ba2e0856d22cdfb5396457366276e01bc9ac7851
[sfrench/cifs-2.6.git] / drivers / s390 / virtio / virtio_ccw.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ccw based virtio transport
4  *
5  * Copyright IBM Corp. 2012, 2014
6  *
7  *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
8  */
9
10 #include <linux/kernel_stat.h>
11 #include <linux/init.h>
12 #include <linux/bootmem.h>
13 #include <linux/err.h>
14 #include <linux/virtio.h>
15 #include <linux/virtio_config.h>
16 #include <linux/slab.h>
17 #include <linux/interrupt.h>
18 #include <linux/virtio_ring.h>
19 #include <linux/pfn.h>
20 #include <linux/async.h>
21 #include <linux/wait.h>
22 #include <linux/list.h>
23 #include <linux/bitops.h>
24 #include <linux/moduleparam.h>
25 #include <linux/io.h>
26 #include <linux/kvm_para.h>
27 #include <linux/notifier.h>
28 #include <asm/diag.h>
29 #include <asm/setup.h>
30 #include <asm/irq.h>
31 #include <asm/cio.h>
32 #include <asm/ccwdev.h>
33 #include <asm/virtio-ccw.h>
34 #include <asm/isc.h>
35 #include <asm/airq.h>
36
37 /*
38  * virtio related functions
39  */
40
41 struct vq_config_block {
42         __u16 index;
43         __u16 num;
44 } __packed;
45
46 #define VIRTIO_CCW_CONFIG_SIZE 0x100
47 /* same as PCI config space size, should be enough for all drivers */
48
49 struct virtio_ccw_device {
50         struct virtio_device vdev;
51         __u8 *status;
52         __u8 config[VIRTIO_CCW_CONFIG_SIZE];
53         struct ccw_device *cdev;
54         __u32 curr_io;
55         int err;
56         unsigned int revision; /* Transport revision */
57         wait_queue_head_t wait_q;
58         spinlock_t lock;
59         struct list_head virtqueues;
60         unsigned long indicators;
61         unsigned long indicators2;
62         struct vq_config_block *config_block;
63         bool is_thinint;
64         bool going_away;
65         bool device_lost;
66         unsigned int config_ready;
67         void *airq_info;
68 };
69
70 struct vq_info_block_legacy {
71         __u64 queue;
72         __u32 align;
73         __u16 index;
74         __u16 num;
75 } __packed;
76
77 struct vq_info_block {
78         __u64 desc;
79         __u32 res0;
80         __u16 index;
81         __u16 num;
82         __u64 avail;
83         __u64 used;
84 } __packed;
85
86 struct virtio_feature_desc {
87         __le32 features;
88         __u8 index;
89 } __packed;
90
91 struct virtio_thinint_area {
92         unsigned long summary_indicator;
93         unsigned long indicator;
94         u64 bit_nr;
95         u8 isc;
96 } __packed;
97
98 struct virtio_rev_info {
99         __u16 revision;
100         __u16 length;
101         __u8 data[];
102 };
103
104 /* the highest virtio-ccw revision we support */
105 #define VIRTIO_CCW_REV_MAX 1
106
107 struct virtio_ccw_vq_info {
108         struct virtqueue *vq;
109         int num;
110         void *queue;
111         union {
112                 struct vq_info_block s;
113                 struct vq_info_block_legacy l;
114         } *info_block;
115         int bit_nr;
116         struct list_head node;
117         long cookie;
118 };
119
120 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
121
122 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
123 #define MAX_AIRQ_AREAS 20
124
125 static int virtio_ccw_use_airq = 1;
126
127 struct airq_info {
128         rwlock_t lock;
129         u8 summary_indicator;
130         struct airq_struct airq;
131         struct airq_iv *aiv;
132 };
133 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
134
135 #define CCW_CMD_SET_VQ 0x13
136 #define CCW_CMD_VDEV_RESET 0x33
137 #define CCW_CMD_SET_IND 0x43
138 #define CCW_CMD_SET_CONF_IND 0x53
139 #define CCW_CMD_READ_FEAT 0x12
140 #define CCW_CMD_WRITE_FEAT 0x11
141 #define CCW_CMD_READ_CONF 0x22
142 #define CCW_CMD_WRITE_CONF 0x21
143 #define CCW_CMD_WRITE_STATUS 0x31
144 #define CCW_CMD_READ_VQ_CONF 0x32
145 #define CCW_CMD_READ_STATUS 0x72
146 #define CCW_CMD_SET_IND_ADAPTER 0x73
147 #define CCW_CMD_SET_VIRTIO_REV 0x83
148
149 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
150 #define VIRTIO_CCW_DOING_RESET 0x00040000
151 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
152 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
153 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
154 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
155 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
156 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
157 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
158 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
159 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
160 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
161 #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
162 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
163
164 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
165 {
166         return container_of(vdev, struct virtio_ccw_device, vdev);
167 }
168
169 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
170 {
171         unsigned long i, flags;
172
173         write_lock_irqsave(&info->lock, flags);
174         for (i = 0; i < airq_iv_end(info->aiv); i++) {
175                 if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
176                         airq_iv_free_bit(info->aiv, i);
177                         airq_iv_set_ptr(info->aiv, i, 0);
178                         break;
179                 }
180         }
181         write_unlock_irqrestore(&info->lock, flags);
182 }
183
184 static void virtio_airq_handler(struct airq_struct *airq)
185 {
186         struct airq_info *info = container_of(airq, struct airq_info, airq);
187         unsigned long ai;
188
189         inc_irq_stat(IRQIO_VAI);
190         read_lock(&info->lock);
191         /* Walk through indicators field, summary indicator active. */
192         for (ai = 0;;) {
193                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
194                 if (ai == -1UL)
195                         break;
