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Revert "virtio_pci: simplify MSI-X setup"
[linux-2.6-block.git] / drivers / virtio / virtio_pci_modern.c
CommitLineData
1fcf0512
MT		 1/*
2 * Virtio PCI driver - modern (virtio 1.0) device support
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 * Copyright Red Hat, Inc. 2014
9 *
10 * Authors:
11 * Anthony Liguori <aliguori@us.ibm.com>
12 * Rusty Russell <rusty@rustcorp.com.au>
13 * Michael S. Tsirkin <mst@redhat.com>
14 *
15 * This work is licensed under the terms of the GNU GPL, version 2 or later.
16 * See the COPYING file in the top-level directory.
17 *
18 */
19
05dbcb43 20#include <linux/delay.h>
1fcf0512
MT		 21#define VIRTIO_PCI_NO_LEGACY
22#include "virtio_pci_common.h"
23
c5d4c2c9
MT		 24/*
25 * Type-safe wrappers for io accesses.
26 * Use these to enforce at compile time the following spec requirement:
27 *
28 * The driver MUST access each field using the “natural” access
29 * method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses
30 * for 16-bit fields and 8-bit accesses for 8-bit fields.
31 */
32static inline u8 vp_ioread8(u8 __iomem *addr)
33{
34 return ioread8(addr);
35}
61bd405f 36static inline u16 vp_ioread16 (__le16 __iomem *addr)
c5d4c2c9
MT		 37{
38 return ioread16(addr);
39}
40
61bd405f 41static inline u32 vp_ioread32(__le32 __iomem *addr)
c5d4c2c9
MT		 42{
43 return ioread32(addr);
44}
45
46static inline void vp_iowrite8(u8 value, u8 __iomem *addr)
47{
48 iowrite8(value, addr);
49}
50
61bd405f 51static inline void vp_iowrite16(u16 value, __le16 __iomem *addr)
c5d4c2c9
MT		 52{
53 iowrite16(value, addr);
54}
55
61bd405f 56static inline void vp_iowrite32(u32 value, __le32 __iomem *addr)
c5d4c2c9
MT		 57{
58 iowrite32(value, addr);
59}
60
a8557d32
MT		 61static void vp_iowrite64_twopart(u64 val,
62 __le32 __iomem *lo, __le32 __iomem *hi)
63{
64 vp_iowrite32((u32)val, lo);
65 vp_iowrite32(val >> 32, hi);
66}
67
1fcf0512
MT		 68static void __iomem *map_capability(struct pci_dev *dev, int off,
69 size_t minlen,
70 u32 align,
71 u32 start, u32 size,
72 size_t *len)
73{
74 u8 bar;
75 u32 offset, length;
76 void __iomem *p;
77
78 pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
79 bar),
80 &bar);
81 pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
82 &offset);
83 pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
84 &length);
85
86 if (length <= start) {
87 dev_err(&dev->dev,
88 "virtio_pci: bad capability len %u (>%u expected)\n",
89 length, start);
90 return NULL;
91 }
92
93 if (length - start < minlen) {
94 dev_err(&dev->dev,
95 "virtio_pci: bad capability len %u (>=%zu expected)\n",
96 length, minlen);
97 return NULL;
98 }
99
100 length -= start;
101
102 if (start + offset < offset) {
103 dev_err(&dev->dev,
104 "virtio_pci: map wrap-around %u+%u\n",
105 start, offset);
106 return NULL;
107 }
108
109 offset += start;
110
111 if (offset & (align - 1)) {
112 dev_err(&dev->dev,
113 "virtio_pci: offset %u not aligned to %u\n",
114 offset, align);
115 return NULL;
116 }
117
118 if (length > size)
119 length = size;
120
121 if (len)
122 *len = length;
123
124 if (minlen + offset < minlen ||
125 minlen + offset > pci_resource_len(dev, bar)) {
126 dev_err(&dev->dev,
127 "virtio_pci: map virtio %zu@%u "
128 "out of range on bar %i length %lu\n",
129 minlen, offset,
130 bar, (unsigned long)pci_resource_len(dev, bar));
131 return NULL;
132 }
133
134 p = pci_iomap_range(dev, bar, offset, length);
135 if (!p)
136 dev_err(&dev->dev,
137 "virtio_pci: unable to map virtio %u@%u on bar %i\n",
138 length, offset, bar);
139 return p;
140}
141
1fcf0512
MT		 142/* virtio config->get_features() implementation */
143static u64 vp_get_features(struct virtio_device *vdev)
144{
145 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
146 u64 features;
147
a8557d32
MT		 148 vp_iowrite32(0, &vp_dev->common->device_feature_select);
149 features = vp_ioread32(&vp_dev->common->device_feature);
