xref: /linux/drivers/s390/virtio/virtio_ccw.c (revision 24c776355f4097316a763005434ffff716aa21a8)
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/hex.h>
12 #include <linux/init.h>
13 #include <linux/memblock.h>
14 #include <linux/err.h>
15 #include <linux/virtio.h>
16 #include <linux/virtio_config.h>
17 #include <linux/slab.h>
18 #include <linux/interrupt.h>
19 #include <linux/virtio_ring.h>
20 #include <linux/pfn.h>
21 #include <linux/async.h>
22 #include <linux/wait.h>
23 #include <linux/list.h>
24 #include <linux/bitops.h>
25 #include <linux/moduleparam.h>
26 #include <linux/io.h>
27 #include <linux/kvm_para.h>
28 #include <linux/notifier.h>
29 #include <asm/diag.h>
30 #include <asm/setup.h>
31 #include <asm/irq.h>
32 #include <asm/cio.h>
33 #include <asm/ccwdev.h>
34 #include <asm/virtio-ccw.h>
35 #include <asm/isc.h>
36 #include <asm/airq.h>
37 #include <asm/tpi.h>
38 
39 /*
40  * virtio related functions
41  */
42 
43 struct vq_config_block {
44 	__u16 index;
45 	__u16 num;
46 } __packed;
47 
48 #define VIRTIO_CCW_CONFIG_SIZE 0x100
49 /* same as PCI config space size, should be enough for all drivers */
50 
51 struct vcdev_dma_area {
52 	unsigned long indicators;
53 	unsigned long indicators2;
54 	struct vq_config_block config_block;
55 	__u8 status;
56 };
57 
58 struct virtio_ccw_device {
59 	struct virtio_device vdev;
60 	__u8 config[VIRTIO_CCW_CONFIG_SIZE];
61 	struct ccw_device *cdev;
62 	/* we make cdev->dev.dma_parms point to this */
63 	struct device_dma_parameters dma_parms;
64 	__u32 curr_io;
65 	int err;
66 	unsigned int revision; /* Transport revision */
67 	wait_queue_head_t wait_q;
68 	spinlock_t lock;
69 	rwlock_t irq_lock;
70 	struct mutex io_lock; /* Serializes I/O requests */
71 	struct list_head virtqueues;
72 	bool is_thinint;
73 	bool going_away;
74 	bool device_lost;
75 	unsigned int config_ready;
76 	void *airq_info;
77 	struct vcdev_dma_area *dma_area;
78 	dma32_t dma_area_addr;
79 };
80 
81 static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
82 {
83 	return &vcdev->dma_area->indicators;
84 }
85 
86 static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev)
87 {
88 	return &vcdev->dma_area->indicators2;
89 }
90 
91 /* Spec stipulates a 64 bit address */
92 static inline dma64_t indicators_dma(struct virtio_ccw_device *vcdev)
93 {
94 	u64 dma_area_addr = dma32_to_u32(vcdev->dma_area_addr);
95 
96 	return dma64_add(u64_to_dma64(dma_area_addr),
97 			 offsetof(struct vcdev_dma_area, indicators));
98 }
99 
100 /* Spec stipulates a 64 bit address */
101 static inline dma64_t indicators2_dma(struct virtio_ccw_device *vcdev)
102 {
103 	u64 dma_area_addr = dma32_to_u32(vcdev->dma_area_addr);
104 
105 	return dma64_add(u64_to_dma64(dma_area_addr),
106 			 offsetof(struct vcdev_dma_area, indicators2));
107 }
108 
109 static inline dma32_t config_block_dma(struct virtio_ccw_device *vcdev)
110 {
111 	return dma32_add(vcdev->dma_area_addr,
112 			 offsetof(struct vcdev_dma_area, config_block));
113 }
114 
115 static inline dma32_t status_dma(struct virtio_ccw_device *vcdev)
116 {
117 	return dma32_add(vcdev->dma_area_addr,
118 			 offsetof(struct vcdev_dma_area, status));
119 }
120 
121 struct vq_info_block_legacy {
122 	dma64_t queue;
123 	__u32 align;
124 	__u16 index;
125 	__u16 num;
126 } __packed;
127 
128 struct vq_info_block {
129 	dma64_t desc;
130 	__u32 res0;
131 	__u16 index;
132 	__u16 num;
133 	dma64_t avail;
134 	dma64_t used;
135 } __packed;
136 
137 struct virtio_feature_desc {
138 	__le32 features;
139 	__u8 index;
140 } __packed;
141 
142 struct virtio_thinint_area {
143 	dma64_t summary_indicator;
144 	dma64_t indicator;
145 	u64 bit_nr;
146 	u8 isc;
147 } __packed;
148 
149 struct virtio_rev_info {
150 	__u16 revision;
151 	__u16 length;
152 	__u8 data[];
153 };
154 
155 /* the highest virtio-ccw revision we support */
156 #define VIRTIO_CCW_REV_MAX 2
157 
158 struct virtio_ccw_vq_info {
159 	struct virtqueue *vq;
160 	dma32_t info_block_addr;
161 	int num;
162 	union {
163 		struct vq_info_block s;
164 		struct vq_info_block_legacy l;
165 	} *info_block;
166 	int bit_nr;
167 	struct list_head node;
168 	long cookie;
169 };
170 
171 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
172 
173 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
174 #define MAX_AIRQ_AREAS 20
175 
176 static int virtio_ccw_use_airq = 1;
177 
178 struct airq_info {
179 	rwlock_t lock;
180 	u8 summary_indicator_idx;
181 	struct airq_struct airq;
182 	struct airq_iv *aiv;
183 };
184 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
185 static DEFINE_MUTEX(airq_areas_lock);
186 
187 static u8 *summary_indicators;
188 
189 static inline u8 *get_summary_indicator(struct airq_info *info)
190 {
191 	return summary_indicators + info->summary_indicator_idx;
192 }
193 
194 static inline dma64_t get_summary_indicator_dma(struct airq_info *info)
195 {
196 	return virt_to_dma64(get_summary_indicator(info));
197 }
198 
199 #define CCW_CMD_SET_VQ 0x13
200 #define CCW_CMD_VDEV_RESET 0x33
201 #define CCW_CMD_SET_IND 0x43
202 #define CCW_CMD_SET_CONF_IND 0x53
203 #define CCW_CMD_READ_FEAT 0x12
204 #define CCW_CMD_WRITE_FEAT 0x11
205 #define CCW_CMD_READ_CONF 0x22
206 #define CCW_CMD_WRITE_CONF 0x21
207 #define CCW_CMD_WRITE_STATUS 0x31
208 #define CCW_CMD_READ_VQ_CONF 0x32
209 #define CCW_CMD_READ_STATUS 0x72
210 #define CCW_CMD_SET_IND_ADAPTER 0x73
211 #define CCW_CMD_SET_VIRTIO_REV 0x83
212 
213 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
214 #define VIRTIO_CCW_DOING_RESET 0x00040000
215 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
216 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
217 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
218 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
219 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
220 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
221 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
222 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
223 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
224 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
