474 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
475 {
476 	struct virtqueue *vq, *n;
477 	struct ccw1 *ccw;
478 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
479 
480 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
481 	if (!ccw)
482 		return;
483 
484 	virtio_ccw_drop_indicator(vcdev, ccw);
485 
486 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
487 		virtio_ccw_del_vq(vq, ccw);
488 
489 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
490 }
491 
492 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
493 					     int i, vq_callback_t *callback,
494 					     const char *name, bool ctx,
495 					     struct ccw1 *ccw)
496 {
497 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
498 	int err;
499 	struct virtqueue *vq = NULL;
500 	struct virtio_ccw_vq_info *info;
501 	u64 queue;
502 	unsigned long flags;
503 	bool may_reduce;
504 
505 	/* Allocate queue. */
506 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
507 	if (!info) {
508 		dev_warn(&vcdev->cdev->dev, "no info\n");
509 		err = -ENOMEM;
510 		goto out_err;
511 	}
512 	info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
513 						 sizeof(*info->info_block));
514 	if (!info->info_block) {
515 		dev_warn(&vcdev->cdev->dev, "no info block\n");
516 		err = -ENOMEM;
517 		goto out_err;
518 	}
519 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
520 	if (info->num < 0) {
521 		err = info->num;
522 		goto out_err;
523 	}
524 	may_reduce = vcdev->revision > 0;
525 	vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
526 				    vdev, true, may_reduce, ctx,
527 				    virtio_ccw_kvm_notify, callback, name);
528 
529 	if (!vq) {
530 		/* For now, we fail if we can't get the requested size. */
531 		dev_warn(&vcdev->cdev->dev, "no vq\n");
532 		err = -ENOMEM;
533 		goto out_err;
534 	}
535 	/* it may have been reduced */
536 	info->num = virtqueue_get_vring_size(vq);
537 
538 	/* Register it with the host. */
539 	queue = virtqueue_get_desc_addr(vq);
540 	if (vcdev->revision == 0) {
541 		info->info_block->l.queue = queue;
542 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
543 		info->info_block->l.index = i;
544 		info->info_block->l.num = info->num;
545 		ccw->count = sizeof(info->info_block->l);
546 	} else {
547 		info->info_block->s.desc = queue;
548 		info->info_block->s.index = i;
549 		info->info_block->s.num = info->num;
550 		info->info_block->s.avail = (__u64)virtqueue_get_avail_addr(vq);
551 		info->info_block->s.used = (__u64)virtqueue_get_used_addr(vq);
552 		ccw->count = sizeof(info->info_block->s);
553 	}
554 	ccw->cmd_code = CCW_CMD_SET_VQ;
555 	ccw->flags = 0;
556 	ccw->cda = (__u32)(unsigned long)(info->info_block);
557 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
558 	if (err) {
559 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
560 		goto out_err;
561 	}
562 
563 	info->vq = vq;
564 	vq->priv = info;
565 
566 	/* Save it to our list. */
567 	spin_lock_irqsave(&vcdev->lock, flags);
568 	list_add(&info->node, &vcdev->virtqueues);
569 	spin_unlock_irqrestore(&vcdev->lock, flags);
570 
571 	return vq;
572 
573 out_err:
574 	if (vq)
575 		vring_del_virtqueue(vq);
576 	if (info) {
577 		ccw_device_dma_free(vcdev->cdev, info->info_block,
578 				    sizeof(*info->info_block));
579 	}
580 	kfree(info);
581 	return ERR_PTR(err);
582 }
583 
584 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
585 					   struct virtqueue *vqs[], int nvqs,
586 					   struct ccw1 *ccw)
587 {
588 	int ret;
589 	struct virtio_thinint_area *thinint_area = NULL;
590 	struct airq_info *info;
591 
592 	thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
593 					     sizeof(*thinint_area));
594 	if (!thinint_area) {
595 		ret = -ENOMEM;
596 		goto out;
597 	}
598 	/* Try to get an indicator. */
599 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
600 						     &thinint_area->bit_nr,
601 						     &vcdev->airq_info);
602 	if (!thinint_area->indicator) {
603 		ret = -ENOSPC;
604 		goto out;
605 	}
606 	info = vcdev->airq_info;
607 	thinint_area->summary_indicator =
608 		(unsigned long) get_summary_indicator(info);
609 	thinint_area->isc = VIRTIO_AIRQ_ISC;
610 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
611 	ccw->flags = CCW_FLAG_SLI;
612 	ccw->count = sizeof(*thinint_area);
613 	ccw->cda = (__u32)(unsigned long)thinint_area;
614 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
615 	if (ret) {
616 		if (ret == -EOPNOTSUPP) {
617 			/*
618 			 * The host does not support adapter interrupts
619 			 * for virtio-ccw, stop trying.
