xref: /linux/drivers/s390/virtio/virtio_ccw.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 	/* we make cdev->dev.dma_parms point to this */
62 	struct device_dma_parameters dma_parms;
63 	__u32 curr_io;
64 	int err;
65 	unsigned int revision; /* Transport revision */
66 	wait_queue_head_t wait_q;
67 	spinlock_t lock;
68 	rwlock_t irq_lock;
69 	struct mutex io_lock; /* Serializes I/O requests */
70 	struct list_head virtqueues;
71 	bool is_thinint;
72 	bool going_away;
73 	bool device_lost;
74 	unsigned int config_ready;
75 	void *airq_info;
76 	struct vcdev_dma_area *dma_area;
77 	dma32_t dma_area_addr;
78 };
79 
80 static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
81 {
82 	return &vcdev->dma_area->indicators;
83 }
84 
85 static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev)
86 {
87 	return &vcdev->dma_area->indicators2;
88 }
89 
90 /* Spec stipulates a 64 bit address */
91 static inline dma64_t indicators_dma(struct virtio_ccw_device *vcdev)
92 {
93 	u64 dma_area_addr = dma32_to_u32(vcdev->dma_area_addr);
94 
95 	return dma64_add(u64_to_dma64(dma_area_addr),
96 			 offsetof(struct vcdev_dma_area, indicators));
97 }
98 
99 /* Spec stipulates a 64 bit address */
100 static inline dma64_t indicators2_dma(struct virtio_ccw_device *vcdev)
101 {
102 	u64 dma_area_addr = dma32_to_u32(vcdev->dma_area_addr);
103 
104 	return dma64_add(u64_to_dma64(dma_area_addr),
105 			 offsetof(struct vcdev_dma_area, indicators2));
106 }
107 
108 static inline dma32_t config_block_dma(struct virtio_ccw_device *vcdev)
109 {
110 	return dma32_add(vcdev->dma_area_addr,
111 			 offsetof(struct vcdev_dma_area, config_block));
112 }
113 
114 static inline dma32_t status_dma(struct virtio_ccw_device *vcdev)
115 {
116 	return dma32_add(vcdev->dma_area_addr,
117 			 offsetof(struct vcdev_dma_area, status));
118 }
119 
120 struct vq_info_block_legacy {
121 	dma64_t queue;
122 	__u32 align;
123 	__u16 index;
124 	__u16 num;
125 } __packed;
126 
127 struct vq_info_block {
128 	dma64_t desc;
129 	__u32 res0;
130 	__u16 index;
131 	__u16 num;
132 	dma64_t avail;
133 	dma64_t used;
134 } __packed;
135 
136 struct virtio_feature_desc {
137 	__le32 features;
138 	__u8 index;
139 } __packed;
140 
141 struct virtio_thinint_area {
142 	dma64_t summary_indicator;
143 	dma64_t indicator;
144 	u64 bit_nr;
145 	u8 isc;
146 } __packed;
147 
148 struct virtio_rev_info {
149 	__u16 revision;
150 	__u16 length;
151 	__u8 data[];
152 };
153 
154 /* the highest virtio-ccw revision we support */
155 #define VIRTIO_CCW_REV_MAX 2
156 
157 struct virtio_ccw_vq_info {
158 	struct virtqueue *vq;
159 	dma32_t info_block_addr;
160 	int num;
161 	union {
162 		struct vq_info_block s;
163 		struct vq_info_block_legacy l;
164 	} *info_block;
165 	int bit_nr;
166 	struct list_head node;
167 	long cookie;
168 };
169 
170 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
171 
172 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
173 #define MAX_AIRQ_AREAS 20
174 
175 static int virtio_ccw_use_airq = 1;
176 
177 struct airq_info {
178 	rwlock_t lock;
179 	u8 summary_indicator_idx;
180 	struct airq_struct airq;
181 	struct airq_iv *aiv;
182 };
183 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
184 static DEFINE_MUTEX(airq_areas_lock);
185 
186 static u8 *summary_indicators;
187 
188 static inline u8 *get_summary_indicator(struct airq_info *info)
189 {
190 	return summary_indicators + info->summary_indicator_idx;
191 }
192 
193 static inline dma64_t get_summary_indicator_dma(struct airq_info *info)
194 {
195 	return virt_to_dma64(get_summary_indicator(info));
196 }
197 
198 #define CCW_CMD_SET_VQ 0x13
199 #define CCW_CMD_VDEV_RESET 0x33
200 #define CCW_CMD_SET_IND 0x43
201 #define CCW_CMD_SET_CONF_IND 0x53
202 #define CCW_CMD_READ_FEAT 0x12
203 #define CCW_CMD_WRITE_FEAT 0x11
204 #define CCW_CMD_READ_CONF 0x22
205 #define CCW_CMD_WRITE_CONF 0x21
206 #define CCW_CMD_WRITE_STATUS 0x31
207 #define CCW_CMD_READ_VQ_CONF 0x32
208 #define CCW_CMD_READ_STATUS 0x72
209 #define CCW_CMD_SET_IND_ADAPTER 0x73
210 #define CCW_CMD_SET_VIRTIO_REV 0x83
211 
212 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
213 #define VIRTIO_CCW_DOING_RESET 0x00040000
214 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
215 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
216 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
217 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
218 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
219 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
220 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
221 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
222 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
223 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
224 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
225 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
226 
227 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
228 {
229 	return container_of(vdev, struct virtio_ccw_device, vdev);
230 }
231 
232 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
233 {
234 	unsigned long i, flags;
235 
236 	write_lock_irqsave(&info->lock, flags);
237 	for (i = 0; i < airq_iv_end(info->aiv); i++) {
238 		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
239 			airq_iv_free_bit(info->aiv, i);
