1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Virtio PCI driver - modern (virtio 1.0) device support
4 *
5 * This module allows virtio devices to be used over a virtual PCI device.
6 * This can be used with QEMU based VMMs like KVM or Xen.
7 *
8 * Copyright IBM Corp. 2007
9 * Copyright Red Hat, Inc. 2014
10 *
11 * Authors:
12 * Anthony Liguori <aliguori@us.ibm.com>
13 * Rusty Russell <rusty@rustcorp.com.au>
14 * Michael S. Tsirkin <mst@redhat.com>
15 */
16
17 #include <linux/delay.h>
18 #define VIRTIO_PCI_NO_LEGACY
19 #define VIRTIO_RING_NO_LEGACY
20 #include "virtio_pci_common.h"
21
22 /*
23 * Type-safe wrappers for io accesses.
24 * Use these to enforce at compile time the following spec requirement:
25 *
26 * The driver MUST access each field using the “natural” access
27 * method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses
28 * for 16-bit fields and 8-bit accesses for 8-bit fields.
29 */
vp_ioread8(const u8 __iomem * addr)30 static inline u8 vp_ioread8(const u8 __iomem *addr)
31 {
32 return ioread8(addr);
33 }
vp_ioread16(const __le16 __iomem * addr)34 static inline u16 vp_ioread16 (const __le16 __iomem *addr)
35 {
36 return ioread16(addr);
37 }
38
vp_ioread32(const __le32 __iomem * addr)39 static inline u32 vp_ioread32(const __le32 __iomem *addr)
40 {
41 return ioread32(addr);
42 }
43
vp_iowrite8(u8 value,u8 __iomem * addr)44 static inline void vp_iowrite8(u8 value, u8 __iomem *addr)
45 {
46 iowrite8(value, addr);
47 }
48
vp_iowrite16(u16 value,__le16 __iomem * addr)49 static inline void vp_iowrite16(u16 value, __le16 __iomem *addr)
50 {
51 iowrite16(value, addr);
52 }
53
vp_iowrite32(u32 value,__le32 __iomem * addr)54 static inline void vp_iowrite32(u32 value, __le32 __iomem *addr)
55 {
56 iowrite32(value, addr);
57 }
58
vp_iowrite64_twopart(u64 val,__le32 __iomem * lo,__le32 __iomem * hi)59 static void vp_iowrite64_twopart(u64 val,
60 __le32 __iomem *lo, __le32 __iomem *hi)
61 {
62 vp_iowrite32((u32)val, lo);
63 vp_iowrite32(val >> 32, hi);
64 }
65
map_capability(struct pci_dev * dev,int off,size_t minlen,u32 align,u32 start,u32 size,size_t * len)66 static void __iomem *map_capability(struct pci_dev *dev, int off,
67 size_t minlen,
68 u32 align,
69 u32 start, u32 size,
70 size_t *len)
71 {
72 u8 bar;
73 u32 offset, length;
74 void __iomem *p;
75
76 pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
77 bar),
78 &bar);
79 pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
80 &offset);
81 pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
82 &length);
83
84 if (length <= start) {
85 dev_err(&dev->dev,
86 "virtio_pci: bad capability len %u (>%u expected)\n",
87 length, start);
88 return NULL;
89 }
90
91 if (length - start < minlen) {
92 dev_err(&dev->dev,
93 "virtio_pci: bad capability len %u (>=%zu expected)\n",
94 length, minlen);
95 return NULL;
96 }
97
98 length -= start;
99
100 if (start + offset < offset) {
101 dev_err(&dev->dev,
102 "virtio_pci: map wrap-around %u+%u\n",
103 start, offset);
104 return NULL;
105 }
106
107 offset += start;
108
109 if (offset & (align - 1)) {
110 dev_err(&dev->dev,
111 "virtio_pci: offset %u not aligned to %u\n",
112 offset, align);
113 return NULL;
114 }
115
116 if (length > size)
117 length = size;
118
119 if (len)
120 *len = length;
121
122 if (minlen + offset < minlen ||
123 minlen + offset > pci_resource_len(dev, bar)) {
124 dev_err(&dev->dev,
125 "virtio_pci: map virtio %zu@%u "
126 "out of range on bar %i length %lu\n",
127 minlen, offset,
128 bar, (unsigned long)pci_resource_len(dev, bar));
129 return NULL;
130 }
131
132 p = pci_iomap_range(dev, bar, offset, length);
133 if (!p)
134 dev_err(&dev->dev,