196                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
197         }
198         info->summary_indicator = 0;
199         smp_wmb();
200         /* Walk through indicators field, summary indicator not active. */
201         for (ai = 0;;) {
202                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
203                 if (ai == -1UL)
204                         break;
205                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
206         }
207         read_unlock(&info->lock);
208 }
209
210 static struct airq_info *new_airq_info(void)
211 {
212         struct airq_info *info;
213         int rc;
214
215         info = kzalloc(sizeof(*info), GFP_KERNEL);
216         if (!info)
217                 return NULL;
218         rwlock_init(&info->lock);
219         info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
220         if (!info->aiv) {
221                 kfree(info);
222                 return NULL;
223         }
224         info->airq.handler = virtio_airq_handler;
225         info->airq.lsi_ptr = &info->summary_indicator;
226         info->airq.lsi_mask = 0xff;
227         info->airq.isc = VIRTIO_AIRQ_ISC;
228         rc = register_adapter_interrupt(&info->airq);
229         if (rc) {
230                 airq_iv_release(info->aiv);
231                 kfree(info);
232                 return NULL;
233         }
234         return info;
235 }
236
237 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
238                                         u64 *first, void **airq_info)
239 {
240         int i, j;
241         struct airq_info *info;
242         unsigned long indicator_addr = 0;
243         unsigned long bit, flags;
244
245         for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
246                 if (!airq_areas[i])
247                         airq_areas[i] = new_airq_info();
248                 info = airq_areas[i];
249                 if (!info)
250                         return 0;
251                 write_lock_irqsave(&info->lock, flags);
252                 bit = airq_iv_alloc(info->aiv, nvqs);
253                 if (bit == -1UL) {
254                         /* Not enough vacancies. */
255                         write_unlock_irqrestore(&info->lock, flags);
256                         continue;
257                 }
258                 *first = bit;
259                 *airq_info = info;
260                 indicator_addr = (unsigned long)info->aiv->vector;
261                 for (j = 0; j < nvqs; j++) {
262                         airq_iv_set_ptr(info->aiv, bit + j,
263                                         (unsigned long)vqs[j]);
264                 }
265                 write_unlock_irqrestore(&info->lock, flags);
266         }
267         return indicator_addr;
268 }
269
270 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
271 {
272         struct virtio_ccw_vq_info *info;
273
274         list_for_each_entry(info, &vcdev->virtqueues, node)
275                 drop_airq_indicator(info->vq, vcdev->airq_info);
276 }
277
278 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
279 {
280         unsigned long flags;
281         __u32 ret;
282
283         spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
284         if (vcdev->err)
285                 ret = 0;
286         else
287                 ret = vcdev->curr_io & flag;
288         spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
289         return ret;
290 }
291
292 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
293                          struct ccw1 *ccw, __u32 intparm)
294 {
295         int ret;
296         unsigned long flags;
297         int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
298
299         do {
300                 spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
301                 ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
302                 if (!ret) {
303                         if (!vcdev->curr_io)
304                                 vcdev->err = 0;
305                         vcdev->curr_io |= flag;
306                 }
307                 spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
308                 cpu_relax();
309         } while (ret == -EBUSY);
310         wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
311         return ret ? ret : vcdev->err;
312 }
313
314 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
315                                       struct ccw1 *ccw)
316 {
317         int ret;
318         unsigned long *indicatorp = NULL;
319         struct virtio_thinint_area *thinint_area = NULL;
320         struct airq_info *airq_info = vcdev->airq_info;
321
322         if (vcdev->is_thinint) {
323                 thinint_area = kzalloc(sizeof(*thinint_area),
324                                        GFP_DMA | GFP_KERNEL);
325                 if (!thinint_area)
326                         return;
327                 thinint_area->summary_indicator =
328                         (unsigned long) &airq_info->summary_indicator;
329                 thinint_area->isc = VIRTIO_AIRQ_ISC;
330                 ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
331                 ccw->count = sizeof(*thinint_area);
332                 ccw->cda = (__u32)(unsigned long) thinint_area;
333         } else {
334                 /* payload is the address of the indicators */
335                 indicatorp = kmalloc(sizeof(&vcdev->indicators),
336                                      GFP_DMA | GFP_KERNEL);
337                 if (!indicatorp)
338                         return;
339                 *indicatorp = 0;
340                 ccw->cmd_code = CCW_CMD_SET_IND;
341                 ccw->count = sizeof(&vcdev->indicators);
342                 ccw->cda = (__u32)(unsigned long) indicatorp;
343         }
344         /* Deregister indicators from host. */
345         vcdev->indicators = 0;
346         ccw->flags = 0;
347         ret = ccw_io_helper(vcdev, ccw,
348                             vcdev->is_thinint ?
