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1/*
2 * Virtio PCI driver
3 *
4 * This module allows virtio devices to be used over a virtual PCI device.
5 * This can be used with QEMU based VMMs like KVM or Xen.
6 *
7 * Copyright IBM Corp. 2007
8 *
9 * Authors:
10 * Anthony Liguori <aliguori@us.ibm.com>
11 *
12 * This work is licensed under the terms of the GNU GPL, version 2 or later.
13 * See the COPYING file in the top-level directory.
14 *
15 */
16
17#include <linux/module.h>
18#include <linux/list.h>
19#include <linux/pci.h>
20#include <linux/slab.h>
21#include <linux/interrupt.h>
22#include <linux/virtio.h>
23#include <linux/virtio_config.h>
24#include <linux/virtio_ring.h>
25#include <linux/virtio_pci.h>
26#include <linux/highmem.h>
27#include <linux/spinlock.h>
28
29MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
30MODULE_DESCRIPTION("virtio-pci");
31MODULE_LICENSE("GPL");
32MODULE_VERSION("1");
33
34/* Our device structure */
35struct virtio_pci_device
36{
37 struct virtio_device vdev;
38 struct pci_dev *pci_dev;
39
40 /* the IO mapping for the PCI config space */
41 void __iomem *ioaddr;
42
43 /* a list of queues so we can dispatch IRQs */
44 spinlock_t lock;
45 struct list_head virtqueues;
46
47 /* MSI-X support */
48 int msix_enabled;
49 int intx_enabled;
50 struct msix_entry *msix_entries;
51 /* Name strings for interrupts. This size should be enough,
52 * and I'm too lazy to allocate each name separately. */
53 char (*msix_names)[256];
54 /* Number of available vectors */
55 unsigned msix_vectors;
56 /* Vectors allocated, excluding per-vq vectors if any */
57 unsigned msix_used_vectors;
58 /* Whether we have vector per vq */
59 bool per_vq_vectors;
60};
61
62/* Constants for MSI-X */
63/* Use first vector for configuration changes, second and the rest for
64 * virtqueues Thus, we need at least 2 vectors for MSI. */
65enum {
66 VP_MSIX_CONFIG_VECTOR = 0,
67 VP_MSIX_VQ_VECTOR = 1,
68};
69
70struct virtio_pci_vq_info
71{
72 /* the actual virtqueue */
73 struct virtqueue *vq;
74
75 /* the number of entries in the queue */
76 int num;
77
78 /* the index of the queue */
79 int queue_index;
80
81 /* the virtual address of the ring queue */
82 void *queue;
83
84 /* the list node for the virtqueues list */
85 struct list_head node;
86
87 /* MSI-X vector (or none) */
88 unsigned msix_vector;
89};
90
91/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
92static struct pci_device_id virtio_pci_id_table[] = {
93 { 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
94 { 0 },
95};
96
97MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
98
99/* Convert a generic virtio device to our structure */
100static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
101{
102 return container_of(vdev, struct virtio_pci_device, vdev);
103}
104
105/* virtio config->get_features() implementation */
106static u32 vp_get_features(struct virtio_device *vdev)
107{
108 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
109
110 /* When someone needs more than 32 feature bits, we'll need to
111 * steal a bit to indicate that the rest are somewhere else. */
112 return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
113}
114
115/* virtio config->finalize_features() implementation */
116static void vp_finalize_features(struct virtio_device *vdev)
117{
118 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
119
120 /* Give virtio_ring a chance to accept features. */
121 vring_transport_features(vdev);
122
123 /* We only support 32 feature bits. */
124 BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
125 iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
126}
127
128/* virtio config->get() implementation */
129static void vp_get(struct virtio_device *vdev, unsigned offset,
130 void *buf, unsigned len)
131{
132 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
133 void __iomem *ioaddr = vp_dev->ioaddr +
134 VIRTIO_PCI_CONFIG(vp_dev) + offset;
135 u8 *ptr = buf;
136 int i;
137
138 for (i = 0; i < len; i++)
139 ptr[i] = ioread8(ioaddr + i);
140}
141
142/* the config->set() implementation. it's symmetric to the config->get()
143 * implementation */
144static void vp_set(struct virtio_device *vdev, unsigned offset,
145 const void *buf, unsigned len)
146{
147 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
148 void __iomem *ioaddr = vp_dev->ioaddr +
149 VIRTIO_PCI_CONFIG(vp_dev) + offset;
150 const u8 *ptr = buf;
151 int i;
152
153 for (i = 0; i < len; i++)
154 iowrite8(ptr[i], ioaddr + i);
155}
156
157/* config->{get,set}_status() implementations */
158static u8 vp_get_status(struct virtio_device *vdev)
159{
160 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
161 return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
162}
163
164static void vp_set_status(struct virtio_device *vdev, u8 status)
165{
166 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
167 /* We should never be setting status to 0. */
168 BUG_ON(status == 0);
169 iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
170}
171
172static void vp_reset(struct virtio_device *vdev)
173{
174 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
175 /* 0 status means a reset. */
176 iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
177}
178
179/* the notify function used when creating a virt queue */
180static void vp_notify(struct virtqueue *vq)
181{
182 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
183 struct virtio_pci_vq_info *info = vq->priv;
184
185 /* we write the queue's selector into the notification register to
186 * signal the other end */
187 iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
188}
189
190/* Handle a configuration change: Tell driver if it wants to know. */
191static irqreturn_t vp_config_changed(int irq, void *opaque)
192{
193 struct virtio_pci_device *vp_dev = opaque;
194 struct virtio_driver *drv;
195 drv = container_of(vp_dev->vdev.dev.driver,
196 struct virtio_driver, driver);
197
198 if (drv && drv->config_changed)
199 drv->config_changed(&vp_dev->vdev);
200 return IRQ_HANDLED;
201}
202
203/* Notify all virtqueues on an interrupt. */
204static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
205{
206 struct virtio_pci_device *vp_dev = opaque;
207 struct virtio_pci_vq_info *info;
208 irqreturn_t ret = IRQ_NONE;
209 unsigned long flags;
210
211 spin_lock_irqsave(&vp_dev->lock, flags);
212 list_for_each_entry(info, &vp_dev->virtqueues, node) {
213 if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
214 ret = IRQ_HANDLED;
215 }
216 spin_unlock_irqrestore(&vp_dev->lock, flags);
217
218 return ret;
219}
220
221/* A small wrapper to also acknowledge the interrupt when it's handled.
