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1 /*
2  * ccw based virtio transport
3  *
4  * Copyright IBM Corp. 2012, 2014
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License (version 2 only)
8  * as published by the Free Software Foundation.
9  *
10  *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
11  */
12 
13 #include <linux/kernel_stat.h>
14 #include <linux/init.h>
15 #include <linux/bootmem.h>
16 #include <linux/err.h>
17 #include <linux/virtio.h>
18 #include <linux/virtio_config.h>
19 #include <linux/slab.h>
20 #include <linux/interrupt.h>
21 #include <linux/virtio_ring.h>
22 #include <linux/pfn.h>
23 #include <linux/async.h>
24 #include <linux/wait.h>
25 #include <linux/list.h>
26 #include <linux/bitops.h>
27 #include <linux/module.h>
28 #include <linux/io.h>
29 #include <linux/kvm_para.h>
30 #include <linux/notifier.h>
31 #include <asm/diag.h>
32 #include <asm/setup.h>
33 #include <asm/irq.h>
34 #include <asm/cio.h>
35 #include <asm/ccwdev.h>
36 #include <asm/virtio-ccw.h>
37 #include <asm/isc.h>
38 #include <asm/airq.h>
39 
40 /*
41  * virtio related functions
42  */
43 
44 struct vq_config_block {
45 	__u16 index;
46 	__u16 num;
47 } __packed;
48 
49 #define VIRTIO_CCW_CONFIG_SIZE 0x100
50 /* same as PCI config space size, should be enough for all drivers */
51 
52 struct virtio_ccw_device {
53 	struct virtio_device vdev;
54 	__u8 *status;
55 	__u8 config[VIRTIO_CCW_CONFIG_SIZE];
56 	struct ccw_device *cdev;
57 	__u32 curr_io;
58 	int err;
59 	unsigned int revision; /* Transport revision */
60 	wait_queue_head_t wait_q;
61 	spinlock_t lock;
62 	struct mutex io_lock; /* Serializes I/O requests */
63 	struct list_head virtqueues;
64 	unsigned long indicators;
65 	unsigned long indicators2;
66 	struct vq_config_block *config_block;
67 	bool is_thinint;
68 	bool going_away;
69 	bool device_lost;
70 	unsigned int config_ready;
71 	void *airq_info;
72 };
73 
74 struct vq_info_block_legacy {
75 	__u64 queue;
76 	__u32 align;
77 	__u16 index;
78 	__u16 num;
79 } __packed;
80 
81 struct vq_info_block {
82 	__u64 desc;
83 	__u32 res0;
84 	__u16 index;
85 	__u16 num;
86 	__u64 avail;
87 	__u64 used;
88 } __packed;
89 
90 struct virtio_feature_desc {
91 	__u32 features;
92 	__u8 index;
93 } __packed;
94 
95 struct virtio_thinint_area {
96 	unsigned long summary_indicator;
97 	unsigned long indicator;
98 	u64 bit_nr;
99 	u8 isc;
100 } __packed;
101 
102 struct virtio_rev_info {
103 	__u16 revision;
104 	__u16 length;
105 	__u8 data[];
106 };
107 
108 /* the highest virtio-ccw revision we support */
109 #define VIRTIO_CCW_REV_MAX 1
110 
111 struct virtio_ccw_vq_info {
112 	struct virtqueue *vq;
113 	int num;
114 	void *queue;
115 	union {
116 		struct vq_info_block s;
117 		struct vq_info_block_legacy l;
118 	} *info_block;
119 	int bit_nr;
120 	struct list_head node;
121 	long cookie;
122 };
123 
124 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
125 
126 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
127 #define MAX_AIRQ_AREAS 20
128 
129 static int virtio_ccw_use_airq = 1;
130 
131 struct airq_info {
132 	rwlock_t lock;
133 	u8 summary_indicator;
134 	struct airq_struct airq;
135 	struct airq_iv *aiv;
136 };
137 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
138 
139 #define CCW_CMD_SET_VQ 0x13
140 #define CCW_CMD_VDEV_RESET 0x33
141 #define CCW_CMD_SET_IND 0x43
142 #define CCW_CMD_SET_CONF_IND 0x53
143 #define CCW_CMD_READ_FEAT 0x12
144 #define CCW_CMD_WRITE_FEAT 0x11
145 #define CCW_CMD_READ_CONF 0x22
146 #define CCW_CMD_WRITE_CONF 0x21
147 #define CCW_CMD_WRITE_STATUS 0x31
148 #define CCW_CMD_READ_VQ_CONF 0x32
149 #define CCW_CMD_SET_IND_ADAPTER 0x73
150 #define CCW_CMD_SET_VIRTIO_REV 0x83
151 
152 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
153 #define VIRTIO_CCW_DOING_RESET 0x00040000
154 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
155 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
156 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
157 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
158 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
159 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
160 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
161 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
162 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
163 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
164 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
165 
to_vc_device(struct virtio_device * vdev)166 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
167 {
168 	return container_of(vdev, struct virtio_ccw_device, vdev);
169 }
170 
drop_airq_indicator(struct virtqueue * vq,struct airq_info * info)171 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
172 {
173 	unsigned long i, flags;
174 
175 	write_lock_irqsave(&info->lock, flags);
176 	for (i = 0; i < airq_iv_end(info->aiv); i++) {
177 		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
178 			airq_iv_free_bit(info->aiv, i);
179 			airq_iv_set_ptr(info->aiv, i, 0);
180 			break;
181 		}
182 	}
183 	write_unlock_irqrestore(&info->lock, flags);
184 }
185 
virtio_airq_handler(struct airq_struct * airq)186 static void virtio_airq_handler(struct airq_struct *airq)
187 {
188 	struct airq_info *info = container_of(airq, struct airq_info, airq);
189 	unsigned long ai;
190 
191 	inc_irq_stat(IRQIO_VAI);
192 	read_lock(&info->lock);