225 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
226 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
227 
228 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
229 {
230 	return container_of(vdev, struct virtio_ccw_device, vdev);
231 }
232 
233 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
234 {
235 	unsigned long i, flags;
236 
237 	write_lock_irqsave(&info->lock, flags);
238 	for (i = 0; i < airq_iv_end(info->aiv); i++) {
239 		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
240 			airq_iv_free_bit(info->aiv, i);
241 			airq_iv_set_ptr(info->aiv, i, 0);
242 			break;
243 		}
244 	}
245 	write_unlock_irqrestore(&info->lock, flags);
246 }
247 
248 static void virtio_airq_handler(struct airq_struct *airq,
249 				struct tpi_info *tpi_info)
250 {
251 	struct airq_info *info = container_of(airq, struct airq_info, airq);
252 	unsigned long ai;
253 
254 	inc_irq_stat(IRQIO_VAI);
255 	read_lock(&info->lock);
256 	/* Walk through indicators field, summary indicator active. */
257 	for (ai = 0;;) {
258 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
259 		if (ai == -1UL)
260 			break;
261 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
262 	}
263 	*(get_summary_indicator(info)) = 0;
264 	smp_wmb();
265 	/* Walk through indicators field, summary indicator not active. */
266 	for (ai = 0;;) {
267 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
268 		if (ai == -1UL)
269 			break;
270 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
271 	}
272 	read_unlock(&info->lock);
273 }
274 
275 static struct airq_info *new_airq_info(int index)
276 {
277 	struct airq_info *info;
278 	int rc;
279 
280 	info = kzalloc(sizeof(*info), GFP_KERNEL);
281 	if (!info)
282 		return NULL;
283 	rwlock_init(&info->lock);
284 	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR
285 				   | AIRQ_IV_CACHELINE, NULL);
286 	if (!info->aiv) {
287 		kfree(info);
288 		return NULL;
289 	}
290 	info->airq.handler = virtio_airq_handler;
291 	info->summary_indicator_idx = index;
292 	info->airq.lsi_ptr = get_summary_indicator(info);
293 	info->airq.isc = VIRTIO_AIRQ_ISC;
294 	rc = register_adapter_interrupt(&info->airq);
295 	if (rc) {
296 		airq_iv_release(info->aiv);
297 		kfree(info);
298 		return NULL;
299 	}
300 	return info;
301 }
302 
303 static unsigned long *get_airq_indicator(struct virtqueue *vqs[], int nvqs,
304 					 u64 *first, void **airq_info)
305 {
306 	int i, j, queue_idx, highest_queue_idx = -1;
307 	struct airq_info *info;
308 	unsigned long *indicator_addr = NULL;
309 	unsigned long bit, flags;
310 
311 	/* Array entries without an actual queue pointer must be ignored. */
312 	for (i = 0; i < nvqs; i++) {
313 		if (vqs[i])
314 			highest_queue_idx++;
315 	}
316 
317 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
318 		mutex_lock(&airq_areas_lock);
319 		if (!airq_areas[i])
320 			airq_areas[i] = new_airq_info(i);
321 		info = airq_areas[i];
322 		mutex_unlock(&airq_areas_lock);
323 		if (!info)
324 			return NULL;
325 		write_lock_irqsave(&info->lock, flags);
326 		bit = airq_iv_alloc(info->aiv, highest_queue_idx + 1);
327 		if (bit == -1UL) {
328 			/* Not enough vacancies. */
329 			write_unlock_irqrestore(&info->lock, flags);
330 			continue;
331 		}
332 		*first = bit;
333 		*airq_info = info;
334 		indicator_addr = info->aiv->vector;
335 		for (j = 0, queue_idx = 0; j < nvqs; j++) {
336 			if (!vqs[j])
337 				continue;
338 			airq_iv_set_ptr(info->aiv, bit + queue_idx++,
339 					(unsigned long)vqs[j]);
340 		}
341 		write_unlock_irqrestore(&info->lock, flags);
342 	}
343 	return indicator_addr;
344 }
345 
346 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
347 {
348 	struct virtio_ccw_vq_info *info;
349 
350 	if (!vcdev->airq_info)
351 		return;
352 	list_for_each_entry(info, &vcdev->virtqueues, node)
353 		drop_airq_indicator(info->vq, vcdev->airq_info);
354 }
355 
356 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
357 {
358 	unsigned long flags;
359 	__u32 ret;
360 
361 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
362 	if (vcdev->err)
363 		ret = 0;
364 	else
365 		ret = vcdev->curr_io & flag;
366 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
367 	return ret;
368 }
369 
370 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
371 			 struct ccw1 *ccw, __u32 intparm)
372 {
373 	int ret;
374 	unsigned long flags;
375 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
376 
377 	mutex_lock(&vcdev->io_lock);
378 	do {
379 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
380 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
381 		if (!ret) {
382 			if (!vcdev->curr_io)
383 				vcdev->err = 0;
384 			vcdev->curr_io |= flag;
385 		}
386 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
387 		cpu_relax();
388 	} while (ret == -EBUSY);
389 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
390 	ret = ret ? ret : vcdev->err;
391 	mutex_unlock(&vcdev->io_lock);
392 	return ret;
393 }
394 
395 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
396 				      struct ccw1 *ccw)
397 {
398 	int ret;
399 	struct virtio_thinint_area *thinint_area = NULL;
400 	struct airq_info *airq_info = vcdev->airq_info;
401 	dma64_t *indicatorp = NULL;
402 
403 	if (vcdev->is_thinint) {
404 		thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
405 						     sizeof(*thinint_area),
406 						     &ccw->cda);
407 		if (!thinint_area)
408 			return;
409 		thinint_area->summary_indicator =
410 			get_summary_indicator_dma(airq_info);
411 		thinint_area->isc = VIRTIO_AIRQ_ISC;
412 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
413 		ccw->count = sizeof(*thinint_area);
414 	} else {
415 		/* payload is the address of the indicators */
416 		indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
417 						   sizeof(*indicatorp),
418 						   &ccw->cda);
419 		if (!indicatorp)
420 			return;
421 		*indicatorp = 0;
422 		ccw->cmd_code = CCW_CMD_SET_IND;
423 		ccw->count = sizeof(*indicatorp);
424 	}
425 	/* Deregister indicators from host. */
426 	*indicators(vcdev) = 0;
427 	ccw->flags = 0;
428 	ret = ccw_io_helper(vcdev, ccw,
429 			    vcdev->is_thinint ?