222 * I really need an EIO hook for the vring so I can ack the interrupt once we
223 * know that we'll be handling the IRQ but before we invoke the callback since
224 * the callback may notify the host which results in the host attempting to
225 * raise an interrupt that we would then mask once we acknowledged the
226 * interrupt. */
227static irqreturn_t vp_interrupt(int irq, void *opaque)
228{
229 struct virtio_pci_device *vp_dev = opaque;
230 u8 isr;
231
232 /* reading the ISR has the effect of also clearing it so it's very
233 * important to save off the value. */
234 isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
235
236 /* It's definitely not us if the ISR was not high */
237 if (!isr)
238 return IRQ_NONE;
239
240 /* Configuration change? Tell driver if it wants to know. */
241 if (isr & VIRTIO_PCI_ISR_CONFIG)
242 vp_config_changed(irq, opaque);
243
244 return vp_vring_interrupt(irq, opaque);
245}
246
247static void vp_free_vectors(struct virtio_device *vdev)
248{
249 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
250 int i;
251
252 if (vp_dev->intx_enabled) {
253 free_irq(vp_dev->pci_dev->irq, vp_dev);
254 vp_dev->intx_enabled = 0;
255 }
256
257 for (i = 0; i < vp_dev->msix_used_vectors; ++i)
258 free_irq(vp_dev->msix_entries[i].vector, vp_dev);
259
260 if (vp_dev->msix_enabled) {
261 /* Disable the vector used for configuration */
262 iowrite16(VIRTIO_MSI_NO_VECTOR,
263 vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
264 /* Flush the write out to device */
265 ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
266
267 pci_disable_msix(vp_dev->pci_dev);
268 vp_dev->msix_enabled = 0;
269 vp_dev->msix_vectors = 0;
270 }
271
272 vp_dev->msix_used_vectors = 0;
273 kfree(vp_dev->msix_names);
274 vp_dev->msix_names = NULL;
275 kfree(vp_dev->msix_entries);
276 vp_dev->msix_entries = NULL;
277}
278
279static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
280 bool per_vq_vectors)
281{
282 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
283 const char *name = dev_name(&vp_dev->vdev.dev);
284 unsigned i, v;
285 int err = -ENOMEM;
286
287 vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
288 GFP_KERNEL);
289 if (!vp_dev->msix_entries)
290 goto error;
291 vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
292 GFP_KERNEL);
293 if (!vp_dev->msix_names)
294 goto error;
295
296 for (i = 0; i < nvectors; ++i)
297 vp_dev->msix_entries[i].entry = i;
298
299 /* pci_enable_msix returns positive if we can't get this many. */
300 err = pci_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries, nvectors);
301 if (err > 0)
302 err = -ENOSPC;
303 if (err)
304 goto error;
305 vp_dev->msix_vectors = nvectors;
306 vp_dev->msix_enabled = 1;
307
308 /* Set the vector used for configuration */
309 v = vp_dev->msix_used_vectors;
310 snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
311 "%s-config", name);
312 err = request_irq(vp_dev->msix_entries[v].vector,
313 vp_config_changed, 0, vp_dev->msix_names[v],
314 vp_dev);
315 if (err)
316 goto error;
317 ++vp_dev->msix_used_vectors;
318
319 iowrite16(v, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
320 /* Verify we had enough resources to assign the vector */
321 v = ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
322 if (v == VIRTIO_MSI_NO_VECTOR) {
323 err = -EBUSY;
324 goto error;
325 }
326
327 if (!per_vq_vectors) {
328 /* Shared vector for all VQs */
329 v = vp_dev->msix_used_vectors;
330 snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
331 "%s-virtqueues", name);
332 err = request_irq(vp_dev->msix_entries[v].vector,
333 vp_vring_interrupt, 0, vp_dev->msix_names[v],
334 vp_dev);
335 if (err)
336 goto error;
337 ++vp_dev->msix_used_vectors;
338 }
339 return 0;
340error:
341 vp_free_vectors(vdev);
342 return err;
343}
344
345static int vp_request_intx(struct virtio_device *vdev)
346{
347 int err;
348 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
349
350 err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
351 IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
352 if (!err)
353 vp_dev->intx_enabled = 1;
354 return err;
355}
356
357static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
358 void (*callback)(struct virtqueue *vq),
359 const char *name,
360 u16 msix_vec)
361{
362 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
363 struct virtio_pci_vq_info *info;
364 struct virtqueue *vq;
365 unsigned long flags, size;
366 u16 num;
367 int err;
368
369 /* Select the queue we're interested in */
370 iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
371
372 /* Check if queue is either not available or already active. */
373 num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
374 if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
375 return ERR_PTR(-ENOENT);
376
377 /* allocate and fill out our structure the represents an active
378 * queue */
379 info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
380 if (!info)
381 return ERR_PTR(-ENOMEM);