193 	/* Walk through indicators field, summary indicator active. */
194 	for (ai = 0;;) {
195 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
196 		if (ai == -1UL)
197 			break;
198 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
199 	}
200 	info->summary_indicator = 0;
201 	smp_wmb();
202 	/* Walk through indicators field, summary indicator not active. */
203 	for (ai = 0;;) {
204 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
205 		if (ai == -1UL)
206 			break;
207 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
208 	}
209 	read_unlock(&info->lock);
210 }
211 
new_airq_info(void)212 static struct airq_info *new_airq_info(void)
213 {
214 	struct airq_info *info;
215 	int rc;
216 
217 	info = kzalloc(sizeof(*info), GFP_KERNEL);
218 	if (!info)
219 		return NULL;
220 	rwlock_init(&info->lock);
221 	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
222 	if (!info->aiv) {
223 		kfree(info);
224 		return NULL;
225 	}
226 	info->airq.handler = virtio_airq_handler;
227 	info->airq.lsi_ptr = &info->summary_indicator;
228 	info->airq.lsi_mask = 0xff;
229 	info->airq.isc = VIRTIO_AIRQ_ISC;
230 	rc = register_adapter_interrupt(&info->airq);
231 	if (rc) {
232 		airq_iv_release(info->aiv);
233 		kfree(info);
234 		return NULL;
235 	}
236 	return info;
237 }
238 
destroy_airq_info(struct airq_info * info)239 static void destroy_airq_info(struct airq_info *info)
240 {
241 	if (!info)
242 		return;
243 
244 	unregister_adapter_interrupt(&info->airq);
245 	airq_iv_release(info->aiv);
246 	kfree(info);
247 }
248 
get_airq_indicator(struct virtqueue * vqs[],int nvqs,u64 * first,void ** airq_info)249 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
250 					u64 *first, void **airq_info)
251 {
252 	int i, j;
253 	struct airq_info *info;
254 	unsigned long indicator_addr = 0;
255 	unsigned long bit, flags;
256 
257 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
258 		if (!airq_areas[i])
259 			airq_areas[i] = new_airq_info();
260 		info = airq_areas[i];
261 		if (!info)
262 			return 0;
263 		write_lock_irqsave(&info->lock, flags);
264 		bit = airq_iv_alloc(info->aiv, nvqs);
265 		if (bit == -1UL) {
266 			/* Not enough vacancies. */
267 			write_unlock_irqrestore(&info->lock, flags);
268 			continue;
269 		}
270 		*first = bit;
271 		*airq_info = info;
272 		indicator_addr = (unsigned long)info->aiv->vector;
273 		for (j = 0; j < nvqs; j++) {
274 			airq_iv_set_ptr(info->aiv, bit + j,
275 					(unsigned long)vqs[j]);
276 		}
277 		write_unlock_irqrestore(&info->lock, flags);
278 	}
279 	return indicator_addr;
280 }
281 
virtio_ccw_drop_indicators(struct virtio_ccw_device * vcdev)282 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
283 {
284 	struct virtio_ccw_vq_info *info;
285 
286 	if (!vcdev->airq_info)
287 		return;
288 	list_for_each_entry(info, &vcdev->virtqueues, node)
289 		drop_airq_indicator(info->vq, vcdev->airq_info);
290 }
291 
doing_io(struct virtio_ccw_device * vcdev,__u32 flag)292 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
293 {
294 	unsigned long flags;
295 	__u32 ret;
296 
297 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
298 	if (vcdev->err)
299 		ret = 0;
300 	else
301 		ret = vcdev->curr_io & flag;
302 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
303 	return ret;
304 }
305 
ccw_io_helper(struct virtio_ccw_device * vcdev,struct ccw1 * ccw,__u32 intparm)306 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
307 			 struct ccw1 *ccw, __u32 intparm)
308 {
309 	int ret;
310 	unsigned long flags;
311 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
312 
313 	mutex_lock(&vcdev->io_lock);
314 	do {
315 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
316 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
317 		if (!ret) {
318 			if (!vcdev->curr_io)
319 				vcdev->err = 0;
320 			vcdev->curr_io |= flag;
321 		}
322 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
323 		cpu_relax();
324 	} while (ret == -EBUSY);
325 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
326 	ret = ret ? ret : vcdev->err;
327 	mutex_unlock(&vcdev->io_lock);
328 	return ret;
329 }
330 
virtio_ccw_drop_indicator(struct virtio_ccw_device * vcdev,struct ccw1 * ccw)331 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
332 				      struct ccw1 *ccw)
333 {
334 	int ret;
335 	unsigned long *indicatorp = NULL;
336 	struct virtio_thinint_area *thinint_area = NULL;
337 	struct airq_info *airq_info = vcdev->airq_info;
338 
339 	if (vcdev->is_thinint) {
340 		thinint_area = kzalloc(sizeof(*thinint_area),
341 				       GFP_DMA | GFP_KERNEL);
342 		if (!thinint_area)
343 			return;
344 		thinint_area->summary_indicator =
345 			(unsigned long) &airq_info->summary_indicator;
346 		thinint_area->isc = VIRTIO_AIRQ_ISC;
347 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
348 		ccw->count = sizeof(*thinint_area);
349 		ccw->cda = (__u32)(unsigned long) thinint_area;
350 	} else {
351 		indicatorp = kmalloc(sizeof(&vcdev->indicators),
352 				     GFP_DMA | GFP_KERNEL);
353 		if (!indicatorp)
354 			return;
355 		*indicatorp = 0;
356 		ccw->cmd_code = CCW_CMD_SET_IND;
357 		ccw->count = sizeof(vcdev->indicators);
358 		ccw->cda = (__u32)(unsigned long) indicatorp;
359 	}
360 	/* Deregister indicators from host. */
361 	vcdev->indicators = 0;
362 	ccw->flags = 0;
363 	ret = ccw_io_helper(vcdev, ccw,
364 			    vcdev->is_thinint ?