430 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
431 			    VIRTIO_CCW_DOING_SET_IND);
432 	if (ret && (ret != -ENODEV))
433 		dev_info(&vcdev->cdev->dev,
434 			 "Failed to deregister indicators (%d)\n", ret);
435 	else if (vcdev->is_thinint)
436 		virtio_ccw_drop_indicators(vcdev);
437 	ccw_device_dma_free(vcdev->cdev, indicatorp, sizeof(*indicatorp));
438 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
439 }
440 
441 static inline bool virtio_ccw_do_kvm_notify(struct virtqueue *vq, u32 data)
442 {
443 	struct virtio_ccw_vq_info *info = vq->priv;
444 	struct virtio_ccw_device *vcdev;
445 	struct subchannel_id schid;
446 
447 	vcdev = to_vc_device(info->vq->vdev);
448 	ccw_device_get_schid(vcdev->cdev, &schid);
449 	BUILD_BUG_ON(sizeof(struct subchannel_id) != sizeof(unsigned int));
450 	info->cookie = kvm_hypercall3(KVM_S390_VIRTIO_CCW_NOTIFY,
451 				      *((unsigned int *)&schid),
452 				      data, info->cookie);
453 	if (info->cookie < 0)
454 		return false;
455 	return true;
456 }
457 
458 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
459 {
460 	return virtio_ccw_do_kvm_notify(vq, vq->index);
461 }
462 
463 static bool virtio_ccw_kvm_notify_with_data(struct virtqueue *vq)
464 {
465 	return virtio_ccw_do_kvm_notify(vq, vring_notification_data(vq));
466 }
467 
468 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
469 				   struct ccw1 *ccw, int index)
470 {
471 	int ret;
472 
473 	vcdev->dma_area->config_block.index = index;
474 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
475 	ccw->flags = 0;
476 	ccw->count = sizeof(struct vq_config_block);
477 	ccw->cda = config_block_dma(vcdev);
478 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
479 	if (ret)
480 		return ret;
481 	return vcdev->dma_area->config_block.num ?: -ENOENT;
482 }
483 
484 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
485 {
486 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
487 	struct virtio_ccw_vq_info *info = vq->priv;
488 	unsigned long flags;
489 	int ret;
490 	unsigned int index = vq->index;
491 
492 	/* Remove from our list. */
493 	spin_lock_irqsave(&vcdev->lock, flags);
494 	list_del(&info->node);
495 	spin_unlock_irqrestore(&vcdev->lock, flags);
496 
497 	/* Release from host. */
498 	if (vcdev->revision == 0) {
499 		info->info_block->l.queue = 0;
500 		info->info_block->l.align = 0;
501 		info->info_block->l.index = index;
502 		info->info_block->l.num = 0;
503 		ccw->count = sizeof(info->info_block->l);
504 	} else {
505 		info->info_block->s.desc = 0;
506 		info->info_block->s.index = index;
507 		info->info_block->s.num = 0;
508 		info->info_block->s.avail = 0;
509 		info->info_block->s.used = 0;
510 		ccw->count = sizeof(info->info_block->s);
511 	}
512 	ccw->cmd_code = CCW_CMD_SET_VQ;
513 	ccw->flags = 0;
514 	ccw->cda = info->info_block_addr;
515 	ret = ccw_io_helper(vcdev, ccw,
516 			    VIRTIO_CCW_DOING_SET_VQ | index);
517 	/*
518 	 * -ENODEV isn't considered an error: The device is gone anyway.
519 	 * This may happen on device detach.