240 			airq_iv_set_ptr(info->aiv, i, 0);
241 			break;
242 		}
243 	}
244 	write_unlock_irqrestore(&info->lock, flags);
245 }
246 
247 static void virtio_airq_handler(struct airq_struct *airq,
248 				struct tpi_info *tpi_info)
249 {
250 	struct airq_info *info = container_of(airq, struct airq_info, airq);
251 	unsigned long ai;
252 
253 	inc_irq_stat(IRQIO_VAI);
254 	read_lock(&info->lock);
255 	/* Walk through indicators field, summary indicator active. */
256 	for (ai = 0;;) {
257 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
258 		if (ai == -1UL)
259 			break;
260 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
261 	}
262 	*(get_summary_indicator(info)) = 0;
263 	smp_wmb();
264 	/* Walk through indicators field, summary indicator not active. */
265 	for (ai = 0;;) {
266 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
267 		if (ai == -1UL)
268 			break;
269 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
270 	}
271 	read_unlock(&info->lock);
272 }
273 
274 static struct airq_info *new_airq_info(int index)
275 {
276 	struct airq_info *info;
277 	int rc;
278 
279 	info = kzalloc(sizeof(*info), GFP_KERNEL);
280 	if (!info)
281 		return NULL;
282 	rwlock_init(&info->lock);
283 	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR
284 				   | AIRQ_IV_CACHELINE, NULL);
285 	if (!info->aiv) {
286 		kfree(info);
287 		return NULL;
288 	}
289 	info->airq.handler = virtio_airq_handler;
290 	info->summary_indicator_idx = index;
291 	info->airq.lsi_ptr = get_summary_indicator(info);
292 	info->airq.isc = VIRTIO_AIRQ_ISC;
293 	rc = register_adapter_interrupt(&info->airq);
294 	if (rc) {
295 		airq_iv_release(info->aiv);
296 		kfree(info);
297 		return NULL;
298 	}
299 	return info;
300 }
301 
302 static unsigned long *get_airq_indicator(struct virtqueue *vqs[], int nvqs,
303 					 u64 *first, void **airq_info)
304 {
305 	int i, j;
306 	struct airq_info *info;
307 	unsigned long *indicator_addr = NULL;
308 	unsigned long bit, flags;
309 
310 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
311 		mutex_lock(&airq_areas_lock);
312 		if (!airq_areas[i])
313 			airq_areas[i] = new_airq_info(i);
314 		info = airq_areas[i];
315 		mutex_unlock(&airq_areas_lock);
316 		if (!info)
317 			return NULL;
318 		write_lock_irqsave(&info->lock, flags);
319 		bit = airq_iv_alloc(info->aiv, nvqs);
320 		if (bit == -1UL) {
321 			/* Not enough vacancies. */
322 			write_unlock_irqrestore(&info->lock, flags);
323 			continue;
324 		}
325 		*first = bit;
326 		*airq_info = info;
327 		indicator_addr = info->aiv->vector;
328 		for (j = 0; j < nvqs; j++) {
329 			airq_iv_set_ptr(info->aiv, bit + j,
330 					(unsigned long)vqs[j]);
331 		}
332 		write_unlock_irqrestore(&info->lock, flags);
333 	}
334 	return indicator_addr;
335 }
336 
337 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
338 {
339 	struct virtio_ccw_vq_info *info;
340 
341 	if (!vcdev->airq_info)
342 		return;
343 	list_for_each_entry(info, &vcdev->virtqueues, node)
344 		drop_airq_indicator(info->vq, vcdev->airq_info);
345 }
346 
347 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
348 {
349 	unsigned long flags;
350 	__u32 ret;
351 
352 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
353 	if (vcdev->err)
354 		ret = 0;
355 	else
356 		ret = vcdev->curr_io & flag;
357 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
358 	return ret;
359 }
360 
361 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
362 			 struct ccw1 *ccw, __u32 intparm)
363 {
364 	int ret;
365 	unsigned long flags;
366 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
367 
368 	mutex_lock(&vcdev->io_lock);
369 	do {
370 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
371 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
372 		if (!ret) {
373 			if (!vcdev->curr_io)
374 				vcdev->err = 0;
375 			vcdev->curr_io |= flag;
376 		}
377 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
378 		cpu_relax();
379 	} while (ret == -EBUSY);
380 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
381 	ret = ret ? ret : vcdev->err;
382 	mutex_unlock(&vcdev->io_lock);
383 	return ret;
384 }
385 
386 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
387 				      struct ccw1 *ccw)
388 {
389 	int ret;
390 	struct virtio_thinint_area *thinint_area = NULL;
391 	struct airq_info *airq_info = vcdev->airq_info;
392 	dma64_t *indicatorp = NULL;
393 
394 	if (vcdev->is_thinint) {
395 		thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
396 						     sizeof(*thinint_area),
397 						     &ccw->cda);
398 		if (!thinint_area)
399 			return;
400 		thinint_area->summary_indicator =
401 			get_summary_indicator_dma(airq_info);
402 		thinint_area->isc = VIRTIO_AIRQ_ISC;
403 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
404 		ccw->count = sizeof(*thinint_area);
405 	} else {
406 		/* payload is the address of the indicators */
407 		indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
408 						   sizeof(*indicatorp),
409 						   &ccw->cda);
410 		if (!indicatorp)
411 			return;
412 		*indicatorp = 0;
413 		ccw->cmd_code = CCW_CMD_SET_IND;
414 		ccw->count = sizeof(*indicatorp);
415 	}
416 	/* Deregister indicators from host. */
417 	*indicators(vcdev) = 0;
418 	ccw->flags = 0;
419 	ret = ccw_io_helper(vcdev, ccw,
420 			    vcdev->is_thinint ?
