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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/moduleparam.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 	__le32 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_READ_STATUS 0x72
150 #define CCW_CMD_SET_IND_ADAPTER 0x73
151 #define CCW_CMD_SET_VIRTIO_REV 0x83
152 
153 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
154 #define VIRTIO_CCW_DOING_RESET 0x00040000
155 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
156 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
157 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
158 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
159 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
160 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
161 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
162 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
163 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
164 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
165 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
166 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
167 
to_vc_device(struct virtio_device * vdev)168 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
169 {
170 	return container_of(vdev, struct virtio_ccw_device, vdev);
171 }
172 
drop_airq_indicator(struct virtqueue * vq,struct airq_info * info)173 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
174 {
175 	unsigned long i, flags;
176 
177 	write_lock_irqsave(&info->lock, flags);
178 	for (i = 0; i < airq_iv_end(info->aiv); i++) {
179 		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
180 			airq_iv_free_bit(info->aiv, i);
181 			airq_iv_set_ptr(info->aiv, i, 0);
182 			break;
183 		}
184 	}
185 	write_unlock_irqrestore(&info->lock, flags);
186 }
187 
virtio_airq_handler(struct airq_struct * airq)188 static void virtio_airq_handler(struct airq_struct *airq)
189 {
190 	struct airq_info *info = container_of(airq, struct airq_info, airq);
191 	unsigned long ai;
192 
193 	inc_irq_stat(IRQIO_VAI);
194 	read_lock(&info->lock);
195 	/* Walk through indicators field, summary indicator active. */
196 	for (ai = 0;;) {
197 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
198 		if (ai == -1UL)
199 			break;
200 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
201 	}
202 	info->summary_indicator = 0;
203 	smp_wmb();
204 	/* Walk through indicators field, summary indicator not active. */
205 	for (ai = 0;;) {
206 		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
207 		if (ai == -1UL)
208 			break;
209 		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
210 	}
211 	read_unlock(&info->lock);
212 }
213 
new_airq_info(void)214 static struct airq_info *new_airq_info(void)
215 {
216 	struct airq_info *info;
217 	int rc;
218 
219 	info = kzalloc(sizeof(*info), GFP_KERNEL);
220 	if (!info)
221 		return NULL;
222 	rwlock_init(&info->lock);
223 	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
224 	if (!info->aiv) {
225 		kfree(info);
226 		return NULL;
227 	}
228 	info->airq.handler = virtio_airq_handler;
229 	info->airq.lsi_ptr = &info->summary_indicator;
230 	info->airq.lsi_mask = 0xff;
231 	info->airq.isc = VIRTIO_AIRQ_ISC;
232 	rc = register_adapter_interrupt(&info->airq);
233 	if (rc) {
234 		airq_iv_release(info->aiv);
235 		kfree(info);
236 		return NULL;
237 	}
238 	return info;
239 }
240 
get_airq_indicator(struct virtqueue * vqs[],int nvqs,u64 * first,void ** airq_info)241 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
242 					u64 *first, void **airq_info)
243 {
244 	int i, j;
245 	struct airq_info *info;
246 	unsigned long indicator_addr = 0;
247 	unsigned long bit, flags;
248 
249 	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
250 		if (!airq_areas[i])
251 			airq_areas[i] = new_airq_info();
252 		info = airq_areas[i];
253 		if (!info)
254 			return 0;
255 		write_lock_irqsave(&info->lock, flags);
256 		bit = airq_iv_alloc(info->aiv, nvqs);
257 		if (bit == -1UL) {
258 			/* Not enough vacancies. */
259 			write_unlock_irqrestore(&info->lock, flags);
260 			continue;
261 		}
262 		*first = bit;
263 		*airq_info = info;
264 		indicator_addr = (unsigned long)info->aiv->vector;
265 		for (j = 0; j < nvqs; j++) {
266 			airq_iv_set_ptr(info->aiv, bit + j,
267 					(unsigned long)vqs[j]);
268 		}
269 		write_unlock_irqrestore(&info->lock, flags);
270 	}
271 	return indicator_addr;
272 }
273 
virtio_ccw_drop_indicators(struct virtio_ccw_device * vcdev)274 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
275 {
276 	struct virtio_ccw_vq_info *info;
277 
278 	if (!vcdev->airq_info)
279 		return;
280 	list_for_each_entry(info, &vcdev->virtqueues, node)
281 		drop_airq_indicator(info->vq, vcdev->airq_info);
282 }
283 
doing_io(struct virtio_ccw_device * vcdev,__u32 flag)284 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
285 {
286 	unsigned long flags;
287 	__u32 ret;
288 
289 	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
290 	if (vcdev->err)
291 		ret = 0;
292 	else
293 		ret = vcdev->curr_io & flag;
294 	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
295 	return ret;
296 }
297 
ccw_io_helper(struct virtio_ccw_device * vcdev,struct ccw1 * ccw,__u32 intparm)298 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
299 			 struct ccw1 *ccw, __u32 intparm)
300 {
301 	int ret;
302 	unsigned long flags;
303 	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
304 
305 	mutex_lock(&vcdev->io_lock);
306 	do {
