Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

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

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