421 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
422 			    VIRTIO_CCW_DOING_SET_IND);
423 	if (ret && (ret != -ENODEV))
424 		dev_info(&vcdev->cdev->dev,
425 			 "Failed to deregister indicators (%d)\n", ret);
426 	else if (vcdev->is_thinint)
427 		virtio_ccw_drop_indicators(vcdev);
428 	ccw_device_dma_free(vcdev->cdev, indicatorp, sizeof(*indicatorp));
429 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
430 }
431 
432 static inline bool virtio_ccw_do_kvm_notify(struct virtqueue *vq, u32 data)
433 {
434 	struct virtio_ccw_vq_info *info = vq->priv;
435 	struct virtio_ccw_device *vcdev;
436 	struct subchannel_id schid;
437 
438 	vcdev = to_vc_device(info->vq->vdev);
439 	ccw_device_get_schid(vcdev->cdev, &schid);
440 	BUILD_BUG_ON(sizeof(struct subchannel_id) != sizeof(unsigned int));
441 	info->cookie = kvm_hypercall3(KVM_S390_VIRTIO_CCW_NOTIFY,
442 				      *((unsigned int *)&schid),
443 				      data, info->cookie);
444 	if (info->cookie < 0)
445 		return false;
446 	return true;
447 }
448 
449 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
450 {
451 	return virtio_ccw_do_kvm_notify(vq, vq->index);
452 }
453 
454 static bool virtio_ccw_kvm_notify_with_data(struct virtqueue *vq)
455 {
456 	return virtio_ccw_do_kvm_notify(vq, vring_notification_data(vq));
457 }
458 
459 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
460 				   struct ccw1 *ccw, int index)
461 {
462 	int ret;
463 
464 	vcdev->dma_area->config_block.index = index;
465 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
466 	ccw->flags = 0;
467 	ccw->count = sizeof(struct vq_config_block);
468 	ccw->cda = config_block_dma(vcdev);
469 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
470 	if (ret)
471 		return ret;
472 	return vcdev->dma_area->config_block.num ?: -ENOENT;
473 }
474 
475 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
476 {
477 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
478 	struct virtio_ccw_vq_info *info = vq->priv;
479 	unsigned long flags;
480 	int ret;
481 	unsigned int index = vq->index;
482 
483 	/* Remove from our list. */
484 	spin_lock_irqsave(&vcdev->lock, flags);
485 	list_del(&info->node);
486 	spin_unlock_irqrestore(&vcdev->lock, flags);
487 
488 	/* Release from host. */
489 	if (vcdev->revision == 0) {
490 		info->info_block->l.queue = 0;
491 		info->info_block->l.align = 0;
492 		info->info_block->l.index = index;
493 		info->info_block->l.num = 0;
494 		ccw->count = sizeof(info->info_block->l);
495 	} else {
496 		info->info_block->s.desc = 0;
497 		info->info_block->s.index = index;
498 		info->info_block->s.num = 0;
499 		info->info_block->s.avail = 0;
500 		info->info_block->s.used = 0;
501 		ccw->count = sizeof(info->info_block->s);
502 	}
503 	ccw->cmd_code = CCW_CMD_SET_VQ;
504 	ccw->flags = 0;
505 	ccw->cda = info->info_block_addr;
506 	ret = ccw_io_helper(vcdev, ccw,
507 			    VIRTIO_CCW_DOING_SET_VQ | index);
508 	/*
509 	 * -ENODEV isn't considered an error: The device is gone anyway.
510 	 * This may happen on device detach.
511 	 */
512 	if (ret && (ret != -ENODEV))
513 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
514 			 ret, index);
515 
516 	vring_del_virtqueue(vq);
517 	ccw_device_dma_free(vcdev->cdev, info->info_block,
518 			    sizeof(*info->info_block));
519 	kfree(info);
520 }
521 
522 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
523 {
524 	struct virtqueue *vq, *n;
525 	struct ccw1 *ccw;
526 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
527 
528 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
529 	if (!ccw)
530 		return;
531 
532 	virtio_ccw_drop_indicator(vcdev, ccw);
533 
534 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
535 		virtio_ccw_del_vq(vq, ccw);
536 
537 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
538 }
539 
540 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
541 					     int i, vq_callback_t *callback,
542 					     const char *name, bool ctx,
543 					     struct ccw1 *ccw)
544 {
545 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
546 	bool (*notify)(struct virtqueue *vq);
547 	int err;
548 	struct virtqueue *vq = NULL;
549 	struct virtio_ccw_vq_info *info;
550 	u64 queue;
551 	unsigned long flags;
552 	bool may_reduce;
553 
554 	if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA))
555 		notify = virtio_ccw_kvm_notify_with_data;
556 	else
557 		notify = virtio_ccw_kvm_notify;
558 
559 	/* Allocate queue. */
560 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
561 	if (!info) {
562 		dev_warn(&vcdev->cdev->dev, "no info\n");
563 		err = -ENOMEM;
564 		goto out_err;
565 	}
566 	info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
567 						 sizeof(*info->info_block),
568 						 &info->info_block_addr);
569 	if (!info->info_block) {