520 	 */
521 	if (ret && (ret != -ENODEV))
522 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
523 			 ret, index);
524 
525 	vring_del_virtqueue(vq);
526 	ccw_device_dma_free(vcdev->cdev, info->info_block,
527 			    sizeof(*info->info_block));
528 	kfree(info);
529 }
530 
531 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
532 {
533 	struct virtqueue *vq, *n;
534 	struct ccw1 *ccw;
535 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
536 
537 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
538 	if (!ccw)
539 		return;
540 
541 	virtio_ccw_drop_indicator(vcdev, ccw);
542 
543 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
544 		virtio_ccw_del_vq(vq, ccw);
545 
546 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
547 }
548 
549 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
550 					     int i, vq_callback_t *callback,
551 					     const char *name, bool ctx,
552 					     struct ccw1 *ccw)
553 {
554 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
555 	bool (*notify)(struct virtqueue *vq);
556 	int err;
557 	struct virtqueue *vq = NULL;
558 	struct virtio_ccw_vq_info *info;
559 	u64 queue;
560 	unsigned long flags;
561 	bool may_reduce;
562 
563 	if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA))
564 		notify = virtio_ccw_kvm_notify_with_data;
565 	else
566 		notify = virtio_ccw_kvm_notify;
567 
568 	/* Allocate queue. */
569 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
570 	if (!info) {
571 		dev_warn(&vcdev->cdev->dev, "no info\n");
572 		err = -ENOMEM;
573 		goto out_err;
574 	}
575 	info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
576 						 sizeof(*info->info_block),
577 						 &info->info_block_addr);
578 	if (!info->info_block) {
579 		dev_warn(&vcdev->cdev->dev, "no info block\n");
580 		err = -ENOMEM;
581 		goto out_err;
582 	}
583 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
584 	if (info->num < 0) {
585 		err = info->num;
586 		goto out_err;
587 	}
588 	may_reduce = vcdev->revision > 0;
589 	vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
590 				    vdev, true, may_reduce, ctx,
591 				    notify, callback, name);
592 
593 	if (!vq) {
594 		/* For now, we fail if we can't get the requested size. */
595 		dev_warn(&vcdev->cdev->dev, "no vq\n");
596 		err = -ENOMEM;
597 		goto out_err;
598 	}
599 
600 	vq->num_max = info->num;
601 
602 	/* it may have been reduced */
603 	info->num = virtqueue_get_vring_size(vq);
604 
605 	/* Register it with the host. */
606 	queue = virtqueue_get_desc_addr(vq);
607 	if (vcdev->revision == 0) {
608 		info->info_block->l.queue = u64_to_dma64(queue);
609 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
610 		info->info_block->l.index = i;
611 		info->info_block->l.num = info->num;
612 		ccw->count = sizeof(info->info_block->l);
613 	} else {
614 		info->info_block->s.desc = u64_to_dma64(queue);
615 		info->info_block->s.index = i;
616 		info->info_block->s.num = info->num;
617 		info->info_block->s.avail = u64_to_dma64(virtqueue_get_avail_addr(vq));
618 		info->info_block->s.used = u64_to_dma64(virtqueue_get_used_addr(vq));
619 		ccw->count = sizeof(info->info_block->s);
620 	}
621 	ccw->cmd_code = CCW_CMD_SET_VQ;
622 	ccw->flags = 0;
623 	ccw->cda = info->info_block_addr;
624 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
625 	if (err) {
626 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
627 		goto out_err;
628 	}
629 
630 	info->vq = vq;
631 	vq->priv = info;
632 
633 	/* Save it to our list. */
634 	spin_lock_irqsave(&vcdev->lock, flags);
635 	list_add(&info->node, &vcdev->virtqueues);
636 	spin_unlock_irqrestore(&vcdev->lock, flags);
637 
638 	return vq;
639 
640 out_err:
641 	if (vq)
642 		vring_del_virtqueue(vq);
643 	if (info) {
644 		ccw_device_dma_free(vcdev->cdev, info->info_block,
645 				    sizeof(*info->info_block));
646 	}
647 	kfree(info);
648 	return ERR_PTR(err);
649 }
650 
651 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
652 					   struct virtqueue *vqs[], int nvqs,
653 					   struct ccw1 *ccw)
654 {
655 	int ret;
656 	struct virtio_thinint_area *thinint_area = NULL;
657 	unsigned long *indicator_addr;
658 	struct airq_info *info;
659 
660 	thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
661 					     sizeof(*thinint_area),
662 					     &ccw->cda);
663 	if (!thinint_area) {
664 		ret = -ENOMEM;
665 		goto out;
666 	}
667 	/* Try to get an indicator. */
668 	indicator_addr = get_airq_indicator(vqs, nvqs,
669 					    &thinint_area->bit_nr,
670 					    &vcdev->airq_info);
671 	if (!indicator_addr) {
672 		ret = -ENOSPC;
673 		goto out;
674 	}
675 	thinint_area->indicator = virt_to_dma64(indicator_addr);
676 	info = vcdev->airq_info;
677 	thinint_area->summary_indicator = get_summary_indicator_dma(info);
678 	thinint_area->isc = VIRTIO_AIRQ_ISC;
679 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
680 	ccw->flags = CCW_FLAG_SLI;
681 	ccw->count = sizeof(*thinint_area);
682 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
683 	if (ret) {
684 		if (ret == -EOPNOTSUPP) {
685 			/*
686 			 * The host does not support adapter interrupts
687 			 * for virtio-ccw, stop trying.
688 			 */
689 			virtio_ccw_use_airq = 0;
690 			pr_info("Adapter interrupts unsupported on host\n");
691 		} else
692 			dev_warn(&vcdev->cdev->dev,
693 				 "enabling adapter interrupts = %d\n", ret);
694 		virtio_ccw_drop_indicators(vcdev);
695 	}
696 out:
697 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
698 	return ret;
699 }
700 
701 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
702 			       struct virtqueue *vqs[],
703 			       struct virtqueue_info vqs_info[],
704 			       struct irq_affinity *desc)
705 {
706 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
707 	dma64_t *indicatorp = NULL;
708 	int ret, i, queue_idx = 0;
709 	struct ccw1 *ccw;
710 	dma32_t indicatorp_dma = 0;
711 
712 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
713 	if (!ccw)
714 		return -ENOMEM;
715 
716 	for (i = 0; i < nvqs; ++i) {
717 		struct virtqueue_info *vqi = &vqs_info[i];
718 
719 		if (!vqi->name) {
720 			vqs[i] = NULL;
721 			continue;
722 		}
723 
724 		vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, vqi->callback,
725 					     vqi->name, vqi->ctx, ccw);
726 		if (IS_ERR(vqs[i])) {
727 			ret = PTR_ERR(vqs[i]);
728 			vqs[i] = NULL;
729 			goto out;
730 		}
731 	}
732 	ret = -ENOMEM;
733 	/*
734 	 * We need a data area under 2G to communicate. Our payload is
735 	 * the address of the indicators.