150 vp_iowrite32(1, &vp_dev->common->device_feature_select);
151 features |= ((u64)vp_ioread32(&vp_dev->common->device_feature) << 32);
1fcf0512
MT		 152
153 return features;
154}
155
156/* virtio config->finalize_features() implementation */
157static int vp_finalize_features(struct virtio_device *vdev)
158{
159 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
160
161 /* Give virtio_ring a chance to accept features. */
162 vring_transport_features(vdev);
163
164 if (!__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
165 dev_err(&vdev->dev, "virtio: device uses modern interface "
166 "but does not have VIRTIO_F_VERSION_1\n");
167 return -EINVAL;
168 }
169
a8557d32
MT		 170 vp_iowrite32(0, &vp_dev->common->guest_feature_select);
171 vp_iowrite32((u32)vdev->features, &vp_dev->common->guest_feature);
172 vp_iowrite32(1, &vp_dev->common->guest_feature_select);
173 vp_iowrite32(vdev->features >> 32, &vp_dev->common->guest_feature);
1fcf0512
MT		 174
175 return 0;
176}
177
178/* virtio config->get() implementation */
179static void vp_get(struct virtio_device *vdev, unsigned offset,
180 void *buf, unsigned len)
181{
182 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
183 u8 b;
184 __le16 w;
185 __le32 l;
186
187 BUG_ON(offset + len > vp_dev->device_len);
188
189 switch (len) {
190 case 1:
191 b = ioread8(vp_dev->device + offset);
192 memcpy(buf, &b, sizeof b);
193 break;
194 case 2:
195 w = cpu_to_le16(ioread16(vp_dev->device + offset));
196 memcpy(buf, &w, sizeof w);
197 break;
198 case 4:
199 l = cpu_to_le32(ioread32(vp_dev->device + offset));
200 memcpy(buf, &l, sizeof l);
201 break;
202 case 8:
203 l = cpu_to_le32(ioread32(vp_dev->device + offset));
204 memcpy(buf, &l, sizeof l);
205 l = cpu_to_le32(ioread32(vp_dev->device + offset + sizeof l));
206 memcpy(buf + sizeof l, &l, sizeof l);
207 break;
208 default:
209 BUG();
210 }
211}
212
213/* the config->set() implementation. it's symmetric to the config->get()
214 * implementation */
215static void vp_set(struct virtio_device *vdev, unsigned offset,
216 const void *buf, unsigned len)
217{
218 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
219 u8 b;
220 __le16 w;
221 __le32 l;
222
223 BUG_ON(offset + len > vp_dev->device_len);
224
225 switch (len) {
226 case 1:
227 memcpy(&b, buf, sizeof b);
228 iowrite8(b, vp_dev->device + offset);
229 break;
230 case 2:
231 memcpy(&w, buf, sizeof w);
232 iowrite16(le16_to_cpu(w), vp_dev->device + offset);
233 break;
234 case 4:
235 memcpy(&l, buf, sizeof l);
236 iowrite32(le32_to_cpu(l), vp_dev->device + offset);
237 break;
238 case 8:
239 memcpy(&l, buf, sizeof l);
240 iowrite32(le32_to_cpu(l), vp_dev->device + offset);
241 memcpy(&l, buf + sizeof l, sizeof l);
242 iowrite32(le32_to_cpu(l), vp_dev->device + offset + sizeof l);
243 break;
244 default:
245 BUG();
246 }
247}
248
249static u32 vp_generation(struct virtio_device *vdev)
250{
251 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
a8557d32 252 return vp_ioread8(&vp_dev->common->config_generation);
1fcf0512
MT		 253}
254
255/* config->{get,set}_status() implementations */
256static u8 vp_get_status(struct virtio_device *vdev)
257{
258 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
a8557d32 259 return vp_ioread8(&vp_dev->common->device_status);
1fcf0512
MT		 260}
261
262static void vp_set_status(struct virtio_device *vdev, u8 status)
263{
264 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
265 /* We should never be setting status to 0. */
266 BUG_ON(status == 0);
a8557d32 267 vp_iowrite8(status, &vp_dev->common->device_status);
1fcf0512
MT		 268}
269
270static void vp_reset(struct virtio_device *vdev)
271{
272 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
273 /* 0 status means a reset. */
a8557d32 274 vp_iowrite8(0, &vp_dev->common->device_status);
05dbcb43
MT		 275 /* After writing 0 to device_status, the driver MUST wait for a read of
276 * device_status to return 0 before reinitializing the device.
