These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / drivers / s390 / virtio / virtio_ccw.c
1 /*
2  * ccw based virtio transport
3  *
4  * Copyright IBM Corp. 2012, 2014
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License (version 2 only)
8  * as published by the Free Software Foundation.
9  *
10  *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
11  */
12
13 #include <linux/kernel_stat.h>
14 #include <linux/init.h>
15 #include <linux/bootmem.h>
16 #include <linux/err.h>
17 #include <linux/virtio.h>
18 #include <linux/virtio_config.h>
19 #include <linux/slab.h>
20 #include <linux/interrupt.h>
21 #include <linux/virtio_ring.h>
22 #include <linux/pfn.h>
23 #include <linux/async.h>
24 #include <linux/wait.h>
25 #include <linux/list.h>
26 #include <linux/bitops.h>
27 #include <linux/module.h>
28 #include <linux/io.h>
29 #include <linux/kvm_para.h>
30 #include <linux/notifier.h>
31 #include <asm/diag.h>
32 #include <asm/setup.h>
33 #include <asm/irq.h>
34 #include <asm/cio.h>
35 #include <asm/ccwdev.h>
36 #include <asm/virtio-ccw.h>
37 #include <asm/isc.h>
38 #include <asm/airq.h>
39
40 /*
41  * virtio related functions
42  */
43
44 struct vq_config_block {
45         __u16 index;
46         __u16 num;
47 } __packed;
48
49 #define VIRTIO_CCW_CONFIG_SIZE 0x100
50 /* same as PCI config space size, should be enough for all drivers */
51
52 struct virtio_ccw_device {
53         struct virtio_device vdev;
54         __u8 *status;
55         __u8 config[VIRTIO_CCW_CONFIG_SIZE];
56         struct ccw_device *cdev;
57         __u32 curr_io;
58         int err;
59         unsigned int revision; /* Transport revision */
60         wait_queue_head_t wait_q;
61         spinlock_t lock;
62         struct list_head virtqueues;
63         unsigned long indicators;
64         unsigned long indicators2;
65         struct vq_config_block *config_block;
66         bool is_thinint;
67         bool going_away;
68         bool device_lost;
69         unsigned int config_ready;
70         void *airq_info;
71 };
72
73 struct vq_info_block_legacy {
74         __u64 queue;
75         __u32 align;
76         __u16 index;
77         __u16 num;
78 } __packed;
79
80 struct vq_info_block {
81         __u64 desc;
82         __u32 res0;
83         __u16 index;
84         __u16 num;
85         __u64 avail;
86         __u64 used;
87 } __packed;
88
89 struct virtio_feature_desc {
90         __u32 features;
91         __u8 index;
92 } __packed;
93
94 struct virtio_thinint_area {
95         unsigned long summary_indicator;
96         unsigned long indicator;
97         u64 bit_nr;
98         u8 isc;
99 } __packed;
100
101 struct virtio_rev_info {
102         __u16 revision;
103         __u16 length;
104         __u8 data[];
105 };
106
107 /* the highest virtio-ccw revision we support */
108 #define VIRTIO_CCW_REV_MAX 1
109
110 struct virtio_ccw_vq_info {
111         struct virtqueue *vq;
112         int num;
113         void *queue;
114         union {
115                 struct vq_info_block s;
116                 struct vq_info_block_legacy l;
117         } *info_block;
118         int bit_nr;
119         struct list_head node;
120         long cookie;
121 };
122
123 #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
124
125 #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
126 #define MAX_AIRQ_AREAS 20
127
128 static int virtio_ccw_use_airq = 1;
129
130 struct airq_info {
131         rwlock_t lock;
132         u8 summary_indicator;
133         struct airq_struct airq;
134         struct airq_iv *aiv;
135 };
136 static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
137
138 #define CCW_CMD_SET_VQ 0x13
139 #define CCW_CMD_VDEV_RESET 0x33
140 #define CCW_CMD_SET_IND 0x43
141 #define CCW_CMD_SET_CONF_IND 0x53
142 #define CCW_CMD_READ_FEAT 0x12
143 #define CCW_CMD_WRITE_FEAT 0x11
144 #define CCW_CMD_READ_CONF 0x22
145 #define CCW_CMD_WRITE_CONF 0x21
146 #define CCW_CMD_WRITE_STATUS 0x31
147 #define CCW_CMD_READ_VQ_CONF 0x32
148 #define CCW_CMD_SET_IND_ADAPTER 0x73
149 #define CCW_CMD_SET_VIRTIO_REV 0x83
150
151 #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
152 #define VIRTIO_CCW_DOING_RESET 0x00040000
153 #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
154 #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
155 #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
156 #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
157 #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
158 #define VIRTIO_CCW_DOING_SET_IND 0x01000000
159 #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
160 #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
161 #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
162 #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
163 #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
164
165 static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
166 {
167         return container_of(vdev, struct virtio_ccw_device, vdev);
168 }
169
170 static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
171 {
172         unsigned long i, flags;
173
174         write_lock_irqsave(&info->lock, flags);
175         for (i = 0; i < airq_iv_end(info->aiv); i++) {
176                 if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
177                         airq_iv_free_bit(info->aiv, i);
178                         airq_iv_set_ptr(info->aiv, i, 0);
179                         break;
180                 }
181         }
182         write_unlock_irqrestore(&info->lock, flags);
183 }
184
185 static void virtio_airq_handler(struct airq_struct *airq)
186 {
187         struct airq_info *info = container_of(airq, struct airq_info, airq);
188         unsigned long ai;
189
190         inc_irq_stat(IRQIO_VAI);
191         read_lock(&info->lock);
192         /* Walk through indicators field, summary indicator active. */
193         for (ai = 0;;) {
194                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
195                 if (ai == -1UL)
196                         break;
197                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
198         }
199         info->summary_indicator = 0;