736 	*/
737 	indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
738 					   sizeof(*indicatorp),
739 					   &indicatorp_dma);
740 	if (!indicatorp)
741 		goto out;
742 	*indicatorp = indicators_dma(vcdev);
743 	if (vcdev->is_thinint) {
744 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
745 		if (ret)
746 			/* no error, just fall back to legacy interrupts */
747 			vcdev->is_thinint = false;
748 	}
749 	ccw->cda = indicatorp_dma;
750 	if (!vcdev->is_thinint) {
751 		/* Register queue indicators with host. */
752 		*indicators(vcdev) = 0;
753 		ccw->cmd_code = CCW_CMD_SET_IND;
754 		ccw->flags = 0;
755 		ccw->count = sizeof(*indicatorp);
756 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
757 		if (ret)
758 			goto out;
759 	}
760 	/* Register indicators2 with host for config changes */
761 	*indicatorp = indicators2_dma(vcdev);
762 	*indicators2(vcdev) = 0;
763 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
764 	ccw->flags = 0;
765 	ccw->count = sizeof(*indicatorp);
766 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
767 	if (ret)
768 		goto out;
769 
770 	if (indicatorp)
771 		ccw_device_dma_free(vcdev->cdev, indicatorp,
772 				    sizeof(*indicatorp));
773 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
774 	return 0;
775 out:
776 	if (indicatorp)
777 		ccw_device_dma_free(vcdev->cdev, indicatorp,
778 				    sizeof(*indicatorp));
779 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
780 	virtio_ccw_del_vqs(vdev);
781 	return ret;
782 }
783 
784 static void virtio_ccw_reset(struct virtio_device *vdev)
785 {
786 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
787 	struct ccw1 *ccw;
788 
789 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
790 	if (!ccw)
791 		return;
792 
793 	/* Zero status bits. */
794 	vcdev->dma_area->status = 0;
795 
796 	/* Send a reset ccw on device. */
797 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
798 	ccw->flags = 0;
799 	ccw->count = 0;
800 	ccw->cda = 0;
801 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
802 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
803 }
804 
805 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
806 {
807 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
808 	struct virtio_feature_desc *features;
809 	int ret;
810 	u64 rc;
811 	struct ccw1 *ccw;
812 
813 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
814 	if (!ccw)
815 		return 0;
816 
817 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features),
818 					 &ccw->cda);
819 	if (!features) {
820 		rc = 0;
821 		goto out_free;
822 	}
823 	/* Read the feature bits from the host. */
824 	features->index = 0;
825 	ccw->cmd_code = CCW_CMD_READ_FEAT;
826 	ccw->flags = 0;
827 	ccw->count = sizeof(*features);
828 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
829 	if (ret) {
830 		rc = 0;
831 		goto out_free;
832 	}
833 
834 	rc = le32_to_cpu(features->features);
835 
836 	if (vcdev->revision == 0)
837 		goto out_free;
838 
839 	/* Read second half of the feature bits from the host. */
840 	features->index = 1;
841 	ccw->cmd_code = CCW_CMD_READ_FEAT;
842 	ccw->flags = 0;
843 	ccw->count = sizeof(*features);
844 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
845 	if (ret == 0)
846 		rc |= (u64)le32_to_cpu(features->features) << 32;
847 
848 out_free:
849 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
850 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
851 	return rc;
852 }
853 
854 static void ccw_transport_features(struct virtio_device *vdev)
855 {
856 	/*
857 	 * Currently nothing to do here.
858 	 */
859 }
860 
861 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
862 {
863 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
864 	struct virtio_feature_desc *features;
865 	struct ccw1 *ccw;
866 	int ret;
867 
868 	if (vcdev->revision >= 1 &&
869 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
870 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
871 			"but does not have VIRTIO_F_VERSION_1\n");
872 		return -EINVAL;
873 	}
874 
875 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
876 	if (!ccw)
877 		return -ENOMEM;
878 
879 	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features),
880 					 &ccw->cda);
881 	if (!features) {
882 		ret = -ENOMEM;
883 		goto out_free;
884 	}
885 	/* Give virtio_ring a chance to accept features. */
886 	vring_transport_features(vdev);
887 
888 	/* Give virtio_ccw a chance to accept features. */
889 	ccw_transport_features(vdev);
890 
891 	features->index = 0;
892 	features->features = cpu_to_le32((u32)vdev->features);
893 	/* Write the first half of the feature bits to the host. */
894 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
895 	ccw->flags = 0;
896 	ccw->count = sizeof(*features);
897 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
898 	if (ret)
899 		goto out_free;
900 
901 	if (vcdev->revision == 0)
902 		goto out_free;
903 
904 	features->index = 1;
905 	features->features = cpu_to_le32(vdev->features >> 32);
906 	/* Write the second half of the feature bits to the host. */
907 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
908 	ccw->flags = 0;
909 	ccw->count = sizeof(*features);
910 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
911 
912 out_free:
913 	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
914 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
915 
916 	return ret;
917 }
918 
919 static void virtio_ccw_get_config(struct virtio_device *vdev,
920 				  unsigned int offset, void *buf, unsigned len)
921 {
922 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
923 	int ret;
924 	struct ccw1 *ccw;
925 	void *config_area;
926 	unsigned long flags;
927 
928 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
929 	if (!ccw)
930 		return;
931 
932 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
933 					    VIRTIO_CCW_CONFIG_SIZE,
934 					    &ccw->cda);
935 	if (!config_area)
936 		goto out_free;
937 
938 	/* Read the config area from the host. */
939 	ccw->cmd_code = CCW_CMD_READ_CONF;
940 	ccw->flags = 0;
941 	ccw->count = offset + len;
942 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
943 	if (ret)
944 		goto out_free;
945 
946 	spin_lock_irqsave(&vcdev->lock, flags);
947 	memcpy(vcdev->config, config_area, offset + len);
948 	if (vcdev->config_ready < offset + len)
949 		vcdev->config_ready = offset + len;
950 	spin_unlock_irqrestore(&vcdev->lock, flags);
951 	if (buf)
952 		memcpy(buf, config_area + offset, len);
953 
954 out_free:
955 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
956 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
957 }
958 
959 static void virtio_ccw_set_config(struct virtio_device *vdev,
960 				  unsigned int offset, const void *buf,
961 				  unsigned len)
962 {
963 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
964 	struct ccw1 *ccw;
965 	void *config_area;
966 	unsigned long flags;
967 
968 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
969 	if (!ccw)
970 		return;
971 
972 	config_area = ccw_device_dma_zalloc(vcdev->cdev,
973 					    VIRTIO_CCW_CONFIG_SIZE,
974 					    &ccw->cda);
975 	if (!config_area)
976 		goto out_free;
977 
978 	/* Make sure we don't overwrite fields. */
979 	if (vcdev->config_ready < offset)
980 		virtio_ccw_get_config(vdev, 0, NULL, offset);
981 	spin_lock_irqsave(&vcdev->lock, flags);
982 	memcpy(&vcdev->config[offset], buf, len);
983 	/* Write the config area to the host. */
984 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
985 	spin_unlock_irqrestore(&vcdev->lock, flags);
986 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
987 	ccw->flags = 0;
988 	ccw->count = offset + len;
989 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
990 
991 out_free:
992 	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
993 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
994 }
995 
996 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
997 {
998 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
999 	u8 old_status = vcdev->dma_area->status;
1000 	struct ccw1 *ccw;
1001 
1002 	if (vcdev->revision < 2)
1003 		return vcdev->dma_area->status;
1004 
1005 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
1006 	if (!ccw)
1007 		return old_status;
1008 
1009 	ccw->cmd_code = CCW_CMD_READ_STATUS;
1010 	ccw->flags = 0;
1011 	ccw->count = sizeof(vcdev->dma_area->status);
1012 	ccw->cda = status_dma(vcdev);
1013 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
1014 /*
1015  * If the channel program failed (should only happen if the device
1016  * was hotunplugged, and then we clean up via the machine check
1017  * handler anyway), vcdev->dma_area->status was not overwritten and we just
1018  * return the old status, which is fine.