382
383 info->queue_index = index;
384 info->num = num;
385 info->msix_vector = msix_vec;
386
387 size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
388 info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
389 if (info->queue == NULL) {
390 err = -ENOMEM;
391 goto out_info;
392 }
393
394 /* activate the queue */
395 iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
396 vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
397
398 /* create the vring */
399 vq = vring_new_virtqueue(info->num, VIRTIO_PCI_VRING_ALIGN,
400 vdev, info->queue, vp_notify, callback, name);
401 if (!vq) {
402 err = -ENOMEM;
403 goto out_activate_queue;
404 }
405
406 vq->priv = info;
407 info->vq = vq;
408
409 if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
410 iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
411 msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
412 if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
413 err = -EBUSY;
414 goto out_assign;
415 }
416 }
417
418 spin_lock_irqsave(&vp_dev->lock, flags);
419 list_add(&info->node, &vp_dev->virtqueues);
420 spin_unlock_irqrestore(&vp_dev->lock, flags);
421
422 return vq;
423
424out_assign:
425 vring_del_virtqueue(vq);
426out_activate_queue:
427 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
428 free_pages_exact(info->queue, size);
429out_info:
430 kfree(info);
431 return ERR_PTR(err);
432}
433
434static void vp_del_vq(struct virtqueue *vq)
435{
436 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
437 struct virtio_pci_vq_info *info = vq->priv;
438 unsigned long flags, size;
439
440 spin_lock_irqsave(&vp_dev->lock, flags);
441 list_del(&info->node);
442 spin_unlock_irqrestore(&vp_dev->lock, flags);
443
444 iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
445
446 if (vp_dev->msix_enabled) {
447 iowrite16(VIRTIO_MSI_NO_VECTOR,
448 vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
449 /* Flush the write out to device */
450 ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
451 }
452
453 vring_del_virtqueue(vq);
454
455 /* Select and deactivate the queue */
456 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
457
458 size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
459 free_pages_exact(info->queue, size);
460 kfree(info);
461}
462
463/* the config->del_vqs() implementation */
464static void vp_del_vqs(struct virtio_device *vdev)
465{
466 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
467 struct virtqueue *vq, *n;
468 struct virtio_pci_vq_info *info;
469
470 list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
471 info = vq->priv;
472 if (vp_dev->per_vq_vectors &&
473 info->msix_vector != VIRTIO_MSI_NO_VECTOR)
474 free_irq(vp_dev->msix_entries[info->msix_vector].vector,
475 vq);
476 vp_del_vq(vq);
477 }
478 vp_dev->per_vq_vectors = false;
479
480 vp_free_vectors(vdev);
481}
482
483static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
484 struct virtqueue *vqs[],
485 vq_callback_t *callbacks[],
486 const char *names[],
487 bool use_msix,
488 bool per_vq_vectors)
489{
490 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
491 u16 msix_vec;
492 int i, err, nvectors, allocated_vectors;
493
494 if (!use_msix) {
495 /* Old style: one normal interrupt for change and all vqs. */
496 err = vp_request_intx(vdev);
497 if (err)
498 goto error_request;
499 } else {
500 if (per_vq_vectors) {
501 /* Best option: one for change interrupt, one per vq. */
502 nvectors = 1;
503 for (i = 0; i < nvqs; ++i)
504 if (callbacks[i])
505 ++nvectors;
506 } else {
507 /* Second best: one for change, shared for all vqs. */
508 nvectors = 2;
509 }
510
511 err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
512 if (err)
513 goto error_request;
514 }
515
516 vp_dev->per_vq_vectors = per_vq_vectors;
517 allocated_vectors = vp_dev->msix_used_vectors;
518 for (i = 0; i < nvqs; ++i) {
519 if (!callbacks[i] || !vp_dev->msix_enabled)
520 msix_vec = VIRTIO_MSI_NO_VECTOR;
521 else if (vp_dev->per_vq_vectors)
522 msix_vec = allocated_vectors++;
523 else
524 msix_vec = VP_MSIX_VQ_VECTOR;
525 vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
526 if (IS_ERR(vqs[i])) {
527 err = PTR_ERR(vqs[i]);
528 goto error_find;
529 }
530
531 if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
532 continue;
533
534 /* allocate per-vq irq if available and necessary */
535 snprintf(vp_dev->msix_names[msix_vec],
536 sizeof *vp_dev->msix_names,
537 "%s-%s",
538 dev_name(&vp_dev->vdev.dev), names[i]);
539 err = request_irq(vp_dev->msix_entries[msix_vec].vector,
540 vring_interrupt, 0,
541 vp_dev->msix_names[msix_vec],
542 vqs[i]);
543 if (err) {
544 vp_del_vq(vqs[i]);
545 goto error_find;
546 }
547 }
548 return 0;
549
550error_find:
551 vp_del_vqs(vdev);
552
553error_request:
554 return err;
555}
556
557/* the config->find_vqs() implementation */
558static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
559 struct virtqueue *vqs[],
560 vq_callback_t *callbacks[],
561 const char *names[])
562{