135 "virtio_pci: unable to map virtio %u@%u on bar %i\n",
136 length, offset, bar);
137 return p;
138 }
139
140 /* virtio config->get_features() implementation */
vp_get_features(struct virtio_device * vdev)141 static u64 vp_get_features(struct virtio_device *vdev)
142 {
143 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
144 u64 features;
145
146 vp_iowrite32(0, &vp_dev->common->device_feature_select);
147 features = vp_ioread32(&vp_dev->common->device_feature);
148 vp_iowrite32(1, &vp_dev->common->device_feature_select);
149 features |= ((u64)vp_ioread32(&vp_dev->common->device_feature) << 32);
150
151 return features;
152 }
153
vp_transport_features(struct virtio_device * vdev,u64 features)154 static void vp_transport_features(struct virtio_device *vdev, u64 features)
155 {
156 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
157 struct pci_dev *pci_dev = vp_dev->pci_dev;
158
159 if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
160 pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))
161 __virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
162 }
163
164 /* virtio config->finalize_features() implementation */
vp_finalize_features(struct virtio_device * vdev)165 static int vp_finalize_features(struct virtio_device *vdev)
166 {
167 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
168 u64 features = vdev->features;
169
170 /* Give virtio_ring a chance to accept features. */
171 vring_transport_features(vdev);
172
173 /* Give virtio_pci a chance to accept features. */
174 vp_transport_features(vdev, features);
175
176 if (!__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
177 dev_err(&vdev->dev, "virtio: device uses modern interface "
178 "but does not have VIRTIO_F_VERSION_1\n");
179 return -EINVAL;
180 }
181
182 vp_iowrite32(0, &vp_dev->common->guest_feature_select);
183 vp_iowrite32((u32)vdev->features, &vp_dev->common->guest_feature);
184 vp_iowrite32(1, &vp_dev->common->guest_feature_select);
185 vp_iowrite32(vdev->features >> 32, &vp_dev->common->guest_feature);
186
187 return 0;
188 }
189
190 /* virtio config->get() implementation */
vp_get(struct virtio_device * vdev,unsigned offset,void * buf,unsigned len)191 static void vp_get(struct virtio_device *vdev, unsigned offset,
192 void *buf, unsigned len)
193 {
194 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
195 u8 b;
196 __le16 w;
197 __le32 l;
198
199 BUG_ON(offset + len > vp_dev->device_len);
200
201 switch (len) {
202 case 1:
203 b = ioread8(vp_dev->device + offset);
204 memcpy(buf, &b, sizeof b);
205 break;
206 case 2:
207 w = cpu_to_le16(ioread16(vp_dev->device + offset));
208 memcpy(buf, &w, sizeof w);
209 break;
210 case 4:
211 l = cpu_to_le32(ioread32(vp_dev->device + offset));
212 memcpy(buf, &l, sizeof l);
213 break;
214 case 8:
215 l = cpu_to_le32(ioread32(vp_dev->device + offset));
216 memcpy(buf, &l, sizeof l);
217 l = cpu_to_le32(ioread32(vp_dev->device + offset + sizeof l));
218 memcpy(buf + sizeof l, &l, sizeof l);
219 break;
220 default:
221 BUG();
222 }
223 }
224
225 /* the config->set() implementation. it's symmetric to the config->get()
226 * implementation */
vp_set(struct virtio_device * vdev,unsigned offset,const void * buf,unsigned len)227 static void vp_set(struct virtio_device *vdev, unsigned offset,
228 const void *buf, unsigned len)
229 {
230 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
231 u8 b;
232 __le16 w;
233 __le32 l;
234
235 BUG_ON(offset + len > vp_dev->device_len);
236
237 switch (len) {
238 case 1:
239 memcpy(&b, buf, sizeof b);
240 iowrite8(b, vp_dev->device + offset);
241 break;
242 case 2:
243 memcpy(&w, buf, sizeof w);
244 iowrite16(le16_to_cpu(w), vp_dev->device + offset);