349                             VIRTIO_CCW_DOING_SET_IND_ADAPTER :
350                             VIRTIO_CCW_DOING_SET_IND);
351         if (ret && (ret != -ENODEV))
352                 dev_info(&vcdev->cdev->dev,
353                          "Failed to deregister indicators (%d)\n", ret);
354         else if (vcdev->is_thinint)
355                 virtio_ccw_drop_indicators(vcdev);
356         kfree(indicatorp);
357         kfree(thinint_area);
358 }
359
360 static inline long __do_kvm_notify(struct subchannel_id schid,
361                                    unsigned long queue_index,
362                                    long cookie)
363 {
364         register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
365         register struct subchannel_id __schid asm("2") = schid;
366         register unsigned long __index asm("3") = queue_index;
367         register long __rc asm("2");
368         register long __cookie asm("4") = cookie;
369
370         asm volatile ("diag 2,4,0x500\n"
371                       : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
372                       "d"(__cookie)
373                       : "memory", "cc");
374         return __rc;
375 }
376
377 static inline long do_kvm_notify(struct subchannel_id schid,
378                                  unsigned long queue_index,
379                                  long cookie)
380 {
381         diag_stat_inc(DIAG_STAT_X500);
382         return __do_kvm_notify(schid, queue_index, cookie);
383 }
384
385 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
386 {
387         struct virtio_ccw_vq_info *info = vq->priv;
388         struct virtio_ccw_device *vcdev;
389         struct subchannel_id schid;
390
391         vcdev = to_vc_device(info->vq->vdev);
392         ccw_device_get_schid(vcdev->cdev, &schid);
393         info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
394         if (info->cookie < 0)
395                 return false;
396         return true;
397 }
398
399 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
400                                    struct ccw1 *ccw, int index)
401 {
402         int ret;
403
404         vcdev->config_block->index = index;
405         ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
406         ccw->flags = 0;
407         ccw->count = sizeof(struct vq_config_block);
408         ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
409         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
410         if (ret)
411                 return ret;
412         return vcdev->config_block->num;
413 }
414
415 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
416 {
417         struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
418         struct virtio_ccw_vq_info *info = vq->priv;
419         unsigned long flags;
420         unsigned long size;
421         int ret;
422         unsigned int index = vq->index;
423
424         /* Remove from our list. */
425         spin_lock_irqsave(&vcdev->lock, flags);
426         list_del(&info->node);
427         spin_unlock_irqrestore(&vcdev->lock, flags);
428
429         /* Release from host. */
430         if (vcdev->revision == 0) {
431                 info->info_block->l.queue = 0;
432                 info->info_block->l.align = 0;
433                 info->info_block->l.index = index;
434                 info->info_block->l.num = 0;
435                 ccw->count = sizeof(info->info_block->l);
436         } else {
437                 info->info_block->s.desc = 0;
438                 info->info_block->s.index = index;
439                 info->info_block->s.num = 0;
440                 info->info_block->s.avail = 0;
441                 info->info_block->s.used = 0;
442                 ccw->count = sizeof(info->info_block->s);
443         }
444         ccw->cmd_code = CCW_CMD_SET_VQ;
445         ccw->flags = 0;
446         ccw->cda = (__u32)(unsigned long)(info->info_block);
447         ret = ccw_io_helper(vcdev, ccw,
448                             VIRTIO_CCW_DOING_SET_VQ | index);
449         /*
450          * -ENODEV isn't considered an error: The device is gone anyway.
451          * This may happen on device detach.
452          */
453         if (ret && (ret != -ENODEV))
454                 dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
455                          ret, index);
456
457         vring_del_virtqueue(vq);
458         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
459         free_pages_exact(info->queue, size);
460         kfree(info->info_block);
461         kfree(info);
462 }
463
464 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
465 {
466         struct virtqueue *vq, *n;
467         struct ccw1 *ccw;
468         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
469
470         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
471         if (!ccw)
472                 return;
473
474         virtio_ccw_drop_indicator(vcdev, ccw);
475
476         list_for_each_entry_safe(vq, n, &vdev->vqs, list)
477                 virtio_ccw_del_vq(vq, ccw);
478
479         kfree(ccw);
480 }
481
482 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
483                                              int i, vq_callback_t *callback,
484                                              const char *name, bool ctx,
485                                              struct ccw1 *ccw)
486 {
487         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
488         int err;
489         struct virtqueue *vq = NULL;
490         struct virtio_ccw_vq_info *info;
491         unsigned long size = 0; /* silence the compiler */
492         unsigned long flags;
493
494         /* Allocate queue. */
495         info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
496         if (!info) {
497                 dev_warn(&vcdev->cdev->dev, "no info\n");
498                 err = -ENOMEM;
499                 goto out_err;
500         }
501         info->info_block = kzalloc(sizeof(*info->info_block),
502                                    GFP_DMA | GFP_KERNEL);
503         if (!info->info_block) {
504                 dev_warn(&vcdev->cdev->dev, "no info block\n");