307 		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
308 		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
309 		if (!ret) {
310 			if (!vcdev->curr_io)
311 				vcdev->err = 0;
312 			vcdev->curr_io |= flag;
313 		}
314 		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
315 		cpu_relax();
316 	} while (ret == -EBUSY);
317 	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
318 	ret = ret ? ret : vcdev->err;
319 	mutex_unlock(&vcdev->io_lock);
320 	return ret;
321 }
322 
virtio_ccw_drop_indicator(struct virtio_ccw_device * vcdev,struct ccw1 * ccw)323 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
324 				      struct ccw1 *ccw)
325 {
326 	int ret;
327 	unsigned long *indicatorp = NULL;
328 	struct virtio_thinint_area *thinint_area = NULL;
329 	struct airq_info *airq_info = vcdev->airq_info;
330 
331 	if (vcdev->is_thinint) {
332 		thinint_area = kzalloc(sizeof(*thinint_area),
333 				       GFP_DMA | GFP_KERNEL);
334 		if (!thinint_area)
335 			return;
336 		thinint_area->summary_indicator =
337 			(unsigned long) &airq_info->summary_indicator;
338 		thinint_area->isc = VIRTIO_AIRQ_ISC;
339 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
340 		ccw->count = sizeof(*thinint_area);
341 		ccw->cda = (__u32)(unsigned long) thinint_area;
342 	} else {
343 		/* payload is the address of the indicators */
344 		indicatorp = kmalloc(sizeof(&vcdev->indicators),
345 				     GFP_DMA | GFP_KERNEL);
346 		if (!indicatorp)
347 			return;
348 		*indicatorp = 0;
349 		ccw->cmd_code = CCW_CMD_SET_IND;
350 		ccw->count = sizeof(&vcdev->indicators);
351 		ccw->cda = (__u32)(unsigned long) indicatorp;
352 	}
353 	/* Deregister indicators from host. */
354 	vcdev->indicators = 0;
355 	ccw->flags = 0;
356 	ret = ccw_io_helper(vcdev, ccw,
357 			    vcdev->is_thinint ?
358 			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
359 			    VIRTIO_CCW_DOING_SET_IND);
360 	if (ret && (ret != -ENODEV))
361 		dev_info(&vcdev->cdev->dev,
362 			 "Failed to deregister indicators (%d)\n", ret);
363 	else if (vcdev->is_thinint)
364 		virtio_ccw_drop_indicators(vcdev);
365 	kfree(indicatorp);
366 	kfree(thinint_area);
367 }
368 
__do_kvm_notify(struct subchannel_id schid,unsigned long queue_index,long cookie)369 static inline long __do_kvm_notify(struct subchannel_id schid,
370 				   unsigned long queue_index,
371 				   long cookie)
372 {
373 	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
374 	register struct subchannel_id __schid asm("2") = schid;
375 	register unsigned long __index asm("3") = queue_index;
376 	register long __rc asm("2");
377 	register long __cookie asm("4") = cookie;
378 
379 	asm volatile ("diag 2,4,0x500\n"
380 		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
381 		      "d"(__cookie)
382 		      : "memory", "cc");
383 	return __rc;
384 }
385 
do_kvm_notify(struct subchannel_id schid,unsigned long queue_index,long cookie)386 static inline long do_kvm_notify(struct subchannel_id schid,
387 				 unsigned long queue_index,
388 				 long cookie)
389 {
390 	diag_stat_inc(DIAG_STAT_X500);
391 	return __do_kvm_notify(schid, queue_index, cookie);
392 }
393 
virtio_ccw_kvm_notify(struct virtqueue * vq)394 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
395 {
396 	struct virtio_ccw_vq_info *info = vq->priv;
397 	struct virtio_ccw_device *vcdev;
398 	struct subchannel_id schid;
399 
400 	vcdev = to_vc_device(info->vq->vdev);
401 	ccw_device_get_schid(vcdev->cdev, &schid);
402 	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
403 	if (info->cookie < 0)
404 		return false;
405 	return true;
406 }
407 
virtio_ccw_read_vq_conf(struct virtio_ccw_device * vcdev,struct ccw1 * ccw,int index)408 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
409 				   struct ccw1 *ccw, int index)
410 {
411 	int ret;
412 
413 	vcdev->config_block->index = index;
414 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
415 	ccw->flags = 0;
416 	ccw->count = sizeof(struct vq_config_block);
417 	ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
418 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
419 	if (ret)
420 		return ret;
421 	return vcdev->config_block->num ?: -ENOENT;
422 }
423 
virtio_ccw_del_vq(struct virtqueue * vq,struct ccw1 * ccw)424 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
425 {
426 	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
427 	struct virtio_ccw_vq_info *info = vq->priv;
428 	unsigned long flags;
429 	unsigned long size;
430 	int ret;
431 	unsigned int index = vq->index;
432 
433 	/* Remove from our list. */
434 	spin_lock_irqsave(&vcdev->lock, flags);
435 	list_del(&info->node);
436 	spin_unlock_irqrestore(&vcdev->lock, flags);
437 
438 	/* Release from host. */
439 	if (vcdev->revision == 0) {
440 		info->info_block->l.queue = 0;
441 		info->info_block->l.align = 0;
442 		info->info_block->l.index = index;
443 		info->info_block->l.num = 0;
444 		ccw->count = sizeof(info->info_block->l);
445 	} else {
446 		info->info_block->s.desc = 0;
447 		info->info_block->s.index = index;
448 		info->info_block->s.num = 0;
449 		info->info_block->s.avail = 0;
450 		info->info_block->s.used = 0;
451 		ccw->count = sizeof(info->info_block->s);
452 	}
453 	ccw->cmd_code = CCW_CMD_SET_VQ;
454 	ccw->flags = 0;
455 	ccw->cda = (__u32)(unsigned long)(info->info_block);
456 	ret = ccw_io_helper(vcdev, ccw,
457 			    VIRTIO_CCW_DOING_SET_VQ | index);
458 	/*
459 	 * -ENODEV isn't considered an error: The device is gone anyway.