563 int err;
564
565 /* Try MSI-X with one vector per queue. */
566 err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
567 if (!err)
568 return 0;
569 /* Fallback: MSI-X with one vector for config, one shared for queues. */
570 err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
571 true, false);
572 if (!err)
573 return 0;
574 /* Finally fall back to regular interrupts. */
575 return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
576 false, false);
577}
578
579static struct virtio_config_ops virtio_pci_config_ops = {
580 .get = vp_get,
581 .set = vp_set,
582 .get_status = vp_get_status,
583 .set_status = vp_set_status,
584 .reset = vp_reset,
585 .find_vqs = vp_find_vqs,
586 .del_vqs = vp_del_vqs,
587 .get_features = vp_get_features,
588 .finalize_features = vp_finalize_features,
589};
590
591static void virtio_pci_release_dev(struct device *_d)
592{
593 struct virtio_device *dev = container_of(_d, struct virtio_device,
594 dev);
595 struct virtio_pci_device *vp_dev = to_vp_device(dev);
596
597 kfree(vp_dev);
598}
599
600/* the PCI probing function */
601static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
602 const struct pci_device_id *id)
603{
604 struct virtio_pci_device *vp_dev;
605 int err;
606
607 /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
608 if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
609 return -ENODEV;
610
611 if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
612 printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
613 VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
614 return -ENODEV;
615 }
616
617 /* allocate our structure and fill it out */
618 vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
619 if (vp_dev == NULL)
620 return -ENOMEM;
621
622 vp_dev->vdev.dev.parent = &pci_dev->dev;
623 vp_dev->vdev.dev.release = virtio_pci_release_dev;
624 vp_dev->vdev.config = &virtio_pci_config_ops;
625 vp_dev->pci_dev = pci_dev;
626 INIT_LIST_HEAD(&vp_dev->virtqueues);
627 spin_lock_init(&vp_dev->lock);
628
629 /* Disable MSI/MSIX to bring device to a known good state. */
630 pci_msi_off(pci_dev);
631
632 /* enable the device */
633 err = pci_enable_device(pci_dev);
634 if (err)
635 goto out;
636
637 err = pci_request_regions(pci_dev, "virtio-pci");
638 if (err)
639 goto out_enable_device;
640
641 vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
642 if (vp_dev->ioaddr == NULL)
643 goto out_req_regions;
644
645 pci_set_drvdata(pci_dev, vp_dev);
646 pci_set_master(pci_dev);
647
648 /* we use the subsystem vendor/device id as the virtio vendor/device
649 * id. this allows us to use the same PCI vendor/device id for all
650 * virtio devices and to identify the particular virtio driver by
651 * the subsystem ids */
652 vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
653 vp_dev->vdev.id.device = pci_dev->subsystem_device;
654
655 /* finally register the virtio device */
656 err = register_virtio_device(&vp_dev->vdev);
657 if (err)
658 goto out_set_drvdata;
659
660 return 0;
661
662out_set_drvdata:
663 pci_set_drvdata(pci_dev, NULL);
664 pci_iounmap(pci_dev, vp_dev->ioaddr);
665out_req_regions:
666 pci_release_regions(pci_dev);
667out_enable_device:
668 pci_disable_device(pci_dev);
669out:
670 kfree(vp_dev);
671 return err;
672}
673
674static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
675{
676 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
677
678 unregister_virtio_device(&vp_dev->vdev);
679
680 vp_del_vqs(&vp_dev->vdev);
681 pci_set_drvdata(pci_dev, NULL);
682 pci_iounmap(pci_dev, vp_dev->ioaddr);
683 pci_release_regions(pci_dev);
684 pci_disable_device(pci_dev);
685}
686
687#ifdef CONFIG_PM
688static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state)
689{
690 pci_save_state(pci_dev);
691 pci_set_power_state(pci_dev, PCI_D3hot);
692 return 0;
693}
694
695static int virtio_pci_resume(struct pci_dev *pci_dev)
696{
697 pci_restore_state(pci_dev);
698 pci_set_power_state(pci_dev, PCI_D0);
699 return 0;
700}
701#endif
702
703static struct pci_driver virtio_pci_driver = {
704 .name = "virtio-pci",
705 .id_table = virtio_pci_id_table,
706 .probe = virtio_pci_probe,
707 .remove = __devexit_p(virtio_pci_remove),
708#ifdef CONFIG_PM
709 .suspend = virtio_pci_suspend,
710 .resume = virtio_pci_resume,
711#endif
712};
713
714static int __init virtio_pci_init(void)
715{
716 return pci_register_driver(&virtio_pci_driver);
717}
718
719module_init(virtio_pci_init);
720
721static void __exit virtio_pci_exit(void)
722{
723 pci_unregister_driver(&virtio_pci_driver);
724}
725
726module_exit(virtio_pci_exit);
1/*
2 * Virtio PCI driver
3 *
4 * This module allows virtio devices to be used over a virtual PCI device.
5 * This can be used with QEMU based VMMs like KVM or Xen.
6 *
7 * Copyright IBM Corp. 2007
8 *
9 * Authors:
10 * Anthony Liguori <aliguori@us.ibm.com>
11 *
12 * This work is licensed under the terms of the GNU GPL, version 2 or later.
13 * See the COPYING file in the top-level directory.