1019 */
1020 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1021 
1022 	return vcdev->dma_area->status;
1023 }
1024 
1025 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
1026 {
1027 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1028 	u8 old_status = vcdev->dma_area->status;
1029 	struct ccw1 *ccw;
1030 	int ret;
1031 
1032 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
1033 	if (!ccw)
1034 		return;
1035 
1036 	/* Write the status to the host. */
1037 	vcdev->dma_area->status = status;
1038 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
1039 	ccw->flags = 0;
1040 	ccw->count = sizeof(status);
1041 	/* We use ssch for setting the status which is a serializing
1042 	 * instruction that guarantees the memory writes have
1043 	 * completed before ssch.
1044 	 */
1045 	ccw->cda = status_dma(vcdev);
1046 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
1047 	/* Write failed? We assume status is unchanged. */
1048 	if (ret)
1049 		vcdev->dma_area->status = old_status;
1050 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1051 }
1052 
1053 static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
1054 {
1055 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1056 
1057 	return dev_name(&vcdev->cdev->dev);
1058 }
1059 
1060 static void virtio_ccw_synchronize_cbs(struct virtio_device *vdev)
1061 {
1062 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1063 	struct airq_info *info = vcdev->airq_info;
1064 
1065 	if (info) {
1066 		/*
1067 		 * This device uses adapter interrupts: synchronize with
1068 		 * vring_interrupt() called by virtio_airq_handler()
1069 		 * via the indicator area lock.
1070 		 */
1071 		write_lock_irq(&info->lock);
1072 		write_unlock_irq(&info->lock);
1073 	} else {
1074 		/* This device uses classic interrupts: synchronize
1075 		 * with vring_interrupt() called by
1076 		 * virtio_ccw_int_handler() via the per-device
1077 		 * irq_lock
1078 		 */
1079 		write_lock_irq(&vcdev->irq_lock);
1080 		write_unlock_irq(&vcdev->irq_lock);
1081 	}
1082 }
1083 
1084 static const struct virtio_config_ops virtio_ccw_config_ops = {
1085 	.get_features = virtio_ccw_get_features,
1086 	.finalize_features = virtio_ccw_finalize_features,
1087 	.get = virtio_ccw_get_config,
1088 	.set = virtio_ccw_set_config,
1089 	.get_status = virtio_ccw_get_status,
1090 	.set_status = virtio_ccw_set_status,
1091 	.reset = virtio_ccw_reset,
1092 	.find_vqs = virtio_ccw_find_vqs,
1093 	.del_vqs = virtio_ccw_del_vqs,
1094 	.bus_name = virtio_ccw_bus_name,
1095 	.synchronize_cbs = virtio_ccw_synchronize_cbs,
1096 };
1097 
1098 
1099 /*
1100  * ccw bus driver related functions
1101  */
1102 
1103 static void virtio_ccw_release_dev(struct device *_d)
1104 {
1105 	struct virtio_device *dev = dev_to_virtio(_d);
1106 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
1107 
1108 	ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1109 			    sizeof(*vcdev->dma_area));
1110 	kfree(vcdev);
1111 }
1112 
1113 static int irb_is_error(struct irb *irb)
1114 {
1115 	if (scsw_cstat(&irb->scsw) != 0)
1116 		return 1;
1117 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1118 		return 1;
1119 	if (scsw_cc(&irb->scsw) != 0)
1120 		return 1;
1121 	return 0;
1122 }
1123 
1124 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1125 					      int index)
1126 {
1127 	struct virtio_ccw_vq_info *info;
1128 	unsigned long flags;
1129 	struct virtqueue *vq;
1130 
1131 	vq = NULL;
1132 	spin_lock_irqsave(&vcdev->lock, flags);
1133 	list_for_each_entry(info, &vcdev->virtqueues, node) {
1134 		if (info->vq->index == index) {
1135 			vq = info->vq;
1136 			break;
1137 		}
1138 	}
1139 	spin_unlock_irqrestore(&vcdev->lock, flags);
1140 	return vq;
1141 }
1142 
1143 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1144 				      __u32 activity)
1145 {
1146 	if (vcdev->curr_io & activity) {
1147 		switch (activity) {
1148 		case VIRTIO_CCW_DOING_READ_FEAT:
1149 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1150 		case VIRTIO_CCW_DOING_READ_CONFIG:
1151 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1152 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1153 		case VIRTIO_CCW_DOING_READ_STATUS:
1154 		case VIRTIO_CCW_DOING_SET_VQ:
1155 		case VIRTIO_CCW_DOING_SET_IND:
1156 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1157 		case VIRTIO_CCW_DOING_RESET:
1158 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1159 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1160 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1161 			vcdev->curr_io &= ~activity;
1162 			wake_up(&vcdev->wait_q);
1163 			break;
1164 		default:
1165 			/* don't know what to do... */
1166 			dev_warn(&vcdev->cdev->dev,
1167 				 "Suspicious activity '%08x'\n", activity);
1168 			WARN_ON(1);
1169 			break;
1170 		}
1171 	}
1172 }
1173 
1174 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1175 				   unsigned long intparm,
1176 				   struct irb *irb)
1177 {
1178 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1179 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1180 	int i;
1181 	struct virtqueue *vq;
1182 
1183 	if (!vcdev)
1184 		return;
1185 	if (IS_ERR(irb)) {
1186 		vcdev->err = PTR_ERR(irb);
1187 		virtio_ccw_check_activity(vcdev, activity);
1188 		/* Don't poke around indicators, something's wrong. */
1189 		return;
1190 	}
1191 	/* Check if it's a notification from the host. */
1192 	if ((intparm == 0) &&
1193 	    (scsw_stctl(&irb->scsw) ==
1194 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1195 		/* OK */
1196 	}
1197 	if (irb_is_error(irb)) {
1198 		/* Command reject? */
1199 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1200 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1201 			vcdev->err = -EOPNOTSUPP;
1202 		else
1203 			/* Map everything else to -EIO. */
1204 			vcdev->err = -EIO;
1205 	}
1206 	virtio_ccw_check_activity(vcdev, activity);
1207 #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
1208 	/*
1209 	 * Paired with virtio_ccw_synchronize_cbs() and interrupts are
1210 	 * disabled here.