460 	 * This may happen on device detach.
461 	 */
462 	if (ret && (ret != -ENODEV))
463 		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
464 			 ret, index);
465 
466 	vring_del_virtqueue(vq);
467 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
468 	free_pages_exact(info->queue, size);
469 	kfree(info->info_block);
470 	kfree(info);
471 }
472 
virtio_ccw_del_vqs(struct virtio_device * vdev)473 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
474 {
475 	struct virtqueue *vq, *n;
476 	struct ccw1 *ccw;
477 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
478 
479 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
480 	if (!ccw)
481 		return;
482 
483 	virtio_ccw_drop_indicator(vcdev, ccw);
484 
485 	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
486 		virtio_ccw_del_vq(vq, ccw);
487 
488 	kfree(ccw);
489 }
490 
virtio_ccw_setup_vq(struct virtio_device * vdev,int i,vq_callback_t * callback,const char * name,bool ctx,struct ccw1 * ccw)491 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
492 					     int i, vq_callback_t *callback,
493 					     const char *name, bool ctx,
494 					     struct ccw1 *ccw)
495 {
496 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
497 	int err;
498 	struct virtqueue *vq = NULL;
499 	struct virtio_ccw_vq_info *info;
500 	unsigned long size = 0; /* silence the compiler */
501 	unsigned long flags;
502 
503 	/* Allocate queue. */
504 	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
505 	if (!info) {
506 		dev_warn(&vcdev->cdev->dev, "no info\n");
507 		err = -ENOMEM;
508 		goto out_err;
509 	}
510 	info->info_block = kzalloc(sizeof(*info->info_block),
511 				   GFP_DMA | GFP_KERNEL);
512 	if (!info->info_block) {
513 		dev_warn(&vcdev->cdev->dev, "no info block\n");
514 		err = -ENOMEM;
515 		goto out_err;
516 	}
517 	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
518 	if (info->num < 0) {
519 		err = info->num;
520 		goto out_err;
521 	}
522 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
523 	info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
524 	if (info->queue == NULL) {
525 		dev_warn(&vcdev->cdev->dev, "no queue\n");
526 		err = -ENOMEM;
527 		goto out_err;
528 	}
529 
530 	vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
531 				 true, ctx, info->queue, virtio_ccw_kvm_notify,
532 				 callback, name);
533 	if (!vq) {
534 		/* For now, we fail if we can't get the requested size. */
535 		dev_warn(&vcdev->cdev->dev, "no vq\n");
536 		err = -ENOMEM;
537 		goto out_err;
538 	}
539 
540 	/* Register it with the host. */
541 	if (vcdev->revision == 0) {
542 		info->info_block->l.queue = (__u64)info->queue;
543 		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
544 		info->info_block->l.index = i;
545 		info->info_block->l.num = info->num;
546 		ccw->count = sizeof(info->info_block->l);
547 	} else {
548 		info->info_block->s.desc = (__u64)info->queue;
549 		info->info_block->s.index = i;
550 		info->info_block->s.num = info->num;
551 		info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
552 		info->info_block->s.used = (__u64)virtqueue_get_used(vq);
553 		ccw->count = sizeof(info->info_block->s);
554 	}
555 	ccw->cmd_code = CCW_CMD_SET_VQ;
556 	ccw->flags = 0;
557 	ccw->cda = (__u32)(unsigned long)(info->info_block);
558 	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
559 	if (err) {
560 		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
561 		goto out_err;
562 	}
563 
564 	info->vq = vq;
565 	vq->priv = info;
566 
567 	/* Save it to our list. */
568 	spin_lock_irqsave(&vcdev->lock, flags);
569 	list_add(&info->node, &vcdev->virtqueues);
570 	spin_unlock_irqrestore(&vcdev->lock, flags);
571 
572 	return vq;
573 
574 out_err:
575 	if (vq)
576 		vring_del_virtqueue(vq);
577 	if (info) {
578 		if (info->queue)
579 			free_pages_exact(info->queue, size);
580 		kfree(info->info_block);
581 	}
582 	kfree(info);
583 	return ERR_PTR(err);
584 }
585 
virtio_ccw_register_adapter_ind(struct virtio_ccw_device * vcdev,struct virtqueue * vqs[],int nvqs,struct ccw1 * ccw)586 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
587 					   struct virtqueue *vqs[], int nvqs,
588 					   struct ccw1 *ccw)
589 {
590 	int ret;
591 	struct virtio_thinint_area *thinint_area = NULL;
592 	struct airq_info *info;
593 
594 	thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
595 	if (!thinint_area) {
596 		ret = -ENOMEM;
597 		goto out;
598 	}
599 	/* Try to get an indicator. */
600 	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
601 						     &thinint_area->bit_nr,
602 						     &vcdev->airq_info);
603 	if (!thinint_area->indicator) {
604 		ret = -ENOSPC;
605 		goto out;
606 	}
607 	info = vcdev->airq_info;
608 	thinint_area->summary_indicator =
609 		(unsigned long) &info->summary_indicator;
610 	thinint_area->isc = VIRTIO_AIRQ_ISC;
611 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
612 	ccw->flags = CCW_FLAG_SLI;
613 	ccw->count = sizeof(*thinint_area);
614 	ccw->cda = (__u32)(unsigned long)thinint_area;
615 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
616 	if (ret) {
617 		if (ret == -EOPNOTSUPP) {
618 			/*
619 			 * The host does not support adapter interrupts
620 			 * for virtio-ccw, stop trying.
