1// SPDX-License-Identifier: GPL-2.0-or-later
2
3#include <linux/virtio_pci_modern.h>
4#include <linux/module.h>
5#include <linux/pci.h>
6#include <linux/delay.h>
7
8/*
9 * vp_modern_map_capability - map a part of virtio pci capability
10 * @mdev: the modern virtio-pci device
11 * @off: offset of the capability
12 * @minlen: minimal length of the capability
13 * @align: align requirement
14 * @start: start from the capability
15 * @size: map size
16 * @len: the length that is actually mapped
17 * @pa: physical address of the capability
18 *
19 * Returns the io address of for the part of the capability
20 */
21static void __iomem *
22vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off,
23 size_t minlen, u32 align, u32 start, u32 size,
24 size_t *len, resource_size_t *pa)
25{
26 struct pci_dev *dev = mdev->pci_dev;
27 u8 bar;
28 u32 offset, length;
29 void __iomem *p;
30
31 pci_read_config_byte(dev, where: off + offsetof(struct virtio_pci_cap,
32 bar),
33 val: &bar);
34 pci_read_config_dword(dev, where: off + offsetof(struct virtio_pci_cap, offset),
35 val: &offset);
36 pci_read_config_dword(dev, where: off + offsetof(struct virtio_pci_cap, length),
37 val: &length);
38
39 /* Check if the BAR may have changed since we requested the region. */
40 if (bar >= PCI_STD_NUM_BARS || !(mdev->modern_bars & (1 << bar))) {
41 dev_err(&dev->dev,
42 "virtio_pci: bar unexpectedly changed to %u\n", bar);
43 return NULL;
44 }
45
46 if (length <= start) {
47 dev_err(&dev->dev,
48 "virtio_pci: bad capability len %u (>%u expected)\n",
49 length, start);
50 return NULL;
51 }
52
53 if (length - start < minlen) {
54 dev_err(&dev->dev,
55 "virtio_pci: bad capability len %u (>=%zu expected)\n",
56 length, minlen);
57 return NULL;
58 }
59
60 length -= start;
61
62 if (start + offset < offset) {
63 dev_err(&dev->dev,
64 "virtio_pci: map wrap-around %u+%u\n",
65 start, offset);
66 return NULL;
67 }
68
69 offset += start;
70
71 if (offset & (align - 1)) {
72 dev_err(&dev->dev,
73 "virtio_pci: offset %u not aligned to %u\n",
74 offset, align);
75 return NULL;
76 }
77
78 if (length > size)
79 length = size;
80
81 if (len)
82 *len = length;
83
84 if (minlen + offset < minlen ||
85 minlen + offset > pci_resource_len(dev, bar)) {
86 dev_err(&dev->dev,
87 "virtio_pci: map virtio %zu@%u "
88 "out of range on bar %i length %lu\n",
89 minlen, offset,
90 bar, (unsigned long)pci_resource_len(dev, bar));
91 return NULL;
92 }
93
94 p = pci_iomap_range(dev, bar, offset, maxlen: length);
95 if (!p)
96 dev_err(&dev->dev,
97 "virtio_pci: unable to map virtio %u@%u on bar %i\n",
98 length, offset, bar);
99 else if (pa)
100 *pa = pci_resource_start(dev, bar) + offset;
101
102 return p;
103}
104
105/**
106 * virtio_pci_find_capability - walk capabilities to find device info.
107 * @dev: the pci device
108 * @cfg_type: the VIRTIO_PCI_CAP_* value we seek
109 * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
110 * @bars: the bitmask of BARs
111 *
112 * Returns offset of the capability, or 0.