365 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
366 			    VIRTIO_CCW_DOING_SET_IND);
367 	if (ret && (ret != -ENODEV))
368 		dev_info(&vcdev->cdev->dev,
369 			 "Failed to deregister indicators (%d)\n", ret);
370 	else if (vcdev->is_thinint)
371 		virtio_ccw_drop_indicators(vcdev);
372 	kfree(indicatorp);
373 	kfree(thinint_area);
374 }
375 
__do_kvm_notify(struct subchannel_id schid,unsigned long queue_index,long cookie)376 static inline long __do_kvm_notify(struct subchannel_id schid,
377 				   unsigned long queue_index,
378 				   long cookie)
379 {
380 	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
381 	register struct subchannel_id __schid asm("2") = schid;
382 	register unsigned long __index asm("3") = queue_index;
383 	register long __rc asm("2");
384 	register long __cookie asm("4") = cookie;
385 
386 	asm volatile ("diag 2,4,0x500\n"
387 		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
388 		      "d"(__cookie)
389 		      : "memory", "cc");
390 	return __rc;
391 }
392 
do_kvm_notify(struct subchannel_id schid,unsigned long queue_index,long cookie)393 static inline long do_kvm_notify(struct subchannel_id schid,
394 				 unsigned long queue_index,
395 				 long cookie)
396 {
397 	diag_stat_inc(DIAG_STAT_X500);
398 	return __do_kvm_notify(schid, queue_index, cookie);
399 }
400 
virtio_ccw_kvm_notify(struct virtqueue * vq)401 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
402 {
403 	struct virtio_ccw_vq_info *info = vq->priv;
404 	struct virtio_ccw_device *vcdev;
405 	struct subchannel_id schid;
406 
407 	vcdev = to_vc_device(info->vq->vdev);
408 	ccw_device_get_schid(vcdev->cdev, &schid);
409 	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
410 	if (info->cookie < 0)
411 		return false;
412 	return true;
413 }
414 
virtio_ccw_read_vq_conf(struct virtio_ccw_device * vcdev,struct ccw1 * ccw,int index)415 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
416 				   struct ccw1 *ccw, int index)
417 {
418 	int ret;
419 
420 	vcdev->config_block->index = index;
421 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
422 	ccw->flags = 0;
423 	ccw->count = sizeof(struct vq_config_block);
424 	ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
425 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
426 	if (ret)
427 		return ret;
428 	return vcdev->config_block->num ?: -ENOENT;
429 }
430 
virtio_ccw_del_vq(struct virtqueue * vq,struct ccw1 * ccw)431 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
432 {
433 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
434 	struct virtio_ccw_vq_info *info = vq->priv;
435 	unsigned long flags;
436 	unsigned long size;
437 	int ret;
438 	unsigned int index = vq->index;
439 
440 	/* Remove from our list. */
441 	spin_lock_irqsave(&vcdev->lock, flags);
442 	list_del(&info->node);
443 	spin_unlock_irqrestore(&vcdev->lock, flags);
444 
445 	/* Release from host. */
446 	if (vcdev->revision == 0) {
447 		info->info_block->l.queue = 0;
448 		info->info_block->l.align = 0;
449 		info->info_block->l.index = index;
450 		info->info_block->l.num = 0;
451 		ccw->count = sizeof(info->info_block->l);
452 	} else {
453 		info->info_block->s.desc = 0;
454 		info->info_block->s.index = index;
455 		info->info_block->s.num = 0;
456 		info->info_block->s.avail = 0;
457 		info->info_block->s.used = 0;
458 		ccw->count = sizeof(info->info_block->s);
459 	}
460 	ccw->cmd_code = CCW_CMD_SET_VQ;
461 	ccw->flags = 0;
462 	ccw->cda = (__u32)(unsigned long)(info->info_block);
463 	ret = ccw_io_helper(vcdev, ccw,
464 			    VIRTIO_CCW_DOING_SET_VQ | index);
465 	/*
466 	 * -ENODEV isn't considered an error: The device is gone anyway.
467 	 * This may happen on device detach.