621 			 */
622 			virtio_ccw_use_airq = 0;
623 			pr_info("Adapter interrupts unsupported on host\n");
624 		} else
625 			dev_warn(&vcdev->cdev->dev,
626 				 "enabling adapter interrupts = %d\n", ret);
627 		virtio_ccw_drop_indicators(vcdev);
628 	}
629 out:
630 	kfree(thinint_area);
631 	return ret;
632 }
633 
virtio_ccw_find_vqs(struct virtio_device * vdev,unsigned nvqs,struct virtqueue * vqs[],vq_callback_t * callbacks[],const char * const names[],const bool * ctx,struct irq_affinity * desc)634 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
635 			       struct virtqueue *vqs[],
636 			       vq_callback_t *callbacks[],
637 			       const char * const names[],
638 			       const bool *ctx,
639 			       struct irq_affinity *desc)
640 {
641 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
642 	unsigned long *indicatorp = NULL;
643 	int ret, i;
644 	struct ccw1 *ccw;
645 
646 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
647 	if (!ccw)
648 		return -ENOMEM;
649 
650 	for (i = 0; i < nvqs; ++i) {
651 		vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
652 					     ctx ? ctx[i] : false, ccw);
653 		if (IS_ERR(vqs[i])) {
654 			ret = PTR_ERR(vqs[i]);
655 			vqs[i] = NULL;
656 			goto out;
657 		}
658 	}
659 	ret = -ENOMEM;
660 	/*
661 	 * We need a data area under 2G to communicate. Our payload is
662 	 * the address of the indicators.
663 	*/
664 	indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
665 	if (!indicatorp)
666 		goto out;
667 	*indicatorp = (unsigned long) &vcdev->indicators;
668 	if (vcdev->is_thinint) {
669 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
670 		if (ret)
671 			/* no error, just fall back to legacy interrupts */
672 			vcdev->is_thinint = false;
673 	}
674 	if (!vcdev->is_thinint) {
675 		/* Register queue indicators with host. */
676 		vcdev->indicators = 0;
677 		ccw->cmd_code = CCW_CMD_SET_IND;
678 		ccw->flags = 0;
679 		ccw->count = sizeof(&vcdev->indicators);
680 		ccw->cda = (__u32)(unsigned long) indicatorp;
681 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
682 		if (ret)
683 			goto out;
684 	}
685 	/* Register indicators2 with host for config changes */
686 	*indicatorp = (unsigned long) &vcdev->indicators2;
687 	vcdev->indicators2 = 0;
688 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
689 	ccw->flags = 0;
690 	ccw->count = sizeof(&vcdev->indicators2);
691 	ccw->cda = (__u32)(unsigned long) indicatorp;
692 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
693 	if (ret)
694 		goto out;
695 
696 	kfree(indicatorp);
697 	kfree(ccw);
698 	return 0;
699 out:
700 	kfree(indicatorp);
701 	kfree(ccw);
702 	virtio_ccw_del_vqs(vdev);
703 	return ret;
704 }
705 
virtio_ccw_reset(struct virtio_device * vdev)706 static void virtio_ccw_reset(struct virtio_device *vdev)
707 {
708 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
709 	struct ccw1 *ccw;
710 
711 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
712 	if (!ccw)
713 		return;
714 
715 	/* Zero status bits. */
716 	*vcdev->status = 0;
717 
718 	/* Send a reset ccw on device. */
719 	ccw->cmd_code = CCW_CMD_VDEV_RESET;
720 	ccw->flags = 0;
721 	ccw->count = 0;
722 	ccw->cda = 0;
723 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
724 	kfree(ccw);
725 }
726 
virtio_ccw_get_features(struct virtio_device * vdev)727 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
728 {
729 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
730 	struct virtio_feature_desc *features;
731 	int ret;
732 	u64 rc;
733 	struct ccw1 *ccw;
734 
735 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
736 	if (!ccw)
737 		return 0;
738 
739 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
740 	if (!features) {
741 		rc = 0;
742 		goto out_free;
743 	}
744 	/* Read the feature bits from the host. */
745 	features->index = 0;
746 	ccw->cmd_code = CCW_CMD_READ_FEAT;
747 	ccw->flags = 0;
748 	ccw->count = sizeof(*features);
749 	ccw->cda = (__u32)(unsigned long)features;
750 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
751 	if (ret) {
752 		rc = 0;
753 		goto out_free;
754 	}
755 
756 	rc = le32_to_cpu(features->features);
757 
758 	if (vcdev->revision == 0)
759 		goto out_free;
760 
761 	/* Read second half of the feature bits from the host. */
762 	features->index = 1;
763 	ccw->cmd_code = CCW_CMD_READ_FEAT;
764 	ccw->flags = 0;
765 	ccw->count = sizeof(*features);
766 	ccw->cda = (__u32)(unsigned long)features;
767 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
768 	if (ret == 0)
769 		rc |= (u64)le32_to_cpu(features->features) << 32;
770 
771 out_free:
772 	kfree(features);
773 	kfree(ccw);
774 	return rc;
775 }
776 
virtio_ccw_finalize_features(struct virtio_device * vdev)777 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
778 {
779 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
780 	struct virtio_feature_desc *features;