277 * This will flush out the status write, and flush in device writes,
278 * including MSI-X interrupts, if any.
279 */
280 while (vp_ioread8(&vp_dev->common->device_status))
281 msleep(1);
1fcf0512
MT		 282 /* Flush pending VQ/configuration callbacks. */
283 vp_synchronize_vectors(vdev);
284}
285
286static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
287{
288 /* Setup the vector used for configuration events */
a8557d32 289 vp_iowrite16(vector, &vp_dev->common->msix_config);
1fcf0512
MT		 290 /* Verify we had enough resources to assign the vector */
291 /* Will also flush the write out to device */
a8557d32 292 return vp_ioread16(&vp_dev->common->msix_config);
1fcf0512
MT		 293}
294
1fcf0512 295static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
1fcf0512
MT		 296 unsigned index,
297 void (*callback)(struct virtqueue *vq),
298 const char *name,
299 u16 msix_vec)
300{
301 struct virtio_pci_common_cfg __iomem *cfg = vp_dev->common;
302 struct virtqueue *vq;
303 u16 num, off;
304 int err;
305
a8557d32 306 if (index >= vp_ioread16(&cfg->num_queues))
1fcf0512
MT		 307 return ERR_PTR(-ENOENT);
308
309 /* Select the queue we're interested in */
a8557d32 310 vp_iowrite16(index, &cfg->queue_select);
1fcf0512
MT		 311
312 /* Check if queue is either not available or already active. */
a8557d32
MT		 313 num = vp_ioread16(&cfg->queue_size);
314 if (!num || vp_ioread16(&cfg->queue_enable))
1fcf0512
MT		 315 return ERR_PTR(-ENOENT);
316
317 if (num & (num - 1)) {
318 dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u", num);
319 return ERR_PTR(-EINVAL);
320 }
321
322 /* get offset of notification word for this vq */
a8557d32 323 off = vp_ioread16(&cfg->queue_notify_off);
1fcf0512 324
1fcf0512 325 /* create the vring */
7a5589b2
AL		 326 vq = vring_create_virtqueue(index, num,
327 SMP_CACHE_BYTES, &vp_dev->vdev,
328 true, true, vp_notify, callback, name);
329 if (!vq)
330 return ERR_PTR(-ENOMEM);
1fcf0512
MT		 331
332 /* activate the queue */
7a5589b2
AL		 333 vp_iowrite16(virtqueue_get_vring_size(vq), &cfg->queue_size);
334 vp_iowrite64_twopart(virtqueue_get_desc_addr(vq),
a8557d32 335 &cfg->queue_desc_lo, &cfg->queue_desc_hi);
7a5589b2 336 vp_iowrite64_twopart(virtqueue_get_avail_addr(vq),
a8557d32 337 &cfg->queue_avail_lo, &cfg->queue_avail_hi);
7a5589b2 338 vp_iowrite64_twopart(virtqueue_get_used_addr(vq),
a8557d32 339 &cfg->queue_used_lo, &cfg->queue_used_hi);
1fcf0512 340
3909213c
MT		 341 if (vp_dev->notify_base) {
342 /* offset should not wrap */
343 if ((u64)off * vp_dev->notify_offset_multiplier + 2
344 > vp_dev->notify_len) {
345 dev_warn(&vp_dev->pci_dev->dev,
346 "bad notification offset %u (x %u) "
347 "for queue %u > %zd",
348 off, vp_dev->notify_offset_multiplier,
349 index, vp_dev->notify_len);
350 err = -EINVAL;
351 goto err_map_notify;
352 }
353 vq->priv = (void __force *)vp_dev->notify_base +
354 off * vp_dev->notify_offset_multiplier;
355 } else {
356 vq->priv = (void __force *)map_capability(vp_dev->pci_dev,
357 vp_dev->notify_map_cap, 2, 2,
358 off * vp_dev->notify_offset_multiplier, 2,
359 NULL);
360 }
1fcf0512
MT		 361
362 if (!vq->priv) {
363 err = -ENOMEM;
364 goto err_map_notify;
365 }
366
367 if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
a8557d32
MT		 368 vp_iowrite16(msix_vec, &cfg->queue_msix_vector);
369 msix_vec = vp_ioread16(&cfg->queue_msix_vector);
1fcf0512
MT		 370 if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
371 err = -EBUSY;
372 goto err_assign_vector;
373 }
374 }
375
376 return vq;
377
378err_assign_vector:
3909213c
MT		 379 if (!vp_dev->notify_base)
380 pci_iounmap(vp_dev->pci_dev, (void __iomem __force *)vq->priv);
1fcf0512
MT		 381err_map_notify:
382 vring_del_virtqueue(vq);
1fcf0512
MT		 383 return ERR_PTR(err);
384}
385
386static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned nvqs,
fb5e31d9
CH		 387 struct virtqueue *vqs[], vq_callback_t *callbacks[],
388 const char * const names[], struct irq_affinity *desc)
1fcf0512
MT		 389{
390 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
391 struct virtqueue *vq;
fb5e31d9 392 int rc = vp_find_vqs(vdev, nvqs, vqs, callbacks, names, desc);
1fcf0512
MT		 393
394 if (rc)
395 return rc;
396
397 /* Select and activate all queues. Has to be done last: once we do
398 * this, there's no way to go back except reset.