505                 err = -ENOMEM;
506                 goto out_err;
507         }
508         info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
509         if (info->num < 0) {
510                 err = info->num;
511                 goto out_err;
512         }
513         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
514         info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
515         if (info->queue == NULL) {
516                 dev_warn(&vcdev->cdev->dev, "no queue\n");
517                 err = -ENOMEM;
518                 goto out_err;
519         }
520
521         vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
522                                  true, ctx, info->queue, virtio_ccw_kvm_notify,
523                                  callback, name);
524         if (!vq) {
525                 /* For now, we fail if we can't get the requested size. */
526                 dev_warn(&vcdev->cdev->dev, "no vq\n");
527                 err = -ENOMEM;
528                 goto out_err;
529         }
530
531         /* Register it with the host. */
532         if (vcdev->revision == 0) {
533                 info->info_block->l.queue = (__u64)info->queue;
534                 info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
535                 info->info_block->l.index = i;
536                 info->info_block->l.num = info->num;
537                 ccw->count = sizeof(info->info_block->l);
538         } else {
539                 info->info_block->s.desc = (__u64)info->queue;
540                 info->info_block->s.index = i;
541                 info->info_block->s.num = info->num;
542                 info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
543                 info->info_block->s.used = (__u64)virtqueue_get_used(vq);
544                 ccw->count = sizeof(info->info_block->s);
545         }
546         ccw->cmd_code = CCW_CMD_SET_VQ;
547         ccw->flags = 0;
548         ccw->cda = (__u32)(unsigned long)(info->info_block);
549         err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
550         if (err) {
551                 dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
552                 goto out_err;
553         }
554
555         info->vq = vq;
556         vq->priv = info;
557
558         /* Save it to our list. */
559         spin_lock_irqsave(&vcdev->lock, flags);
560         list_add(&info->node, &vcdev->virtqueues);
561         spin_unlock_irqrestore(&vcdev->lock, flags);
562
563         return vq;
564
565 out_err:
566         if (vq)
567                 vring_del_virtqueue(vq);
568         if (info) {
569                 if (info->queue)
570                         free_pages_exact(info->queue, size);
571                 kfree(info->info_block);
572         }
573         kfree(info);
574         return ERR_PTR(err);
575 }
576
577 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
578                                            struct virtqueue *vqs[], int nvqs,
579                                            struct ccw1 *ccw)
580 {
581         int ret;
582         struct virtio_thinint_area *thinint_area = NULL;
583         struct airq_info *info;
584
585         thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
586         if (!thinint_area) {
587                 ret = -ENOMEM;
588                 goto out;
589         }
590         /* Try to get an indicator. */
591         thinint_area->indicator = get_airq_indicator(vqs, nvqs,
592                                                      &thinint_area->bit_nr,
593                                                      &vcdev->airq_info);
594         if (!thinint_area->indicator) {
595                 ret = -ENOSPC;
596                 goto out;
597         }
598         info = vcdev->airq_info;
599         thinint_area->summary_indicator =
600                 (unsigned long) &info->summary_indicator;
601         thinint_area->isc = VIRTIO_AIRQ_ISC;
602         ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
603         ccw->flags = CCW_FLAG_SLI;
604         ccw->count = sizeof(*thinint_area);
605         ccw->cda = (__u32)(unsigned long)thinint_area;
606         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
607         if (ret) {
608                 if (ret == -EOPNOTSUPP) {
609                         /*
610                          * The host does not support adapter interrupts
611                          * for virtio-ccw, stop trying.
612                          */
613                         virtio_ccw_use_airq = 0;
614                         pr_info("Adapter interrupts unsupported on host\n");
615                 } else
616                         dev_warn(&vcdev->cdev->dev,
617                                  "enabling adapter interrupts = %d\n", ret);
618                 virtio_ccw_drop_indicators(vcdev);
619         }
620 out:
621         kfree(thinint_area);
622         return ret;
623 }
624
625 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
626                                struct virtqueue *vqs[],
627                                vq_callback_t *callbacks[],
628                                const char * const names[],
629                                const bool *ctx,
630                                struct irq_affinity *desc)
631 {
632         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
633         unsigned long *indicatorp = NULL;
634         int ret, i;
635         struct ccw1 *ccw;
636
637         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
638         if (!ccw)
639                 return -ENOMEM;
640
641         for (i = 0; i < nvqs; ++i) {
642                 vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
643                                              ctx ? ctx[i] : false, ccw);
644                 if (IS_ERR(vqs[i])) {
645                         ret = PTR_ERR(vqs[i]);
646                         vqs[i] = NULL;
647                         goto out;
648                 }
649         }
650         ret = -ENOMEM;
651         /*
652          * We need a data area under 2G to communicate. Our payload is
653          * the address of the indicators.