200         smp_wmb();
201         /* Walk through indicators field, summary indicator not active. */
202         for (ai = 0;;) {
203                 ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
204                 if (ai == -1UL)
205                         break;
206                 vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
207         }
208         read_unlock(&info->lock);
209 }
210
211 static struct airq_info *new_airq_info(void)
212 {
213         struct airq_info *info;
214         int rc;
215
216         info = kzalloc(sizeof(*info), GFP_KERNEL);
217         if (!info)
218                 return NULL;
219         rwlock_init(&info->lock);
220         info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
221         if (!info->aiv) {
222                 kfree(info);
223                 return NULL;
224         }
225         info->airq.handler = virtio_airq_handler;
226         info->airq.lsi_ptr = &info->summary_indicator;
227         info->airq.lsi_mask = 0xff;
228         info->airq.isc = VIRTIO_AIRQ_ISC;
229         rc = register_adapter_interrupt(&info->airq);
230         if (rc) {
231                 airq_iv_release(info->aiv);
232                 kfree(info);
233                 return NULL;
234         }
235         return info;
236 }
237
238 static void destroy_airq_info(struct airq_info *info)
239 {
240         if (!info)
241                 return;
242
243         unregister_adapter_interrupt(&info->airq);
244         airq_iv_release(info->aiv);
245         kfree(info);
246 }
247
248 static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
249                                         u64 *first, void **airq_info)
250 {
251         int i, j;
252         struct airq_info *info;
253         unsigned long indicator_addr = 0;
254         unsigned long bit, flags;
255
256         for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
257                 if (!airq_areas[i])
258                         airq_areas[i] = new_airq_info();
259                 info = airq_areas[i];
260                 if (!info)
261                         return 0;
262                 write_lock_irqsave(&info->lock, flags);
263                 bit = airq_iv_alloc(info->aiv, nvqs);
264                 if (bit == -1UL) {
265                         /* Not enough vacancies. */
266                         write_unlock_irqrestore(&info->lock, flags);
267                         continue;
268                 }
269                 *first = bit;
270                 *airq_info = info;
271                 indicator_addr = (unsigned long)info->aiv->vector;
272                 for (j = 0; j < nvqs; j++) {
273                         airq_iv_set_ptr(info->aiv, bit + j,
274                                         (unsigned long)vqs[j]);
275                 }
276                 write_unlock_irqrestore(&info->lock, flags);
277         }
278         return indicator_addr;
279 }
280
281 static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
282 {
283         struct virtio_ccw_vq_info *info;
284
285         list_for_each_entry(info, &vcdev->virtqueues, node)
286                 drop_airq_indicator(info->vq, vcdev->airq_info);
287 }
288
289 static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
290 {
291         unsigned long flags;
292         __u32 ret;
293
294         spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
295         if (vcdev->err)
296                 ret = 0;
297         else
298                 ret = vcdev->curr_io & flag;
299         spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
300         return ret;
301 }
302
303 static int ccw_io_helper(struct virtio_ccw_device *vcdev,
304                          struct ccw1 *ccw, __u32 intparm)
305 {
306         int ret;
307         unsigned long flags;
308         int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
309
310         do {
311                 spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
312                 ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
313                 if (!ret) {
314                         if (!vcdev->curr_io)
315                                 vcdev->err = 0;
316                         vcdev->curr_io |= flag;
317                 }
318                 spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
319                 cpu_relax();
320         } while (ret == -EBUSY);
321         wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
322         return ret ? ret : vcdev->err;
323 }
324
325 static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
326                                       struct ccw1 *ccw)
327 {
328         int ret;
329         unsigned long *indicatorp = NULL;
330         struct virtio_thinint_area *thinint_area = NULL;
331         struct airq_info *airq_info = vcdev->airq_info;
332
333         if (vcdev->is_thinint) {
334                 thinint_area = kzalloc(sizeof(*thinint_area),
335                                        GFP_DMA | GFP_KERNEL);
336                 if (!thinint_area)
337                         return;
338                 thinint_area->summary_indicator =
339                         (unsigned long) &airq_info->summary_indicator;
340                 thinint_area->isc = VIRTIO_AIRQ_ISC;
341                 ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
342                 ccw->count = sizeof(*thinint_area);
343                 ccw->cda = (__u32)(unsigned long) thinint_area;
344         } else {
345                 indicatorp = kmalloc(sizeof(&vcdev->indicators),
346                                      GFP_DMA | GFP_KERNEL);
347                 if (!indicatorp)
348                         return;
349                 *indicatorp = 0;
350                 ccw->cmd_code = CCW_CMD_SET_IND;
351                 ccw->count = sizeof(vcdev->indicators);
352                 ccw->cda = (__u32)(unsigned long) indicatorp;
353         }
354         /* Deregister indicators from host. */
355         vcdev->indicators = 0;
356         ccw->flags = 0;
357         ret = ccw_io_helper(vcdev, ccw,
358                             vcdev->is_thinint ?