399 */
400 list_for_each_entry(vq, &vdev->vqs, list) {
a8557d32
MT		 401 vp_iowrite16(vq->index, &vp_dev->common->queue_select);
402 vp_iowrite16(1, &vp_dev->common->queue_enable);
1fcf0512
MT		 403 }
404
405 return 0;
406}
407
5c34d002 408static void del_vq(struct virtqueue *vq)
1fcf0512 409{
1fcf0512
MT		 410 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
411
a8557d32 412 vp_iowrite16(vq->index, &vp_dev->common->queue_select);
1fcf0512 413
53a020c6 414 if (vp_dev->pci_dev->msix_enabled) {
a8557d32
MT		 415 vp_iowrite16(VIRTIO_MSI_NO_VECTOR,
416 &vp_dev->common->queue_msix_vector);
1fcf0512 417 /* Flush the write out to device */
a8557d32 418 vp_ioread16(&vp_dev->common->queue_msix_vector);
1fcf0512
MT		 419 }
420
3909213c
MT		 421 if (!vp_dev->notify_base)
422 pci_iounmap(vp_dev->pci_dev, (void __force __iomem *)vq->priv);
1fcf0512
MT		 423
424 vring_del_virtqueue(vq);
1fcf0512
MT		 425}
426
d3f5f065
MT		 427static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
428 .get = NULL,
429 .set = NULL,
430 .generation = vp_generation,
431 .get_status = vp_get_status,
432 .set_status = vp_set_status,
433 .reset = vp_reset,
434 .find_vqs = vp_modern_find_vqs,
435 .del_vqs = vp_del_vqs,
436 .get_features = vp_get_features,
437 .finalize_features = vp_finalize_features,
438 .bus_name = vp_bus_name,
439 .set_vq_affinity = vp_set_vq_affinity,
bbaba479 440 .get_vq_affinity = vp_get_vq_affinity,
d3f5f065
MT		 441};
442
1fcf0512
MT		 443static const struct virtio_config_ops virtio_pci_config_ops = {
444 .get = vp_get,
445 .set = vp_set,
446 .generation = vp_generation,
447 .get_status = vp_get_status,
448 .set_status = vp_set_status,
449 .reset = vp_reset,
450 .find_vqs = vp_modern_find_vqs,
451 .del_vqs = vp_del_vqs,
452 .get_features = vp_get_features,
453 .finalize_features = vp_finalize_features,
454 .bus_name = vp_bus_name,
455 .set_vq_affinity = vp_set_vq_affinity,
bbaba479 456 .get_vq_affinity = vp_get_vq_affinity,
1fcf0512
MT		 457};
458
459/**
460 * virtio_pci_find_capability - walk capabilities to find device info.
461 * @dev: the pci device
462 * @cfg_type: the VIRTIO_PCI_CAP_* value we seek
463 * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
464 *
465 * Returns offset of the capability, or 0.