14 *
15 */
16
17#include <linux/module.h>
18#include <linux/list.h>
19#include <linux/pci.h>
20#include <linux/slab.h>
21#include <linux/interrupt.h>
22#include <linux/virtio.h>
23#include <linux/virtio_config.h>
24#include <linux/virtio_ring.h>
25#include <linux/virtio_pci.h>
26#include <linux/highmem.h>
27#include <linux/spinlock.h>
28
29MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
30MODULE_DESCRIPTION("virtio-pci");
31MODULE_LICENSE("GPL");
32MODULE_VERSION("1");
33
34/* Our device structure */
35struct virtio_pci_device
36{
37 struct virtio_device vdev;
38 struct pci_dev *pci_dev;
39
40 /* the IO mapping for the PCI config space */
41 void __iomem *ioaddr;
42
43 /* a list of queues so we can dispatch IRQs */
44 spinlock_t lock;
45 struct list_head virtqueues;
46
47 /* MSI-X support */
48 int msix_enabled;
49 int intx_enabled;
50 struct msix_entry *msix_entries;
51 cpumask_var_t *msix_affinity_masks;
52 /* Name strings for interrupts. This size should be enough,
53 * and I'm too lazy to allocate each name separately. */
54 char (*msix_names)[256];
55 /* Number of available vectors */
56 unsigned msix_vectors;
57 /* Vectors allocated, excluding per-vq vectors if any */
58 unsigned msix_used_vectors;
59
60 /* Status saved during hibernate/restore */
61 u8 saved_status;
62
63 /* Whether we have vector per vq */
64 bool per_vq_vectors;
65};
66
67/* Constants for MSI-X */
68/* Use first vector for configuration changes, second and the rest for
69 * virtqueues Thus, we need at least 2 vectors for MSI. */
70enum {
71 VP_MSIX_CONFIG_VECTOR = 0,
72 VP_MSIX_VQ_VECTOR = 1,
73};
74
75struct virtio_pci_vq_info
76{
77 /* the actual virtqueue */
78 struct virtqueue *vq;
79
80 /* the number of entries in the queue */
81 int num;
82
83 /* the virtual address of the ring queue */
84 void *queue;
85
86 /* the list node for the virtqueues list */
87 struct list_head node;
88
89 /* MSI-X vector (or none) */
90 unsigned msix_vector;
91};
92
93/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
94static DEFINE_PCI_DEVICE_TABLE(virtio_pci_id_table) = {
95 { PCI_DEVICE(0x1af4, PCI_ANY_ID) },
96 { 0 }
97};
98
99MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
100
101/* Convert a generic virtio device to our structure */
102static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
103{
104 return container_of(vdev, struct virtio_pci_device, vdev);
105}
106
107/* virtio config->get_features() implementation */
108static u32 vp_get_features(struct virtio_device *vdev)
109{
110 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
111
112 /* When someone needs more than 32 feature bits, we'll need to
113 * steal a bit to indicate that the rest are somewhere else. */
114 return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
115}
116
117/* virtio config->finalize_features() implementation */
118static void vp_finalize_features(struct virtio_device *vdev)
119{
120 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
121
122 /* Give virtio_ring a chance to accept features. */
123 vring_transport_features(vdev);
124
125 /* We only support 32 feature bits. */
126 BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
127 iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
128}
129
130/* virtio config->get() implementation */
131static void vp_get(struct virtio_device *vdev, unsigned offset,
132 void *buf, unsigned len)
133{
134 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
135 void __iomem *ioaddr = vp_dev->ioaddr +
136 VIRTIO_PCI_CONFIG(vp_dev) + offset;
137 u8 *ptr = buf;
138 int i;
139
140 for (i = 0; i < len; i++)
141 ptr[i] = ioread8(ioaddr + i);
142}
143
144/* the config->set() implementation. it's symmetric to the config->get()
145 * implementation */
146static void vp_set(struct virtio_device *vdev, unsigned offset,
147 const void *buf, unsigned len)
148{
149 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
150 void __iomem *ioaddr = vp_dev->ioaddr +
151 VIRTIO_PCI_CONFIG(vp_dev) + offset;
152 const u8 *ptr = buf;
153 int i;
154
155 for (i = 0; i < len; i++)
156 iowrite8(ptr[i], ioaddr + i);
157}
158
159/* config->{get,set}_status() implementations */
160static u8 vp_get_status(struct virtio_device *vdev)
161{
162 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
163 return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
164}
165
166static void vp_set_status(struct virtio_device *vdev, u8 status)
167{
168 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
169 /* We should never be setting status to 0. */
170 BUG_ON(status == 0);
171 iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
172}
173
174/* wait for pending irq handlers */
175static void vp_synchronize_vectors(struct virtio_device *vdev)
176{
177 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
178 int i;
179
180 if (vp_dev->intx_enabled)
181 synchronize_irq(vp_dev->pci_dev->irq);
182
183 for (i = 0; i < vp_dev->msix_vectors; ++i)
184 synchronize_irq(vp_dev->msix_entries[i].vector);
185}
186
187static void vp_reset(struct virtio_device *vdev)
188{
189 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
190 /* 0 status means a reset. */
191 iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
192 /* Flush out the status write, and flush in device writes,
193 * including MSi-X interrupts, if any. */
194 ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
195 /* Flush pending VQ/configuration callbacks. */
196 vp_synchronize_vectors(vdev);
197}
198
199/* the notify function used when creating a virt queue */
200static bool vp_notify(struct virtqueue *vq)
201{
202 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
203
204 /* we write the queue's selector into the notification register to
205 * signal the other end */
206 iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
207 return true;
208}
209
210/* Handle a configuration change: Tell driver if it wants to know. */
211static irqreturn_t vp_config_changed(int irq, void *opaque)
212{
213 struct virtio_pci_device *vp_dev = opaque;
214 struct virtio_driver *drv;
215 drv = container_of(vp_dev->vdev.dev.driver,
216 struct virtio_driver, driver);
217
218 if (drv && drv->config_changed)
219 drv->config_changed(&vp_dev->vdev);
220 return IRQ_HANDLED;
221}
222
223/* Notify all virtqueues on an interrupt. */
224static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
225{
226 struct virtio_pci_device *vp_dev = opaque;
227 struct virtio_pci_vq_info *info;
228 irqreturn_t ret = IRQ_NONE;
229 unsigned long flags;
230
231 spin_lock_irqsave(&vp_dev->lock, flags);
232 list_for_each_entry(info, &vp_dev->virtqueues, node) {
233 if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
234 ret = IRQ_HANDLED;
235 }
236 spin_unlock_irqrestore(&vp_dev->lock, flags);
237
238 return ret;
239}
240
241/* A small wrapper to also acknowledge the interrupt when it's handled.