113 */
114static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
115 u32 ioresource_types, int *bars)
116{
117 int pos;
118
119 for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
120 pos > 0;
121 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
122 u8 type, bar;
123 pci_read_config_byte(dev, where: pos + offsetof(struct virtio_pci_cap,
124 cfg_type),
125 val: &type);
126 pci_read_config_byte(dev, where: pos + offsetof(struct virtio_pci_cap,
127 bar),
128 val: &bar);
129
130 /* Ignore structures with reserved BAR values */
131 if (bar >= PCI_STD_NUM_BARS)
132 continue;
133
134 if (type == cfg_type) {
135 if (pci_resource_len(dev, bar) &&
136 pci_resource_flags(dev, bar) & ioresource_types) {
137 *bars |= (1 << bar);
138 return pos;
139 }
140 }
141 }
142 return 0;
143}
144
145/* This is part of the ABI. Don't screw with it. */
146static inline void check_offsets(void)
147{
148 /* Note: disk space was harmed in compilation of this function. */
149 BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
150 offsetof(struct virtio_pci_cap, cap_vndr));
151 BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
152 offsetof(struct virtio_pci_cap, cap_next));
153 BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
154 offsetof(struct virtio_pci_cap, cap_len));
155 BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE !=
156 offsetof(struct virtio_pci_cap, cfg_type));
157 BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR !=
158 offsetof(struct virtio_pci_cap, bar));
159 BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
160 offsetof(struct virtio_pci_cap, offset));
161 BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
162 offsetof(struct virtio_pci_cap, length));
163 BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
164 offsetof(struct virtio_pci_notify_cap,
165 notify_off_multiplier));
166 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
167 offsetof(struct virtio_pci_common_cfg,
168 device_feature_select));
169 BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
170 offsetof(struct virtio_pci_common_cfg, device_feature));
171 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
172 offsetof(struct virtio_pci_common_cfg,
173 guest_feature_select));
174 BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
175 offsetof(struct virtio_pci_common_cfg, guest_feature));
176 BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
177 offsetof(struct virtio_pci_common_cfg, msix_config));
178 BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
179 offsetof(struct virtio_pci_common_cfg, num_queues));
180 BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
181 offsetof(struct virtio_pci_common_cfg, device_status));
182 BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
183 offsetof(struct virtio_pci_common_cfg, config_generation));
184 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
185 offsetof(struct virtio_pci_common_cfg, queue_select));
186 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
187 offsetof(struct virtio_pci_common_cfg, queue_size));
188 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
189 offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
190 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
191 offsetof(struct virtio_pci_common_cfg, queue_enable));
192 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
193 offsetof(struct virtio_pci_common_cfg, queue_notify_off));
194 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
195 offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
196 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
197 offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
198 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
199 offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
200 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
201 offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
202 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
203 offsetof(struct virtio_pci_common_cfg, queue_used_lo));
204 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
205 offsetof(struct virtio_pci_common_cfg, queue_used_hi));
206 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NDATA !=
207 offsetof(struct virtio_pci_modern_common_cfg, queue_notify_data));
208 BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_RESET !=
209 offsetof(struct virtio_pci_modern_common_cfg, queue_reset));
210}
211
212/*
213 * vp_modern_probe: probe the modern virtio pci device, note that the
214 * caller is required to enable PCI device before calling this function.
215 * @mdev: the modern virtio-pci device
216 *
217 * Return 0 on succeed otherwise fail
218 */
219int vp_modern_probe(struct virtio_pci_modern_device *mdev)
220{
221 struct pci_dev *pci_dev = mdev->pci_dev;
222 int err, common, isr, notify, device;
223 u32 notify_length;
224 u32 notify_offset;
225 int devid;
226
227 check_offsets();
228
229 if (mdev->device_id_check) {
230 devid = mdev->device_id_check(pci_dev);
231 if (devid < 0)
232 return devid;
233 mdev->id.device = devid;
234 } else {
235 /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
236 if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
237 return -ENODEV;
238
239 if (pci_dev->device < 0x1040) {
240 /* Transitional devices: use the PCI subsystem device id as
241 * virtio device id, same as legacy driver always did.