468 	 */
469 	if (ret && (ret != -ENODEV))
470 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d",
471 			 ret, index);
472 
473 	vring_del_virtqueue(vq);
474 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
475 	free_pages_exact(info->queue, size);
476 	kfree(info->info_block);
477 	kfree(info);
478 }
479 
virtio_ccw_del_vqs(struct virtio_device * vdev)480 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
481 {
482 	struct virtqueue *vq, *n;
483 	struct ccw1 *ccw;
484 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
485 
486 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
487 	if (!ccw)
488 		return;
489 
490 	virtio_ccw_drop_indicator(vcdev, ccw);
491 
492 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
493 		virtio_ccw_del_vq(vq, ccw);
494 
495 	kfree(ccw);
496 }
497 
virtio_ccw_setup_vq(struct virtio_device * vdev,int i,vq_callback_t * callback,const char * name,struct ccw1 * ccw)498 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
499 					     int i, vq_callback_t *callback,
500 					     const char *name,
501 					     struct ccw1 *ccw)
502 {
503 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
504 	int err;
505 	struct virtqueue *vq = NULL;
506 	struct virtio_ccw_vq_info *info;
507 	unsigned long size = 0; /* silence the compiler */
508 	unsigned long flags;
509 
510 	/* Allocate queue. */
511 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
512 	if (!info) {
513 		dev_warn(&vcdev->cdev->dev, "no info\n");
514 		err = -ENOMEM;
515 		goto out_err;
516 	}
517 	info->info_block = kzalloc(sizeof(*info->info_block),
518 				   GFP_DMA | GFP_KERNEL);
519 	if (!info->info_block) {
520 		dev_warn(&vcdev->cdev->dev, "no info block\n");
521 		err = -ENOMEM;
522 		goto out_err;
523 	}
524 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
525 	if (info->num < 0) {
526 		err = info->num;
527 		goto out_err;
528 	}
529 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
530 	info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
531 	if (info->queue == NULL) {
532 		dev_warn(&vcdev->cdev->dev, "no queue\n");
533 		err = -ENOMEM;
534 		goto out_err;
535 	}
536 
537 	vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
538 				 true, info->queue, virtio_ccw_kvm_notify,
539 				 callback, name);
540 	if (!vq) {
541 		/* For now, we fail if we can't get the requested size. */
542 		dev_warn(&vcdev->cdev->dev, "no vq\n");
543 		err = -ENOMEM;
544 		goto out_err;
545 	}
546 
547 	/* Register it with the host. */
548 	if (vcdev->revision == 0) {
549 		info->info_block->l.queue = (__u64)info->queue;
550 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
551 		info->info_block->l.index = i;
552 		info->info_block->l.num = info->num;
553 		ccw->count = sizeof(info->info_block->l);
554 	} else {
555 		info->info_block->s.desc = (__u64)info->queue;
556 		info->info_block->s.index = i;
557 		info->info_block->s.num = info->num;
558 		info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
559 		info->info_block->s.used = (__u64)virtqueue_get_used(vq);
560 		ccw->count = sizeof(info->info_block->s);
561 	}
562 	ccw->cmd_code = CCW_CMD_SET_VQ;
563 	ccw->flags = 0;
564 	ccw->cda = (__u32)(unsigned long)(info->info_block);
565 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
566 	if (err) {
567 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
568 		goto out_err;
569 	}
570 
571 	info->vq = vq;
572 	vq->priv = info;
573 
574 	/* Save it to our list. */
575 	spin_lock_irqsave(&vcdev->lock, flags);
576 	list_add(&info->node, &vcdev->virtqueues);
577 	spin_unlock_irqrestore(&vcdev->lock, flags);
578 
579 	return vq;
580 
581 out_err:
582 	if (vq)
583 		vring_del_virtqueue(vq);
584 	if (info) {
585 		if (info->queue)
586 			free_pages_exact(info->queue, size);
587 		kfree(info->info_block);
588 	}
589 	kfree(info);
590 	return ERR_PTR(err);
591 }
592 
virtio_ccw_register_adapter_ind(struct virtio_ccw_device * vcdev,struct virtqueue * vqs[],int nvqs,struct ccw1 * ccw)593 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
594 					   struct virtqueue *vqs[], int nvqs,
595 					   struct ccw1 *ccw)
596 {
597 	int ret;
598 	struct virtio_thinint_area *thinint_area = NULL;
599 	struct airq_info *info;
600 
601 	thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
602 	if (!thinint_area) {
603 		ret = -ENOMEM;
604 		goto out;
605 	}
606 	/* Try to get an indicator. */
607 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
608 						     &thinint_area->bit_nr,
609 						     &vcdev->airq_info);
610 	if (!thinint_area->indicator) {
611 		ret = -ENOSPC;
612 		goto out;
613 	}
614 	info = vcdev->airq_info;
615 	thinint_area->summary_indicator =
616 		(unsigned long) &info->summary_indicator;
617 	thinint_area->isc = VIRTIO_AIRQ_ISC;
618 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
619 	ccw->flags = CCW_FLAG_SLI;
620 	ccw->count = sizeof(*thinint_area);
621 	ccw->cda = (__u32)(unsigned long)thinint_area;
622 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
623 	if (ret) {
624 		if (ret == -EOPNOTSUPP) {
625 			/*
626 			 * The host does not support adapter interrupts
627 			 * for virtio-ccw, stop trying.
628 			 */
629 			virtio_ccw_use_airq = 0;
630 			pr_info("Adapter interrupts unsupported on host\n");
631 		} else
632 			dev_warn(&vcdev->cdev->dev,
633 				 "enabling adapter interrupts = %d\n", ret);
634 		virtio_ccw_drop_indicators(vcdev);
635 	}
636 out:
637 	kfree(thinint_area);
638 	return ret;
639 }
640 
virtio_ccw_find_vqs(struct virtio_device * vdev,unsigned nvqs,struct virtqueue * vqs[],vq_callback_t * callbacks[],const char * const names[])641 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
642 			       struct virtqueue *vqs[],
643 			       vq_callback_t *callbacks[],
644 			       const char * const names[])
645 {
646 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
647 	unsigned long *indicatorp = NULL;
648 	int ret, i;
649 	struct ccw1 *ccw;
650 
651 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
652 	if (!ccw)
653 		return -ENOMEM;
654 
655 	for (i = 0; i < nvqs; ++i) {
656 		vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
657 					     ccw);
658 		if (IS_ERR(vqs[i])) {
659 			ret = PTR_ERR(vqs[i]);
660 			vqs[i] = NULL;
661 			goto out;
662 		}
663 	}
664 	ret = -ENOMEM;
665 	/* We need a data area under 2G to communicate. */
666 	indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
667 	if (!indicatorp)
668 		goto out;
669 	*indicatorp = (unsigned long) &vcdev->indicators;
