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17#include <linux/module.h>
18#include <linux/list.h>
19#include <linux/pci.h>
20#include <linux/interrupt.h>
21#include <linux/virtio.h>
22#include <linux/virtio_config.h>
23#include <linux/virtio_ring.h>
24#include <linux/virtio_pci.h>
25#include <linux/highmem.h>
26#include <linux/spinlock.h>
27
28MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
29MODULE_DESCRIPTION("virtio-pci");
30MODULE_LICENSE("GPL");
31MODULE_VERSION("1");
32
33
34struct virtio_pci_device
35{
36 struct virtio_device vdev;
37 struct pci_dev *pci_dev;
38
39
40 void __iomem *ioaddr;
41
42
43 spinlock_t lock;
44 struct list_head virtqueues;
45
46
47 int msix_enabled;
48 int intx_enabled;
49 struct msix_entry *msix_entries;
50
51
52 char (*msix_names)[256];
53
54 unsigned msix_vectors;
55
56 unsigned msix_used_vectors;
57
58 bool per_vq_vectors;
59};
60
61
62
63
64enum {
65 VP_MSIX_CONFIG_VECTOR = 0,
66 VP_MSIX_VQ_VECTOR = 1,
67};
68
69struct virtio_pci_vq_info
70{
71
72 struct virtqueue *vq;
73
74
75 int num;
76
77
78 int queue_index;
79
80
81 void *queue;
82
83
84 struct list_head node;
85
86
87 unsigned msix_vector;
88};
89
90
91static struct pci_device_id virtio_pci_id_table[] = {
92 { 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
93 { 0 },
94};
95
96MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
97
98
99
100
101static struct device *virtio_pci_root;
102
103
104static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
105{
106 return container_of(vdev, struct virtio_pci_device, vdev);
107}
108
109
110static u32 vp_get_features(struct virtio_device *vdev)
111{
112 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
113
114
115
116 return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
117}
118
119
120static void vp_finalize_features(struct virtio_device *vdev)
121{
122 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
123
124
125 vring_transport_features(vdev);
126
127
128 BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
129 iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
130}
131
132
133static void vp_get(struct virtio_device *vdev, unsigned offset,
134 void *buf, unsigned len)
135{
136 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
137 void __iomem *ioaddr = vp_dev->ioaddr +
138 VIRTIO_PCI_CONFIG(vp_dev) + offset;
139 u8 *ptr = buf;
140 int i;
141
142 for (i = 0; i < len; i++)
143 ptr[i] = ioread8(ioaddr + i);
144}
145
146
147
148static void vp_set(struct virtio_device *vdev, unsigned offset,
149 const void *buf, unsigned len)
150{
151 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
152 void __iomem *ioaddr = vp_dev->ioaddr +
153 VIRTIO_PCI_CONFIG(vp_dev) + offset;
154 const u8 *ptr = buf;
155 int i;
156
157 for (i = 0; i < len; i++)
158 iowrite8(ptr[i], ioaddr + i);
159}
160
161
162static u8 vp_get_status(struct virtio_device *vdev)
163{
164 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
165 return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
166}
167
168static void vp_set_status(struct virtio_device *vdev, u8 status)
169{
170 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
171
172 BUG_ON(status == 0);
173 iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
174}
175
176static void vp_reset(struct virtio_device *vdev)
177{
178 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
179
180 iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
181}
182
183
184static void vp_notify(struct virtqueue *vq)
185{
186 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
187 struct virtio_pci_vq_info *info = vq->priv;
188
189
190
191 iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
192}
193
194
195static irqreturn_t vp_config_changed(int irq, void *opaque)
196{
197 struct virtio_pci_device *vp_dev = opaque;
198 struct virtio_driver *drv;
199 drv = container_of(vp_dev->vdev.dev.driver,
200 struct virtio_driver, driver);
201
202 if (drv && drv->config_changed)
203 drv->config_changed(&vp_dev->vdev);
204 return IRQ_HANDLED;
205}
206
207
208static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
209{
210 struct virtio_pci_device *vp_dev = opaque;
211 struct virtio_pci_vq_info *info;
212 irqreturn_t ret = IRQ_NONE;
213 unsigned long flags;
214
215 spin_lock_irqsave(&vp_dev->lock, flags);