570 		dev_warn(&vcdev->cdev->dev, "no info block\n");
571 		err = -ENOMEM;
572 		goto out_err;
573 	}
574 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
575 	if (info->num < 0) {
576 		err = info->num;
577 		goto out_err;
578 	}
579 	may_reduce = vcdev->revision > 0;
580 	vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
581 				    vdev, true, may_reduce, ctx,
582 				    notify, callback, name);
583 
584 	if (!vq) {
585 		/* For now, we fail if we can't get the requested size. */
586 		dev_warn(&vcdev->cdev->dev, "no vq\n");
587 		err = -ENOMEM;
588 		goto out_err;
589 	}
590 
591 	vq->num_max = info->num;
592 
593 	/* it may have been reduced */
594 	info->num = virtqueue_get_vring_size(vq);
595 
596 	/* Register it with the host. */
597 	queue = virtqueue_get_desc_addr(vq);
598 	if (vcdev->revision == 0) {
599 		info->info_block->l.queue = u64_to_dma64(queue);
600 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
601 		info->info_block->l.index = i;
602 		info->info_block->l.num = info->num;
603 		ccw->count = sizeof(info->info_block->l);
604 	} else {
605 		info->info_block->s.desc = u64_to_dma64(queue);
606 		info->info_block->s.index = i;
607 		info->info_block->s.num = info->num;
608 		info->info_block->s.avail = u64_to_dma64(virtqueue_get_avail_addr(vq));
609 		info->info_block->s.used = u64_to_dma64(virtqueue_get_used_addr(vq));
610 		ccw->count = sizeof(info->info_block->s);
611 	}
612 	ccw->cmd_code = CCW_CMD_SET_VQ;
613 	ccw->flags = 0;
614 	ccw->cda = info->info_block_addr;
615 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
616 	if (err) {
617 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
618 		goto out_err;
619 	}
620 
621 	info->vq = vq;
622 	vq->priv = info;
623 
624 	/* Save it to our list. */
625 	spin_lock_irqsave(&vcdev->lock, flags);
626 	list_add(&info->node, &vcdev->virtqueues);
627 	spin_unlock_irqrestore(&vcdev->lock, flags);
628 
629 	return vq;
630 
631 out_err:
632 	if (vq)
633 		vring_del_virtqueue(vq);
634 	if (info) {
635 		ccw_device_dma_free(vcdev->cdev, info->info_block,
636 				    sizeof(*info->info_block));
637 	}
638 	kfree(info);
639 	return ERR_PTR(err);
640 }
641 
642 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
643 					   struct virtqueue *vqs[], int nvqs,
644 					   struct ccw1 *ccw)
645 {
646 	int ret;
647 	struct virtio_thinint_area *thinint_area = NULL;
648 	unsigned long *indicator_addr;
649 	struct airq_info *info;
650 
651 	thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
652 					     sizeof(*thinint_area),
653 					     &ccw->cda);
654 	if (!thinint_area) {
655 		ret = -ENOMEM;
656 		goto out;
657 	}
658 	/* Try to get an indicator. */
659 	indicator_addr = get_airq_indicator(vqs, nvqs,
660 					    &thinint_area->bit_nr,
661 					    &vcdev->airq_info);
662 	if (!indicator_addr) {
663 		ret = -ENOSPC;
664 		goto out;
665 	}
666 	thinint_area->indicator = virt_to_dma64(indicator_addr);
667 	info = vcdev->airq_info;
668 	thinint_area->summary_indicator = get_summary_indicator_dma(info);
669 	thinint_area->isc = VIRTIO_AIRQ_ISC;
670 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
671 	ccw->flags = CCW_FLAG_SLI;
672 	ccw->count = sizeof(*thinint_area);
673 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
674 	if (ret) {
675 		if (ret == -EOPNOTSUPP) {
676 			/*
677 			 * The host does not support adapter interrupts
678 			 * for virtio-ccw, stop trying.
679 			 */
680 			virtio_ccw_use_airq = 0;
681 			pr_info("Adapter interrupts unsupported on host\n");
682 		} else
683 			dev_warn(&vcdev->cdev->dev,
684 				 "enabling adapter interrupts = %d\n", ret);
685 		virtio_ccw_drop_indicators(vcdev);
686 	}
687 out:
688 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
689 	return ret;
690 }
691 
692 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
693 			       struct virtqueue *vqs[],
694 			       struct virtqueue_info vqs_info[],
695 			       struct irq_affinity *desc)
696 {
697 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
698 	dma64_t *indicatorp = NULL;
699 	int ret, i, queue_idx = 0;
700 	struct ccw1 *ccw;
701 	dma32_t indicatorp_dma = 0;
702 
703 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
704 	if (!ccw)
705 		return -ENOMEM;
706 
707 	for (i = 0; i < nvqs; ++i) {
708 		struct virtqueue_info *vqi = &vqs_info[i];
709 
710 		if (!vqi->name) {
711 			vqs[i] = NULL;
712 			continue;
713 		}
714 
715 		vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, vqi->callback,
716 					     vqi->name, vqi->ctx, ccw);
717 		if (IS_ERR(vqs[i])) {
718 			ret = PTR_ERR(vqs[i]);
719 			vqs[i] = NULL;
720 			goto out;
721 		}
722 	}
723 	ret = -ENOMEM;
724 	/*
725 	 * We need a data area under 2G to communicate. Our payload is
726 	 * the address of the indicators.