670 	if (vcdev->is_thinint) {
671 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
672 		if (ret)
673 			/* no error, just fall back to legacy interrupts */
674 			vcdev->is_thinint = 0;
675 	}
676 	if (!vcdev->is_thinint) {
677 		/* Register queue indicators with host. */
678 		vcdev->indicators = 0;
679 		ccw->cmd_code = CCW_CMD_SET_IND;
680 		ccw->flags = 0;
681 		ccw->count = sizeof(vcdev->indicators);
682 		ccw->cda = (__u32)(unsigned long) indicatorp;
683 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
684 		if (ret)
685 			goto out;
686 	}
687 	/* Register indicators2 with host for config changes */
688 	*indicatorp = (unsigned long) &vcdev->indicators2;
689 	vcdev->indicators2 = 0;
690 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
691 	ccw->flags = 0;
692 	ccw->count = sizeof(vcdev->indicators2);
693 	ccw->cda = (__u32)(unsigned long) indicatorp;
694 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
695 	if (ret)
696 		goto out;
697 
698 	kfree(indicatorp);
699 	kfree(ccw);
700 	return 0;
701 out:
702 	kfree(indicatorp);
703 	kfree(ccw);
704 	virtio_ccw_del_vqs(vdev);
705 	return ret;
706 }
707 
virtio_ccw_reset(struct virtio_device * vdev)708 static void virtio_ccw_reset(struct virtio_device *vdev)
709 {
710 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
711 	struct ccw1 *ccw;
712 
713 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
714 	if (!ccw)
715 		return;
716 
717 	/* Zero status bits. */
718 	*vcdev->status = 0;
719 
720 	/* Send a reset ccw on device. */
721 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
722 	ccw->flags = 0;
723 	ccw->count = 0;
724 	ccw->cda = 0;
725 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
726 	kfree(ccw);
727 }
728 
virtio_ccw_get_features(struct virtio_device * vdev)729 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
730 {
731 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
732 	struct virtio_feature_desc *features;
733 	int ret;
734 	u64 rc;
735 	struct ccw1 *ccw;
736 
737 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
738 	if (!ccw)
739 		return 0;
740 
741 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
742 	if (!features) {
743 		rc = 0;
744 		goto out_free;
745 	}
746 	/* Read the feature bits from the host. */
747 	features->index = 0;
748 	ccw->cmd_code = CCW_CMD_READ_FEAT;
749 	ccw->flags = 0;
750 	ccw->count = sizeof(*features);
751 	ccw->cda = (__u32)(unsigned long)features;
752 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
753 	if (ret) {
754 		rc = 0;
755 		goto out_free;
756 	}
757 
758 	rc = le32_to_cpu(features->features);
759 
760 	if (vcdev->revision == 0)
761 		goto out_free;
762 
763 	/* Read second half of the feature bits from the host. */
764 	features->index = 1;
765 	ccw->cmd_code = CCW_CMD_READ_FEAT;
766 	ccw->flags = 0;
767 	ccw->count = sizeof(*features);
768 	ccw->cda = (__u32)(unsigned long)features;
769 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
770 	if (ret == 0)
771 		rc |= (u64)le32_to_cpu(features->features) << 32;
772 
773 out_free:
774 	kfree(features);
775 	kfree(ccw);
776 	return rc;
777 }
778 
virtio_ccw_finalize_features(struct virtio_device * vdev)779 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
780 {
781 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
782 	struct virtio_feature_desc *features;
783 	struct ccw1 *ccw;
784 	int ret;
785 
786 	if (vcdev->revision >= 1 &&
787 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
788 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
789 			"but does not have VIRTIO_F_VERSION_1\n");
790 		return -EINVAL;
791 	}
792 
793 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
794 	if (!ccw)
795 		return -ENOMEM;
796 
797 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
798 	if (!features) {
799 		ret = -ENOMEM;
800 		goto out_free;
801 	}
802 	/* Give virtio_ring a chance to accept features. */
803 	vring_transport_features(vdev);
804 
805 	features->index = 0;
806 	features->features = cpu_to_le32((u32)vdev->features);
807 	/* Write the first half of the feature bits to the host. */
808 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
809 	ccw->flags = 0;
810 	ccw->count = sizeof(*features);
811 	ccw->cda = (__u32)(unsigned long)features;
812 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
813 	if (ret)
814 		goto out_free;
815 
816 	if (vcdev->revision == 0)
817 		goto out_free;
818 
819 	features->index = 1;
820 	features->features = cpu_to_le32(vdev->features >> 32);
821 	/* Write the second half of the feature bits to the host. */
822 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
823 	ccw->flags = 0;
824 	ccw->count = sizeof(*features);
825 	ccw->cda = (__u32)(unsigned long)features;
826 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
827 
828 out_free:
829 	kfree(features);
830 	kfree(ccw);
831 
832 	return ret;
833 }
834 
virtio_ccw_get_config(struct virtio_device * vdev,unsigned int offset,void * buf,unsigned len)835 static void virtio_ccw_get_config(struct virtio_device *vdev,
836 				  unsigned int offset, void *buf, unsigned len)
837 {
838 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
839 	int ret;
840 	struct ccw1 *ccw;
841 	void *config_area;
842 	unsigned long flags;
843 
844 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
845 	if (!ccw)
846 		return;
847 
848 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
849 	if (!config_area)
850 		goto out_free;
851 
852 	/* Read the config area from the host. */
853 	ccw->cmd_code = CCW_CMD_READ_CONF;
854 	ccw->flags = 0;
855 	ccw->count = offset + len;
856 	ccw->cda = (__u32)(unsigned long)config_area;
857 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
858 	if (ret)
859 		goto out_free;
860 
861 	spin_lock_irqsave(&vcdev->lock, flags);
862 	memcpy(vcdev->config, config_area, offset + len);
863 	if (vcdev->config_ready < offset + len)
864 		vcdev->config_ready = offset + len;
865 	spin_unlock_irqrestore(&vcdev->lock, flags);
866 	if (buf)
867 		memcpy(buf, config_area + offset, len);
868 
869 out_free:
870 	kfree(config_area);
871 	kfree(ccw);
872 }
873 
virtio_ccw_set_config(struct virtio_device * vdev,unsigned int offset,const void * buf,unsigned len)874 static void virtio_ccw_set_config(struct virtio_device *vdev,
875 				  unsigned int offset, const void *buf,
876 				  unsigned len)
877 {
878 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
879 	struct ccw1 *ccw;