245 break;
246 case 4:
247 memcpy(&l, buf, sizeof l);
248 iowrite32(le32_to_cpu(l), vp_dev->device + offset);
249 break;
250 case 8:
251 memcpy(&l, buf, sizeof l);
252 iowrite32(le32_to_cpu(l), vp_dev->device + offset);
253 memcpy(&l, buf + sizeof l, sizeof l);
254 iowrite32(le32_to_cpu(l), vp_dev->device + offset + sizeof l);
255 break;
256 default:
257 BUG();
258 }
259 }
260
vp_generation(struct virtio_device * vdev)261 static u32 vp_generation(struct virtio_device *vdev)
262 {
263 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
264 return vp_ioread8(&vp_dev->common->config_generation);
265 }
266
267 /* config->{get,set}_status() implementations */
vp_get_status(struct virtio_device * vdev)268 static u8 vp_get_status(struct virtio_device *vdev)
269 {
270 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
271 return vp_ioread8(&vp_dev->common->device_status);
272 }
273
vp_set_status(struct virtio_device * vdev,u8 status)274 static void vp_set_status(struct virtio_device *vdev, u8 status)
275 {
276 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
277 /* We should never be setting status to 0. */
278 BUG_ON(status == 0);
279 vp_iowrite8(status, &vp_dev->common->device_status);
280 }
281
vp_reset(struct virtio_device * vdev)282 static void vp_reset(struct virtio_device *vdev)
283 {
284 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
285 /* 0 status means a reset. */
286 vp_iowrite8(0, &vp_dev->common->device_status);
287 /* After writing 0 to device_status, the driver MUST wait for a read of
288 * device_status to return 0 before reinitializing the device.
289 * This will flush out the status write, and flush in device writes,
290 * including MSI-X interrupts, if any.
291 */
292 while (vp_ioread8(&vp_dev->common->device_status))
293 msleep(1);
294 /* Flush pending VQ/configuration callbacks. */
295 vp_synchronize_vectors(vdev);
296 }
297
vp_config_vector(struct virtio_pci_device * vp_dev,u16 vector)298 static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
299 {
300 /* Setup the vector used for configuration events */
301 vp_iowrite16(vector, &vp_dev->common->msix_config);
302 /* Verify we had enough resources to assign the vector */
303 /* Will also flush the write out to device */
304 return vp_ioread16(&vp_dev->common->msix_config);
305 }
306
setup_vq(struct virtio_pci_device * vp_dev,struct virtio_pci_vq_info * info,unsigned index,void (* callback)(struct virtqueue * vq),const char * name,bool ctx,u16 msix_vec)307 static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
308 struct virtio_pci_vq_info *info,
309 unsigned index,
310 void (*callback)(struct virtqueue *vq),
311 const char *name,
312 bool ctx,
313 u16 msix_vec)
314 {
315 struct virtio_pci_common_cfg __iomem *cfg = vp_dev->common;
316 struct virtqueue *vq;
317 u16 num, off;
318 int err;
319
320 if (index >= vp_ioread16(&cfg->num_queues))
321 return ERR_PTR(-ENOENT);
322
323 /* Select the queue we're interested in */
324 vp_iowrite16(index, &cfg->queue_select);
325
326 /* Check if queue is either not available or already active. */
327 num = vp_ioread16(&cfg->queue_size);
328 if (!num || vp_ioread16(&cfg->queue_enable))
329 return ERR_PTR(-ENOENT);
330
331 if (num & (num - 1)) {
332 dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u", num);
333 return ERR_PTR(-EINVAL);
334 }
335
336 /* get offset of notification word for this vq */
337 off = vp_ioread16(&cfg->queue_notify_off);
338
339 info->msix_vector = msix_vec;
340
341 /* create the vring */
342 vq = vring_create_virtqueue(index, num,
343 SMP_CACHE_BYTES, &vp_dev->vdev,
344 true, true, ctx,
345 vp_notify, callback, name);
346 if (!vq)