359                             VIRTIO_CCW_DOING_SET_IND_ADAPTER :
360                             VIRTIO_CCW_DOING_SET_IND);
361         if (ret && (ret != -ENODEV))
362                 dev_info(&vcdev->cdev->dev,
363                          "Failed to deregister indicators (%d)\n", ret);
364         else if (vcdev->is_thinint)
365                 virtio_ccw_drop_indicators(vcdev);
366         kfree(indicatorp);
367         kfree(thinint_area);
368 }
369
370 static inline long __do_kvm_notify(struct subchannel_id schid,
371                                    unsigned long queue_index,
372                                    long cookie)
373 {
374         register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
375         register struct subchannel_id __schid asm("2") = schid;
376         register unsigned long __index asm("3") = queue_index;
377         register long __rc asm("2");
378         register long __cookie asm("4") = cookie;
379
380         asm volatile ("diag 2,4,0x500\n"
381                       : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
382                       "d"(__cookie)
383                       : "memory", "cc");
384         return __rc;
385 }
386
387 static inline long do_kvm_notify(struct subchannel_id schid,
388                                  unsigned long queue_index,
389                                  long cookie)
390 {
391         diag_stat_inc(DIAG_STAT_X500);
392         return __do_kvm_notify(schid, queue_index, cookie);
393 }
394
395 static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
396 {
397         struct virtio_ccw_vq_info *info = vq->priv;
398         struct virtio_ccw_device *vcdev;
399         struct subchannel_id schid;
400
401         vcdev = to_vc_device(info->vq->vdev);
402         ccw_device_get_schid(vcdev->cdev, &schid);
403         info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
404         if (info->cookie < 0)
405                 return false;
406         return true;
407 }
408
409 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
410                                    struct ccw1 *ccw, int index)
411 {
412         int ret;
413
414         vcdev->config_block->index = index;
415         ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
416         ccw->flags = 0;
417         ccw->count = sizeof(struct vq_config_block);
418         ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
419         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
420         if (ret)
421                 return ret;
422         return vcdev->config_block->num;
423 }
424
425 static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
426 {
427         struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
428         struct virtio_ccw_vq_info *info = vq->priv;
429         unsigned long flags;
430         unsigned long size;
431         int ret;
432         unsigned int index = vq->index;
433
434         /* Remove from our list. */
435         spin_lock_irqsave(&vcdev->lock, flags);
436         list_del(&info->node);
437         spin_unlock_irqrestore(&vcdev->lock, flags);
438
439         /* Release from host. */
440         if (vcdev->revision == 0) {
441                 info->info_block->l.queue = 0;
442                 info->info_block->l.align = 0;
443                 info->info_block->l.index = index;
444                 info->info_block->l.num = 0;
445                 ccw->count = sizeof(info->info_block->l);
446         } else {
447                 info->info_block->s.desc = 0;
448                 info->info_block->s.index = index;
449                 info->info_block->s.num = 0;
450                 info->info_block->s.avail = 0;
451                 info->info_block->s.used = 0;
452                 ccw->count = sizeof(info->info_block->s);
453         }
454         ccw->cmd_code = CCW_CMD_SET_VQ;
455         ccw->flags = 0;
456         ccw->cda = (__u32)(unsigned long)(info->info_block);
457         ret = ccw_io_helper(vcdev, ccw,
458                             VIRTIO_CCW_DOING_SET_VQ | index);
459         /*
460          * -ENODEV isn't considered an error: The device is gone anyway.
461          * This may happen on device detach.
462          */
463         if (ret && (ret != -ENODEV))
464                 dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d",
465                          ret, index);
466
467         vring_del_virtqueue(vq);
468         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
469         free_pages_exact(info->queue, size);
470         kfree(info->info_block);
471         kfree(info);
472 }
473
474 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
475 {
476         struct virtqueue *vq, *n;
477         struct ccw1 *ccw;
478         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
479
480         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
481         if (!ccw)
482                 return;
483
484         virtio_ccw_drop_indicator(vcdev, ccw);
485
486         list_for_each_entry_safe(vq, n, &vdev->vqs, list)
487                 virtio_ccw_del_vq(vq, ccw);
488
489         kfree(ccw);
490 }
491
492 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
493                                              int i, vq_callback_t *callback,
494                                              const char *name,
495                                              struct ccw1 *ccw)
496 {
497         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
498         int err;
499         struct virtqueue *vq = NULL;
500         struct virtio_ccw_vq_info *info;
501         unsigned long size = 0; /* silence the compiler */
502         unsigned long flags;
503
504         /* Allocate queue. */
505         info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
506         if (!info) {
507                 dev_warn(&vcdev->cdev->dev, "no info\n");
508                 err = -ENOMEM;
509                 goto out_err;
510         }
511         info->info_block = kzalloc(sizeof(*info->info_block),
512                                    GFP_DMA | GFP_KERNEL);
513         if (!info->info_block) {
514                 dev_warn(&vcdev->cdev->dev, "no info block\n");
515                 err = -ENOMEM;
516                 goto out_err;
517         }
518         info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
519         if (info->num < 0) {
520                 err = info->num;
521                 goto out_err;
522         }
523         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
524         info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
525         if (info->queue == NULL) {
526                 dev_warn(&vcdev->cdev->dev, "no queue\n");
527                 err = -ENOMEM;
528                 goto out_err;
529         }
530