620 			 */
621 			virtio_ccw_use_airq = 0;
622 			pr_info("Adapter interrupts unsupported on host\n");
623 		} else
624 			dev_warn(&vcdev->cdev->dev,
625 				 "enabling adapter interrupts = %d\n", ret);
626 		virtio_ccw_drop_indicators(vcdev);
627 	}
628 out:
629 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
630 	return ret;
631 }
632 
633 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
634 			       struct virtqueue *vqs[],
635 			       vq_callback_t *callbacks[],
636 			       const char * const names[],
637 			       const bool *ctx,
638 			       struct irq_affinity *desc)
639 {
640 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
641 	unsigned long *indicatorp = NULL;
642 	int ret, i, queue_idx = 0;
643 	struct ccw1 *ccw;
644 
645 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
646 	if (!ccw)
647 		return -ENOMEM;
648 
649 	for (i = 0; i < nvqs; ++i) {
650 		if (!names[i]) {
651 			vqs[i] = NULL;
652 			continue;
653 		}
654 
655 		vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, callbacks[i],
656 					     names[i], ctx ? ctx[i] : false,
657 					     ccw);
658 		if (IS_ERR(vqs[i])) {
659 			ret = PTR_ERR(vqs[i]);
660 			vqs[i] = NULL;
661 			goto out;
662 		}
663 	}
664 	ret = -ENOMEM;
665 	/*
666 	 * We need a data area under 2G to communicate. Our payload is
667 	 * the address of the indicators.
668 	*/
669 	indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
670 					   sizeof(indicators(vcdev)));
671 	if (!indicatorp)
672 		goto out;
673 	*indicatorp = (unsigned long) indicators(vcdev);
674 	if (vcdev->is_thinint) {
675 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
676 		if (ret)
677 			/* no error, just fall back to legacy interrupts */
678 			vcdev->is_thinint = false;
679 	}
680 	if (!vcdev->is_thinint) {
681 		/* Register queue indicators with host. */
682 		*indicators(vcdev) = 0;
683 		ccw->cmd_code = CCW_CMD_SET_IND;
684 		ccw->flags = 0;
685 		ccw->count = sizeof(indicators(vcdev));
686 		ccw->cda = (__u32)(unsigned long) indicatorp;
687 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
688 		if (ret)
689 			goto out;
690 	}
691 	/* Register indicators2 with host for config changes */
692 	*indicatorp = (unsigned long) indicators2(vcdev);
693 	*indicators2(vcdev) = 0;
694 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
695 	ccw->flags = 0;
696 	ccw->count = sizeof(indicators2(vcdev));
697 	ccw->cda = (__u32)(unsigned long) indicatorp;
698 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
699 	if (ret)
700 		goto out;
701 
702 	if (indicatorp)
703 		ccw_device_dma_free(vcdev->cdev, indicatorp,
704 				    sizeof(indicators(vcdev)));
705 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
706 	return 0;
707 out:
708 	if (indicatorp)
709 		ccw_device_dma_free(vcdev->cdev, indicatorp,
710 				    sizeof(indicators(vcdev)));
711 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
712 	virtio_ccw_del_vqs(vdev);
713 	return ret;
714 }
715 
716 static void virtio_ccw_reset(struct virtio_device *vdev)
717 {
718 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
719 	struct ccw1 *ccw;
720 
721 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
722 	if (!ccw)
723 		return;
724 
725 	/* Zero status bits. */
726 	vcdev->dma_area->status = 0;
727 
728 	/* Send a reset ccw on device. */
729 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
730 	ccw->flags = 0;
731 	ccw->count = 0;
732 	ccw->cda = 0;
733 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
734 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
735 }
736 
737 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
738 {
739 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
740 	struct virtio_feature_desc *features;