347 return ERR_PTR(-ENOMEM);
348
349 /* activate the queue */
350 vp_iowrite16(virtqueue_get_vring_size(vq), &cfg->queue_size);
351 vp_iowrite64_twopart(virtqueue_get_desc_addr(vq),
352 &cfg->queue_desc_lo, &cfg->queue_desc_hi);
353 vp_iowrite64_twopart(virtqueue_get_avail_addr(vq),
354 &cfg->queue_avail_lo, &cfg->queue_avail_hi);
355 vp_iowrite64_twopart(virtqueue_get_used_addr(vq),
356 &cfg->queue_used_lo, &cfg->queue_used_hi);
357
358 if (vp_dev->notify_base) {
359 /* offset should not wrap */
360 if ((u64)off * vp_dev->notify_offset_multiplier + 2
361 > vp_dev->notify_len) {
362 dev_warn(&vp_dev->pci_dev->dev,
363 "bad notification offset %u (x %u) "
364 "for queue %u > %zd",
365 off, vp_dev->notify_offset_multiplier,
366 index, vp_dev->notify_len);
367 err = -EINVAL;
368 goto err_map_notify;
369 }
370 vq->priv = (void __force *)vp_dev->notify_base +
371 off * vp_dev->notify_offset_multiplier;
372 } else {
373 vq->priv = (void __force *)map_capability(vp_dev->pci_dev,
374 vp_dev->notify_map_cap, 2, 2,
375 off * vp_dev->notify_offset_multiplier, 2,
376 NULL);
377 }
378
379 if (!vq->priv) {
380 err = -ENOMEM;
381 goto err_map_notify;
382 }
383
384 if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
385 vp_iowrite16(msix_vec, &cfg->queue_msix_vector);
386 msix_vec = vp_ioread16(&cfg->queue_msix_vector);
387 if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
388 err = -EBUSY;
389 goto err_assign_vector;
390 }
391 }
392
393 return vq;
394
395 err_assign_vector:
396 if (!vp_dev->notify_base)
397 pci_iounmap(vp_dev->pci_dev, (void __iomem __force *)vq->priv);
398 err_map_notify:
399 vring_del_virtqueue(vq);
400 return ERR_PTR(err);
401 }
402
vp_modern_find_vqs(struct virtio_device * vdev,unsigned nvqs,struct virtqueue * vqs[],vq_callback_t * callbacks[],const char * const names[],const bool * ctx,struct irq_affinity * desc)403 static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned nvqs,
404 struct virtqueue *vqs[],
405 vq_callback_t *callbacks[],
406 const char * const names[], const bool *ctx,
407 struct irq_affinity *desc)
408 {
409 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
410 struct virtqueue *vq;
411 int rc = vp_find_vqs(vdev, nvqs, vqs, callbacks, names, ctx, desc);
412
413 if (rc)
414 return rc;
415
416 /* Select and activate all queues. Has to be done last: once we do
417 * this, there's no way to go back except reset.
418 */
419 list_for_each_entry(vq, &vdev->vqs, list) {
420 vp_iowrite16(vq->index, &vp_dev->common->queue_select);
421 vp_iowrite16(1, &vp_dev->common->queue_enable);
422 }
423
424 return 0;
425 }
426
del_vq(struct virtio_pci_vq_info * info)427 static void del_vq(struct virtio_pci_vq_info *info)
428 {
429 struct virtqueue *vq = info->vq;
430 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
431
432 vp_iowrite16(vq->index, &vp_dev->common->queue_select);
433
434 if (vp_dev->msix_enabled) {
435 vp_iowrite16(VIRTIO_MSI_NO_VECTOR,
436 &vp_dev->common->queue_msix_vector);
437 /* Flush the write out to device */
438 vp_ioread16(&vp_dev->common->queue_msix_vector);
439 }
440
441 if (!vp_dev->notify_base)
442 pci_iounmap(vp_dev->pci_dev, (void __force __iomem *)vq->priv);
443
444 vring_del_virtqueue(vq);
445 }
446
virtio_pci_find_shm_cap(struct pci_dev * dev,u8 required_id,u8 * bar,u64 * offset,u64 * len)447 static int virtio_pci_find_shm_cap(struct pci_dev *dev, u8 required_id,
448 u8 *bar, u64 *offset, u64 *len)
449 {
450 int pos;
451
452 for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); pos > 0;
453 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
454 u8 type, cap_len, id;
455 u32 tmp32;
456 u64 res_offset, res_length;
457