727 	*/
728 	indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
729 					   sizeof(*indicatorp),
730 					   &indicatorp_dma);
731 	if (!indicatorp)
732 		goto out;
733 	*indicatorp = indicators_dma(vcdev);
734 	if (vcdev->is_thinint) {
735 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
736 		if (ret)
737 			/* no error, just fall back to legacy interrupts */
738 			vcdev->is_thinint = false;
739 	}
740 	ccw->cda = indicatorp_dma;
741 	if (!vcdev->is_thinint) {
742 		/* Register queue indicators with host. */
743 		*indicators(vcdev) = 0;
744 		ccw->cmd_code = CCW_CMD_SET_IND;
745 		ccw->flags = 0;
746 		ccw->count = sizeof(*indicatorp);
747 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
748 		if (ret)
749 			goto out;
750 	}
751 	/* Register indicators2 with host for config changes */
752 	*indicatorp = indicators2_dma(vcdev);
753 	*indicators2(vcdev) = 0;
754 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
755 	ccw->flags = 0;
756 	ccw->count = sizeof(*indicatorp);
757 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
758 	if (ret)
759 		goto out;
760 
761 	if (indicatorp)
762 		ccw_device_dma_free(vcdev->cdev, indicatorp,
763 				    sizeof(*indicatorp));
764 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
765 	return 0;
766 out:
767 	if (indicatorp)
768 		ccw_device_dma_free(vcdev->cdev, indicatorp,
769 				    sizeof(*indicatorp));
770 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
771 	virtio_ccw_del_vqs(vdev);
772 	return ret;
773 }
774 
775 static void virtio_ccw_reset(struct virtio_device *vdev)
776 {
777 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
778 	struct ccw1 *ccw;
779 
780 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
781 	if (!ccw)
782 		return;
783 
784 	/* Zero status bits. */
785 	vcdev->dma_area->status = 0;
786 
787 	/* Send a reset ccw on device. */
788 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
789 	ccw->flags = 0;
790 	ccw->count = 0;
791 	ccw->cda = 0;
792 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
793 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
794 }
795 
796 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
797 {
798 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
799 	struct virtio_feature_desc *features;
800 	int ret;
801 	u64 rc;
802 	struct ccw1 *ccw;
803 
804 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
805 	if (!ccw)
806 		return 0;
807 
808 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features),
809 					 &ccw->cda);
810 	if (!features) {
811 		rc = 0;
812 		goto out_free;
813 	}
814 	/* Read the feature bits from the host. */
815 	features->index = 0;
816 	ccw->cmd_code = CCW_CMD_READ_FEAT;
817 	ccw->flags = 0;
818 	ccw->count = sizeof(*features);
819 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
820 	if (ret) {
821 		rc = 0;
822 		goto out_free;
823 	}
824 
825 	rc = le32_to_cpu(features->features);
826 
827 	if (vcdev->revision == 0)
828 		goto out_free;
829 
830 	/* Read second half of the feature bits from the host. */
831 	features->index = 1;
832 	ccw->cmd_code = CCW_CMD_READ_FEAT;
833 	ccw->flags = 0;
834 	ccw->count = sizeof(*features);
835 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
836 	if (ret == 0)
837 		rc |= (u64)le32_to_cpu(features->features) << 32;
838 
839 out_free:
840 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
841 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
842 	return rc;
843 }
844 
845 static void ccw_transport_features(struct virtio_device *vdev)
846 {
847 	/*
848 	 * Currently nothing to do here.
849 	 */
850 }
851 
852 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
853 {
854 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
855 	struct virtio_feature_desc *features;
856 	struct ccw1 *ccw;
857 	int ret;
858 
859 	if (vcdev->revision >= 1 &&
860 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
861 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
862 			"but does not have VIRTIO_F_VERSION_1\n");
863 		return -EINVAL;
864 	}
865 
866 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
867 	if (!ccw)
868 		return -ENOMEM;
869 
870 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features),
871 					 &ccw->cda);
872 	if (!features) {
873 		ret = -ENOMEM;
874 		goto out_free;
875 	}
876 	/* Give virtio_ring a chance to accept features. */
877 	vring_transport_features(vdev);
878 
879 	/* Give virtio_ccw a chance to accept features. */
880 	ccw_transport_features(vdev);
881 
882 	features->index = 0;
883 	features->features = cpu_to_le32((u32)vdev->features);
884 	/* Write the first half of the feature bits to the host. */
885 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
886 	ccw->flags = 0;
887 	ccw->count = sizeof(*features);
888 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
889 	if (ret)
890 		goto out_free;
891 
892 	if (vcdev->revision == 0)
893 		goto out_free;
894 
895 	features->index = 1;
896 	features->features = cpu_to_le32(vdev->features >> 32);
897 	/* Write the second half of the feature bits to the host. */
898 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
899 	ccw->flags = 0;
900 	ccw->count = sizeof(*features);
901 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
902 
903 out_free:
904 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
905 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
906 
907 	return ret;
908 }
909 
910 static void virtio_ccw_get_config(struct virtio_device *vdev,
911 				  unsigned int offset, void *buf, unsigned len)
912 {
913 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
914 	int ret;
915 	struct ccw1 *ccw;
916 	void *config_area;
917 	unsigned long flags;
918 
919 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
920 	if (!ccw)
921 		return;
922 
923 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
924 					    VIRTIO_CCW_CONFIG_SIZE,
925 					    &ccw->cda);
926 	if (!config_area)
927 		goto out_free;
928 
929 	/* Read the config area from the host. */
930 	ccw->cmd_code = CCW_CMD_READ_CONF;
931 	ccw->flags = 0;
932 	ccw->count = offset + len;
933 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
934 	if (ret)
935 		goto out_free;
936 
937 	spin_lock_irqsave(&vcdev->lock, flags);
938 	memcpy(vcdev->config, config_area, offset + len);
939 	if (vcdev->config_ready < offset + len)
940 		vcdev->config_ready = offset + len;
941 	spin_unlock_irqrestore(&vcdev->lock, flags);
942 	if (buf)
943 		memcpy(buf, config_area + offset, len);
944 
945 out_free:
946 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
947 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
948 }
949 
950 static void virtio_ccw_set_config(struct virtio_device *vdev,
951 				  unsigned int offset, const void *buf,
952 				  unsigned len)
953 {
954 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
955 	struct ccw1 *ccw;
956 	void *config_area;
957 	unsigned long flags;
958 
959 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
960 	if (!ccw)
961 		return;
962 
963 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
964 					    VIRTIO_CCW_CONFIG_SIZE,
965 					    &ccw->cda);
966 	if (!config_area)
967 		goto out_free;
968 
969 	/* Make sure we don't overwrite fields. */
970 	if (vcdev->config_ready < offset)
971 		virtio_ccw_get_config(vdev, 0, NULL, offset);
972 	spin_lock_irqsave(&vcdev->lock, flags);
973 	memcpy(&vcdev->config[offset], buf, len);
974 	/* Write the config area to the host. */
975 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
976 	spin_unlock_irqrestore(&vcdev->lock, flags);
977 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
978 	ccw->flags = 0;
979 	ccw->count = offset + len;
980 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
981 
982 out_free:
983 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
984 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
985 }
986 
987 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
988 {
989 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
990 	u8 old_status = vcdev->dma_area->status;
991 	struct ccw1 *ccw;
992 
993 	if (vcdev->revision < 2)
994 		return vcdev->dma_area->status;
995 
996 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
997 	if (!ccw)
998 		return old_status;
999 
1000 	ccw->cmd_code = CCW_CMD_READ_STATUS;
1001 	ccw->flags = 0;
1002 	ccw->count = sizeof(vcdev->dma_area->status);
1003 	ccw->cda = status_dma(vcdev);
1004 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
1005 /*
1006  * If the channel program failed (should only happen if the device
1007  * was hotunplugged, and then we clean up via the machine check
1008  * handler anyway), vcdev->dma_area->status was not overwritten and we just
1009  * return the old status, which is fine.