531         vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
532                                  true, info->queue, virtio_ccw_kvm_notify,
533                                  callback, name);
534         if (!vq) {
535                 /* For now, we fail if we can't get the requested size. */
536                 dev_warn(&vcdev->cdev->dev, "no vq\n");
537                 err = -ENOMEM;
538                 goto out_err;
539         }
540
541         /* Register it with the host. */
542         if (vcdev->revision == 0) {
543                 info->info_block->l.queue = (__u64)info->queue;
544                 info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
545                 info->info_block->l.index = i;
546                 info->info_block->l.num = info->num;
547                 ccw->count = sizeof(info->info_block->l);
548         } else {
549                 info->info_block->s.desc = (__u64)info->queue;
550                 info->info_block->s.index = i;
551                 info->info_block->s.num = info->num;
552                 info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
553                 info->info_block->s.used = (__u64)virtqueue_get_used(vq);
554                 ccw->count = sizeof(info->info_block->s);
555         }
556         ccw->cmd_code = CCW_CMD_SET_VQ;
557         ccw->flags = 0;
558         ccw->cda = (__u32)(unsigned long)(info->info_block);
559         err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
560         if (err) {
561                 dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
562                 goto out_err;
563         }
564
565         info->vq = vq;
566         vq->priv = info;
567
568         /* Save it to our list. */
569         spin_lock_irqsave(&vcdev->lock, flags);
570         list_add(&info->node, &vcdev->virtqueues);
571         spin_unlock_irqrestore(&vcdev->lock, flags);
572
573         return vq;
574
575 out_err:
576         if (vq)
577                 vring_del_virtqueue(vq);
578         if (info) {
579                 if (info->queue)
580                         free_pages_exact(info->queue, size);
581                 kfree(info->info_block);
582         }
583         kfree(info);
584         return ERR_PTR(err);
585 }
586
587 static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
588                                            struct virtqueue *vqs[], int nvqs,
589                                            struct ccw1 *ccw)
590 {
591         int ret;
592         struct virtio_thinint_area *thinint_area = NULL;
593         struct airq_info *info;
594
595         thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
596         if (!thinint_area) {
597                 ret = -ENOMEM;
598                 goto out;
599         }
600         /* Try to get an indicator. */
601         thinint_area->indicator = get_airq_indicator(vqs, nvqs,
602                                                      &thinint_area->bit_nr,
603                                                      &vcdev->airq_info);
604         if (!thinint_area->indicator) {
605                 ret = -ENOSPC;
606                 goto out;
607         }
608         info = vcdev->airq_info;
609         thinint_area->summary_indicator =
610                 (unsigned long) &info->summary_indicator;
611         thinint_area->isc = VIRTIO_AIRQ_ISC;
612         ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
613         ccw->flags = CCW_FLAG_SLI;
614         ccw->count = sizeof(*thinint_area);
615         ccw->cda = (__u32)(unsigned long)thinint_area;
616         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
617         if (ret) {
618                 if (ret == -EOPNOTSUPP) {
619                         /*
620                          * The host does not support adapter interrupts
621                          * for virtio-ccw, stop trying.
622                          */
623                         virtio_ccw_use_airq = 0;
624                         pr_info("Adapter interrupts unsupported on host\n");
625                 } else
626                         dev_warn(&vcdev->cdev->dev,
627                                  "enabling adapter interrupts = %d\n", ret);
628                 virtio_ccw_drop_indicators(vcdev);
629         }
630 out:
631         kfree(thinint_area);
632         return ret;
633 }
634
635 static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
636                                struct virtqueue *vqs[],
637                                vq_callback_t *callbacks[],
638                                const char *names[])
639 {
640         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
641         unsigned long *indicatorp = NULL;
642         int ret, i;
643         struct ccw1 *ccw;
644
645         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
646         if (!ccw)
647                 return -ENOMEM;
648
649         for (i = 0; i < nvqs; ++i) {
650                 vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
651                                              ccw);
652                 if (IS_ERR(vqs[i])) {
653                         ret = PTR_ERR(vqs[i]);
654                         vqs[i] = NULL;
655                         goto out;
656                 }
657         }
658         ret = -ENOMEM;
659         /* We need a data area under 2G to communicate. */
660         indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
661         if (!indicatorp)
662                 goto out;
663         *indicatorp = (unsigned long) &vcdev->indicators;
664         if (vcdev->is_thinint) {
665                 ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
666                 if (ret)
667                         /* no error, just fall back to legacy interrupts */
668                         vcdev->is_thinint = 0;
669         }
670         if (!vcdev->is_thinint) {
671                 /* Register queue indicators with host. */
672                 vcdev->indicators = 0;
673                 ccw->cmd_code = CCW_CMD_SET_IND;
674                 ccw->flags = 0;
675                 ccw->count = sizeof(vcdev->indicators);
676                 ccw->cda = (__u32)(unsigned long) indicatorp;
677                 ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
678                 if (ret)
679                         goto out;
680         }
681         /* Register indicators2 with host for config changes */
682         *indicatorp = (unsigned long) &vcdev->indicators2;
683         vcdev->indicators2 = 0;
684         ccw->cmd_code = CCW_CMD_SET_CONF_IND;
685         ccw->flags = 0;
686         ccw->count = sizeof(vcdev->indicators2);
687         ccw->cda = (__u32)(unsigned long) indicatorp;
688         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
689         if (ret)
690                 goto out;