741 	int ret;
742 	u64 rc;
743 	struct ccw1 *ccw;
744 
745 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
746 	if (!ccw)
747 		return 0;
748 
749 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
750 	if (!features) {
751 		rc = 0;
752 		goto out_free;
753 	}
754 	/* Read the feature bits from the host. */
755 	features->index = 0;
756 	ccw->cmd_code = CCW_CMD_READ_FEAT;
757 	ccw->flags = 0;
758 	ccw->count = sizeof(*features);
759 	ccw->cda = (__u32)(unsigned long)features;
760 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
761 	if (ret) {
762 		rc = 0;
763 		goto out_free;
764 	}
765 
766 	rc = le32_to_cpu(features->features);
767 
768 	if (vcdev->revision == 0)
769 		goto out_free;
770 
771 	/* Read second half of the feature bits from the host. */
772 	features->index = 1;
773 	ccw->cmd_code = CCW_CMD_READ_FEAT;
774 	ccw->flags = 0;
775 	ccw->count = sizeof(*features);
776 	ccw->cda = (__u32)(unsigned long)features;
777 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
778 	if (ret == 0)
779 		rc |= (u64)le32_to_cpu(features->features) << 32;
780 
781 out_free:
782 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
783 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
784 	return rc;
785 }
786 
787 static void ccw_transport_features(struct virtio_device *vdev)
788 {
789 	/*
790 	 * Currently nothing to do here.
791 	 */
792 }
793 
794 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
795 {
796 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
797 	struct virtio_feature_desc *features;
798 	struct ccw1 *ccw;
799 	int ret;
800 
801 	if (vcdev->revision >= 1 &&
802 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
803 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
804 			"but does not have VIRTIO_F_VERSION_1\n");
805 		return -EINVAL;
806 	}
807 
808 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
809 	if (!ccw)
810 		return -ENOMEM;
811 
812 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
813 	if (!features) {
814 		ret = -ENOMEM;
815 		goto out_free;
816 	}
817 	/* Give virtio_ring a chance to accept features. */
818 	vring_transport_features(vdev);
819 
820 	/* Give virtio_ccw a chance to accept features. */
821 	ccw_transport_features(vdev);
822 
823 	features->index = 0;
824 	features->features = cpu_to_le32((u32)vdev->features);
825 	/* Write the first half of the feature bits to the host. */
826 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
827 	ccw->flags = 0;
828 	ccw->count = sizeof(*features);
829 	ccw->cda = (__u32)(unsigned long)features;
830 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
831 	if (ret)
832 		goto out_free;
833 
834 	if (vcdev->revision == 0)
835 		goto out_free;
836 
837 	features->index = 1;
838 	features->features = cpu_to_le32(vdev->features >> 32);
839 	/* Write the second half of the feature bits to the host. */
840 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
841 	ccw->flags = 0;
842 	ccw->count = sizeof(*features);
843 	ccw->cda = (__u32)(unsigned long)features;
844 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
845 
846 out_free:
847 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
848 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
849 
850 	return ret;
851 }
852 
853 static void virtio_ccw_get_config(struct virtio_device *vdev,
854 				  unsigned int offset, void *buf, unsigned len)
855 {
856 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
857 	int ret;
858 	struct ccw1 *ccw;
859 	void *config_area;
860 	unsigned long flags;
861 
862 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
863 	if (!ccw)
864 		return;
865 
866 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
867 					    VIRTIO_CCW_CONFIG_SIZE);
868 	if (!config_area)