1211 	 */
1212 	read_lock(&vcdev->irq_lock);
1213 #endif
1214 	for_each_set_bit(i, indicators(vcdev),
1215 			 sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {
1216 		/* The bit clear must happen before the vring kick. */
1217 		clear_bit(i, indicators(vcdev));
1218 		barrier();
1219 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1220 		vring_interrupt(0, vq);
1221 	}
1222 #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
1223 	read_unlock(&vcdev->irq_lock);
1224 #endif
1225 	if (test_bit(0, indicators2(vcdev))) {
1226 		virtio_config_changed(&vcdev->vdev);
1227 		clear_bit(0, indicators2(vcdev));
1228 	}
1229 }
1230 
1231 /*
1232  * We usually want to autoonline all devices, but give the admin
1233  * a way to exempt devices from this.
1234  */
1235 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1236 		     (8*sizeof(long)))
1237 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1238 
1239 static char *no_auto = "";
1240 
1241 module_param(no_auto, charp, 0444);
1242 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1243 
1244 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1245 {
1246 	struct ccw_dev_id id;
1247 
1248 	ccw_device_get_id(cdev, &id);
1249 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1250 		return 0;
1251 	return 1;
1252 }
1253 
1254 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1255 {
1256 	struct ccw_device *cdev = data;
1257 	int ret;
1258 
1259 	ret = ccw_device_set_online(cdev);
1260 	if (ret)
1261 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1262 }
1263 
1264 static int virtio_ccw_probe(struct ccw_device *cdev)
1265 {
1266 	cdev->handler = virtio_ccw_int_handler;
1267 
1268 	if (virtio_ccw_check_autoonline(cdev))
1269 		async_schedule(virtio_ccw_auto_online, cdev);
1270 	return 0;
1271 }
1272 
1273 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1274 {
1275 	unsigned long flags;
1276 	struct virtio_ccw_device *vcdev;
1277 
1278 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1279 	vcdev = dev_get_drvdata(&cdev->dev);
1280 	if (!vcdev || vcdev->going_away) {
1281 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1282 		return NULL;
1283 	}
1284 	vcdev->going_away = true;
1285 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1286 	return vcdev;
1287 }
1288 
1289 static void virtio_ccw_remove(struct ccw_device *cdev)
1290 {
1291 	unsigned long flags;
1292 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1293 
1294 	if (vcdev && cdev->online) {
1295 		if (vcdev->device_lost)
1296 			virtio_break_device(&vcdev->vdev);
1297 		unregister_virtio_device(&vcdev->vdev);
1298 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1299 		dev_set_drvdata(&cdev->dev, NULL);
1300 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1301 	}
1302 	cdev->handler = NULL;
1303 }
1304 
1305 static int virtio_ccw_offline(struct ccw_device *cdev)
1306 {
1307 	unsigned long flags;
1308 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1309 
1310 	if (!vcdev)
1311 		return 0;
1312 	if (vcdev->device_lost)
1313 		virtio_break_device(&vcdev->vdev);
1314 	unregister_virtio_device(&vcdev->vdev);
1315 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1316 	dev_set_drvdata(&cdev->dev, NULL);
1317 	cdev->dev.dma_parms = NULL;
1318 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1319 	return 0;
1320 }
1321 
1322 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1323 {
1324 	struct virtio_rev_info *rev;
1325 	struct ccw1 *ccw;
1326 	int ret;
1327 
1328 	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
1329 	if (!ccw)
1330 		return -ENOMEM;
1331 	rev = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*rev), &ccw->cda);
1332 	if (!rev) {
1333 		ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1334 		return -ENOMEM;
1335 	}
1336 
1337 	/* Set transport revision */
1338 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1339 	ccw->flags = 0;
1340 	ccw->count = sizeof(*rev);
1341 
1342 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1343 	do {
1344 		rev->revision = vcdev->revision;
1345 		/* none of our supported revisions carry payload */
1346 		rev->length = 0;
1347 		ret = ccw_io_helper(vcdev, ccw,
1348 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1349 		if (ret == -EOPNOTSUPP) {
1350 			if (vcdev->revision == 0)
1351 				/*
1352 				 * The host device does not support setting
1353 				 * the revision: let's operate it in legacy
1354 				 * mode.