216 list_for_each_entry(info, &vp_dev->virtqueues, node) {
217 if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
218 ret = IRQ_HANDLED;
219 }
220 spin_unlock_irqrestore(&vp_dev->lock, flags);
221
222 return ret;
223}
224
225
226
227
228
229
230
231static irqreturn_t vp_interrupt(int irq, void *opaque)
232{
233 struct virtio_pci_device *vp_dev = opaque;
234 u8 isr;
235
236
237
238 isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
239
240
241 if (!isr)
242 return IRQ_NONE;
243
244
245 if (isr & VIRTIO_PCI_ISR_CONFIG)
246 vp_config_changed(irq, opaque);
247
248 return vp_vring_interrupt(irq, opaque);
249}
250
251static void vp_free_vectors(struct virtio_device *vdev)
252{
253 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
254 int i;
255
256 if (vp_dev->intx_enabled) {
257 free_irq(vp_dev->pci_dev->irq, vp_dev);
258 vp_dev->intx_enabled = 0;
259 }
260
261 for (i = 0; i < vp_dev->msix_used_vectors; ++i)
262 free_irq(vp_dev->msix_entries[i].vector, vp_dev);
263
264 if (vp_dev->msix_enabled) {
265
266 iowrite16(VIRTIO_MSI_NO_VECTOR,
267 vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
268
269 ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
270
271 pci_disable_msix(vp_dev->pci_dev);
272 vp_dev->msix_enabled = 0;
273 vp_dev->msix_vectors = 0;
274 }
275
276 vp_dev->msix_used_vectors = 0;
277 kfree(vp_dev->msix_names);
278 vp_dev->msix_names = NULL;
279 kfree(vp_dev->msix_entries);
280 vp_dev->msix_entries = NULL;
281}
282
283static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
284 bool per_vq_vectors)
285{
286 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
287 const char *name = dev_name(&vp_dev->vdev.dev);
288 unsigned i, v;
289 int err = -ENOMEM;
290
291 vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
292 GFP_KERNEL);
293 if (!vp_dev->msix_entries)
294 goto error;
295 vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
296 GFP_KERNEL);
297 if (!vp_dev->msix_names)
298 goto error;
299
300 for (i = 0; i < nvectors; ++i)
301 vp_dev->msix_entries[i].entry = i;
302
303
304 err = pci_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries, nvectors);
305 if (err > 0)
306 err = -ENOSPC;
307 if (err)
308 goto error;
309 vp_dev->msix_vectors = nvectors;
310 vp_dev->msix_enabled = 1;
311
312
313 v = vp_dev->msix_used_vectors;
314 snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
315 "%s-config", name);
316 err = request_irq(vp_dev->msix_entries[v].vector,
317 vp_config_changed, 0, vp_dev->msix_names[v],
318 vp_dev);
319 if (err)
320 goto error;
321 ++vp_dev->msix_used_vectors;
322
323 iowrite16(v, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
324
325 v = ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
326 if (v == VIRTIO_MSI_NO_VECTOR) {
327 err = -EBUSY;
328 goto error;
329 }
330
331 if (!per_vq_vectors) {
332
333 v = vp_dev->msix_used_vectors;
334 snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
335 "%s-virtqueues", name);
336 err = request_irq(vp_dev->msix_entries[v].vector,
337 vp_vring_interrupt, 0, vp_dev->msix_names[v],
338 vp_dev);
339 if (err)
340 goto error;
341 ++vp_dev->msix_used_vectors;
342 }
343 return 0;
344error:
345 vp_free_vectors(vdev);
346 return err;
347}
348
349static int vp_request_intx(struct virtio_device *vdev)
350{
351 int err;
352 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
353
354 err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
355 IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
356 if (!err)
357 vp_dev->intx_enabled = 1;
358 return err;
359}
360
361static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
362 void (*callback)(struct virtqueue *vq),
363 const char *name,
364 u16 msix_vec)
365{
366 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
367 struct virtio_pci_vq_info *info;
368 struct virtqueue *vq;
369 unsigned long flags, size;
370 u16 num;
371 int err;
372
373
374 iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
375
376
377 num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
378 if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
379 return ERR_PTR(-ENOENT);
380
381
382
383 info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
384 if (!info)
385 return ERR_PTR(-ENOMEM);
386
387 info->queue_index = index;
388 info->num = num;
389 info->msix_vector = msix_vec;