1010 */
1011 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1012 
1013 	return vcdev->dma_area->status;
1014 }
1015 
1016 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
1017 {
1018 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1019 	u8 old_status = vcdev->dma_area->status;
1020 	struct ccw1 *ccw;
1021 	int ret;
1022 
1023 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
1024 	if (!ccw)
1025 		return;
1026 
1027 	/* Write the status to the host. */
1028 	vcdev->dma_area->status = status;
1029 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
1030 	ccw->flags = 0;
1031 	ccw->count = sizeof(status);
1032 	/* We use ssch for setting the status which is a serializing
1033 	 * instruction that guarantees the memory writes have
1034 	 * completed before ssch.
1035 	 */
1036 	ccw->cda = status_dma(vcdev);
1037 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
1038 	/* Write failed? We assume status is unchanged. */
1039 	if (ret)
1040 		vcdev->dma_area->status = old_status;
1041 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1042 }
1043 
1044 static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
1045 {
1046 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1047 
1048 	return dev_name(&vcdev->cdev->dev);
1049 }
1050 
1051 static void virtio_ccw_synchronize_cbs(struct virtio_device *vdev)
1052 {
1053 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1054 	struct airq_info *info = vcdev->airq_info;
1055 
1056 	if (info) {
1057 		/*
1058 		 * This device uses adapter interrupts: synchronize with
1059 		 * vring_interrupt() called by virtio_airq_handler()
1060 		 * via the indicator area lock.
1061 		 */
1062 		write_lock_irq(&info->lock);
1063 		write_unlock_irq(&info->lock);
1064 	} else {
1065 		/* This device uses classic interrupts: synchronize
1066 		 * with vring_interrupt() called by
1067 		 * virtio_ccw_int_handler() via the per-device
1068 		 * irq_lock
1069 		 */
1070 		write_lock_irq(&vcdev->irq_lock);
1071 		write_unlock_irq(&vcdev->irq_lock);
1072 	}
1073 }
1074 
1075 static const struct virtio_config_ops virtio_ccw_config_ops = {
1076 	.get_features = virtio_ccw_get_features,
1077 	.finalize_features = virtio_ccw_finalize_features,
1078 	.get = virtio_ccw_get_config,
1079 	.set = virtio_ccw_set_config,
1080 	.get_status = virtio_ccw_get_status,
1081 	.set_status = virtio_ccw_set_status,
1082 	.reset = virtio_ccw_reset,
1083 	.find_vqs = virtio_ccw_find_vqs,
1084 	.del_vqs = virtio_ccw_del_vqs,
1085 	.bus_name = virtio_ccw_bus_name,
1086 	.synchronize_cbs = virtio_ccw_synchronize_cbs,
1087 };
1088 
1089 
1090 /*
1091  * ccw bus driver related functions
1092  */
1093 
1094 static void virtio_ccw_release_dev(struct device *_d)
1095 {
1096 	struct virtio_device *dev = dev_to_virtio(_d);
1097 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
1098 
1099 	ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1100 			    sizeof(*vcdev->dma_area));
1101 	kfree(vcdev);
1102 }
1103 
1104 static int irb_is_error(struct irb *irb)
1105 {
1106 	if (scsw_cstat(&irb->scsw) != 0)
1107 		return 1;
1108 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1109 		return 1;
1110 	if (scsw_cc(&irb->scsw) != 0)
1111 		return 1;
1112 	return 0;
1113 }
1114 
1115 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1116 					      int index)
1117 {
1118 	struct virtio_ccw_vq_info *info;
1119 	unsigned long flags;
1120 	struct virtqueue *vq;
1121 
1122 	vq = NULL;
1123 	spin_lock_irqsave(&vcdev->lock, flags);
1124 	list_for_each_entry(info, &vcdev->virtqueues, node) {
1125 		if (info->vq->index == index) {
1126 			vq = info->vq;
1127 			break;
1128 		}
1129 	}
1130 	spin_unlock_irqrestore(&vcdev->lock, flags);
1131 	return vq;
1132 }
1133 
1134 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1135 				      __u32 activity)
1136 {
1137 	if (vcdev->curr_io & activity) {
1138 		switch (activity) {
1139 		case VIRTIO_CCW_DOING_READ_FEAT:
1140 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1141 		case VIRTIO_CCW_DOING_READ_CONFIG:
1142 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1143 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1144 		case VIRTIO_CCW_DOING_READ_STATUS:
1145 		case VIRTIO_CCW_DOING_SET_VQ:
1146 		case VIRTIO_CCW_DOING_SET_IND:
1147 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1148 		case VIRTIO_CCW_DOING_RESET:
1149 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1150 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1151 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1152 			vcdev->curr_io &= ~activity;
1153 			wake_up(&vcdev->wait_q);
1154 			break;
1155 		default:
1156 			/* don't know what to do... */
1157 			dev_warn(&vcdev->cdev->dev,
1158 				 "Suspicious activity '%08x'\n", activity);
1159 			WARN_ON(1);
1160 			break;
1161 		}
1162 	}
1163 }
1164 
1165 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1166 				   unsigned long intparm,
1167 				   struct irb *irb)
1168 {
1169 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1170 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1171 	int i;
1172 	struct virtqueue *vq;
1173 
1174 	if (!vcdev)
1175 		return;
1176 	if (IS_ERR(irb)) {
1177 		vcdev->err = PTR_ERR(irb);
1178 		virtio_ccw_check_activity(vcdev, activity);
1179 		/* Don't poke around indicators, something's wrong. */
1180 		return;
1181 	}
1182 	/* Check if it's a notification from the host. */
1183 	if ((intparm == 0) &&
1184 	    (scsw_stctl(&irb->scsw) ==
1185 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1186 		/* OK */
1187 	}
1188 	if (irb_is_error(irb)) {
1189 		/* Command reject? */
1190 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1191 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1192 			vcdev->err = -EOPNOTSUPP;
1193 		else
1194 			/* Map everything else to -EIO. */
1195 			vcdev->err = -EIO;
1196 	}
1197 	virtio_ccw_check_activity(vcdev, activity);
1198 #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
1199 	/*
1200 	 * Paired with virtio_ccw_synchronize_cbs() and interrupts are
1201 	 * disabled here.