466 */
467static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
59a5b0f7 468 u32 ioresource_types, int *bars)
1fcf0512
MT		 469{
470 int pos;
471
472 for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
473 pos > 0;
474 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
475 u8 type, bar;
476 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
477 cfg_type),
478 &type);
479 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
480 bar),
481 &bar);
482
483 /* Ignore structures with reserved BAR values */
484 if (bar > 0x5)
485 continue;
486
487 if (type == cfg_type) {
488 if (pci_resource_len(dev, bar) &&
59a5b0f7
GH		 489 pci_resource_flags(dev, bar) & ioresource_types) {
490 *bars |= (1 << bar);
1fcf0512 491 return pos;
59a5b0f7 492 }
1fcf0512
MT		 493 }
494 }
495 return 0;
496}
497
89461c4a 498/* This is part of the ABI. Don't screw with it. */
1fcf0512
MT		 499static inline void check_offsets(void)
500{
89461c4a
RR		 501 /* Note: disk space was harmed in compilation of this function. */
502 BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
503 offsetof(struct virtio_pci_cap, cap_vndr));
504 BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
505 offsetof(struct virtio_pci_cap, cap_next));
506 BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
507 offsetof(struct virtio_pci_cap, cap_len));
508 BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE !=
509 offsetof(struct virtio_pci_cap, cfg_type));
510 BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR !=
511 offsetof(struct virtio_pci_cap, bar));
512 BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
513 offsetof(struct virtio_pci_cap, offset));
514 BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
515 offsetof(struct virtio_pci_cap, length));
516 BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
517 offsetof(struct virtio_pci_notify_cap,
518 notify_off_multiplier));
519 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
520 offsetof(struct virtio_pci_common_cfg,
521 device_feature_select));
522 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
523 offsetof(struct virtio_pci_common_cfg, device_feature));
524 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
525 offsetof(struct virtio_pci_common_cfg,
526 guest_feature_select));
527 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
528 offsetof(struct virtio_pci_common_cfg, guest_feature));
529 BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
530 offsetof(struct virtio_pci_common_cfg, msix_config));
531 BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
532 offsetof(struct virtio_pci_common_cfg, num_queues));
533 BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
534 offsetof(struct virtio_pci_common_cfg, device_status));
535 BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
536 offsetof(struct virtio_pci_common_cfg, config_generation));
537 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
538 offsetof(struct virtio_pci_common_cfg, queue_select));
539 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
540 offsetof(struct virtio_pci_common_cfg, queue_size));
541 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
542 offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
543 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
544 offsetof(struct virtio_pci_common_cfg, queue_enable));
545 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
546 offsetof(struct virtio_pci_common_cfg, queue_notify_off));
547 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
548 offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
549 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
550 offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
551 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
552 offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
553 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
554 offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
555 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
556 offsetof(struct virtio_pci_common_cfg, queue_used_lo));
557 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
558 offsetof(struct virtio_pci_common_cfg, queue_used_hi));
1fcf0512
MT		 559}
560
561/* the PCI probing function */
562int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
563{
564 struct pci_dev *pci_dev = vp_dev->pci_dev;
565 int err, common, isr, notify, device;
566 u32 notify_length;
3909213c 567 u32 notify_offset;
1fcf0512
MT		 568
569 check_offsets();
570
571 /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
572 if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
573 return -ENODEV;
574
575 if (pci_dev->device < 0x1040) {
576 /* Transitional devices: use the PCI subsystem device id as
577 * virtio device id, same as legacy driver always did.
578 */
579 vp_dev->vdev.id.device = pci_dev->subsystem_device;
580 } else {
581 /* Modern devices: simply use PCI device id, but start from 0x1040. */
582 vp_dev->vdev.id.device = pci_dev->device - 0x1040;
583 }
584 vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
585
1fcf0512
MT		 586 /* check for a common config: if not, use legacy mode (bar 0). */
587 common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
59a5b0f7
GH		 588 IORESOURCE_IO | IORESOURCE_MEM,
589 &vp_dev->modern_bars);
1fcf0512
MT		 590 if (!common) {
591 dev_info(&pci_dev->dev,
592 "virtio_pci: leaving for legacy driver\n");
593 return -ENODEV;
594 }
595
596 /* If common is there, these should be too... */
597 isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
59a5b0f7
GH		 598 IORESOURCE_IO | IORESOURCE_MEM,
599 &vp_dev->modern_bars);
1fcf0512 600 notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
59a5b0f7
GH		 601 IORESOURCE_IO | IORESOURCE_MEM,
602 &vp_dev->modern_bars);
1fcf0512
MT		 603 if (!isr || !notify) {
604 dev_err(&pci_dev->dev,
605 "virtio_pci: missing capabilities %i/%i/%i\n",
606 common, isr, notify);
607 return -EINVAL;
608 }
609
7a5589b2
AL		 610 err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64));
611 if (err)
612 err = dma_set_mask_and_coherent(&pci_dev->dev,
613 DMA_BIT_MASK(32));
614 if (err)
615 dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
616
1fcf0512
MT		 617 /* Device capability is only mandatory for devices that have
618 * device-specific configuration.