242 * I really need an EIO hook for the vring so I can ack the interrupt once we
243 * know that we'll be handling the IRQ but before we invoke the callback since
244 * the callback may notify the host which results in the host attempting to
245 * raise an interrupt that we would then mask once we acknowledged the
246 * interrupt. */
247static irqreturn_t vp_interrupt(int irq, void *opaque)
248{
249 struct virtio_pci_device *vp_dev = opaque;
250 u8 isr;
251
252 /* reading the ISR has the effect of also clearing it so it's very
253 * important to save off the value. */
254 isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
255
256 /* It's definitely not us if the ISR was not high */
257 if (!isr)
258 return IRQ_NONE;
259
260 /* Configuration change? Tell driver if it wants to know. */
261 if (isr & VIRTIO_PCI_ISR_CONFIG)
262 vp_config_changed(irq, opaque);
263
264 return vp_vring_interrupt(irq, opaque);
265}
266
267static void vp_free_vectors(struct virtio_device *vdev)
268{
269 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
270 int i;
271
272 if (vp_dev->intx_enabled) {
273 free_irq(vp_dev->pci_dev->irq, vp_dev);
274 vp_dev->intx_enabled = 0;
275 }
276
277 for (i = 0; i < vp_dev->msix_used_vectors; ++i)
278 free_irq(vp_dev->msix_entries[i].vector, vp_dev);
279
280 for (i = 0; i < vp_dev->msix_vectors; i++)
281 if (vp_dev->msix_affinity_masks[i])
282 free_cpumask_var(vp_dev->msix_affinity_masks[i]);
283
284 if (vp_dev->msix_enabled) {
285 /* Disable the vector used for configuration */
286 iowrite16(VIRTIO_MSI_NO_VECTOR,
287 vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
288 /* Flush the write out to device */
289 ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
290
291 pci_disable_msix(vp_dev->pci_dev);
292 vp_dev->msix_enabled = 0;
293 }
294
295 vp_dev->msix_vectors = 0;
296 vp_dev->msix_used_vectors = 0;
297 kfree(vp_dev->msix_names);
298 vp_dev->msix_names = NULL;
299 kfree(vp_dev->msix_entries);
300 vp_dev->msix_entries = NULL;
301 kfree(vp_dev->msix_affinity_masks);
302 vp_dev->msix_affinity_masks = NULL;
303}
304
305static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
306 bool per_vq_vectors)
307{
308 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
309 const char *name = dev_name(&vp_dev->vdev.dev);
310 unsigned i, v;
311 int err = -ENOMEM;
312
313 vp_dev->msix_vectors = nvectors;
314
315 vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
316 GFP_KERNEL);
317 if (!vp_dev->msix_entries)
318 goto error;
319 vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
320 GFP_KERNEL);
321 if (!vp_dev->msix_names)
322 goto error;
323 vp_dev->msix_affinity_masks
324 = kzalloc(nvectors * sizeof *vp_dev->msix_affinity_masks,
325 GFP_KERNEL);
326 if (!vp_dev->msix_affinity_masks)
327 goto error;
328 for (i = 0; i < nvectors; ++i)
329 if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i],
330 GFP_KERNEL))
331 goto error;
332
333 for (i = 0; i < nvectors; ++i)
334 vp_dev->msix_entries[i].entry = i;
335
336 err = pci_enable_msix_exact(vp_dev->pci_dev,
337 vp_dev->msix_entries, nvectors);
338 if (err)
339 goto error;
340 vp_dev->msix_enabled = 1;
341
342 /* Set the vector used for configuration */
343 v = vp_dev->msix_used_vectors;
344 snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
345 "%s-config", name);
346 err = request_irq(vp_dev->msix_entries[v].vector,
347 vp_config_changed, 0, vp_dev->msix_names[v],
348 vp_dev);
349 if (err)
350 goto error;
351 ++vp_dev->msix_used_vectors;
352
353 iowrite16(v, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
354 /* Verify we had enough resources to assign the vector */
355 v = ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
356 if (v == VIRTIO_MSI_NO_VECTOR) {
357 err = -EBUSY;
358 goto error;
359 }
360
361 if (!per_vq_vectors) {
362 /* Shared vector for all VQs */
363 v = vp_dev->msix_used_vectors;
364 snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
365 "%s-virtqueues", name);
366 err = request_irq(vp_dev->msix_entries[v].vector,
367 vp_vring_interrupt, 0, vp_dev->msix_names[v],
368 vp_dev);
369 if (err)
370 goto error;
371 ++vp_dev->msix_used_vectors;
372 }
373 return 0;
374error:
375 vp_free_vectors(vdev);
376 return err;
377}
378
379static int vp_request_intx(struct virtio_device *vdev)
380{
381 int err;
382 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
383
384 err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
385 IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
386 if (!err)
387 vp_dev->intx_enabled = 1;
388 return err;
389}
390
391static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
392 void (*callback)(struct virtqueue *vq),
393 const char *name,
394 u16 msix_vec)
395{
396 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
397 struct virtio_pci_vq_info *info;
398 struct virtqueue *vq;
399 unsigned long flags, size;
400 u16 num;
401 int err;
402
403 /* Select the queue we're interested in */
404 iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
405
406 /* Check if queue is either not available or already active. */
407 num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
408 if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
409 return ERR_PTR(-ENOENT);
410
411 /* allocate and fill out our structure the represents an active
412 * queue */
413 info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
414 if (!info)
415 return ERR_PTR(-ENOMEM);
416
417 info->num = num;
418 info->msix_vector = msix_vec;
419
420 size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
421 info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
422 if (info->queue == NULL) {
423 err = -ENOMEM;
424 goto out_info;
425 }
426
427 /* activate the queue */
428 iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
429 vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
430
431 /* create the vring */
432 vq = vring_new_virtqueue(index, info->num, VIRTIO_PCI_VRING_ALIGN, vdev,
433 true, info->queue, vp_notify, callback, name);
434 if (!vq) {
435 err = -ENOMEM;
436 goto out_activate_queue;
437 }
438
439 vq->priv = info;
440 info->vq = vq;
441
442 if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
443 iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
444 msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