242 */
243 mdev->id.device = pci_dev->subsystem_device;
244 } else {
245 /* Modern devices: simply use PCI device id, but start from 0x1040. */
246 mdev->id.device = pci_dev->device - 0x1040;
247 }
248 }
249 mdev->id.vendor = pci_dev->subsystem_vendor;
250
251 /* check for a common config: if not, use legacy mode (bar 0). */
252 common = virtio_pci_find_capability(dev: pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
253 IORESOURCE_IO | IORESOURCE_MEM,
254 bars: &mdev->modern_bars);
255 if (!common) {
256 dev_info(&pci_dev->dev,
257 "virtio_pci: leaving for legacy driver\n");
258 return -ENODEV;
259 }
260
261 /* If common is there, these should be too... */
262 isr = virtio_pci_find_capability(dev: pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
263 IORESOURCE_IO | IORESOURCE_MEM,
264 bars: &mdev->modern_bars);
265 notify = virtio_pci_find_capability(dev: pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
266 IORESOURCE_IO | IORESOURCE_MEM,
267 bars: &mdev->modern_bars);
268 if (!isr || !notify) {
269 dev_err(&pci_dev->dev,
270 "virtio_pci: missing capabilities %i/%i/%i\n",
271 common, isr, notify);
272 return -EINVAL;
273 }
274
275 err = dma_set_mask_and_coherent(dev: &pci_dev->dev,
276 mask: mdev->dma_mask ? : DMA_BIT_MASK(64));
277 if (err)
278 err = dma_set_mask_and_coherent(dev: &pci_dev->dev,
279 DMA_BIT_MASK(32));
280 if (err)
281 dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
282
283 /* Device capability is only mandatory for devices that have
284 * device-specific configuration.
285 */
286 device = virtio_pci_find_capability(dev: pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
287 IORESOURCE_IO | IORESOURCE_MEM,
288 bars: &mdev->modern_bars);
289
290 err = pci_request_selected_regions(pci_dev, mdev->modern_bars,
291 "virtio-pci-modern");
292 if (err)
293 return err;
294
295 err = -EINVAL;
296 mdev->common = vp_modern_map_capability(mdev, off: common,
297 minlen: sizeof(struct virtio_pci_common_cfg), align: 4,
298 start: 0, size: sizeof(struct virtio_pci_modern_common_cfg),
299 len: &mdev->common_len, NULL);
300 if (!mdev->common)
301 goto err_map_common;
302 mdev->isr = vp_modern_map_capability(mdev, off: isr, minlen: sizeof(u8), align: 1,
303 start: 0, size: 1,
304 NULL, NULL);
305 if (!mdev->isr)
306 goto err_map_isr;
307
308 /* Read notify_off_multiplier from config space. */
309 pci_read_config_dword(dev: pci_dev,
310 where: notify + offsetof(struct virtio_pci_notify_cap,
311 notify_off_multiplier),
312 val: &mdev->notify_offset_multiplier);
313 /* Read notify length and offset from config space. */
314 pci_read_config_dword(dev: pci_dev,
315 where: notify + offsetof(struct virtio_pci_notify_cap,
316 cap.length),
317 val: &notify_length);
318
319 pci_read_config_dword(dev: pci_dev,
320 where: notify + offsetof(struct virtio_pci_notify_cap,
321 cap.offset),
322 val: &notify_offset);
323
324 /* We don't know how many VQs we'll map, ahead of the time.
325 * If notify length is small, map it all now.
326 * Otherwise, map each VQ individually later.
327 */
328 if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
329 mdev->notify_base = vp_modern_map_capability(mdev, off: notify,
330 minlen: 2, align: 2,
331 start: 0, size: notify_length,
332 len: &mdev->notify_len,
333 pa: &mdev->notify_pa);
334 if (!mdev->notify_base)
335 goto err_map_notify;
336 } else {
337 mdev->notify_map_cap = notify;
338 }
339
340 /* Again, we don't know how much we should map, but PAGE_SIZE
341 * is more than enough for all existing devices.