691
692         kfree(indicatorp);
693         kfree(ccw);
694         return 0;
695 out:
696         kfree(indicatorp);
697         kfree(ccw);
698         virtio_ccw_del_vqs(vdev);
699         return ret;
700 }
701
702 static void virtio_ccw_reset(struct virtio_device *vdev)
703 {
704         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
705         struct ccw1 *ccw;
706
707         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
708         if (!ccw)
709                 return;
710
711         /* Zero status bits. */
712         *vcdev->status = 0;
713
714         /* Send a reset ccw on device. */
715         ccw->cmd_code = CCW_CMD_VDEV_RESET;
716         ccw->flags = 0;
717         ccw->count = 0;
718         ccw->cda = 0;
719         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
720         kfree(ccw);
721 }
722
723 static u64 virtio_ccw_get_features(struct virtio_device *vdev)
724 {
725         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
726         struct virtio_feature_desc *features;
727         int ret;
728         u64 rc;
729         struct ccw1 *ccw;
730
731         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
732         if (!ccw)
733                 return 0;
734
735         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
736         if (!features) {
737                 rc = 0;
738                 goto out_free;
739         }
740         /* Read the feature bits from the host. */
741         features->index = 0;
742         ccw->cmd_code = CCW_CMD_READ_FEAT;
743         ccw->flags = 0;
744         ccw->count = sizeof(*features);
745         ccw->cda = (__u32)(unsigned long)features;
746         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
747         if (ret) {
748                 rc = 0;
749                 goto out_free;
750         }
751
752         rc = le32_to_cpu(features->features);
753
754         if (vcdev->revision == 0)
755                 goto out_free;
756
757         /* Read second half of the feature bits from the host. */
758         features->index = 1;
759         ccw->cmd_code = CCW_CMD_READ_FEAT;
760         ccw->flags = 0;
761         ccw->count = sizeof(*features);
762         ccw->cda = (__u32)(unsigned long)features;
763         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
764         if (ret == 0)
765                 rc |= (u64)le32_to_cpu(features->features) << 32;
766
767 out_free:
768         kfree(features);
769         kfree(ccw);
770         return rc;
771 }
772
773 static int virtio_ccw_finalize_features(struct virtio_device *vdev)
774 {
775         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
776         struct virtio_feature_desc *features;
777         struct ccw1 *ccw;
778         int ret;
779
780         if (vcdev->revision >= 1 &&
781             !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
782                 dev_err(&vdev->dev, "virtio: device uses revision 1 "
783                         "but does not have VIRTIO_F_VERSION_1\n");
784                 return -EINVAL;
785         }
786
787         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
788         if (!ccw)
789                 return -ENOMEM;
790
791         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
792         if (!features) {
793                 ret = -ENOMEM;
794                 goto out_free;
795         }
796         /* Give virtio_ring a chance to accept features. */
797         vring_transport_features(vdev);
798
799         features->index = 0;
800         features->features = cpu_to_le32((u32)vdev->features);
801         /* Write the first half of the feature bits to the host. */
802         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
803         ccw->flags = 0;
804         ccw->count = sizeof(*features);
805         ccw->cda = (__u32)(unsigned long)features;
806         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
807         if (ret)
808                 goto out_free;
809
810         if (vcdev->revision == 0)
811                 goto out_free;
812
813         features->index = 1;
814         features->features = cpu_to_le32(vdev->features >> 32);
815         /* Write the second half of the feature bits to the host. */
816         ccw->cmd_code = CCW_CMD_WRITE_FEAT;
817         ccw->flags = 0;
818         ccw->count = sizeof(*features);
819         ccw->cda = (__u32)(unsigned long)features;
820         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
821
822 out_free:
823         kfree(features);
824         kfree(ccw);
825
826         return ret;
827 }
828
829 static void virtio_ccw_get_config(struct virtio_device *vdev,
830                                   unsigned int offset, void *buf, unsigned len)
831 {
832         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
833         int ret;
834         struct ccw1 *ccw;
835         void *config_area;
836
837         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
838         if (!ccw)
839                 return;
840
841         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
842         if (!config_area)
843                 goto out_free;
844
845         /* Read the config area from the host. */
846         ccw->cmd_code = CCW_CMD_READ_CONF;
847         ccw->flags = 0;
848         ccw->count = offset + len;
849         ccw->cda = (__u32)(unsigned long)config_area;
850         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
851         if (ret)
852                 goto out_free;
853
854         memcpy(vcdev->config, config_area, offset + len);
855         if (buf)
856                 memcpy(buf, &vcdev->config[offset], len);
857         if (vcdev->config_ready < offset + len)
858                 vcdev->config_ready = offset + len;
859
860 out_free:
861         kfree(config_area);
862         kfree(ccw);
863 }
864
865 static void virtio_ccw_set_config(struct virtio_device *vdev,
866                                   unsigned int offset, const void *buf,
867                                   unsigned len)
868 {
869         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
870         struct ccw1 *ccw;
871         void *config_area;
872
873         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
874         if (!ccw)
875                 return;
876
877         config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
878         if (!config_area)
879                 goto out_free;
880
881         /* Make sure we don't overwrite fields. */
882         if (vcdev->config_ready < offset)
883                 virtio_ccw_get_config(vdev, 0, NULL, offset);
884         memcpy(&vcdev->config[offset], buf, len);
885         /* Write the config area to the host. */
886         memcpy(config_area, vcdev->config, sizeof(vcdev->config));
887         ccw->cmd_code = CCW_CMD_WRITE_CONF;