869 		goto out_free;
870 
871 	/* Read the config area from the host. */
872 	ccw->cmd_code = CCW_CMD_READ_CONF;
873 	ccw->flags = 0;
874 	ccw->count = offset + len;
875 	ccw->cda = (__u32)(unsigned long)config_area;
876 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
877 	if (ret)
878 		goto out_free;
879 
880 	spin_lock_irqsave(&vcdev->lock, flags);
881 	memcpy(vcdev->config, config_area, offset + len);
882 	if (vcdev->config_ready < offset + len)
883 		vcdev->config_ready = offset + len;
884 	spin_unlock_irqrestore(&vcdev->lock, flags);
885 	if (buf)
886 		memcpy(buf, config_area + offset, len);
887 
888 out_free:
889 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
890 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
891 }
892 
893 static void virtio_ccw_set_config(struct virtio_device *vdev,
894 				  unsigned int offset, const void *buf,
895 				  unsigned len)
896 {
897 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
898 	struct ccw1 *ccw;
899 	void *config_area;
900 	unsigned long flags;
901 
902 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
903 	if (!ccw)
904 		return;
905 
906 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
907 					    VIRTIO_CCW_CONFIG_SIZE);
908 	if (!config_area)
909 		goto out_free;
910 
911 	/* Make sure we don't overwrite fields. */
912 	if (vcdev->config_ready < offset)
913 		virtio_ccw_get_config(vdev, 0, NULL, offset);
914 	spin_lock_irqsave(&vcdev->lock, flags);
915 	memcpy(&vcdev->config[offset], buf, len);
916 	/* Write the config area to the host. */
917 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
918 	spin_unlock_irqrestore(&vcdev->lock, flags);
919 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
920 	ccw->flags = 0;
921 	ccw->count = offset + len;
922 	ccw->cda = (__u32)(unsigned long)config_area;
923 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
924 
925 out_free:
926 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
927 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
928 }
929 
930 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
931 {
932 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
933 	u8 old_status = vcdev->dma_area->status;
934 	struct ccw1 *ccw;
935 
936 	if (vcdev->revision < 2)
937 		return vcdev->dma_area->status;
938 
939 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
940 	if (!ccw)
941 		return old_status;
942 
943 	ccw->cmd_code = CCW_CMD_READ_STATUS;
944 	ccw->flags = 0;
945 	ccw->count = sizeof(vcdev->dma_area->status);
946 	ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
947 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
948 /*
949  * If the channel program failed (should only happen if the device
950  * was hotunplugged, and then we clean up via the machine check
951  * handler anyway), vcdev->dma_area->status was not overwritten and we just
952  * return the old status, which is fine.
953 */
954 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
955 
956 	return vcdev->dma_area->status;
957 }
958 
959 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
960 {
961 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
962 	u8 old_status = vcdev->dma_area->status;
963 	struct ccw1 *ccw;
964 	int ret;
965 
966 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
967 	if (!ccw)
968 		return;
969 
970 	/* Write the status to the host. */
971 	vcdev->dma_area->status = status;
972 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
973 	ccw->flags = 0;
974 	ccw->count = sizeof(status);
975 	ccw->cda = (__u32)(unsigned long)&vcdev->dma_area->status;
976 	/* We use ssch for setting the status which is a serializing
977 	 * instruction that guarantees the memory writes have
978 	 * completed before ssch.