458 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
459 cfg_type), &type);
460 if (type != VIRTIO_PCI_CAP_SHARED_MEMORY_CFG)
461 continue;
462
463 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
464 cap_len), &cap_len);
465 if (cap_len != sizeof(struct virtio_pci_cap64)) {
466 dev_err(&dev->dev, "%s: shm cap with bad size offset:"
467 " %d size: %d\n", __func__, pos, cap_len);
468 continue;
469 }
470
471 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
472 id), &id);
473 if (id != required_id)
474 continue;
475
476 /* Type, and ID match, looks good */
477 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
478 bar), bar);
479
480 /* Read the lower 32bit of length and offset */
481 pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap,
482 offset), &tmp32);
483 res_offset = tmp32;
484 pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap,
485 length), &tmp32);
486 res_length = tmp32;
487
488 /* and now the top half */
489 pci_read_config_dword(dev,
490 pos + offsetof(struct virtio_pci_cap64,
491 offset_hi), &tmp32);
492 res_offset |= ((u64)tmp32) << 32;
493 pci_read_config_dword(dev,
494 pos + offsetof(struct virtio_pci_cap64,
495 length_hi), &tmp32);
496 res_length |= ((u64)tmp32) << 32;
497
498 *offset = res_offset;
499 *len = res_length;
500
501 return pos;
502 }
503 return 0;
504 }
505
vp_get_shm_region(struct virtio_device * vdev,struct virtio_shm_region * region,u8 id)506 static bool vp_get_shm_region(struct virtio_device *vdev,
507 struct virtio_shm_region *region, u8 id)
508 {
509 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
510 struct pci_dev *pci_dev = vp_dev->pci_dev;
511 u8 bar;
512 u64 offset, len;
513 phys_addr_t phys_addr;
514 size_t bar_len;
515
516 if (!virtio_pci_find_shm_cap(pci_dev, id, &bar, &offset, &len))
517 return false;
518
519 phys_addr = pci_resource_start(pci_dev, bar);
520 bar_len = pci_resource_len(pci_dev, bar);
521
522 if ((offset + len) < offset) {
523 dev_err(&pci_dev->dev, "%s: cap offset+len overflow detected\n",
524 __func__);
525 return false;
526 }
527
528 if (offset + len > bar_len) {
529 dev_err(&pci_dev->dev, "%s: bar shorter than cap offset+len\n",
530 __func__);
531 return false;
532 }
533
534 region->len = len;
535 region->addr = (u64) phys_addr + offset;
536
537 return true;
538 }
539
540 static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
541 .get = NULL,
542 .set = NULL,
543 .generation = vp_generation,
544 .get_status = vp_get_status,
545 .set_status = vp_set_status,
546 .reset = vp_reset,
547 .find_vqs = vp_modern_find_vqs,
548 .del_vqs = vp_del_vqs,
549 .get_features = vp_get_features,
550 .finalize_features = vp_finalize_features,
551 .bus_name = vp_bus_name,
552 .set_vq_affinity = vp_set_vq_affinity,
553 .get_vq_affinity = vp_get_vq_affinity,
554 .get_shm_region = vp_get_shm_region,
555 };
556
557 static const struct virtio_config_ops virtio_pci_config_ops = {
558 .get = vp_get,
559 .set = vp_set,
560 .generation = vp_generation,
561 .get_status = vp_get_status,
562 .set_status = vp_set_status,
563 .reset = vp_reset,
564 .find_vqs = vp_modern_find_vqs,
565 .del_vqs = vp_del_vqs,
566 .get_features = vp_get_features,
567 .finalize_features = vp_finalize_features,
568 .bus_name = vp_bus_name,
569 .set_vq_affinity = vp_set_vq_affinity,
570 .get_vq_affinity = vp_get_vq_affinity,
571 .get_shm_region = vp_get_shm_region,
572 };
573
574 /**
575 * virtio_pci_find_capability - walk capabilities to find device info.
576 * @dev: the pci device
577 * @cfg_type: the VIRTIO_PCI_CAP_* value we seek
578 * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
579 * @bars: the bitmask of BARs
580 *
581 * Returns offset of the capability, or 0.