888         ccw->flags = 0;
889         ccw->count = offset + len;
890         ccw->cda = (__u32)(unsigned long)config_area;
891         ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
892
893 out_free:
894         kfree(config_area);
895         kfree(ccw);
896 }
897
898 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
899 {
900         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
901
902         return *vcdev->status;
903 }
904
905 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
906 {
907         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
908         u8 old_status = *vcdev->status;
909         struct ccw1 *ccw;
910         int ret;
911
912         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
913         if (!ccw)
914                 return;
915
916         /* Write the status to the host. */
917         *vcdev->status = status;
918         ccw->cmd_code = CCW_CMD_WRITE_STATUS;
919         ccw->flags = 0;
920         ccw->count = sizeof(status);
921         ccw->cda = (__u32)(unsigned long)vcdev->status;
922         ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
923         /* Write failed? We assume status is unchanged. */
924         if (ret)
925                 *vcdev->status = old_status;
926         kfree(ccw);
927 }
928
929 static struct virtio_config_ops virtio_ccw_config_ops = {
930         .get_features = virtio_ccw_get_features,
931         .finalize_features = virtio_ccw_finalize_features,
932         .get = virtio_ccw_get_config,
933         .set = virtio_ccw_set_config,
934         .get_status = virtio_ccw_get_status,
935         .set_status = virtio_ccw_set_status,
936         .reset = virtio_ccw_reset,
937         .find_vqs = virtio_ccw_find_vqs,
938         .del_vqs = virtio_ccw_del_vqs,
939 };
940
941
942 /*
943  * ccw bus driver related functions
944  */
945
946 static void virtio_ccw_release_dev(struct device *_d)
947 {
948         struct virtio_device *dev = container_of(_d, struct virtio_device,
949                                                  dev);
950         struct virtio_ccw_device *vcdev = to_vc_device(dev);
951
952         kfree(vcdev->status);
953         kfree(vcdev->config_block);
954         kfree(vcdev);
955 }
956
957 static int irb_is_error(struct irb *irb)
958 {
959         if (scsw_cstat(&irb->scsw) != 0)
960                 return 1;
961         if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
962                 return 1;
963         if (scsw_cc(&irb->scsw) != 0)
964                 return 1;
965         return 0;
966 }
967
968 static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
969                                               int index)
970 {
971         struct virtio_ccw_vq_info *info;
972         unsigned long flags;
973         struct virtqueue *vq;
974
975         vq = NULL;
976         spin_lock_irqsave(&vcdev->lock, flags);
977         list_for_each_entry(info, &vcdev->virtqueues, node) {
978                 if (info->vq->index == index) {
979                         vq = info->vq;
980                         break;
981                 }
982         }
983         spin_unlock_irqrestore(&vcdev->lock, flags);
984         return vq;
985 }
986
987 static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
988                                       __u32 activity)
989 {
990         if (vcdev->curr_io & activity) {
991                 switch (activity) {
992                 case VIRTIO_CCW_DOING_READ_FEAT:
993                 case VIRTIO_CCW_DOING_WRITE_FEAT:
994                 case VIRTIO_CCW_DOING_READ_CONFIG:
995                 case VIRTIO_CCW_DOING_WRITE_CONFIG:
996                 case VIRTIO_CCW_DOING_WRITE_STATUS:
997                 case VIRTIO_CCW_DOING_SET_VQ:
998                 case VIRTIO_CCW_DOING_SET_IND:
999                 case VIRTIO_CCW_DOING_SET_CONF_IND:
1000                 case VIRTIO_CCW_DOING_RESET:
1001                 case VIRTIO_CCW_DOING_READ_VQ_CONF:
1002                 case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1003                 case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1004                         vcdev->curr_io &= ~activity;
1005                         wake_up(&vcdev->wait_q);
1006                         break;
1007                 default:
1008                         /* don't know what to do... */
1009                         dev_warn(&vcdev->cdev->dev,
1010                                  "Suspicious activity '%08x'\n", activity);
1011                         WARN_ON(1);
1012                         break;
1013                 }
1014         }
1015 }
1016
1017 static void virtio_ccw_int_handler(struct ccw_device *cdev,
1018                                    unsigned long intparm,
1019                                    struct irb *irb)
1020 {
1021         __u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1022         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1023         int i;
1024         struct virtqueue *vq;
1025
1026         if (!vcdev)
1027                 return;
1028         if (IS_ERR(irb)) {
1029                 vcdev->err = PTR_ERR(irb);
1030                 virtio_ccw_check_activity(vcdev, activity);
1031                 /* Don't poke around indicators, something's wrong. */
1032                 return;
1033         }
1034         /* Check if it's a notification from the host. */
1035         if ((intparm == 0) &&
1036             (scsw_stctl(&irb->scsw) ==
1037              (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1038                 /* OK */
1039         }
1040         if (irb_is_error(irb)) {
1041                 /* Command reject? */
1042                 if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1043                     (irb->ecw[0] & SNS0_CMD_REJECT))
1044                         vcdev->err = -EOPNOTSUPP;
1045                 else
1046                         /* Map everything else to -EIO. */
1047                         vcdev->err = -EIO;
1048         }
1049         virtio_ccw_check_activity(vcdev, activity);
1050         for_each_set_bit(i, &vcdev->indicators,
1051                          sizeof(vcdev->indicators) * BITS_PER_BYTE) {
1052                 /* The bit clear must happen before the vring kick. */
1053                 clear_bit(i, &vcdev->indicators);
1054                 barrier();
1055                 vq = virtio_ccw_vq_by_ind(vcdev, i);
1056                 vring_interrupt(0, vq);
1057         }
1058         if (test_bit(0, &vcdev->indicators2)) {
1059                 virtio_config_changed(&vcdev->vdev);
1060                 clear_bit(0, &vcdev->indicators2);
1061         }
1062 }
1063
1064 /*
1065  * We usually want to autoonline all devices, but give the admin
1066  * a way to exempt devices from this.