1202 	 */
1203 	read_lock(&vcdev->irq_lock);
1204 #endif
1205 	for_each_set_bit(i, indicators(vcdev),
1206 			 sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {
1207 		/* The bit clear must happen before the vring kick. */
1208 		clear_bit(i, indicators(vcdev));
1209 		barrier();
1210 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1211 		vring_interrupt(0, vq);
1212 	}
1213 #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
1214 	read_unlock(&vcdev->irq_lock);
1215 #endif
1216 	if (test_bit(0, indicators2(vcdev))) {
1217 		virtio_config_changed(&vcdev->vdev);
1218 		clear_bit(0, indicators2(vcdev));
1219 	}
1220 }
1221 
1222 /*
1223  * We usually want to autoonline all devices, but give the admin
1224  * a way to exempt devices from this.
1225  */
1226 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1227 		     (8*sizeof(long)))
1228 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1229 
1230 static char *no_auto = "";
1231 
1232 module_param(no_auto, charp, 0444);
1233 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1234 
1235 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1236 {
1237 	struct ccw_dev_id id;
1238 
1239 	ccw_device_get_id(cdev, &id);
1240 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1241 		return 0;
1242 	return 1;
1243 }
1244 
1245 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1246 {
1247 	struct ccw_device *cdev = data;
1248 	int ret;
1249 
1250 	ret = ccw_device_set_online(cdev);
1251 	if (ret)
1252 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1253 }
1254 
1255 static int virtio_ccw_probe(struct ccw_device *cdev)
1256 {
1257 	cdev->handler = virtio_ccw_int_handler;
1258 
1259 	if (virtio_ccw_check_autoonline(cdev))
1260 		async_schedule(virtio_ccw_auto_online, cdev);
1261 	return 0;
1262 }
1263 
1264 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1265 {
1266 	unsigned long flags;
1267 	struct virtio_ccw_device *vcdev;
1268 
1269 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1270 	vcdev = dev_get_drvdata(&cdev->dev);
1271 	if (!vcdev || vcdev->going_away) {
1272 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1273 		return NULL;
1274 	}
1275 	vcdev->going_away = true;
1276 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1277 	return vcdev;
1278 }
1279 
1280 static void virtio_ccw_remove(struct ccw_device *cdev)
1281 {
1282 	unsigned long flags;
1283 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1284 
1285 	if (vcdev && cdev->online) {
1286 		if (vcdev->device_lost)
1287 			virtio_break_device(&vcdev->vdev);
1288 		unregister_virtio_device(&vcdev->vdev);
1289 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1290 		dev_set_drvdata(&cdev->dev, NULL);
1291 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1292 	}
1293 	cdev->handler = NULL;
1294 }
1295 
1296 static int virtio_ccw_offline(struct ccw_device *cdev)
1297 {
1298 	unsigned long flags;
1299 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1300 
1301 	if (!vcdev)
1302 		return 0;
1303 	if (vcdev->device_lost)
1304 		virtio_break_device(&vcdev->vdev);
1305 	unregister_virtio_device(&vcdev->vdev);
1306 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1307 	dev_set_drvdata(&cdev->dev, NULL);
1308 	cdev->dev.dma_parms = NULL;
1309 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1310 	return 0;
1311 }
1312 
1313 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1314 {
1315 	struct virtio_rev_info *rev;
1316 	struct ccw1 *ccw;
1317 	int ret;
1318 
1319 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
1320 	if (!ccw)
1321 		return -ENOMEM;
1322 	rev = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*rev), &ccw->cda);
1323 	if (!rev) {
1324 		ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1325 		return -ENOMEM;
1326 	}
1327 
1328 	/* Set transport revision */
1329 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1330 	ccw->flags = 0;
1331 	ccw->count = sizeof(*rev);
1332 
1333 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1334 	do {
1335 		rev->revision = vcdev->revision;
1336 		/* none of our supported revisions carry payload */
1337 		rev->length = 0;
1338 		ret = ccw_io_helper(vcdev, ccw,
1339 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1340 		if (ret == -EOPNOTSUPP) {
1341 			if (vcdev->revision == 0)
1342 				/*
1343 				 * The host device does not support setting
1344 				 * the revision: let's operate it in legacy
1345 				 * mode.