654         */
655         indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
656         if (!indicatorp)
657                 goto out;
658         *indicatorp = (unsigned long) &vcdev->indicators;
659         if (vcdev->is_thinint) {
660                 ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
661                 if (ret)
662                         /* no error, just fall back to legacy interrupts */
663                         vcdev->is_thinint = false;
664         }
665         if (!vcdev->is_thinint) {
666                 /* Register queue indicators with host. */
667                 vcdev->indicators = 0;
668                 ccw->cmd_code = CCW_CMD_SET_IND;
669                 ccw->flags = 0;
670                 ccw->count = sizeof(&vcdev->indicators);
671                 ccw->cda = (__u32)(unsigned long) indicatorp;
672                 ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
673                 if (ret)
674                         goto out;
675         }
676         /* Register indicators2 with host for config changes */
677         *indicatorp = (unsigned long) &vcdev->indicators2;
678         vcdev->indicators2 = 0;
679         ccw->cmd_code = CCW_CMD_SET_CONF_IND;
680         ccw->flags = 0;
681         ccw->count = sizeof(&vcdev->indicators2);
682         ccw->cda = (__u32)(unsigned long) indicatorp;
683         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
684         if (ret)
685                 goto out;
686
687         kfree(indicatorp);
688         kfree(ccw);
689         return 0;
690 out:
691         kfree(indicatorp);
692         kfree(ccw);
693         virtio_ccw_del_vqs(vdev);
694         return ret;
695 }
696
697 static void virtio_ccw_reset(struct virtio_device *vdev)
698 {
699         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
700         struct ccw1 *ccw;
701
702         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
703         if (!ccw)
704                 return;
705
706         /* Zero status bits. */
707         *vcdev->status = 0;
708
709         /* Send a reset ccw on device. */
710         ccw->cmd_code = CCW_CMD_VDEV_RESET;
711         ccw->flags = 0;
712         ccw->count = 0;
713         ccw->cda = 0;
714         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
715         kfree(ccw);
716 }
717
718 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
719 {
720         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
721         struct virtio_feature_desc *features;
722         int ret;
723         u64 rc;
724         struct ccw1 *ccw;
725
726         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
727         if (!ccw)
728                 return 0;
729
730         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
731         if (!features) {
732                 rc = 0;
733                 goto out_free;
734         }
735         /* Read the feature bits from the host. */
736         features->index = 0;
737         ccw->cmd_code = CCW_CMD_READ_FEAT;
738         ccw->flags = 0;
739         ccw->count = sizeof(*features);
740         ccw->cda = (__u32)(unsigned long)features;
741         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
742         if (ret) {
743                 rc = 0;
744                 goto out_free;
745         }
746
747         rc = le32_to_cpu(features->features);
748
749         if (vcdev->revision == 0)
750                 goto out_free;
751
752         /* Read second half of the feature bits from the host. */
753         features->index = 1;
754         ccw->cmd_code = CCW_CMD_READ_FEAT;
755         ccw->flags = 0;
756         ccw->count = sizeof(*features);
757         ccw->cda = (__u32)(unsigned long)features;
758         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
759         if (ret == 0)
760                 rc |= (u64)le32_to_cpu(features->features) << 32;
761
762 out_free:
763         kfree(features);
764         kfree(ccw);
765         return rc;
766 }
767
768 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
769 {
770         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
771         struct virtio_feature_desc *features;
772         struct ccw1 *ccw;
773         int ret;
774
775         if (vcdev->revision >= 1 &&
776             !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
777                 dev_err(&vdev->dev, "virtio: device uses revision 1 "
778                         "but does not have VIRTIO_F_VERSION_1\n");
779                 return -EINVAL;
780         }
781
782         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
783         if (!ccw)
784                 return -ENOMEM;
785
786         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
787         if (!features) {
788                 ret = -ENOMEM;
789                 goto out_free;
790         }
791         /* Give virtio_ring a chance to accept features. */
792         vring_transport_features(vdev);
793
794         features->index = 0;
795         features->features = cpu_to_le32((u32)vdev->features);
796         /* Write the first half of the feature bits to the host. */
797         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
798         ccw->flags = 0;
799         ccw->count = sizeof(*features);
800         ccw->cda = (__u32)(unsigned long)features;
801         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
802         if (ret)
803                 goto out_free;
804
805         if (vcdev->revision == 0)
806                 goto out_free;
807
808         features->index = 1;
809         features->features = cpu_to_le32(vdev->features >> 32);
810         /* Write the second half of the feature bits to the host. */
811         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
812         ccw->flags = 0;
813         ccw->count = sizeof(*features);
814         ccw->cda = (__u32)(unsigned long)features;
815         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
816
817 out_free:
818         kfree(features);
819         kfree(ccw);
820
821         return ret;
822 }
823
824 static void virtio_ccw_get_config(struct virtio_device *vdev,
825                                   unsigned int offset, void *buf, unsigned len)
826 {
827         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
828         int ret;
829         struct ccw1 *ccw;
830         void *config_area;
831
832         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
833         if (!ccw)
834                 return;
835
836         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
837         if (!config_area)
838                 goto out_free;
839
840         /* Read the config area from the host. */
841         ccw->cmd_code = CCW_CMD_READ_CONF;
842         ccw->flags = 0;
843         ccw->count = offset + len;
844         ccw->cda = (__u32)(unsigned long)config_area;
845         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
846         if (ret)
847                 goto out_free;
848
849         memcpy(vcdev->config, config_area, offset + len);
850         if (buf)
851                 memcpy(buf, &vcdev->config[offset], len);
852         if (vcdev->config_ready < offset + len)
853                 vcdev->config_ready = offset + len;
854
855 out_free:
856         kfree(config_area);
857         kfree(ccw);
858 }
859
860 static void virtio_ccw_set_config(struct virtio_device *vdev,
861                                   unsigned int offset, const void *buf,
862                                   unsigned len)
863 {
864         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
865         struct ccw1 *ccw;
866         void *config_area;
867
868         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
869         if (!ccw)
870                 return;
871
872         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
873         if (!config_area)
874                 goto out_free;
875
876         /* Make sure we don't overwrite fields. */
877         if (vcdev->config_ready < offset)
878                 virtio_ccw_get_config(vdev, 0, NULL, offset);
879         memcpy(&vcdev->config[offset], buf, len);
880         /* Write the config area to the host. */
881         memcpy(config_area, vcdev->config, sizeof(vcdev->config));
882         ccw->cmd_code = CCW_CMD_WRITE_CONF;
883         ccw->flags = 0;
884         ccw->count = offset + len;
885         ccw->cda = (__u32)(unsigned long)config_area;
886         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
887
888 out_free:
889         kfree(config_area);
890         kfree(ccw);
891 }
892
893 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
894 {
895         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
896         u8 old_status = *vcdev->status;
897         struct ccw1 *ccw;
898
899         if (vcdev->revision < 1)
900                 return *vcdev->status;
901
902         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
903         if (!ccw)
904                 return old_status;
905
906         ccw->cmd_code = CCW_CMD_READ_STATUS;
907         ccw->flags = 0;
908         ccw->count = sizeof(*vcdev->status);
909         ccw->cda = (__u32)(unsigned long)vcdev->status;
910         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
911 /*
912  * If the channel program failed (should only happen if the device
913  * was hotunplugged, and then we clean up via the machine check
914  * handler anyway), vcdev->status was not overwritten and we just
915  * return the old status, which is fine.