582 */
virtio_pci_find_capability(struct pci_dev * dev,u8 cfg_type,u32 ioresource_types,int * bars)583 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
584 u32 ioresource_types, int *bars)
585 {
586 int pos;
587
588 for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
589 pos > 0;
590 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
591 u8 type, bar;
592 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
593 cfg_type),
594 &type);
595 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
596 bar),
597 &bar);
598
599 /* Ignore structures with reserved BAR values */
600 if (bar > 0x5)
601 continue;
602
603 if (type == cfg_type) {
604 if (pci_resource_len(dev, bar) &&
605 pci_resource_flags(dev, bar) & ioresource_types) {
606 *bars |= (1 << bar);
607 return pos;
608 }
609 }
610 }
611 return 0;
612 }
613
614 /* This is part of the ABI. Don't screw with it. */
check_offsets(void)615 static inline void check_offsets(void)
616 {
617 /* Note: disk space was harmed in compilation of this function. */
618 BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
619 offsetof(struct virtio_pci_cap, cap_vndr));
620 BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
621 offsetof(struct virtio_pci_cap, cap_next));
622 BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
623 offsetof(struct virtio_pci_cap, cap_len));
624 BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE !=
625 offsetof(struct virtio_pci_cap, cfg_type));
626 BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR !=
627 offsetof(struct virtio_pci_cap, bar));
628 BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
629 offsetof(struct virtio_pci_cap, offset));
630 BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
631 offsetof(struct virtio_pci_cap, length));
632 BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
633 offsetof(struct virtio_pci_notify_cap,
634 notify_off_multiplier));
635 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
636 offsetof(struct virtio_pci_common_cfg,
637 device_feature_select));
638 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
639 offsetof(struct virtio_pci_common_cfg, device_feature));
640 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
641 offsetof(struct virtio_pci_common_cfg,
642 guest_feature_select));
643 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
644 offsetof(struct virtio_pci_common_cfg, guest_feature));
645 BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
646 offsetof(struct virtio_pci_common_cfg, msix_config));
647 BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
648 offsetof(struct virtio_pci_common_cfg, num_queues));
649 BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
650 offsetof(struct virtio_pci_common_cfg, device_status));
651 BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
652 offsetof(struct virtio_pci_common_cfg, config_generation));
653 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
654 offsetof(struct virtio_pci_common_cfg, queue_select));
655 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
656 offsetof(struct virtio_pci_common_cfg, queue_size));
657 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
658 offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
659 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
660 offsetof(struct virtio_pci_common_cfg, queue_enable));
661 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
662 offsetof(struct virtio_pci_common_cfg, queue_notify_off));
663 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
664 offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
665 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
666 offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
667 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
668 offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
669 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
670 offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
671 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
672 offsetof(struct virtio_pci_common_cfg, queue_used_lo));
673 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
674 offsetof(struct virtio_pci_common_cfg, queue_used_hi));
675 }
676
677 /* the PCI probing function */
virtio_pci_modern_probe(struct virtio_pci_device * vp_dev)678 int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
679 {
680 struct pci_dev *pci_dev = vp_dev->pci_dev;
681 int err, common, isr, notify, device;
682 u32 notify_length;
683 u32 notify_offset;
684
685 check_offsets();
686
687 /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
688 if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
689 return -ENODEV;
690
691 if (pci_dev->device < 0x1040) {
692 /* Transitional devices: use the PCI subsystem device id as
693 * virtio device id, same as legacy driver always did.
694 */
695 vp_dev->vdev.id.device = pci_dev->subsystem_device;
696 } else {
697 /* Modern devices: simply use PCI device id, but start from 0x1040. */
698 vp_dev->vdev.id.device = pci_dev->device - 0x1040;
699 }
700 vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
701
702 /* check for a common config: if not, use legacy mode (bar 0). */
703 common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
704 IORESOURCE_IO | IORESOURCE_MEM,
705 &vp_dev->modern_bars);
706 if (!common) {
707 dev_info(&pci_dev->dev,
708 "virtio_pci: leaving for legacy driver\n");
709 return -ENODEV;
710 }
711
712 /* If common is there, these should be too... */
713 isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
714 IORESOURCE_IO | IORESOURCE_MEM,
715 &vp_dev->modern_bars);
716 notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
717 IORESOURCE_IO | IORESOURCE_MEM,
718 &vp_dev->modern_bars);
719 if (!isr || !notify) {
720 dev_err(&pci_dev->dev,
721 "virtio_pci: missing capabilities %i/%i/%i\n",
722 common, isr, notify);
723 return -EINVAL;
724 }
725
726 err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64));
727 if (err)
728 err = dma_set_mask_and_coherent(&pci_dev->dev,
729 DMA_BIT_MASK(32));
730 if (err)
731 dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
732
733 /* Device capability is only mandatory for devices that have
734 * device-specific configuration.