1067  */
1068 #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1069                      (8*sizeof(long)))
1070 static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1071
1072 static char *no_auto = "";
1073
1074 module_param(no_auto, charp, 0444);
1075 MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1076
1077 static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1078 {
1079         struct ccw_dev_id id;
1080
1081         ccw_device_get_id(cdev, &id);
1082         if (test_bit(id.devno, devs_no_auto[id.ssid]))
1083                 return 0;
1084         return 1;
1085 }
1086
1087 static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1088 {
1089         struct ccw_device *cdev = data;
1090         int ret;
1091
1092         ret = ccw_device_set_online(cdev);
1093         if (ret)
1094                 dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1095 }
1096
1097 static int virtio_ccw_probe(struct ccw_device *cdev)
1098 {
1099         cdev->handler = virtio_ccw_int_handler;
1100
1101         if (virtio_ccw_check_autoonline(cdev))
1102                 async_schedule(virtio_ccw_auto_online, cdev);
1103         return 0;
1104 }
1105
1106 static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1107 {
1108         unsigned long flags;
1109         struct virtio_ccw_device *vcdev;
1110
1111         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1112         vcdev = dev_get_drvdata(&cdev->dev);
1113         if (!vcdev || vcdev->going_away) {
1114                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1115                 return NULL;
1116         }
1117         vcdev->going_away = true;
1118         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1119         return vcdev;
1120 }
1121
1122 static void virtio_ccw_remove(struct ccw_device *cdev)
1123 {
1124         unsigned long flags;
1125         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1126
1127         if (vcdev && cdev->online) {
1128                 if (vcdev->device_lost)
1129                         virtio_break_device(&vcdev->vdev);
1130                 unregister_virtio_device(&vcdev->vdev);
1131                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1132                 dev_set_drvdata(&cdev->dev, NULL);
1133                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1134         }
1135         cdev->handler = NULL;
1136 }
1137
1138 static int virtio_ccw_offline(struct ccw_device *cdev)
1139 {
1140         unsigned long flags;
1141         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1142
1143         if (!vcdev)
1144                 return 0;
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         return 0;
1152 }
1153
1154 static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1155 {
1156         struct virtio_rev_info *rev;
1157         struct ccw1 *ccw;
1158         int ret;
1159
1160         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
1161         if (!ccw)
1162                 return -ENOMEM;
1163         rev = kzalloc(sizeof(*rev), GFP_DMA | GFP_KERNEL);
1164         if (!rev) {
1165                 kfree(ccw);
1166                 return -ENOMEM;
1167         }
1168
1169         /* Set transport revision */
1170         ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1171         ccw->flags = 0;
1172         ccw->count = sizeof(*rev);
1173         ccw->cda = (__u32)(unsigned long)rev;
1174
1175         vcdev->revision = VIRTIO_CCW_REV_MAX;
1176         do {
1177                 rev->revision = vcdev->revision;
1178                 /* none of our supported revisions carry payload */
1179                 rev->length = 0;
1180                 ret = ccw_io_helper(vcdev, ccw,
1181                                     VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1182                 if (ret == -EOPNOTSUPP) {
1183                         if (vcdev->revision == 0)
1184                                 /*
1185                                  * The host device does not support setting
1186                                  * the revision: let's operate it in legacy
1187                                  * mode.