1346 				 */
1347 				ret = 0;
1348 			else
1349 				vcdev->revision--;
1350 		}
1351 	} while (ret == -EOPNOTSUPP);
1352 
1353 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1354 	ccw_device_dma_free(vcdev->cdev, rev, sizeof(*rev));
1355 	return ret;
1356 }
1357 
1358 static int virtio_ccw_online(struct ccw_device *cdev)
1359 {
1360 	int ret;
1361 	struct virtio_ccw_device *vcdev;
1362 	unsigned long flags;
1363 
1364 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1365 	if (!vcdev) {
1366 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1367 		ret = -ENOMEM;
1368 		goto out_free;
1369 	}
1370 	vcdev->vdev.dev.parent = &cdev->dev;
1371 	vcdev->cdev = cdev;
1372 	cdev->dev.dma_parms = &vcdev->dma_parms;
1373 	vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,
1374 						sizeof(*vcdev->dma_area),
1375 						&vcdev->dma_area_addr);
1376 	if (!vcdev->dma_area) {
1377 		ret = -ENOMEM;
1378 		goto out_free;
1379 	}
1380 
1381 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1382 
1383 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1384 	vcdev->vdev.config = &virtio_ccw_config_ops;
1385 	init_waitqueue_head(&vcdev->wait_q);
1386 	INIT_LIST_HEAD(&vcdev->virtqueues);
1387 	spin_lock_init(&vcdev->lock);
1388 	rwlock_init(&vcdev->irq_lock);
1389 	mutex_init(&vcdev->io_lock);
1390 
1391 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1392 	dev_set_drvdata(&cdev->dev, vcdev);
1393 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1394 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1395 	vcdev->vdev.id.device = cdev->id.cu_model;
1396 
1397 	ret = virtio_ccw_set_transport_rev(vcdev);
1398 	if (ret)
1399 		goto out_free;
1400 
1401 	ret = register_virtio_device(&vcdev->vdev);
1402 	if (ret) {
1403 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1404 			 ret);
1405 		goto out_put;
1406 	}
1407 	return 0;
1408 out_put:
1409 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1410 	dev_set_drvdata(&cdev->dev, NULL);
1411 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1412 	put_device(&vcdev->vdev.dev);
1413 	return ret;
1414 out_free:
1415 	if (vcdev) {
1416 		ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1417 				    sizeof(*vcdev->dma_area));
1418 	}
1419 	kfree(vcdev);
1420 	return ret;
1421 }
1422 
1423 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1424 {
1425 	int rc;
1426 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1427 
1428 	/*
1429 	 * Make sure vcdev is set
1430 	 * i.e. set_offline/remove callback not already running
1431 	 */
1432 	if (!vcdev)
1433 		return NOTIFY_DONE;
1434 
1435 	switch (event) {
1436 	case CIO_GONE:
1437 		vcdev->device_lost = true;
1438 		rc = NOTIFY_DONE;
1439 		break;
1440 	case CIO_OPER:
1441 		rc = NOTIFY_OK;
1442 		break;
1443 	default:
1444 		rc = NOTIFY_DONE;
1445 		break;
1446 	}
1447 	return rc;
1448 }
1449 
1450 static struct ccw_device_id virtio_ids[] = {
1451 	{ CCW_DEVICE(0x3832, 0) },
1452 	{},
1453 };
1454 
1455 static struct ccw_driver virtio_ccw_driver = {
1456 	.driver = {
1457 		.owner = THIS_MODULE,
1458 		.name = "virtio_ccw",
1459 	},
1460 	.ids = virtio_ids,
1461 	.probe = virtio_ccw_probe,
1462 	.remove = virtio_ccw_remove,
1463 	.set_offline = virtio_ccw_offline,
1464 	.set_online = virtio_ccw_online,
1465 	.notify = virtio_ccw_cio_notify,
1466 	.int_class = IRQIO_VIR,
1467 };
1468 
1469 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1470 			   int max_digit, int max_val)
1471 {
1472 	int diff;
1473 
1474 	diff = 0;
1475 	*val = 0;
1476 
1477 	while (diff <= max_digit) {
1478 		int value = hex_to_bin(**cp);
1479 
1480 		if (value < 0)
1481 			break;
1482 		*val = *val * 16 + value;
1483 		(*cp)++;
1484 		diff++;
1485 	}
1486 
1487 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1488 		return 1;
1489 
1490 	return 0;
1491 }
1492 
1493 static int __init parse_busid(char *str, unsigned int *cssid,
1494 			      unsigned int *ssid, unsigned int *devno)
1495 {
1496 	char *str_work;
1497 	int rc, ret;
1498 
1499 	rc = 1;
1500 
1501 	if (*str == '\0')
1502 		goto out;
1503 
1504 	str_work = str;
1505 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1506 	if (ret || (str_work[0] != '.'))
1507 		goto out;
1508 	str_work++;
1509 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1510 	if (ret || (str_work[0] != '.'))
1511 		goto out;
1512 	str_work++;
1513 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1514 	if (ret || (str_work[0] != '\0'))
1515 		goto out;
1516 
1517 	rc = 0;
1518 out:
1519 	return rc;
1520 }
1521 
1522 static void __init no_auto_parse(void)
1523 {
1524 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1525 	char *parm, *str;
1526 	int rc;
1527 
1528 	str = no_auto;
1529 	while ((parm = strsep(&str, ","))) {
1530 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1531 				 &from_ssid, &from);
1532 		if (rc)
1533 			continue;
1534 		if (parm != NULL) {
1535 			rc = parse_busid(parm, &to_cssid,
1536 					 &to_ssid, &to);
1537 			if ((from_ssid > to_ssid) ||
1538 			    ((from_ssid == to_ssid) && (from > to)))
1539 				rc = -EINVAL;
1540 		} else {
1541 			to_cssid = from_cssid;
1542 			to_ssid = from_ssid;
1543 			to = from;
1544 		}
1545 		if (rc)
1546 			continue;
1547 		while ((from_ssid < to_ssid) ||
1548 		       ((from_ssid == to_ssid) && (from <= to))) {
1549 			set_bit(from, devs_no_auto[from_ssid]);
1550 			from++;
1551 			if (from > __MAX_SUBCHANNEL) {
1552 				from_ssid++;
1553 				from = 0;
1554 			}
1555 		}
1556 	}
1557 }
1558 
1559 static int __init virtio_ccw_init(void)
1560 {
1561 	int rc;
1562 
1563 	/* parse no_auto string before we do anything further */
1564 	no_auto_parse();
1565 
1566 	summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS);
1567 	if (!summary_indicators)
1568 		return -ENOMEM;
1569 	rc = ccw_driver_register(&virtio_ccw_driver);
1570 	if (rc)
1571 		cio_dma_free(summary_indicators, MAX_AIRQ_AREAS);
1572 	return rc;
1573 }
1574 device_initcall(virtio_ccw_init);
1575