390
391 size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
392 info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
393 if (info->queue == NULL) {
394 err = -ENOMEM;
395 goto out_info;
396 }
397
398
399 iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
400 vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
401
402
403 vq = vring_new_virtqueue(info->num, VIRTIO_PCI_VRING_ALIGN,
404 vdev, info->queue, vp_notify, callback, name);
405 if (!vq) {
406 err = -ENOMEM;
407 goto out_activate_queue;
408 }
409
410 vq->priv = info;
411 info->vq = vq;
412
413 if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
414 iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
415 msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
416 if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
417 err = -EBUSY;
418 goto out_assign;
419 }
420 }
421
422 spin_lock_irqsave(&vp_dev->lock, flags);
423 list_add(&info->node, &vp_dev->virtqueues);
424 spin_unlock_irqrestore(&vp_dev->lock, flags);
425
426 return vq;
427
428out_assign:
429 vring_del_virtqueue(vq);
430out_activate_queue:
431 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
432 free_pages_exact(info->queue, size);
433out_info:
434 kfree(info);
435 return ERR_PTR(err);
436}
437
438static void vp_del_vq(struct virtqueue *vq)
439{
440 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
441 struct virtio_pci_vq_info *info = vq->priv;
442 unsigned long flags, size;
443
444 spin_lock_irqsave(&vp_dev->lock, flags);
445 list_del(&info->node);
446 spin_unlock_irqrestore(&vp_dev->lock, flags);
447
448 iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
449
450 if (vp_dev->msix_enabled) {
451 iowrite16(VIRTIO_MSI_NO_VECTOR,
452 vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
453
454 ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
455 }
456
457 vring_del_virtqueue(vq);
458
459
460 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
461
462 size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
463 free_pages_exact(info->queue, size);
464 kfree(info);
465}
466
467
468static void vp_del_vqs(struct virtio_device *vdev)
469{
470 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
471 struct virtqueue *vq, *n;
472 struct virtio_pci_vq_info *info;
473
474 list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
475 info = vq->priv;
476 if (vp_dev->per_vq_vectors)
477 free_irq(vp_dev->msix_entries[info->msix_vector].vector,
478 vq);
479 vp_del_vq(vq);
480 }
481 vp_dev->per_vq_vectors = false;
482
483 vp_free_vectors(vdev);
484}
485
486static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
487 struct virtqueue *vqs[],
488 vq_callback_t *callbacks[],
489 const char *names[],
490 bool use_msix,
491 bool per_vq_vectors)
492{
493 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
494 u16 msix_vec;
495 int i, err, nvectors, allocated_vectors;
496
497 if (!use_msix) {
498
499 err = vp_request_intx(vdev);
500 if (err)
501 goto error_request;
502 } else {
503 if (per_vq_vectors) {
504
505 nvectors = 1;
506 for (i = 0; i < nvqs; ++i)
507 if (callbacks[i])
508 ++nvectors;
509 } else {
510
511 nvectors = 2;
512 }
513
514 err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
515 if (err)
516 goto error_request;
517 }
518
519 vp_dev->per_vq_vectors = per_vq_vectors;
520 allocated_vectors = vp_dev->msix_used_vectors;
521 for (i = 0; i < nvqs; ++i) {
522 if (!callbacks[i] || !vp_dev->msix_enabled)
523 msix_vec = VIRTIO_MSI_NO_VECTOR;
524 else if (vp_dev->per_vq_vectors)
525 msix_vec = allocated_vectors++;
526 else
527 msix_vec = VP_MSIX_VQ_VECTOR;
528 vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
529 if (IS_ERR(vqs[i])) {
530 err = PTR_ERR(vqs[i]);
531 goto error_find;
532 }
533
534 if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
535 continue;
536
537
538 snprintf(vp_dev->msix_names[msix_vec],
539 sizeof *vp_dev->msix_names,
540 "%s-%s",
541 dev_name(&vp_dev->vdev.dev), names[i]);
542 err = request_irq(vp_dev->msix_entries[msix_vec].vector,
543 vring_interrupt, 0,
544 vp_dev->msix_names[msix_vec],
545 vqs[i]);
546 if (err) {
547 vp_del_vq(vqs[i]);
548 goto error_find;
549 }
550 }
551 return 0;
552
553error_find:
554 vp_del_vqs(vdev);
555
556error_request:
557 return err;
558}
559
560
561static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