916 */
917         kfree(ccw);
918
919         return *vcdev->status;
920 }
921
922 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
923 {
924         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
925         u8 old_status = *vcdev->status;
926         struct ccw1 *ccw;
927         int ret;
928
929         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
930         if (!ccw)
931                 return;
932
933         /* Write the status to the host. */
934         *vcdev->status = status;
935         ccw->cmd_code = CCW_CMD_WRITE_STATUS;
936         ccw->flags = 0;
937         ccw->count = sizeof(status);
938         ccw->cda = (__u32)(unsigned long)vcdev->status;
939         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
940         /* Write failed? We assume status is unchanged. */
941         if (ret)
942                 *vcdev->status = old_status;
943         kfree(ccw);
944 }
945
946 static const struct virtio_config_ops virtio_ccw_config_ops = {
947         .get_features = virtio_ccw_get_features,
948         .finalize_features = virtio_ccw_finalize_features,
949         .get = virtio_ccw_get_config,
950         .set = virtio_ccw_set_config,
951         .get_status = virtio_ccw_get_status,
952         .set_status = virtio_ccw_set_status,
953         .reset = virtio_ccw_reset,
954         .find_vqs = virtio_ccw_find_vqs,
955         .del_vqs = virtio_ccw_del_vqs,
956 };
957
958
959 /*
960  * ccw bus driver related functions
961  */
962
963 static void virtio_ccw_release_dev(struct device *_d)
964 {
965         struct virtio_device *dev = dev_to_virtio(_d);
966         struct virtio_ccw_device *vcdev = to_vc_device(dev);
967
968         kfree(vcdev->status);
969         kfree(vcdev->config_block);
970         kfree(vcdev);
971 }
972
973 static int irb_is_error(struct irb *irb)
974 {
975         if (scsw_cstat(&irb->scsw) != 0)
976                 return 1;
977         if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
978                 return 1;
979         if (scsw_cc(&irb->scsw) != 0)
980                 return 1;
981         return 0;
982 }
983
984 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
985                                               int index)
986 {
987         struct virtio_ccw_vq_info *info;
988         unsigned long flags;
989         struct virtqueue *vq;
990
991         vq = NULL;
992         spin_lock_irqsave(&vcdev->lock, flags);
993         list_for_each_entry(info, &vcdev->virtqueues, node) {
994                 if (info->vq->index == index) {
995                         vq = info->vq;
996                         break;
997                 }
998         }
999         spin_unlock_irqrestore(&vcdev->lock, flags);
1000         return vq;
1001 }
1002
1003 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1004                                       __u32 activity)
1005 {
1006         if (vcdev->curr_io & activity) {
1007                 switch (activity) {
1008                 case VIRTIO_CCW_DOING_READ_FEAT:
1009                 case VIRTIO_CCW_DOING_WRITE_FEAT:
1010                 case VIRTIO_CCW_DOING_READ_CONFIG:
1011                 case VIRTIO_CCW_DOING_WRITE_CONFIG:
1012                 case VIRTIO_CCW_DOING_WRITE_STATUS:
1013                 case VIRTIO_CCW_DOING_READ_STATUS:
1014                 case VIRTIO_CCW_DOING_SET_VQ:
1015                 case VIRTIO_CCW_DOING_SET_IND:
1016                 case VIRTIO_CCW_DOING_SET_CONF_IND:
1017                 case VIRTIO_CCW_DOING_RESET:
1018                 case VIRTIO_CCW_DOING_READ_VQ_CONF:
1019                 case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1020                 case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1021                         vcdev->curr_io &= ~activity;
1022                         wake_up(&vcdev->wait_q);
1023                         break;
1024                 default:
1025                         /* don't know what to do... */
1026                         dev_warn(&vcdev->cdev->dev,
1027                                  "Suspicious activity '%08x'\n", activity);
1028                         WARN_ON(1);
1029                         break;
1030                 }
1031         }
1032 }
1033
1034 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1035                                    unsigned long intparm,
1036                                    struct irb *irb)
1037 {
1038         __u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1039         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1040         int i;
1041         struct virtqueue *vq;
1042
1043         if (!vcdev)
1044                 return;
1045         if (IS_ERR(irb)) {
1046                 vcdev->err = PTR_ERR(irb);
1047                 virtio_ccw_check_activity(vcdev, activity);
1048                 /* Don't poke around indicators, something's wrong. */
1049                 return;
1050         }
1051         /* Check if it's a notification from the host. */
1052         if ((intparm == 0) &&
1053             (scsw_stctl(&irb->scsw) ==
1054              (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1055                 /* OK */
1056         }
1057         if (irb_is_error(irb)) {
1058                 /* Command reject? */
1059                 if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1060                     (irb->ecw[0] & SNS0_CMD_REJECT))
1061                         vcdev->err = -EOPNOTSUPP;
1062                 else
1063                         /* Map everything else to -EIO. */
1064                         vcdev->err = -EIO;
1065         }
1066         virtio_ccw_check_activity(vcdev, activity);
1067         for_each_set_bit(i, &vcdev->indicators,
1068                          sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1069                 /* The bit clear must happen before the vring kick. */
1070                 clear_bit(i, &vcdev->indicators);
1071                 barrier();
1072                 vq = virtio_ccw_vq_by_ind(vcdev, i);
1073                 vring_interrupt(0, vq);
1074         }
1075         if (test_bit(0, &vcdev->indicators2)) {
1076                 virtio_config_changed(&vcdev->vdev);
1077                 clear_bit(0, &vcdev->indicators2);
1078         }
1079 }
1080
1081 /*
1082  * We usually want to autoonline all devices, but give the admin
1083  * a way to exempt devices from this.