880 	void *config_area;
881 	unsigned long flags;
882 
883 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
884 	if (!ccw)
885 		return;
886 
887 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
888 	if (!config_area)
889 		goto out_free;
890 
891 	/* Make sure we don't overwrite fields. */
892 	if (vcdev->config_ready < offset)
893 		virtio_ccw_get_config(vdev, 0, NULL, offset);
894 	spin_lock_irqsave(&vcdev->lock, flags);
895 	memcpy(&vcdev->config[offset], buf, len);
896 	/* Write the config area to the host. */
897 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
898 	spin_unlock_irqrestore(&vcdev->lock, flags);
899 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
900 	ccw->flags = 0;
901 	ccw->count = offset + len;
902 	ccw->cda = (__u32)(unsigned long)config_area;
903 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
904 
905 out_free:
906 	kfree(config_area);
907 	kfree(ccw);
908 }
909 
virtio_ccw_get_status(struct virtio_device * vdev)910 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
911 {
912 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
913 
914 	return *vcdev->status;
915 }
916 
virtio_ccw_set_status(struct virtio_device * vdev,u8 status)917 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
918 {
919 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
920 	u8 old_status = *vcdev->status;
921 	struct ccw1 *ccw;
922 	int ret;
923 
924 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
925 	if (!ccw)
926 		return;
927 
928 	/* Write the status to the host. */
929 	*vcdev->status = status;
930 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
931 	ccw->flags = 0;
932 	ccw->count = sizeof(status);
933 	ccw->cda = (__u32)(unsigned long)vcdev->status;
934 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
935 	/* Write failed? We assume status is unchanged. */
936 	if (ret)
937 		*vcdev->status = old_status;
938 	kfree(ccw);
939 }
940 
941 static struct virtio_config_ops virtio_ccw_config_ops = {
942 	.get_features = virtio_ccw_get_features,
943 	.finalize_features = virtio_ccw_finalize_features,
944 	.get = virtio_ccw_get_config,
945 	.set = virtio_ccw_set_config,
946 	.get_status = virtio_ccw_get_status,
947 	.set_status = virtio_ccw_set_status,
948 	.reset = virtio_ccw_reset,
949 	.find_vqs = virtio_ccw_find_vqs,
950 	.del_vqs = virtio_ccw_del_vqs,
951 };
952 
953 
954 /*
955  * ccw bus driver related functions
956  */
957 
virtio_ccw_release_dev(struct device * _d)958 static void virtio_ccw_release_dev(struct device *_d)
959 {
960 	struct virtio_device *dev = container_of(_d, struct virtio_device,
961 						 dev);
962 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
963 
964 	kfree(vcdev->status);
965 	kfree(vcdev->config_block);
966 	kfree(vcdev);
967 }
968 
irb_is_error(struct irb * irb)969 static int irb_is_error(struct irb *irb)
970 {
971 	if (scsw_cstat(&irb->scsw) != 0)
972 		return 1;
973 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
974 		return 1;
975 	if (scsw_cc(&irb->scsw) != 0)
976 		return 1;
977 	return 0;
978 }
979 
virtio_ccw_vq_by_ind(struct virtio_ccw_device * vcdev,int index)980 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
981 					      int index)
982 {
983 	struct virtio_ccw_vq_info *info;
984 	unsigned long flags;
985 	struct virtqueue *vq;
986 
987 	vq = NULL;
988 	spin_lock_irqsave(&vcdev->lock, flags);
989 	list_for_each_entry(info, &vcdev->virtqueues, node) {
990 		if (info->vq->index == index) {
991 			vq = info->vq;
992 			break;
993 		}
994 	}
995 	spin_unlock_irqrestore(&vcdev->lock, flags);
996 	return vq;
997 }
998 
virtio_ccw_check_activity(struct virtio_ccw_device * vcdev,__u32 activity)999 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1000 				      __u32 activity)
1001 {
1002 	if (vcdev->curr_io & activity) {
1003 		switch (activity) {
1004 		case VIRTIO_CCW_DOING_READ_FEAT:
1005 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1006 		case VIRTIO_CCW_DOING_READ_CONFIG:
1007 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1008 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1009 		case VIRTIO_CCW_DOING_SET_VQ:
1010 		case VIRTIO_CCW_DOING_SET_IND:
1011 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1012 		case VIRTIO_CCW_DOING_RESET:
1013 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1014 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1015 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1016 			vcdev->curr_io &= ~activity;
1017 			wake_up(&vcdev->wait_q);
1018 			break;
1019 		default:
1020 			/* don't know what to do... */
1021 			dev_warn(&vcdev->cdev->dev,
1022 				 "Suspicious activity '%08x'\n", activity);
1023 			WARN_ON(1);
1024 			break;
1025 		}
1026 	}
1027 }
1028 
virtio_ccw_int_handler(struct ccw_device * cdev,unsigned long intparm,struct irb * irb)1029 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1030 				   unsigned long intparm,
1031 				   struct irb *irb)
1032 {
1033 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1034 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1035 	int i;
1036 	struct virtqueue *vq;
1037 
1038 	if (!vcdev)
1039 		return;
1040 	if (IS_ERR(irb)) {
1041 		vcdev->err = PTR_ERR(irb);
1042 		virtio_ccw_check_activity(vcdev, activity);
1043 		/* Don't poke around indicators, something's wrong. */
1044 		return;
1045 	}
1046 	/* Check if it's a notification from the host. */
1047 	if ((intparm == 0) &&
1048 	    (scsw_stctl(&irb->scsw) ==
1049 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1050 		/* OK */
1051 	}
1052 	if (irb_is_error(irb)) {
1053 		/* Command reject? */
1054 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1055 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1056 			vcdev->err = -EOPNOTSUPP;
1057 		else
1058 			/* Map everything else to -EIO. */
1059 			vcdev->err = -EIO;
1060 	}
1061 	virtio_ccw_check_activity(vcdev, activity);
1062 	for_each_set_bit(i, &vcdev->indicators,
1063 			 sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1064 		/* The bit clear must happen before the vring kick. */
1065 		clear_bit(i, &vcdev->indicators);
1066 		barrier();
1067 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1068 		vring_interrupt(0, vq);
1069 	}
1070 	if (test_bit(0, &vcdev->indicators2)) {
1071 		virtio_config_changed(&vcdev->vdev);
1072 		clear_bit(0, &vcdev->indicators2);
1073 	}
1074 }
1075 
1076 /*
1077  * We usually want to autoonline all devices, but give the admin
1078  * a way to exempt devices from this.