1188                                  */
1189                                 ret = 0;
1190                         else
1191                                 vcdev->revision--;
1192                 }
1193         } while (ret == -EOPNOTSUPP);
1194
1195         kfree(ccw);
1196         kfree(rev);
1197         return ret;
1198 }
1199
1200 static int virtio_ccw_online(struct ccw_device *cdev)
1201 {
1202         int ret;
1203         struct virtio_ccw_device *vcdev;
1204         unsigned long flags;
1205
1206         vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1207         if (!vcdev) {
1208                 dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1209                 ret = -ENOMEM;
1210                 goto out_free;
1211         }
1212         vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
1213                                    GFP_DMA | GFP_KERNEL);
1214         if (!vcdev->config_block) {
1215                 ret = -ENOMEM;
1216                 goto out_free;
1217         }
1218         vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
1219         if (!vcdev->status) {
1220                 ret = -ENOMEM;
1221                 goto out_free;
1222         }
1223
1224         vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1225
1226         vcdev->vdev.dev.parent = &cdev->dev;
1227         vcdev->vdev.dev.release = virtio_ccw_release_dev;
1228         vcdev->vdev.config = &virtio_ccw_config_ops;
1229         vcdev->cdev = cdev;
1230         init_waitqueue_head(&vcdev->wait_q);
1231         INIT_LIST_HEAD(&vcdev->virtqueues);
1232         spin_lock_init(&vcdev->lock);
1233
1234         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1235         dev_set_drvdata(&cdev->dev, vcdev);
1236         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1237         vcdev->vdev.id.vendor = cdev->id.cu_type;
1238         vcdev->vdev.id.device = cdev->id.cu_model;
1239
1240         ret = virtio_ccw_set_transport_rev(vcdev);
1241         if (ret)
1242                 goto out_free;
1243
1244         ret = register_virtio_device(&vcdev->vdev);
1245         if (ret) {
1246                 dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1247                          ret);
1248                 goto out_put;
1249         }
1250         return 0;
1251 out_put:
1252         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1253         dev_set_drvdata(&cdev->dev, NULL);
1254         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1255         put_device(&vcdev->vdev.dev);
1256         return ret;
1257 out_free:
1258         if (vcdev) {
1259                 kfree(vcdev->status);
1260                 kfree(vcdev->config_block);
1261         }
1262         kfree(vcdev);
1263         return ret;
1264 }
1265
1266 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1267 {
1268         int rc;
1269         struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1270
1271         /*
1272          * Make sure vcdev is set
1273          * i.e. set_offline/remove callback not already running
1274          */
1275         if (!vcdev)
1276                 return NOTIFY_DONE;
1277
1278         switch (event) {
1279         case CIO_GONE:
1280                 vcdev->device_lost = true;
1281                 rc = NOTIFY_DONE;
1282                 break;
1283         default:
1284                 rc = NOTIFY_DONE;
1285                 break;
1286         }
1287         return rc;
1288 }
1289
1290 static struct ccw_device_id virtio_ids[] = {
1291         { CCW_DEVICE(0x3832, 0) },
1292         {},
1293 };
1294 MODULE_DEVICE_TABLE(ccw, virtio_ids);
1295
1296 static struct ccw_driver virtio_ccw_driver = {
1297         .driver = {
1298                 .owner = THIS_MODULE,
1299                 .name = "virtio_ccw",
1300         },
1301         .ids = virtio_ids,
1302         .probe = virtio_ccw_probe,
1303         .remove = virtio_ccw_remove,
1304         .set_offline = virtio_ccw_offline,
1305         .set_online = virtio_ccw_online,
1306         .notify = virtio_ccw_cio_notify,
1307         .int_class = IRQIO_VIR,
1308 };
1309
1310 static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1311                            int max_digit, int max_val)
1312 {
1313         int diff;
1314
1315         diff = 0;
1316         *val = 0;
1317
1318         while (diff <= max_digit) {
1319                 int value = hex_to_bin(**cp);
1320
1321                 if (value < 0)
1322                         break;
1323                 *val = *val * 16 + value;
1324                 (*cp)++;
1325                 diff++;
1326         }
1327
1328         if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1329                 return 1;
1330
1331         return 0;
1332 }
1333
1334 static int __init parse_busid(char *str, unsigned int *cssid,
1335                               unsigned int *ssid, unsigned int *devno)
1336 {
1337         char *str_work;
1338         int rc, ret;
1339
1340         rc = 1;
1341
1342         if (*str == '\0')
1343                 goto out;
1344
1345         str_work = str;
1346         ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1347         if (ret || (str_work[0] != '.'))
1348                 goto out;
1349         str_work++;
1350         ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1351         if (ret || (str_work[0] != '.'))
1352                 goto out;
1353         str_work++;
1354         ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1355         if (ret || (str_work[0] != '\0'))
1356                 goto out;
1357
1358         rc = 0;
1359 out:
1360         return rc;
1361 }
1362
1363 static void __init no_auto_parse(void)
1364 {
1365         unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1366         char *parm, *str;
1367         int rc;
1368
1369         str = no_auto;
1370         while ((parm = strsep(&str, ","))) {
1371                 rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1372                                  &from_ssid, &from);
1373                 if (rc)
1374                         continue;
1375                 if (parm != NULL) {
1376                         rc = parse_busid(parm, &to_cssid,
1377                                          &to_ssid, &to);
1378                         if ((from_ssid > to_ssid) ||
1379                             ((from_ssid == to_ssid) && (from > to)))
1380                                 rc = -EINVAL;
1381                 } else {
1382                         to_cssid = from_cssid;
1383                         to_ssid = from_ssid;
1384                         to = from;
1385                 }
1386                 if (rc)
1387                         continue;
1388                 while ((from_ssid < to_ssid) ||
1389                        ((from_ssid == to_ssid) && (from <= to))) {
1390                         set_bit(from, devs_no_auto[from_ssid]);
1391                         from++;
1392                         if (from > __MAX_SUBCHANNEL) {
1393                                 from_ssid++;
1394                                 from = 0;
1395                         }
1396                 }
1397         }
1398 }
1399
1400 static int __init virtio_ccw_init(void)
1401 {
1402         /* parse no_auto string before we do anything further */
1403         no_auto_parse();
1404         return ccw_driver_register(&virtio_ccw_driver);
1405 }
1406 module_init(virtio_ccw_init);
1407
1408 static void __exit virtio_ccw_exit(void)
1409 {
1410         int i;
1411
1412         ccw_driver_unregister(&virtio_ccw_driver);
1413         for (i = 0; i < MAX_AIRQ_AREAS; i++)
1414                 destroy_airq_info(airq_areas[i]);
1415 }
1416 module_exit(virtio_ccw_exit);