781 	struct ccw1 *ccw;
782 	int ret;
783 
784 	if (vcdev->revision >= 1 &&
785 	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
786 		dev_err(&vdev->dev, "virtio: device uses revision 1 "
787 			"but does not have VIRTIO_F_VERSION_1\n");
788 		return -EINVAL;
789 	}
790 
791 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
792 	if (!ccw)
793 		return -ENOMEM;
794 
795 	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
796 	if (!features) {
797 		ret = -ENOMEM;
798 		goto out_free;
799 	}
800 	/* Give virtio_ring a chance to accept features. */
801 	vring_transport_features(vdev);
802 
803 	features->index = 0;
804 	features->features = cpu_to_le32((u32)vdev->features);
805 	/* Write the first half of the feature bits to the host. */
806 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
807 	ccw->flags = 0;
808 	ccw->count = sizeof(*features);
809 	ccw->cda = (__u32)(unsigned long)features;
810 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
811 	if (ret)
812 		goto out_free;
813 
814 	if (vcdev->revision == 0)
815 		goto out_free;
816 
817 	features->index = 1;
818 	features->features = cpu_to_le32(vdev->features >> 32);
819 	/* Write the second half of the feature bits to the host. */
820 	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
821 	ccw->flags = 0;
822 	ccw->count = sizeof(*features);
823 	ccw->cda = (__u32)(unsigned long)features;
824 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
825 
826 out_free:
827 	kfree(features);
828 	kfree(ccw);
829 
830 	return ret;
831 }
832 
virtio_ccw_get_config(struct virtio_device * vdev,unsigned int offset,void * buf,unsigned len)833 static void virtio_ccw_get_config(struct virtio_device *vdev,
834 				  unsigned int offset, void *buf, unsigned len)
835 {
836 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
837 	int ret;
838 	struct ccw1 *ccw;
839 	void *config_area;
840 	unsigned long flags;
841 
842 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
843 	if (!ccw)
844 		return;
845 
846 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
847 	if (!config_area)
848 		goto out_free;
849 
850 	/* Read the config area from the host. */
851 	ccw->cmd_code = CCW_CMD_READ_CONF;
852 	ccw->flags = 0;
853 	ccw->count = offset + len;
854 	ccw->cda = (__u32)(unsigned long)config_area;
855 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
856 	if (ret)
857 		goto out_free;
858 
859 	spin_lock_irqsave(&vcdev->lock, flags);
860 	memcpy(vcdev->config, config_area, offset + len);
861 	if (vcdev->config_ready < offset + len)
862 		vcdev->config_ready = offset + len;
863 	spin_unlock_irqrestore(&vcdev->lock, flags);
864 	if (buf)
865 		memcpy(buf, config_area + offset, len);
866 
867 out_free:
868 	kfree(config_area);
869 	kfree(ccw);
870 }
871 
virtio_ccw_set_config(struct virtio_device * vdev,unsigned int offset,const void * buf,unsigned len)872 static void virtio_ccw_set_config(struct virtio_device *vdev,
873 				  unsigned int offset, const void *buf,
874 				  unsigned len)
875 {
876 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
877 	struct ccw1 *ccw;
878 	void *config_area;
879 	unsigned long flags;
880 
881 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
882 	if (!ccw)
883 		return;
884 
885 	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
886 	if (!config_area)
887 		goto out_free;
888 
889 	/* Make sure we don't overwrite fields. */
890 	if (vcdev->config_ready < offset)
891 		virtio_ccw_get_config(vdev, 0, NULL, offset);
892 	spin_lock_irqsave(&vcdev->lock, flags);
893 	memcpy(&vcdev->config[offset], buf, len);
894 	/* Write the config area to the host. */
895 	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
896 	spin_unlock_irqrestore(&vcdev->lock, flags);
897 	ccw->cmd_code = CCW_CMD_WRITE_CONF;
898 	ccw->flags = 0;
899 	ccw->count = offset + len;
900 	ccw->cda = (__u32)(unsigned long)config_area;
901 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
902 
903 out_free:
904 	kfree(config_area);
905 	kfree(ccw);
906 }
907 
virtio_ccw_get_status(struct virtio_device * vdev)908 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
909 {
910 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
911 	u8 old_status = *vcdev->status;
912 	struct ccw1 *ccw;
913 
914 	if (vcdev->revision < 1)
915 		return *vcdev->status;
916 
917 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
918 	if (!ccw)
919 		return old_status;
920 
921 	ccw->cmd_code = CCW_CMD_READ_STATUS;
922 	ccw->flags = 0;
923 	ccw->count = sizeof(*vcdev->status);
924 	ccw->cda = (__u32)(unsigned long)vcdev->status;
925 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
926 /*
927  * If the channel program failed (should only happen if the device
928  * was hotunplugged, and then we clean up via the machine check
929  * handler anyway), vcdev->status was not overwritten and we just
930  * return the old status, which is fine.