979 	 */
980 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
981 	/* Write failed? We assume status is unchanged. */
982 	if (ret)
983 		vcdev->dma_area->status = old_status;
984 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
985 }
986 
987 static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
988 {
989 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
990 
991 	return dev_name(&vcdev->cdev->dev);
992 }
993 
994 static void virtio_ccw_synchronize_cbs(struct virtio_device *vdev)
995 {
996 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
997 	struct airq_info *info = vcdev->airq_info;
998 
999 	if (info) {
1000 		/*
1001 		 * This device uses adapter interrupts: synchronize with
1002 		 * vring_interrupt() called by virtio_airq_handler()
1003 		 * via the indicator area lock.
1004 		 */
1005 		write_lock_irq(&info->lock);
1006 		write_unlock_irq(&info->lock);
1007 	} else {
1008 		/* This device uses classic interrupts: synchronize
1009 		 * with vring_interrupt() called by
1010 		 * virtio_ccw_int_handler() via the per-device
1011 		 * irq_lock
1012 		 */
1013 		write_lock_irq(&vcdev->irq_lock);
1014 		write_unlock_irq(&vcdev->irq_lock);
1015 	}
1016 }
1017 
1018 static const struct virtio_config_ops virtio_ccw_config_ops = {
1019 	.get_features = virtio_ccw_get_features,
1020 	.finalize_features = virtio_ccw_finalize_features,
1021 	.get = virtio_ccw_get_config,
1022 	.set = virtio_ccw_set_config,
1023 	.get_status = virtio_ccw_get_status,
1024 	.set_status = virtio_ccw_set_status,
1025 	.reset = virtio_ccw_reset,
1026 	.find_vqs = virtio_ccw_find_vqs,
1027 	.del_vqs = virtio_ccw_del_vqs,
1028 	.bus_name = virtio_ccw_bus_name,
1029 	.synchronize_cbs = virtio_ccw_synchronize_cbs,
1030 };
1031 
1032 
1033 /*
1034  * ccw bus driver related functions
1035  */
1036 
1037 static void virtio_ccw_release_dev(struct device *_d)
1038 {
1039 	struct virtio_device *dev = dev_to_virtio(_d);
1040 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
1041 
1042 	ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1043 			    sizeof(*vcdev->dma_area));
1044 	kfree(vcdev);
1045 }
1046 
1047 static int irb_is_error(struct irb *irb)
1048 {
1049 	if (scsw_cstat(&irb->scsw) != 0)
1050 		return 1;
1051 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1052 		return 1;
1053 	if (scsw_cc(&irb->scsw) != 0)
1054 		return 1;
1055 	return 0;
1056 }
1057 
1058 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1059 					      int index)
1060 {
1061 	struct virtio_ccw_vq_info *info;
1062 	unsigned long flags;
1063 	struct virtqueue *vq;
1064 
1065 	vq = NULL;
1066 	spin_lock_irqsave(&vcdev->lock, flags);
1067 	list_for_each_entry(info, &vcdev->virtqueues, node) {
1068 		if (info->vq->index == index) {
1069 			vq = info->vq;
1070 			break;
1071 		}
1072 	}
1073 	spin_unlock_irqrestore(&vcdev->lock, flags);
1074 	return vq;
1075 }
1076 
1077 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1078 				      __u32 activity)
1079 {
1080 	if (vcdev->curr_io & activity) {
1081 		switch (activity) {
1082 		case VIRTIO_CCW_DOING_READ_FEAT:
1083 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1084 		case VIRTIO_CCW_DOING_READ_CONFIG:
1085 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1086 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1087 		case VIRTIO_CCW_DOING_READ_STATUS:
1088 		case VIRTIO_CCW_DOING_SET_VQ:
1089 		case VIRTIO_CCW_DOING_SET_IND:
1090 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1091 		case VIRTIO_CCW_DOING_RESET:
1092 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1093 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1094 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1095 			vcdev->curr_io &= ~activity;
1096 			wake_up(&vcdev->wait_q);
1097 			break;
1098 		default:
1099 			/* don't know what to do... */
1100 			dev_warn(&vcdev->cdev->dev,
1101 				 "Suspicious activity '%08x'\n", activity);
1102 			WARN_ON(1);
1103 			break;
1104 		}
1105 	}
1106 }
1107 
1108 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1109 				   unsigned long intparm,
1110 				   struct irb *irb)
1111 {
1112 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1113 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1114 	int i;
1115 	struct virtqueue *vq;
1116 
1117 	if (!vcdev)
1118 		return;
1119 	if (IS_ERR(irb)) {
1120 		vcdev->err = PTR_ERR(irb);
1121 		virtio_ccw_check_activity(vcdev, activity);
1122 		/* Don't poke around indicators, something's wrong. */
1123 		return;
1124 	}
1125 	/* Check if it's a notification from the host. */
1126 	if ((intparm == 0) &&
1127 	    (scsw_stctl(&irb->scsw) ==
1128 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1129 		/* OK */
1130 	}
1131 	if (irb_is_error(irb)) {
1132 		/* Command reject? */
1133 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1134 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1135 			vcdev->err = -EOPNOTSUPP;
1136 		else
1137 			/* Map everything else to -EIO. */
1138 			vcdev->err = -EIO;
1139 	}
1140 	virtio_ccw_check_activity(vcdev, activity);
1141 #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
1142 	/*
1143 	 * Paired with virtio_ccw_synchronize_cbs() and interrupts are
1144 	 * disabled here.
1145 	 */
1146 	read_lock(&vcdev->irq_lock);
1147 #endif
1148 	for_each_set_bit(i, indicators(vcdev),
1149 			 sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {
1150 		/* The bit clear must happen before the vring kick. */
1151 		clear_bit(i, indicators(vcdev));
1152 		barrier();
1153 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1154 		vring_interrupt(0, vq);
1155 	}
1156 #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
1157 	read_unlock(&vcdev->irq_lock);
1158 #endif
1159 	if (test_bit(0, indicators2(vcdev))) {
1160 		virtio_config_changed(&vcdev->vdev);
1161 		clear_bit(0, indicators2(vcdev));
1162 	}
1163 }
1164 
1165 /*
1166  * We usually want to autoonline all devices, but give the admin
1167  * a way to exempt devices from this.
1168  */
1169 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1170 		     (8*sizeof(long)))
1171 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1172 
1173 static char *no_auto = "";
1174 
1175 module_param(no_auto, charp, 0444);
1176 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1177 
1178 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1179 {
1180 	struct ccw_dev_id id;
1181 
1182 	ccw_device_get_id(cdev, &id);
1183 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1184 		return 0;
1185 	return 1;
1186 }
1187 
1188 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1189 {
1190 	struct ccw_device *cdev = data;
1191 	int ret;
1192 
1193 	ret = ccw_device_set_online(cdev);
1194 	if (ret)
1195 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1196 }
1197 
1198 static int virtio_ccw_probe(struct ccw_device *cdev)
1199 {
1200 	cdev->handler = virtio_ccw_int_handler;
1201 
1202 	if (virtio_ccw_check_autoonline(cdev))
1203 		async_schedule(virtio_ccw_auto_online, cdev);
1204 	return 0;
1205 }
1206 
1207 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1208 {
1209 	unsigned long flags;
1210 	struct virtio_ccw_device *vcdev;
1211 
1212 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1213 	vcdev = dev_get_drvdata(&cdev->dev);
1214 	if (!vcdev || vcdev->going_away) {
1215 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1216 		return NULL;
1217 	}
1218 	vcdev->going_away = true;
1219 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1220 	return vcdev;
1221 }
1222 
1223 static void virtio_ccw_remove(struct ccw_device *cdev)
1224 {
1225 	unsigned long flags;