1079  */
1080 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1081 		     (8*sizeof(long)))
1082 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1083 
1084 static char *no_auto = "";
1085 
1086 module_param(no_auto, charp, 0444);
1087 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1088 
virtio_ccw_check_autoonline(struct ccw_device * cdev)1089 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1090 {
1091 	struct ccw_dev_id id;
1092 
1093 	ccw_device_get_id(cdev, &id);
1094 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1095 		return 0;
1096 	return 1;
1097 }
1098 
virtio_ccw_auto_online(void * data,async_cookie_t cookie)1099 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1100 {
1101 	struct ccw_device *cdev = data;
1102 	int ret;
1103 
1104 	ret = ccw_device_set_online(cdev);
1105 	if (ret)
1106 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1107 }
1108 
virtio_ccw_probe(struct ccw_device * cdev)1109 static int virtio_ccw_probe(struct ccw_device *cdev)
1110 {
1111 	cdev->handler = virtio_ccw_int_handler;
1112 
1113 	if (virtio_ccw_check_autoonline(cdev))
1114 		async_schedule(virtio_ccw_auto_online, cdev);
1115 	return 0;
1116 }
1117 
virtio_grab_drvdata(struct ccw_device * cdev)1118 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1119 {
1120 	unsigned long flags;
1121 	struct virtio_ccw_device *vcdev;
1122 
1123 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1124 	vcdev = dev_get_drvdata(&cdev->dev);
1125 	if (!vcdev || vcdev->going_away) {
1126 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1127 		return NULL;
1128 	}
1129 	vcdev->going_away = true;
1130 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1131 	return vcdev;
1132 }
1133 
virtio_ccw_remove(struct ccw_device * cdev)1134 static void virtio_ccw_remove(struct ccw_device *cdev)
1135 {
1136 	unsigned long flags;
1137 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1138 
1139 	if (vcdev && cdev->online) {
1140 		if (vcdev->device_lost)
1141 			virtio_break_device(&vcdev->vdev);
1142 		unregister_virtio_device(&vcdev->vdev);
1143 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1144 		dev_set_drvdata(&cdev->dev, NULL);
1145 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1146 	}
1147 	cdev->handler = NULL;
1148 }
1149 
virtio_ccw_offline(struct ccw_device * cdev)1150 static int virtio_ccw_offline(struct ccw_device *cdev)
1151 {
1152 	unsigned long flags;
1153 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1154 
1155 	if (!vcdev)
1156 		return 0;
1157 	if (vcdev->device_lost)
1158 		virtio_break_device(&vcdev->vdev);
1159 	unregister_virtio_device(&vcdev->vdev);
1160 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1161 	dev_set_drvdata(&cdev->dev, NULL);
1162 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1163 	return 0;
1164 }
1165 
virtio_ccw_set_transport_rev(struct virtio_ccw_device * vcdev)1166 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1167 {
1168 	struct virtio_rev_info *rev;
1169 	struct ccw1 *ccw;
1170 	int ret;
1171 
1172 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1173 	if (!ccw)
1174 		return -ENOMEM;
1175 	rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1176 	if (!rev) {
1177 		kfree(ccw);
1178 		return -ENOMEM;
1179 	}
1180 
1181 	/* Set transport revision */
1182 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1183 	ccw->flags = 0;
1184 	ccw->count = sizeof(*rev);
1185 	ccw->cda = (__u32)(unsigned long)rev;
1186 
1187 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1188 	do {
1189 		rev->revision = vcdev->revision;
1190 		/* none of our supported revisions carry payload */
1191 		rev->length = 0;
1192 		ret = ccw_io_helper(vcdev, ccw,
1193 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1194 		if (ret == -EOPNOTSUPP) {
1195 			if (vcdev->revision == 0)
1196 				/*
1197 				 * The host device does not support setting
1198 				 * the revision: let's operate it in legacy
1199 				 * mode.