445 if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
446 err = -EBUSY;
447 goto out_assign;
448 }
449 }
450
451 if (callback) {
452 spin_lock_irqsave(&vp_dev->lock, flags);
453 list_add(&info->node, &vp_dev->virtqueues);
454 spin_unlock_irqrestore(&vp_dev->lock, flags);
455 } else {
456 INIT_LIST_HEAD(&info->node);
457 }
458
459 return vq;
460
461out_assign:
462 vring_del_virtqueue(vq);
463out_activate_queue:
464 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
465 free_pages_exact(info->queue, size);
466out_info:
467 kfree(info);
468 return ERR_PTR(err);
469}
470
471static void vp_del_vq(struct virtqueue *vq)
472{
473 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
474 struct virtio_pci_vq_info *info = vq->priv;
475 unsigned long flags, size;
476
477 spin_lock_irqsave(&vp_dev->lock, flags);
478 list_del(&info->node);
479 spin_unlock_irqrestore(&vp_dev->lock, flags);
480
481 iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
482
483 if (vp_dev->msix_enabled) {
484 iowrite16(VIRTIO_MSI_NO_VECTOR,
485 vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
486 /* Flush the write out to device */
487 ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
488 }
489
490 vring_del_virtqueue(vq);
491
492 /* Select and deactivate the queue */
493 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
494
495 size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
496 free_pages_exact(info->queue, size);
497 kfree(info);
498}
499
500/* the config->del_vqs() implementation */
501static void vp_del_vqs(struct virtio_device *vdev)
502{
503 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
504 struct virtqueue *vq, *n;
505 struct virtio_pci_vq_info *info;
506
507 list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
508 info = vq->priv;
509 if (vp_dev->per_vq_vectors &&
510 info->msix_vector != VIRTIO_MSI_NO_VECTOR)
511 free_irq(vp_dev->msix_entries[info->msix_vector].vector,
512 vq);
513 vp_del_vq(vq);
514 }
515 vp_dev->per_vq_vectors = false;
516
517 vp_free_vectors(vdev);
518}
519
520static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
521 struct virtqueue *vqs[],
522 vq_callback_t *callbacks[],
523 const char *names[],
524 bool use_msix,
525 bool per_vq_vectors)
526{
527 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
528 u16 msix_vec;
529 int i, err, nvectors, allocated_vectors;
530
531 if (!use_msix) {
532 /* Old style: one normal interrupt for change and all vqs. */
533 err = vp_request_intx(vdev);
534 if (err)
535 goto error_request;
536 } else {
537 if (per_vq_vectors) {
538 /* Best option: one for change interrupt, one per vq. */
539 nvectors = 1;
540 for (i = 0; i < nvqs; ++i)
541 if (callbacks[i])
542 ++nvectors;
543 } else {
544 /* Second best: one for change, shared for all vqs. */
545 nvectors = 2;
546 }
547
548 err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
549 if (err)
550 goto error_request;
551 }
552
553 vp_dev->per_vq_vectors = per_vq_vectors;
554 allocated_vectors = vp_dev->msix_used_vectors;
555 for (i = 0; i < nvqs; ++i) {
556 if (!names[i]) {
557 vqs[i] = NULL;
558 continue;
559 } else if (!callbacks[i] || !vp_dev->msix_enabled)
560 msix_vec = VIRTIO_MSI_NO_VECTOR;
561 else if (vp_dev->per_vq_vectors)
562 msix_vec = allocated_vectors++;
563 else
564 msix_vec = VP_MSIX_VQ_VECTOR;
565 vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
566 if (IS_ERR(vqs[i])) {
567 err = PTR_ERR(vqs[i]);
568 goto error_find;
569 }
570
571 if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
572 continue;
573
574 /* allocate per-vq irq if available and necessary */
575 snprintf(vp_dev->msix_names[msix_vec],
576 sizeof *vp_dev->msix_names,
577 "%s-%s",
578 dev_name(&vp_dev->vdev.dev), names[i]);
579 err = request_irq(vp_dev->msix_entries[msix_vec].vector,
580 vring_interrupt, 0,
581 vp_dev->msix_names[msix_vec],
582 vqs[i]);
583 if (err) {
584 vp_del_vq(vqs[i]);
585 goto error_find;
586 }
587 }
588 return 0;
589
590error_find:
591 vp_del_vqs(vdev);
592
593error_request:
594 return err;
595}
596
597/* the config->find_vqs() implementation */
598static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
599 struct virtqueue *vqs[],
600 vq_callback_t *callbacks[],
601 const char *names[])
602{
603 int err;
604
605 /* Try MSI-X with one vector per queue. */
606 err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
607 if (!err)
608 return 0;
609 /* Fallback: MSI-X with one vector for config, one shared for queues. */
610 err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
611 true, false);
612 if (!err)
613 return 0;
614 /* Finally fall back to regular interrupts. */
615 return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
616 false, false);
617}
618
619static const char *vp_bus_name(struct virtio_device *vdev)
620{
621 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
622
623 return pci_name(vp_dev->pci_dev);
624}
625
626/* Setup the affinity for a virtqueue:
627 * - force the affinity for per vq vector
628 * - OR over all affinities for shared MSI
629 * - ignore the affinity request if we're using INTX
630 */
631static int vp_set_vq_affinity(struct virtqueue *vq, int cpu)
632{
633 struct virtio_device *vdev = vq->vdev;
634 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
635 struct virtio_pci_vq_info *info = vq->priv;
636 struct cpumask *mask;
637 unsigned int irq;
638
639 if (!vq->callback)
640 return -EINVAL;
641
642 if (vp_dev->msix_enabled) {
643 mask = vp_dev->msix_affinity_masks[info->msix_vector];
644 irq = vp_dev->msix_entries[info->msix_vector].vector;
645 if (cpu == -1)
646 irq_set_affinity_hint(irq, NULL);
647 else {
648 cpumask_set_cpu(cpu, mask);
649 irq_set_affinity_hint(irq, mask);
650 }
651 }
652 return 0;
653}
654
655static const struct virtio_config_ops virtio_pci_config_ops = {
656 .get = vp_get,
657 .set = vp_set,
658 .get_status = vp_get_status,
659 .set_status = vp_set_status,
660 .reset = vp_reset,
661 .find_vqs = vp_find_vqs,
662 .del_vqs = vp_del_vqs,
663 .get_features = vp_get_features,
664 .finalize_features = vp_finalize_features,
665 .bus_name = vp_bus_name,
666 .set_vq_affinity = vp_set_vq_affinity,
667};
668
669static void virtio_pci_release_dev(struct device *_d)
670{
671 /*
672 * No need for a release method as we allocate/free
673 * all devices together with the pci devices.