1226 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1227 
1228 	if (vcdev && cdev->online) {
1229 		if (vcdev->device_lost)
1230 			virtio_break_device(&vcdev->vdev);
1231 		unregister_virtio_device(&vcdev->vdev);
1232 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1233 		dev_set_drvdata(&cdev->dev, NULL);
1234 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1235 	}
1236 	cdev->handler = NULL;
1237 }
1238 
1239 static int virtio_ccw_offline(struct ccw_device *cdev)
1240 {
1241 	unsigned long flags;
1242 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1243 
1244 	if (!vcdev)
1245 		return 0;
1246 	if (vcdev->device_lost)
1247 		virtio_break_device(&vcdev->vdev);
1248 	unregister_virtio_device(&vcdev->vdev);
1249 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1250 	dev_set_drvdata(&cdev->dev, NULL);
1251 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1252 	return 0;
1253 }
1254 
1255 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1256 {
1257 	struct virtio_rev_info *rev;
1258 	struct ccw1 *ccw;
1259 	int ret;
1260 
1261 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
1262 	if (!ccw)
1263 		return -ENOMEM;
1264 	rev = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*rev));
1265 	if (!rev) {
1266 		ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1267 		return -ENOMEM;
1268 	}
1269 
1270 	/* Set transport revision */
1271 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1272 	ccw->flags = 0;
1273 	ccw->count = sizeof(*rev);
1274 	ccw->cda = (__u32)(unsigned long)rev;
1275 
1276 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1277 	do {
1278 		rev->revision = vcdev->revision;
1279 		/* none of our supported revisions carry payload */
1280 		rev->length = 0;
1281 		ret = ccw_io_helper(vcdev, ccw,
1282 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1283 		if (ret == -EOPNOTSUPP) {
1284 			if (vcdev->revision == 0)
1285 				/*
1286 				 * The host device does not support setting
1287 				 * the revision: let's operate it in legacy
1288 				 * mode.
1289 				 */
1290 				ret = 0;
1291 			else
1292 				vcdev->revision--;
1293 		}
1294 	} while (ret == -EOPNOTSUPP);
1295 
1296 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1297 	ccw_device_dma_free(vcdev->cdev, rev, sizeof(*rev));
1298 	return ret;
1299 }
1300 
1301 static int virtio_ccw_online(struct ccw_device *cdev)
1302 {
1303 	int ret;
1304 	struct virtio_ccw_device *vcdev;
1305 	unsigned long flags;
1306 
1307 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1308 	if (!vcdev) {
1309 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1310 		ret = -ENOMEM;
1311 		goto out_free;
1312 	}
1313 	vcdev->vdev.dev.parent = &cdev->dev;
1314 	vcdev->cdev = cdev;
1315 	vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,
1316 						sizeof(*vcdev->dma_area));
1317 	if (!vcdev->dma_area) {
1318 		ret = -ENOMEM;
1319 		goto out_free;
1320 	}
1321 
1322 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1323 
1324 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1325 	vcdev->vdev.config = &virtio_ccw_config_ops;
1326 	init_waitqueue_head(&vcdev->wait_q);
1327 	INIT_LIST_HEAD(&vcdev->virtqueues);
1328 	spin_lock_init(&vcdev->lock);
1329 	rwlock_init(&vcdev->irq_lock);
1330 	mutex_init(&vcdev->io_lock);
1331 
1332 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1333 	dev_set_drvdata(&cdev->dev, vcdev);
1334 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1335 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1336 	vcdev->vdev.id.device = cdev->id.cu_model;
1337 
1338 	ret = virtio_ccw_set_transport_rev(vcdev);
1339 	if (ret)
1340 		goto out_free;
1341 
1342 	ret = register_virtio_device(&vcdev->vdev);
1343 	if (ret) {
1344 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1345 			 ret);