562 struct virtqueue *vqs[],
563 vq_callback_t *callbacks[],
564 const char *names[])
565{
566 int err;
567
568
569 err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
570 if (!err)
571 return 0;
572
573 err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
574 true, false);
575 if (!err)
576 return 0;
577
578 return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
579 false, false);
580}
581
582static struct virtio_config_ops virtio_pci_config_ops = {
583 .get = vp_get,
584 .set = vp_set,
585 .get_status = vp_get_status,
586 .set_status = vp_set_status,
587 .reset = vp_reset,
588 .find_vqs = vp_find_vqs,
589 .del_vqs = vp_del_vqs,
590 .get_features = vp_get_features,
591 .finalize_features = vp_finalize_features,
592};
593
594static void virtio_pci_release_dev(struct device *_d)
595{
596 struct virtio_device *dev = container_of(_d, struct virtio_device, dev);
597 struct virtio_pci_device *vp_dev = to_vp_device(dev);
598 struct pci_dev *pci_dev = vp_dev->pci_dev;
599
600 vp_del_vqs(dev);
601 pci_set_drvdata(pci_dev, NULL);
602 pci_iounmap(pci_dev, vp_dev->ioaddr);
603 pci_release_regions(pci_dev);
604 pci_disable_device(pci_dev);
605 kfree(vp_dev);
606}
607
608
609static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
610 const struct pci_device_id *id)
611{
612 struct virtio_pci_device *vp_dev;
613 int err;
614
615
616 if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
617 return -ENODEV;
618
619 if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
620 printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
621 VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
622 return -ENODEV;
623 }
624
625
626 vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
627 if (vp_dev == NULL)
628 return -ENOMEM;
629
630 vp_dev->vdev.dev.parent = virtio_pci_root;
631 vp_dev->vdev.dev.release = virtio_pci_release_dev;
632 vp_dev->vdev.config = &virtio_pci_config_ops;
633 vp_dev->pci_dev = pci_dev;
634 INIT_LIST_HEAD(&vp_dev->virtqueues);
635 spin_lock_init(&vp_dev->lock);
636
637
638 err = pci_enable_device(pci_dev);
639 if (err)
640 goto out;
641
642 err = pci_request_regions(pci_dev, "virtio-pci");
643 if (err)
644 goto out_enable_device;
645
646 vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
647 if (vp_dev->ioaddr == NULL)
648 goto out_req_regions;
649
650 pci_set_drvdata(pci_dev, vp_dev);
651
652
653
654
655
656 vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
657 vp_dev->vdev.id.device = pci_dev->subsystem_device;
658
659
660 err = register_virtio_device(&vp_dev->vdev);
661 if (err)
662 goto out_set_drvdata;
663
664 return 0;
665
666out_set_drvdata:
667 pci_set_drvdata(pci_dev, NULL);
668 pci_iounmap(pci_dev, vp_dev->ioaddr);
669out_req_regions:
670 pci_release_regions(pci_dev);
671out_enable_device:
672 pci_disable_device(pci_dev);
673out:
674 kfree(vp_dev);
675 return err;
676}
677
678static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
679{
680 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
681
682 unregister_virtio_device(&vp_dev->vdev);
683}
684
685#ifdef CONFIG_PM
686static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state)
687{
688 pci_save_state(pci_dev);
689 pci_set_power_state(pci_dev, PCI_D3hot);
690 return 0;
691}
692
693static int virtio_pci_resume(struct pci_dev *pci_dev)
694{
695 pci_restore_state(pci_dev);
696 pci_set_power_state(pci_dev, PCI_D0);
697 return 0;
698}
699#endif
700
701static struct pci_driver virtio_pci_driver = {
702 .name = "virtio-pci",
703 .id_table = virtio_pci_id_table,
704 .probe = virtio_pci_probe,
705 .remove = virtio_pci_remove,
706#ifdef CONFIG_PM
707 .suspend = virtio_pci_suspend,
708 .resume = virtio_pci_resume,
709#endif
710};
711
712static int __init virtio_pci_init(void)
713{
714 int err;
715
716 virtio_pci_root = root_device_register("virtio-pci");
717 if (IS_ERR(virtio_pci_root))
718 return PTR_ERR(virtio_pci_root);
719
720 err = pci_register_driver(&virtio_pci_driver);
721 if (err)
722 root_device_unregister(virtio_pci_root);
723
724 return err;
725}
726
727module_init(virtio_pci_init);
728
729static void __exit virtio_pci_exit(void)
730{
731 pci_unregister_driver(&virtio_pci_driver);
732 root_device_unregister(virtio_pci_root);
733}
734
735module_exit(virtio_pci_exit);
736