1355 				 */
1356 				ret = 0;
1357 			else
1358 				vcdev->revision--;
1359 		}
1360 	} while (ret == -EOPNOTSUPP);
1361 
1362 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1363 	ccw_device_dma_free(vcdev->cdev, rev, sizeof(*rev));
1364 	return ret;
1365 }
1366 
1367 static int virtio_ccw_online(struct ccw_device *cdev)
1368 {
1369 	int ret;
1370 	struct virtio_ccw_device *vcdev;
1371 	unsigned long flags;
1372 
1373 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1374 	if (!vcdev) {
1375 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1376 		ret = -ENOMEM;
1377 		goto out_free;
1378 	}
1379 	vcdev->vdev.dev.parent = &cdev->dev;
1380 	vcdev->cdev = cdev;
1381 	cdev->dev.dma_parms = &vcdev->dma_parms;
1382 	vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,
1383 						sizeof(*vcdev->dma_area),
1384 						&vcdev->dma_area_addr);
1385 	if (!vcdev->dma_area) {
1386 		ret = -ENOMEM;
1387 		goto out_free;
1388 	}
1389 
1390 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1391 
1392 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1393 	vcdev->vdev.config = &virtio_ccw_config_ops;
1394 	init_waitqueue_head(&vcdev->wait_q);
1395 	INIT_LIST_HEAD(&vcdev->virtqueues);
1396 	spin_lock_init(&vcdev->lock);
1397 	rwlock_init(&vcdev->irq_lock);
1398 	mutex_init(&vcdev->io_lock);
1399 
1400 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1401 	dev_set_drvdata(&cdev->dev, vcdev);
1402 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1403 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1404 	vcdev->vdev.id.device = cdev->id.cu_model;
1405 
1406 	ret = virtio_ccw_set_transport_rev(vcdev);
1407 	if (ret)
1408 		goto out_free;
1409 
1410 	ret = register_virtio_device(&vcdev->vdev);
1411 	if (ret) {
1412 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1413 			 ret);
1414 		goto out_put;
1415 	}
1416 	return 0;
1417 out_put:
1418 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1419 	dev_set_drvdata(&cdev->dev, NULL);
1420 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1421 	put_device(&vcdev->vdev.dev);
1422 	return ret;
1423 out_free:
1424 	if (vcdev) {
1425 		ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1426 				    sizeof(*vcdev->dma_area));
1427 	}
1428 	kfree(vcdev);
1429 	return ret;
1430 }
1431 
1432 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1433 {
1434 	int rc;
1435 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1436 
1437 	/*
1438 	 * Make sure vcdev is set
1439 	 * i.e. set_offline/remove callback not already running
1440 	 */
1441 	if (!vcdev)
1442 		return NOTIFY_DONE;
1443 
1444 	switch (event) {
1445 	case CIO_GONE:
1446 		vcdev->device_lost = true;
1447 		rc = NOTIFY_DONE;
1448 		break;
1449 	case CIO_OPER:
1450 		rc = NOTIFY_OK;
1451 		break;
1452 	default:
1453 		rc = NOTIFY_DONE;
1454 		break;
1455 	}
1456 	return rc;
1457 }
1458 
1459 static struct ccw_device_id virtio_ids[] = {
1460 	{ CCW_DEVICE(0x3832, 0) },
1461 	{},
1462 };
1463 
1464 static struct ccw_driver virtio_ccw_driver = {
1465 	.driver = {
1466 		.owner = THIS_MODULE,
1467 		.name = "virtio_ccw",
1468 	},
1469 	.ids = virtio_ids,
1470 	.probe = virtio_ccw_probe,
1471 	.remove = virtio_ccw_remove,
1472 	.set_offline = virtio_ccw_offline,
1473 	.set_online = virtio_ccw_online,
1474 	.notify = virtio_ccw_cio_notify,
1475 	.int_class = IRQIO_VIR,
1476 };
1477 
1478 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1479 			   int max_digit, int max_val)
1480 {
1481 	int diff;
1482 
1483 	diff = 0;
1484 	*val = 0;
1485 
1486 	while (diff <= max_digit) {
1487 		int value = hex_to_bin(**cp);
1488 
1489 		if (value < 0)
1490 			break;
1491 		*val = *val * 16 + value;
1492 		(*cp)++;
1493 		diff++;
1494 	}
1495 
1496 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1497 		return 1;
1498 
1499 	return 0;
1500 }
1501 
1502 static int __init parse_busid(char *str, unsigned int *cssid,
1503 			      unsigned int *ssid, unsigned int *devno)
1504 {
1505 	char *str_work;
1506 	int rc, ret;
1507 
1508 	rc = 1;
1509 
1510 	if (*str == '\0')
1511 		goto out;
1512 
1513 	str_work = str;
1514 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1515 	if (ret || (str_work[0] != '.'))
1516 		goto out;
1517 	str_work++;
1518 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1519 	if (ret || (str_work[0] != '.'))
1520 		goto out;
1521 	str_work++;
1522 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1523 	if (ret || (str_work[0] != '\0'))
1524 		goto out;
1525 
1526 	rc = 0;
1527 out:
1528 	return rc;
1529 }
1530 
1531 static void __init no_auto_parse(void)
1532 {
1533 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1534 	char *parm, *str;
1535 	int rc;
1536 
1537 	str = no_auto;
1538 	while ((parm = strsep(&str, ","))) {
1539 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1540 				 &from_ssid, &from);
1541 		if (rc)
1542 			continue;
1543 		if (parm != NULL) {
1544 			rc = parse_busid(parm, &to_cssid,
1545 					 &to_ssid, &to);
1546 			if ((from_ssid > to_ssid) ||
1547 			    ((from_ssid == to_ssid) && (from > to)))
1548 				rc = -EINVAL;
1549 		} else {
1550 			to_cssid = from_cssid;
1551 			to_ssid = from_ssid;
1552 			to = from;
1553 		}
1554 		if (rc)
1555 			continue;
1556 		while ((from_ssid < to_ssid) ||
1557 		       ((from_ssid == to_ssid) && (from <= to))) {
1558 			set_bit(from, devs_no_auto[from_ssid]);
1559 			from++;
1560 			if (from > __MAX_SUBCHANNEL) {
1561 				from_ssid++;
1562 				from = 0;
1563 			}
1564 		}
1565 	}
1566 }
1567 
1568 static int __init virtio_ccw_init(void)
1569 {
1570 	int rc;
1571 
1572 	/* parse no_auto string before we do anything further */
1573 	no_auto_parse();
1574 
1575 	summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS);
1576 	if (!summary_indicators)
1577 		return -ENOMEM;
1578 	rc = ccw_driver_register(&virtio_ccw_driver);
1579 	if (rc)
1580 		cio_dma_free(summary_indicators, MAX_AIRQ_AREAS);
1581 	return rc;
1582 }
1583 device_initcall(virtio_ccw_init);
1584