674 * Provide an empty one to avoid getting a warning from core.
675 */
676}
677
678/* the PCI probing function */
679static int virtio_pci_probe(struct pci_dev *pci_dev,
680 const struct pci_device_id *id)
681{
682 struct virtio_pci_device *vp_dev;
683 int err;
684
685 /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
686 if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
687 return -ENODEV;
688
689 if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
690 printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
691 VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
692 return -ENODEV;
693 }
694
695 /* allocate our structure and fill it out */
696 vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
697 if (vp_dev == NULL)
698 return -ENOMEM;
699
700 vp_dev->vdev.dev.parent = &pci_dev->dev;
701 vp_dev->vdev.dev.release = virtio_pci_release_dev;
702 vp_dev->vdev.config = &virtio_pci_config_ops;
703 vp_dev->pci_dev = pci_dev;
704 INIT_LIST_HEAD(&vp_dev->virtqueues);
705 spin_lock_init(&vp_dev->lock);
706
707 /* Disable MSI/MSIX to bring device to a known good state. */
708 pci_msi_off(pci_dev);
709
710 /* enable the device */
711 err = pci_enable_device(pci_dev);
712 if (err)
713 goto out;
714
715 err = pci_request_regions(pci_dev, "virtio-pci");
716 if (err)
717 goto out_enable_device;
718
719 vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
720 if (vp_dev->ioaddr == NULL) {
721 err = -ENOMEM;
722 goto out_req_regions;
723 }
724
725 pci_set_drvdata(pci_dev, vp_dev);
726 pci_set_master(pci_dev);
727
728 /* we use the subsystem vendor/device id as the virtio vendor/device
729 * id. this allows us to use the same PCI vendor/device id for all
730 * virtio devices and to identify the particular virtio driver by
731 * the subsystem ids */
732 vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
733 vp_dev->vdev.id.device = pci_dev->subsystem_device;
734
735 /* finally register the virtio device */
736 err = register_virtio_device(&vp_dev->vdev);
737 if (err)
738 goto out_set_drvdata;
739
740 return 0;
741
742out_set_drvdata:
743 pci_iounmap(pci_dev, vp_dev->ioaddr);
744out_req_regions:
745 pci_release_regions(pci_dev);
746out_enable_device:
747 pci_disable_device(pci_dev);
748out:
749 kfree(vp_dev);
750 return err;
751}
752
753static void virtio_pci_remove(struct pci_dev *pci_dev)
754{
755 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
756
757 unregister_virtio_device(&vp_dev->vdev);
758
759 vp_del_vqs(&vp_dev->vdev);
760 pci_iounmap(pci_dev, vp_dev->ioaddr);
761 pci_release_regions(pci_dev);
762 pci_disable_device(pci_dev);
763 kfree(vp_dev);
764}
765
766#ifdef CONFIG_PM_SLEEP
767static int virtio_pci_freeze(struct device *dev)
768{
769 struct pci_dev *pci_dev = to_pci_dev(dev);
770 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
771 struct virtio_driver *drv;
772 int ret;
773
774 drv = container_of(vp_dev->vdev.dev.driver,
775 struct virtio_driver, driver);
776
777 ret = 0;
778 vp_dev->saved_status = vp_get_status(&vp_dev->vdev);
779 if (drv && drv->freeze)
780 ret = drv->freeze(&vp_dev->vdev);
781
782 if (!ret)
783 pci_disable_device(pci_dev);
784 return ret;
785}
786
787static int virtio_pci_restore(struct device *dev)
788{
789 struct pci_dev *pci_dev = to_pci_dev(dev);
790 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
791 struct virtio_driver *drv;
792 int ret;
793
794 drv = container_of(vp_dev->vdev.dev.driver,
795 struct virtio_driver, driver);
796
797 ret = pci_enable_device(pci_dev);
798 if (ret)
799 return ret;
800
801 pci_set_master(pci_dev);
802 vp_finalize_features(&vp_dev->vdev);
803
804 if (drv && drv->restore)
805 ret = drv->restore(&vp_dev->vdev);
806
807 /* Finally, tell the device we're all set */
808 if (!ret)
809 vp_set_status(&vp_dev->vdev, vp_dev->saved_status);
810
811 return ret;
812}
813
814static const struct dev_pm_ops virtio_pci_pm_ops = {
815 SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
816};
817#endif
818
819static struct pci_driver virtio_pci_driver = {
820 .name = "virtio-pci",
821 .id_table = virtio_pci_id_table,
822 .probe = virtio_pci_probe,
823 .remove = virtio_pci_remove,
824#ifdef CONFIG_PM_SLEEP
825 .driver.pm = &virtio_pci_pm_ops,
826#endif
827};
828
829module_pci_driver(virtio_pci_driver);