1084  */
1085 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1086                      (8*sizeof(long)))
1087 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1088
1089 static char *no_auto = "";
1090
1091 module_param(no_auto, charp, 0444);
1092 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1093
1094 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1095 {
1096         struct ccw_dev_id id;
1097
1098         ccw_device_get_id(cdev, &id);
1099         if (test_bit(id.devno, devs_no_auto[id.ssid]))
1100                 return 0;
1101         return 1;
1102 }
1103
1104 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1105 {
1106         struct ccw_device *cdev = data;
1107         int ret;
1108
1109         ret = ccw_device_set_online(cdev);
1110         if (ret)
1111                 dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1112 }
1113
1114 static int virtio_ccw_probe(struct ccw_device *cdev)
1115 {
1116         cdev->handler = virtio_ccw_int_handler;
1117
1118         if (virtio_ccw_check_autoonline(cdev))
1119                 async_schedule(virtio_ccw_auto_online, cdev);
1120         return 0;
1121 }
1122
1123 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1124 {
1125         unsigned long flags;
1126         struct virtio_ccw_device *vcdev;
1127
1128         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1129         vcdev = dev_get_drvdata(&cdev->dev);
1130         if (!vcdev || vcdev->going_away) {
1131                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1132                 return NULL;
1133         }
1134         vcdev->going_away = true;
1135         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1136         return vcdev;
1137 }
1138
1139 static void virtio_ccw_remove(struct ccw_device *cdev)
1140 {
1141         unsigned long flags;
1142         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1143
1144         if (vcdev && cdev->online) {
1145                 if (vcdev->device_lost)
1146                         virtio_break_device(&vcdev->vdev);
1147                 unregister_virtio_device(&vcdev->vdev);
1148                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1149                 dev_set_drvdata(&cdev->dev, NULL);
1150                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1151         }
1152         cdev->handler = NULL;
1153 }
1154
1155 static int virtio_ccw_offline(struct ccw_device *cdev)
1156 {
1157         unsigned long flags;
1158         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1159
1160         if (!vcdev)
1161                 return 0;
1162         if (vcdev->device_lost)
1163                 virtio_break_device(&vcdev->vdev);
1164         unregister_virtio_device(&vcdev->vdev);
1165         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1166         dev_set_drvdata(&cdev->dev, NULL);
1167         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1168         return 0;
1169 }
1170
1171 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1172 {
1173         struct virtio_rev_info *rev;
1174         struct ccw1 *ccw;
1175         int ret;
1176
1177         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1178         if (!ccw)
1179                 return -ENOMEM;
1180         rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1181         if (!rev) {
1182                 kfree(ccw);
1183                 return -ENOMEM;
1184         }
1185
1186         /* Set transport revision */
1187         ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1188         ccw->flags = 0;
1189         ccw->count = sizeof(*rev);
1190         ccw->cda = (__u32)(unsigned long)rev;
1191
1192         vcdev->revision = VIRTIO_CCW_REV_MAX;
1193         do {
1194                 rev->revision = vcdev->revision;
1195                 /* none of our supported revisions carry payload */
1196                 rev->length = 0;
1197                 ret = ccw_io_helper(vcdev, ccw,
1198                                     VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1199                 if (ret == -EOPNOTSUPP) {
1200                         if (vcdev->revision == 0)
1201                                 /*
1202                                  * The host device does not support setting
1203                                  * the revision: let's operate it in legacy
1204                                  * mode.