931 */
932 	kfree(ccw);
933 
934 	return *vcdev->status;
935 }
936 
virtio_ccw_set_status(struct virtio_device * vdev,u8 status)937 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
938 {
939 	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
940 	u8 old_status = *vcdev->status;
941 	struct ccw1 *ccw;
942 	int ret;
943 
944 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
945 	if (!ccw)
946 		return;
947 
948 	/* Write the status to the host. */
949 	*vcdev->status = status;
950 	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
951 	ccw->flags = 0;
952 	ccw->count = sizeof(status);
953 	ccw->cda = (__u32)(unsigned long)vcdev->status;
954 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
955 	/* Write failed? We assume status is unchanged. */
956 	if (ret)
957 		*vcdev->status = old_status;
958 	kfree(ccw);
959 }
960 
961 static const struct virtio_config_ops virtio_ccw_config_ops = {
962 	.get_features = virtio_ccw_get_features,
963 	.finalize_features = virtio_ccw_finalize_features,
964 	.get = virtio_ccw_get_config,
965 	.set = virtio_ccw_set_config,
966 	.get_status = virtio_ccw_get_status,
967 	.set_status = virtio_ccw_set_status,
968 	.reset = virtio_ccw_reset,
969 	.find_vqs = virtio_ccw_find_vqs,
970 	.del_vqs = virtio_ccw_del_vqs,
971 };
972 
973 
974 /*
975  * ccw bus driver related functions
976  */
977 
virtio_ccw_release_dev(struct device * _d)978 static void virtio_ccw_release_dev(struct device *_d)
979 {
980 	struct virtio_device *dev = dev_to_virtio(_d);
981 	struct virtio_ccw_device *vcdev = to_vc_device(dev);
982 
983 	kfree(vcdev->status);
984 	kfree(vcdev->config_block);
985 	kfree(vcdev);
986 }
987 
irb_is_error(struct irb * irb)988 static int irb_is_error(struct irb *irb)
989 {
990 	if (scsw_cstat(&irb->scsw) != 0)
991 		return 1;
992 	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
993 		return 1;
994 	if (scsw_cc(&irb->scsw) != 0)
995 		return 1;
996 	return 0;
997 }
998 
virtio_ccw_vq_by_ind(struct virtio_ccw_device * vcdev,int index)999 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1000 					      int index)
1001 {
1002 	struct virtio_ccw_vq_info *info;
1003 	unsigned long flags;
1004 	struct virtqueue *vq;
1005 
1006 	vq = NULL;
1007 	spin_lock_irqsave(&vcdev->lock, flags);
1008 	list_for_each_entry(info, &vcdev->virtqueues, node) {
1009 		if (info->vq->index == index) {
1010 			vq = info->vq;
1011 			break;
1012 		}
1013 	}
1014 	spin_unlock_irqrestore(&vcdev->lock, flags);
1015 	return vq;
1016 }
1017 
virtio_ccw_check_activity(struct virtio_ccw_device * vcdev,__u32 activity)1018 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1019 				      __u32 activity)
1020 {
1021 	if (vcdev->curr_io & activity) {
1022 		switch (activity) {
1023 		case VIRTIO_CCW_DOING_READ_FEAT:
1024 		case VIRTIO_CCW_DOING_WRITE_FEAT:
1025 		case VIRTIO_CCW_DOING_READ_CONFIG:
1026 		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1027 		case VIRTIO_CCW_DOING_WRITE_STATUS:
1028 		case VIRTIO_CCW_DOING_READ_STATUS:
1029 		case VIRTIO_CCW_DOING_SET_VQ:
1030 		case VIRTIO_CCW_DOING_SET_IND:
1031 		case VIRTIO_CCW_DOING_SET_CONF_IND:
1032 		case VIRTIO_CCW_DOING_RESET:
1033 		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1034 		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1035 		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1036 			vcdev->curr_io &= ~activity;
1037 			wake_up(&vcdev->wait_q);
1038 			break;
1039 		default:
1040 			/* don't know what to do... */
1041 			dev_warn(&vcdev->cdev->dev,
1042 				 "Suspicious activity '%08x'\n", activity);
1043 			WARN_ON(1);
1044 			break;
1045 		}
1046 	}
1047 }
1048 
virtio_ccw_int_handler(struct ccw_device * cdev,unsigned long intparm,struct irb * irb)1049 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1050 				   unsigned long intparm,
1051 				   struct irb *irb)
1052 {
1053 	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1054 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1055 	int i;
1056 	struct virtqueue *vq;
1057 
1058 	if (!vcdev)
1059 		return;
1060 	if (IS_ERR(irb)) {
1061 		vcdev->err = PTR_ERR(irb);
1062 		virtio_ccw_check_activity(vcdev, activity);
1063 		/* Don't poke around indicators, something's wrong. */
1064 		return;
1065 	}
1066 	/* Check if it's a notification from the host. */
1067 	if ((intparm == 0) &&
1068 	    (scsw_stctl(&irb->scsw) ==
1069 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1070 		/* OK */
1071 	}
1072 	if (irb_is_error(irb)) {
1073 		/* Command reject? */
1074 		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1075 		    (irb->ecw[0] & SNS0_CMD_REJECT))
1076 			vcdev->err = -EOPNOTSUPP;
1077 		else
1078 			/* Map everything else to -EIO. */
1079 			vcdev->err = -EIO;
1080 	}
1081 	virtio_ccw_check_activity(vcdev, activity);
1082 	for_each_set_bit(i, &vcdev->indicators,
1083 			 sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1084 		/* The bit clear must happen before the vring kick. */
1085 		clear_bit(i, &vcdev->indicators);
1086 		barrier();
1087 		vq = virtio_ccw_vq_by_ind(vcdev, i);
1088 		vring_interrupt(0, vq);
1089 	}
1090 	if (test_bit(0, &vcdev->indicators2)) {
1091 		virtio_config_changed(&vcdev->vdev);
1092 		clear_bit(0, &vcdev->indicators2);
1093 	}
1094 }
1095 
1096 /*
1097  * We usually want to autoonline all devices, but give the admin
1098  * a way to exempt devices from this.