735 */
736 device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
737 IORESOURCE_IO | IORESOURCE_MEM,
738 &vp_dev->modern_bars);
739
740 err = pci_request_selected_regions(pci_dev, vp_dev->modern_bars,
741 "virtio-pci-modern");
742 if (err)
743 return err;
744
745 err = -EINVAL;
746 vp_dev->common = map_capability(pci_dev, common,
747 sizeof(struct virtio_pci_common_cfg), 4,
748 0, sizeof(struct virtio_pci_common_cfg),
749 NULL);
750 if (!vp_dev->common)
751 goto err_map_common;
752 vp_dev->isr = map_capability(pci_dev, isr, sizeof(u8), 1,
753 0, 1,
754 NULL);
755 if (!vp_dev->isr)
756 goto err_map_isr;
757
758 /* Read notify_off_multiplier from config space. */
759 pci_read_config_dword(pci_dev,
760 notify + offsetof(struct virtio_pci_notify_cap,
761 notify_off_multiplier),
762 &vp_dev->notify_offset_multiplier);
763 /* Read notify length and offset from config space. */
764 pci_read_config_dword(pci_dev,
765 notify + offsetof(struct virtio_pci_notify_cap,
766 cap.length),
767 ¬ify_length);
768
769 pci_read_config_dword(pci_dev,
770 notify + offsetof(struct virtio_pci_notify_cap,
771 cap.offset),
772 ¬ify_offset);
773
774 /* We don't know how many VQs we'll map, ahead of the time.
775 * If notify length is small, map it all now.
776 * Otherwise, map each VQ individually later.
777 */
778 if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
779 vp_dev->notify_base = map_capability(pci_dev, notify, 2, 2,
780 0, notify_length,
781 &vp_dev->notify_len);
782 if (!vp_dev->notify_base)
783 goto err_map_notify;
784 } else {
785 vp_dev->notify_map_cap = notify;
786 }
787
788 /* Again, we don't know how much we should map, but PAGE_SIZE
789 * is more than enough for all existing devices.
790 */
791 if (device) {
792 vp_dev->device = map_capability(pci_dev, device, 0, 4,
793 0, PAGE_SIZE,
794 &vp_dev->device_len);
795 if (!vp_dev->device)
796 goto err_map_device;
797
798 vp_dev->vdev.config = &virtio_pci_config_ops;
799 } else {
800 vp_dev->vdev.config = &virtio_pci_config_nodev_ops;
801 }
802
803 vp_dev->config_vector = vp_config_vector;
804 vp_dev->setup_vq = setup_vq;
805 vp_dev->del_vq = del_vq;
806
807 return 0;
808
809 err_map_device:
810 if (vp_dev->notify_base)
811 pci_iounmap(pci_dev, vp_dev->notify_base);
812 err_map_notify:
813 pci_iounmap(pci_dev, vp_dev->isr);
814 err_map_isr:
815 pci_iounmap(pci_dev, vp_dev->common);
816 err_map_common:
817 return err;
818 }
819
virtio_pci_modern_remove(struct virtio_pci_device * vp_dev)820 void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev)
821 {
822 struct pci_dev *pci_dev = vp_dev->pci_dev;
823
824 if (vp_dev->device)
825 pci_iounmap(pci_dev, vp_dev->device);
826 if (vp_dev->notify_base)
827 pci_iounmap(pci_dev, vp_dev->notify_base);
828 pci_iounmap(pci_dev, vp_dev->isr);
829 pci_iounmap(pci_dev, vp_dev->common);
830 pci_release_selected_regions(pci_dev, vp_dev->modern_bars);
831 }
832