1200 				 */
1201 				ret = 0;
1202 			else
1203 				vcdev->revision--;
1204 		}
1205 	} while (ret == -EOPNOTSUPP);
1206 
1207 	kfree(ccw);
1208 	kfree(rev);
1209 	return ret;
1210 }
1211 
virtio_ccw_online(struct ccw_device * cdev)1212 static int virtio_ccw_online(struct ccw_device *cdev)
1213 {
1214 	int ret;
1215 	struct virtio_ccw_device *vcdev;
1216 	unsigned long flags;
1217 
1218 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1219 	if (!vcdev) {
1220 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1221 		ret = -ENOMEM;
1222 		goto out_free;
1223 	}
1224 	vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1225 				   GFP_DMA | GFP_KERNEL);
1226 	if (!vcdev->config_block) {
1227 		ret = -ENOMEM;
1228 		goto out_free;
1229 	}
1230 	vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1231 	if (!vcdev->status) {
1232 		ret = -ENOMEM;
1233 		goto out_free;
1234 	}
1235 
1236 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1237 
1238 	vcdev->vdev.dev.parent = &cdev->dev;
1239 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1240 	vcdev->vdev.config = &virtio_ccw_config_ops;
1241 	vcdev->cdev = cdev;
1242 	init_waitqueue_head(&vcdev->wait_q);
1243 	INIT_LIST_HEAD(&vcdev->virtqueues);
1244 	spin_lock_init(&vcdev->lock);
1245 	mutex_init(&vcdev->io_lock);
1246 
1247 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1248 	dev_set_drvdata(&cdev->dev, vcdev);
1249 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1250 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1251 	vcdev->vdev.id.device = cdev->id.cu_model;
1252 
1253 	ret = virtio_ccw_set_transport_rev(vcdev);
1254 	if (ret)
1255 		goto out_free;
1256 
1257 	ret = register_virtio_device(&vcdev->vdev);
1258 	if (ret) {
1259 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1260 			 ret);
1261 		goto out_put;
1262 	}
1263 	return 0;
1264 out_put:
1265 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1266 	dev_set_drvdata(&cdev->dev, NULL);
1267 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1268 	put_device(&vcdev->vdev.dev);
1269 	return ret;
1270 out_free:
1271 	if (vcdev) {
1272 		kfree(vcdev->status);
1273 		kfree(vcdev->config_block);
1274 	}
1275 	kfree(vcdev);
1276 	return ret;
1277 }
1278 
virtio_ccw_cio_notify(struct ccw_device * cdev,int event)1279 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1280 {
1281 	int rc;
1282 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1283 
1284 	/*
1285 	 * Make sure vcdev is set
1286 	 * i.e. set_offline/remove callback not already running
1287 	 */
1288 	if (!vcdev)
1289 		return NOTIFY_DONE;
1290 
1291 	switch (event) {
1292 	case CIO_GONE:
1293 		vcdev->device_lost = true;
1294 		rc = NOTIFY_DONE;
1295 		break;
1296 	default:
1297 		rc = NOTIFY_DONE;
1298 		break;
1299 	}
1300 	return rc;
1301 }
1302 
1303 static struct ccw_device_id virtio_ids[] = {
1304 	{ CCW_DEVICE(0x3832, 0) },
1305 	{},
1306 };
1307 MODULE_DEVICE_TABLE(ccw, virtio_ids);
1308 
1309 static struct ccw_driver virtio_ccw_driver = {
1310 	.driver = {
1311 		.owner = THIS_MODULE,
1312 		.name = "virtio_ccw",
1313 	},
1314 	.ids = virtio_ids,
1315 	.probe = virtio_ccw_probe,
1316 	.remove = virtio_ccw_remove,
1317 	.set_offline = virtio_ccw_offline,
1318 	.set_online = virtio_ccw_online,
1319 	.notify = virtio_ccw_cio_notify,
1320 	.int_class = IRQIO_VIR,
1321 };
1322 
pure_hex(char ** cp,unsigned int * val,int min_digit,int max_digit,int max_val)1323 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1324 			   int max_digit, int max_val)
1325 {
1326 	int diff;
1327 
1328 	diff = 0;
1329 	*val = 0;
1330 
1331 	while (diff <= max_digit) {
1332 		int value = hex_to_bin(**cp);
1333 
1334 		if (value < 0)
1335 			break;
1336 		*val = *val * 16 + value;
1337 		(*cp)++;
1338 		diff++;
1339 	}
1340 
1341 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1342 		return 1;
1343 
1344 	return 0;
1345 }
1346 
parse_busid(char * str,unsigned int * cssid,unsigned int * ssid,unsigned int * devno)1347 static int __init parse_busid(char *str, unsigned int *cssid,
1348 			      unsigned int *ssid, unsigned int *devno)
1349 {
1350 	char *str_work;
1351 	int rc, ret;
1352 
1353 	rc = 1;
1354 
1355 	if (*str == '\0')
1356 		goto out;
1357 
1358 	str_work = str;
1359 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1360 	if (ret || (str_work[0] != '.'))
1361 		goto out;
1362 	str_work++;
1363 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1364 	if (ret || (str_work[0] != '.'))
1365 		goto out;
1366 	str_work++;
1367 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1368 	if (ret || (str_work[0] != '\0'))
1369 		goto out;
1370 
1371 	rc = 0;
1372 out:
1373 	return rc;
1374 }
1375 
no_auto_parse(void)1376 static void __init no_auto_parse(void)
1377 {
1378 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1379 	char *parm, *str;
1380 	int rc;
1381 
1382 	str = no_auto;
1383 	while ((parm = strsep(&str, ","))) {
1384 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1385 				 &from_ssid, &from);
1386 		if (rc)
1387 			continue;
1388 		if (parm != NULL) {
1389 			rc = parse_busid(parm, &to_cssid,
1390 					 &to_ssid, &to);
1391 			if ((from_ssid > to_ssid) ||
1392 			    ((from_ssid == to_ssid) && (from > to)))
1393 				rc = -EINVAL;
1394 		} else {
1395 			to_cssid = from_cssid;
1396 			to_ssid = from_ssid;
1397 			to = from;
1398 		}
1399 		if (rc)
1400 			continue;
1401 		while ((from_ssid < to_ssid) ||
1402 		       ((from_ssid == to_ssid) && (from <= to))) {
1403 			set_bit(from, devs_no_auto[from_ssid]);
1404 			from++;
1405 			if (from > __MAX_SUBCHANNEL) {
1406 				from_ssid++;
1407 				from = 0;
1408 			}
1409 		}
1410 	}
1411 }
1412 
virtio_ccw_init(void)1413 static int __init virtio_ccw_init(void)
1414 {
1415 	/* parse no_auto string before we do anything further */
1416 	no_auto_parse();
1417 	return ccw_driver_register(&virtio_ccw_driver);
1418 }
1419 module_init(virtio_ccw_init);
1420 
virtio_ccw_exit(void)1421 static void __exit virtio_ccw_exit(void)
1422 {
1423 	int i;
1424 
1425 	ccw_driver_unregister(&virtio_ccw_driver);
1426 	for (i = 0; i < MAX_AIRQ_AREAS; i++)
1427 		destroy_airq_info(airq_areas[i]);
1428 }
1429 module_exit(virtio_ccw_exit);
1430