1099  */
1100 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1101 		     (8*sizeof(long)))
1102 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1103 
1104 static char *no_auto = "";
1105 
1106 module_param(no_auto, charp, 0444);
1107 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1108 
virtio_ccw_check_autoonline(struct ccw_device * cdev)1109 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1110 {
1111 	struct ccw_dev_id id;
1112 
1113 	ccw_device_get_id(cdev, &id);
1114 	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1115 		return 0;
1116 	return 1;
1117 }
1118 
virtio_ccw_auto_online(void * data,async_cookie_t cookie)1119 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1120 {
1121 	struct ccw_device *cdev = data;
1122 	int ret;
1123 
1124 	ret = ccw_device_set_online(cdev);
1125 	if (ret)
1126 		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1127 }
1128 
virtio_ccw_probe(struct ccw_device * cdev)1129 static int virtio_ccw_probe(struct ccw_device *cdev)
1130 {
1131 	cdev->handler = virtio_ccw_int_handler;
1132 
1133 	if (virtio_ccw_check_autoonline(cdev))
1134 		async_schedule(virtio_ccw_auto_online, cdev);
1135 	return 0;
1136 }
1137 
virtio_grab_drvdata(struct ccw_device * cdev)1138 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1139 {
1140 	unsigned long flags;
1141 	struct virtio_ccw_device *vcdev;
1142 
1143 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1144 	vcdev = dev_get_drvdata(&cdev->dev);
1145 	if (!vcdev || vcdev->going_away) {
1146 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1147 		return NULL;
1148 	}
1149 	vcdev->going_away = true;
1150 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1151 	return vcdev;
1152 }
1153 
virtio_ccw_remove(struct ccw_device * cdev)1154 static void virtio_ccw_remove(struct ccw_device *cdev)
1155 {
1156 	unsigned long flags;
1157 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1158 
1159 	if (vcdev && cdev->online) {
1160 		if (vcdev->device_lost)
1161 			virtio_break_device(&vcdev->vdev);
1162 		unregister_virtio_device(&vcdev->vdev);
1163 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1164 		dev_set_drvdata(&cdev->dev, NULL);
1165 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1166 	}
1167 	cdev->handler = NULL;
1168 }
1169 
virtio_ccw_offline(struct ccw_device * cdev)1170 static int virtio_ccw_offline(struct ccw_device *cdev)
1171 {
1172 	unsigned long flags;
1173 	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1174 
1175 	if (!vcdev)
1176 		return 0;
1177 	if (vcdev->device_lost)
1178 		virtio_break_device(&vcdev->vdev);
1179 	unregister_virtio_device(&vcdev->vdev);
1180 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1181 	dev_set_drvdata(&cdev->dev, NULL);
1182 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1183 	return 0;
1184 }
1185 
virtio_ccw_set_transport_rev(struct virtio_ccw_device * vcdev)1186 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1187 {
1188 	struct virtio_rev_info *rev;
1189 	struct ccw1 *ccw;
1190 	int ret;
1191 
1192 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1193 	if (!ccw)
1194 		return -ENOMEM;
1195 	rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1196 	if (!rev) {
1197 		kfree(ccw);
1198 		return -ENOMEM;
1199 	}
1200 
1201 	/* Set transport revision */
1202 	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1203 	ccw->flags = 0;
1204 	ccw->count = sizeof(*rev);
1205 	ccw->cda = (__u32)(unsigned long)rev;
1206 
1207 	vcdev->revision = VIRTIO_CCW_REV_MAX;
1208 	do {
1209 		rev->revision = vcdev->revision;
1210 		/* none of our supported revisions carry payload */
1211 		rev->length = 0;
1212 		ret = ccw_io_helper(vcdev, ccw,
1213 				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1214 		if (ret == -EOPNOTSUPP) {
1215 			if (vcdev->revision == 0)
1216 				/*
1217 				 * The host device does not support setting
1218 				 * the revision: let's operate it in legacy
1219 				 * mode.