1346 		goto out_put;
1347 	}
1348 	return 0;
1349 out_put:
1350 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1351 	dev_set_drvdata(&cdev->dev, NULL);
1352 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1353 	put_device(&vcdev->vdev.dev);
1354 	return ret;
1355 out_free:
1356 	if (vcdev) {
1357 		ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1358 				    sizeof(*vcdev->dma_area));
1359 	}
1360 	kfree(vcdev);
1361 	return ret;
1362 }
1363 
1364 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1365 {
1366 	int rc;
1367 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1368 
1369 	/*
1370 	 * Make sure vcdev is set
1371 	 * i.e. set_offline/remove callback not already running
1372 	 */
1373 	if (!vcdev)
1374 		return NOTIFY_DONE;
1375 
1376 	switch (event) {
1377 	case CIO_GONE:
1378 		vcdev->device_lost = true;
1379 		rc = NOTIFY_DONE;
1380 		break;
1381 	case CIO_OPER:
1382 		rc = NOTIFY_OK;
1383 		break;
1384 	default:
1385 		rc = NOTIFY_DONE;
1386 		break;
1387 	}
1388 	return rc;
1389 }
1390 
1391 static struct ccw_device_id virtio_ids[] = {
1392 	{ CCW_DEVICE(0x3832, 0) },
1393 	{},
1394 };
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 };
1409 
1410 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1411 			   int max_digit, int max_val)
1412 {
1413 	int diff;
1414 
1415 	diff = 0;
1416 	*val = 0;
1417 
1418 	while (diff <= max_digit) {
1419 		int value = hex_to_bin(**cp);
1420 
1421 		if (value < 0)
1422 			break;
1423 		*val = *val * 16 + value;
1424 		(*cp)++;
1425 		diff++;
1426 	}
1427 
1428 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1429 		return 1;
1430 
1431 	return 0;
1432 }
1433 
1434 static int __init parse_busid(char *str, unsigned int *cssid,
1435 			      unsigned int *ssid, unsigned int *devno)
1436 {
1437 	char *str_work;
1438 	int rc, ret;
1439 
1440 	rc = 1;
1441 
1442 	if (*str == '\0')
1443 		goto out;
1444 
1445 	str_work = str;
1446 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1447 	if (ret || (str_work[0] != '.'))
1448 		goto out;
1449 	str_work++;
1450 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1451 	if (ret || (str_work[0] != '.'))
1452 		goto out;
1453 	str_work++;
1454 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1455 	if (ret || (str_work[0] != '\0'))
1456 		goto out;
1457 
1458 	rc = 0;
1459 out:
1460 	return rc;
1461 }
1462 
1463 static void __init no_auto_parse(void)
1464 {
1465 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1466 	char *parm, *str;
1467 	int rc;
1468 
1469 	str = no_auto;
1470 	while ((parm = strsep(&str, ","))) {
1471 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1472 				 &from_ssid, &from);
1473 		if (rc)
1474 			continue;
1475 		if (parm != NULL) {
1476 			rc = parse_busid(parm, &to_cssid,
1477 					 &to_ssid, &to);
1478 			if ((from_ssid > to_ssid) ||
1479 			    ((from_ssid == to_ssid) && (from > to)))
1480 				rc = -EINVAL;
1481 		} else {
1482 			to_cssid = from_cssid;
1483 			to_ssid = from_ssid;
1484 			to = from;
1485 		}
1486 		if (rc)
1487 			continue;
1488 		while ((from_ssid < to_ssid) ||
1489 		       ((from_ssid == to_ssid) && (from <= to))) {
1490 			set_bit(from, devs_no_auto[from_ssid]);
1491 			from++;
1492 			if (from > __MAX_SUBCHANNEL) {
1493 				from_ssid++;
1494 				from = 0;
1495 			}
1496 		}
1497 	}
1498 }
1499 
1500 static int __init virtio_ccw_init(void)
1501 {
1502 	int rc;
1503 
1504 	/* parse no_auto string before we do anything further */
1505 	no_auto_parse();
1506 
1507 	summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS);
1508 	if (!summary_indicators)
1509 		return -ENOMEM;
1510 	rc = ccw_driver_register(&virtio_ccw_driver);
1511 	if (rc)
1512 		cio_dma_free(summary_indicators, MAX_AIRQ_AREAS);
1513 	return rc;
1514 }
1515 device_initcall(virtio_ccw_init);
1516