1205                                  */
1206                                 ret = 0;
1207                         else
1208                                 vcdev->revision--;
1209                 }
1210         } while (ret == -EOPNOTSUPP);
1211
1212         kfree(ccw);
1213         kfree(rev);
1214         return ret;
1215 }
1216
1217 static int virtio_ccw_online(struct ccw_device *cdev)
1218 {
1219         int ret;
1220         struct virtio_ccw_device *vcdev;
1221         unsigned long flags;
1222
1223         vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1224         if (!vcdev) {
1225                 dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1226                 ret = -ENOMEM;
1227                 goto out_free;
1228         }
1229         vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1230                                    GFP_DMA | GFP_KERNEL);
1231         if (!vcdev->config_block) {
1232                 ret = -ENOMEM;
1233                 goto out_free;
1234         }
1235         vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1236         if (!vcdev->status) {
1237                 ret = -ENOMEM;
1238                 goto out_free;
1239         }
1240
1241         vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1242
1243         vcdev->vdev.dev.parent = &cdev->dev;
1244         vcdev->vdev.dev.release = virtio_ccw_release_dev;
1245         vcdev->vdev.config = &virtio_ccw_config_ops;
1246         vcdev->cdev = cdev;
1247         init_waitqueue_head(&vcdev->wait_q);
1248         INIT_LIST_HEAD(&vcdev->virtqueues);
1249         spin_lock_init(&vcdev->lock);
1250
1251         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1252         dev_set_drvdata(&cdev->dev, vcdev);
1253         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1254         vcdev->vdev.id.vendor = cdev->id.cu_type;
1255         vcdev->vdev.id.device = cdev->id.cu_model;
1256
1257         ret = virtio_ccw_set_transport_rev(vcdev);
1258         if (ret)
1259                 goto out_free;
1260
1261         ret = register_virtio_device(&vcdev->vdev);
1262         if (ret) {
1263                 dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1264                          ret);
1265                 goto out_put;
1266         }
1267         return 0;
1268 out_put:
1269         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1270         dev_set_drvdata(&cdev->dev, NULL);
1271         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1272         put_device(&vcdev->vdev.dev);
1273         return ret;
1274 out_free:
1275         if (vcdev) {
1276                 kfree(vcdev->status);
1277                 kfree(vcdev->config_block);
1278         }
1279         kfree(vcdev);
1280         return ret;
1281 }
1282
1283 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1284 {
1285         int rc;
1286         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1287
1288         /*
1289          * Make sure vcdev is set
1290          * i.e. set_offline/remove callback not already running
1291          */
1292         if (!vcdev)
1293                 return NOTIFY_DONE;
1294
1295         switch (event) {
1296         case CIO_GONE:
1297                 vcdev->device_lost = true;
1298                 rc = NOTIFY_DONE;
1299                 break;
1300         default:
1301                 rc = NOTIFY_DONE;
1302                 break;
1303         }
1304         return rc;
1305 }
1306
1307 static struct ccw_device_id virtio_ids[] = {
1308         { CCW_DEVICE(0x3832, 0) },
1309         {},
1310 };
1311
1312 static struct ccw_driver virtio_ccw_driver = {
1313         .driver = {
1314                 .owner = THIS_MODULE,
1315                 .name = "virtio_ccw",
1316         },
1317         .ids = virtio_ids,
1318         .probe = virtio_ccw_probe,
1319         .remove = virtio_ccw_remove,
1320         .set_offline = virtio_ccw_offline,
1321         .set_online = virtio_ccw_online,
1322         .notify = virtio_ccw_cio_notify,
1323         .int_class = IRQIO_VIR,
1324 };
1325
1326 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1327                            int max_digit, int max_val)
1328 {
1329         int diff;
1330
1331         diff = 0;
1332         *val = 0;
1333
1334         while (diff <= max_digit) {
1335                 int value = hex_to_bin(**cp);
1336
1337                 if (value < 0)
1338                         break;
1339                 *val = *val * 16 + value;
1340                 (*cp)++;
1341                 diff++;
1342         }
1343
1344         if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1345                 return 1;
1346
1347         return 0;
1348 }
1349
1350 static int __init parse_busid(char *str, unsigned int *cssid,
1351                               unsigned int *ssid, unsigned int *devno)
1352 {
1353         char *str_work;
1354         int rc, ret;
1355
1356         rc = 1;
1357
1358         if (*str == '\0')
1359                 goto out;
1360
1361         str_work = str;
1362         ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1363         if (ret || (str_work[0] != '.'))
1364                 goto out;
1365         str_work++;
1366         ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1367         if (ret || (str_work[0] != '.'))
1368                 goto out;
1369         str_work++;
1370         ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1371         if (ret || (str_work[0] != '\0'))
1372                 goto out;
1373
1374         rc = 0;
1375 out:
1376         return rc;
1377 }
1378
1379 static void __init no_auto_parse(void)
1380 {
1381         unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1382         char *parm, *str;
1383         int rc;
1384
1385         str = no_auto;
1386         while ((parm = strsep(&str, ","))) {
1387                 rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1388                                  &from_ssid, &from);
1389                 if (rc)
1390                         continue;
1391                 if (parm != NULL) {
1392                         rc = parse_busid(parm, &to_cssid,
1393                                          &to_ssid, &to);
1394                         if ((from_ssid > to_ssid) ||
1395                             ((from_ssid == to_ssid) && (from > to)))
1396                                 rc = -EINVAL;
1397                 } else {
1398                         to_cssid = from_cssid;
1399                         to_ssid = from_ssid;
1400                         to = from;
1401                 }
1402                 if (rc)
1403                         continue;
1404                 while ((from_ssid < to_ssid) ||
1405                        ((from_ssid == to_ssid) && (from <= to))) {
1406                         set_bit(from, devs_no_auto[from_ssid]);
1407                         from++;
1408                         if (from > __MAX_SUBCHANNEL) {
1409                                 from_ssid++;
1410                                 from = 0;
1411                         }
1412                 }
1413         }
1414 }
1415
1416 static int __init virtio_ccw_init(void)
1417 {
1418         /* parse no_auto string before we do anything further */
1419         no_auto_parse();
1420         return ccw_driver_register(&virtio_ccw_driver);
1421 }
1422 device_initcall(virtio_ccw_init);