1220 				 */
1221 				ret = 0;
1222 			else
1223 				vcdev->revision--;
1224 		}
1225 	} while (ret == -EOPNOTSUPP);
1226 
1227 	kfree(ccw);
1228 	kfree(rev);
1229 	return ret;
1230 }
1231 
virtio_ccw_online(struct ccw_device * cdev)1232 static int virtio_ccw_online(struct ccw_device *cdev)
1233 {
1234 	int ret;
1235 	struct virtio_ccw_device *vcdev;
1236 	unsigned long flags;
1237 
1238 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1239 	if (!vcdev) {
1240 		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1241 		ret = -ENOMEM;
1242 		goto out_free;
1243 	}
1244 	vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1245 				   GFP_DMA | GFP_KERNEL);
1246 	if (!vcdev->config_block) {
1247 		ret = -ENOMEM;
1248 		goto out_free;
1249 	}
1250 	vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1251 	if (!vcdev->status) {
1252 		ret = -ENOMEM;
1253 		goto out_free;
1254 	}
1255 
1256 	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1257 
1258 	vcdev->vdev.dev.parent = &cdev->dev;
1259 	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1260 	vcdev->vdev.config = &virtio_ccw_config_ops;
1261 	vcdev->cdev = cdev;
1262 	init_waitqueue_head(&vcdev->wait_q);
1263 	INIT_LIST_HEAD(&vcdev->virtqueues);
1264 	spin_lock_init(&vcdev->lock);
1265 	mutex_init(&vcdev->io_lock);
1266 
1267 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1268 	dev_set_drvdata(&cdev->dev, vcdev);
1269 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1270 	vcdev->vdev.id.vendor = cdev->id.cu_type;
1271 	vcdev->vdev.id.device = cdev->id.cu_model;
1272 
1273 	ret = virtio_ccw_set_transport_rev(vcdev);
1274 	if (ret)
1275 		goto out_free;
1276 
1277 	ret = register_virtio_device(&vcdev->vdev);
1278 	if (ret) {
1279 		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1280 			 ret);
1281 		goto out_put;
1282 	}
1283 	return 0;
1284 out_put:
1285 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1286 	dev_set_drvdata(&cdev->dev, NULL);
1287 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1288 	put_device(&vcdev->vdev.dev);
1289 	return ret;
1290 out_free:
1291 	if (vcdev) {
1292 		kfree(vcdev->status);
1293 		kfree(vcdev->config_block);
1294 	}
1295 	kfree(vcdev);
1296 	return ret;
1297 }
1298 
virtio_ccw_cio_notify(struct ccw_device * cdev,int event)1299 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1300 {
1301 	int rc;
1302 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1303 
1304 	/*
1305 	 * Make sure vcdev is set
1306 	 * i.e. set_offline/remove callback not already running
1307 	 */
1308 	if (!vcdev)
1309 		return NOTIFY_DONE;
1310 
1311 	switch (event) {
1312 	case CIO_GONE:
1313 		vcdev->device_lost = true;
1314 		rc = NOTIFY_DONE;
1315 		break;
1316 	default:
1317 		rc = NOTIFY_DONE;
1318 		break;
1319 	}
1320 	return rc;
1321 }
1322 
1323 static struct ccw_device_id virtio_ids[] = {
1324 	{ CCW_DEVICE(0x3832, 0) },
1325 	{},
1326 };
1327 
1328 static struct ccw_driver virtio_ccw_driver = {
1329 	.driver = {
1330 		.owner = THIS_MODULE,
1331 		.name = "virtio_ccw",
1332 	},
1333 	.ids = virtio_ids,
1334 	.probe = virtio_ccw_probe,
1335 	.remove = virtio_ccw_remove,
1336 	.set_offline = virtio_ccw_offline,
1337 	.set_online = virtio_ccw_online,
1338 	.notify = virtio_ccw_cio_notify,
1339 	.int_class = IRQIO_VIR,
1340 };
1341 
pure_hex(char ** cp,unsigned int * val,int min_digit,int max_digit,int max_val)1342 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1343 			   int max_digit, int max_val)
1344 {
1345 	int diff;
1346 
1347 	diff = 0;
1348 	*val = 0;
1349 
1350 	while (diff <= max_digit) {
1351 		int value = hex_to_bin(**cp);
1352 
1353 		if (value < 0)
1354 			break;
1355 		*val = *val * 16 + value;
1356 		(*cp)++;
1357 		diff++;
1358 	}
1359 
1360 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1361 		return 1;
1362 
1363 	return 0;
1364 }
1365 
parse_busid(char * str,unsigned int * cssid,unsigned int * ssid,unsigned int * devno)1366 static int __init parse_busid(char *str, unsigned int *cssid,
1367 			      unsigned int *ssid, unsigned int *devno)
1368 {
1369 	char *str_work;
1370 	int rc, ret;
1371 
1372 	rc = 1;
1373 
1374 	if (*str == '\0')
1375 		goto out;
1376 
1377 	str_work = str;
1378 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1379 	if (ret || (str_work[0] != '.'))
1380 		goto out;
1381 	str_work++;
1382 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1383 	if (ret || (str_work[0] != '.'))
1384 		goto out;
1385 	str_work++;
1386 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1387 	if (ret || (str_work[0] != '\0'))
1388 		goto out;
1389 
1390 	rc = 0;
1391 out:
1392 	return rc;
1393 }
1394 
no_auto_parse(void)1395 static void __init no_auto_parse(void)
1396 {
1397 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1398 	char *parm, *str;
1399 	int rc;
1400 
1401 	str = no_auto;
1402 	while ((parm = strsep(&str, ","))) {
1403 		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1404 				 &from_ssid, &from);
1405 		if (rc)
1406 			continue;
1407 		if (parm != NULL) {
1408 			rc = parse_busid(parm, &to_cssid,
1409 					 &to_ssid, &to);
1410 			if ((from_ssid > to_ssid) ||
1411 			    ((from_ssid == to_ssid) && (from > to)))
1412 				rc = -EINVAL;
1413 		} else {
1414 			to_cssid = from_cssid;
1415 			to_ssid = from_ssid;
1416 			to = from;
1417 		}
1418 		if (rc)
1419 			continue;
1420 		while ((from_ssid < to_ssid) ||
1421 		       ((from_ssid == to_ssid) && (from <= to))) {
1422 			set_bit(from, devs_no_auto[from_ssid]);
1423 			from++;
1424 			if (from > __MAX_SUBCHANNEL) {
1425 				from_ssid++;
1426 				from = 0;
1427 			}
1428 		}
1429 	}
1430 }
1431 
virtio_ccw_init(void)1432 static int __init virtio_ccw_init(void)
1433 {
1434 	/* parse no_auto string before we do anything further */
1435 	no_auto_parse();
1436 	return ccw_driver_register(&virtio_ccw_driver);
1437 }
1438 device_initcall(virtio_ccw_init);
1439