619 */
620 device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
59a5b0f7
GH		 621 IORESOURCE_IO | IORESOURCE_MEM,
622 &vp_dev->modern_bars);
623
624 err = pci_request_selected_regions(pci_dev, vp_dev->modern_bars,
625 "virtio-pci-modern");
626 if (err)
627 return err;
1fcf0512
MT		 628
629 err = -EINVAL;
630 vp_dev->common = map_capability(pci_dev, common,
631 sizeof(struct virtio_pci_common_cfg), 4,
632 0, sizeof(struct virtio_pci_common_cfg),
633 NULL);
634 if (!vp_dev->common)
635 goto err_map_common;
636 vp_dev->isr = map_capability(pci_dev, isr, sizeof(u8), 1,
637 0, 1,
638 NULL);
639 if (!vp_dev->isr)
640 goto err_map_isr;
641
642 /* Read notify_off_multiplier from config space. */
643 pci_read_config_dword(pci_dev,
644 notify + offsetof(struct virtio_pci_notify_cap,
645 notify_off_multiplier),
646 &vp_dev->notify_offset_multiplier);
3909213c 647 /* Read notify length and offset from config space. */
1fcf0512
MT		 648 pci_read_config_dword(pci_dev,
649 notify + offsetof(struct virtio_pci_notify_cap,
650 cap.length),
651 &notify_length);
652
3909213c
MT		 653 pci_read_config_dword(pci_dev,
654 notify + offsetof(struct virtio_pci_notify_cap,
4e94ebdd 655 cap.offset),
3909213c
MT		 656 &notify_offset);
657
658 /* We don't know how many VQs we'll map, ahead of the time.
659 * If notify length is small, map it all now.
660 * Otherwise, map each VQ individually later.
661 */
662 if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
663 vp_dev->notify_base = map_capability(pci_dev, notify, 2, 2,
664 0, notify_length,
665 &vp_dev->notify_len);
666 if (!vp_dev->notify_base)
667 goto err_map_notify;
668 } else {
669 vp_dev->notify_map_cap = notify;
670 }
1fcf0512
MT		 671
672 /* Again, we don't know how much we should map, but PAGE_SIZE
673 * is more than enough for all existing devices.
674 */
675 if (device) {
676 vp_dev->device = map_capability(pci_dev, device, 0, 4,
677 0, PAGE_SIZE,
678 &vp_dev->device_len);
679 if (!vp_dev->device)
680 goto err_map_device;
1fcf0512 681
d3f5f065
MT		 682 vp_dev->vdev.config = &virtio_pci_config_ops;
683 } else {
684 vp_dev->vdev.config = &virtio_pci_config_nodev_ops;
685 }
1fcf0512
MT		 686
687 vp_dev->config_vector = vp_config_vector;
688 vp_dev->setup_vq = setup_vq;
689 vp_dev->del_vq = del_vq;
690
691 return 0;
692
693err_map_device:
3909213c
MT		 694 if (vp_dev->notify_base)
695 pci_iounmap(pci_dev, vp_dev->notify_base);
696err_map_notify:
1fcf0512
MT		 697 pci_iounmap(pci_dev, vp_dev->isr);
698err_map_isr:
699 pci_iounmap(pci_dev, vp_dev->common);
700err_map_common:
701 return err;
702}
703
704void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev)
705{
706 struct pci_dev *pci_dev = vp_dev->pci_dev;
707
708 if (vp_dev->device)
709 pci_iounmap(pci_dev, vp_dev->device);
3909213c
MT		 710 if (vp_dev->notify_base)
711 pci_iounmap(pci_dev, vp_dev->notify_base);
1fcf0512
MT		 712 pci_iounmap(pci_dev, vp_dev->isr);
713 pci_iounmap(pci_dev, vp_dev->common);
59a5b0f7 714 pci_release_selected_regions(pci_dev, vp_dev->modern_bars);
1fcf0512 715}
Linux 6.x block layer and io_uring tree(s)