342 */
343 if (device) {
344 mdev->device = vp_modern_map_capability(mdev, off: device, minlen: 0, align: 4,
345 start: 0, PAGE_SIZE,
346 len: &mdev->device_len,
347 NULL);
348 if (!mdev->device)
349 goto err_map_device;
350 }
351
352 return 0;
353
354err_map_device:
355 if (mdev->notify_base)
356 pci_iounmap(dev: pci_dev, mdev->notify_base);
357err_map_notify:
358 pci_iounmap(dev: pci_dev, mdev->isr);
359err_map_isr:
360 pci_iounmap(dev: pci_dev, mdev->common);
361err_map_common:
362 pci_release_selected_regions(pci_dev, mdev->modern_bars);
363 return err;
364}
365EXPORT_SYMBOL_GPL(vp_modern_probe);
366
367/*
368 * vp_modern_remove: remove and cleanup the modern virtio pci device
369 * @mdev: the modern virtio-pci device
370 */
371void vp_modern_remove(struct virtio_pci_modern_device *mdev)
372{
373 struct pci_dev *pci_dev = mdev->pci_dev;
374
375 if (mdev->device)
376 pci_iounmap(dev: pci_dev, mdev->device);
377 if (mdev->notify_base)
378 pci_iounmap(dev: pci_dev, mdev->notify_base);
379 pci_iounmap(dev: pci_dev, mdev->isr);
380 pci_iounmap(dev: pci_dev, mdev->common);
381 pci_release_selected_regions(pci_dev, mdev->modern_bars);
382}
383EXPORT_SYMBOL_GPL(vp_modern_remove);
384
385/*
386 * vp_modern_get_features - get features from device
387 * @mdev: the modern virtio-pci device
388 *
389 * Returns the features read from the device
390 */
391u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)
392{
393 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
394
395 u64 features;
396
397 vp_iowrite32(value: 0, addr: &cfg->device_feature_select);
398 features = vp_ioread32(addr: &cfg->device_feature);
399 vp_iowrite32(value: 1, addr: &cfg->device_feature_select);
400 features |= ((u64)vp_ioread32(addr: &cfg->device_feature) << 32);
401
402 return features;
403}
404EXPORT_SYMBOL_GPL(vp_modern_get_features);
405
406/*
407 * vp_modern_get_driver_features - get driver features from device
408 * @mdev: the modern virtio-pci device
409 *
410 * Returns the driver features read from the device
411 */
412u64 vp_modern_get_driver_features(struct virtio_pci_modern_device *mdev)
413{
414 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
415
416 u64 features;
417
418 vp_iowrite32(value: 0, addr: &cfg->guest_feature_select);
419 features = vp_ioread32(addr: &cfg->guest_feature);
420 vp_iowrite32(value: 1, addr: &cfg->guest_feature_select);
421 features |= ((u64)vp_ioread32(addr: &cfg->guest_feature) << 32);
422
423 return features;
424}
425EXPORT_SYMBOL_GPL(vp_modern_get_driver_features);
426
427/*
428 * vp_modern_set_features - set features to device
429 * @mdev: the modern virtio-pci device
430 * @features: the features set to device
431 */
432void vp_modern_set_features(struct virtio_pci_modern_device *mdev,
433 u64 features)
434{
435 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
436
437 vp_iowrite32(value: 0, addr: &cfg->guest_feature_select);
438 vp_iowrite32(value: (u32)features, addr: &cfg->guest_feature);
439 vp_iowrite32(value: 1, addr: &cfg->guest_feature_select);
440 vp_iowrite32(value: features >> 32, addr: &cfg->guest_feature);
441}
442EXPORT_SYMBOL_GPL(vp_modern_set_features);
443
444/*
445 * vp_modern_generation - get the device genreation
446 * @mdev: the modern virtio-pci device
447 *
448 * Returns the genreation read from device
449 */
450u32 vp_modern_generation(struct virtio_pci_modern_device *mdev)
451{
452 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
453
454 return vp_ioread8(addr: &cfg->config_generation);
455}
456EXPORT_SYMBOL_GPL(vp_modern_generation);
457
458/*
459 * vp_modern_get_status - get the device status
460 * @mdev: the modern virtio-pci device
461 *
462 * Returns the status read from device
463 */
464u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
465{
466 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
467
468 return vp_ioread8(addr: &cfg->device_status);
469}
470EXPORT_SYMBOL_GPL(vp_modern_get_status);
471
472/*
473 * vp_modern_set_status - set status to device
474 * @mdev: the modern virtio-pci device
475 * @status: the status set to device
476 */
477void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
478 u8 status)
479{
480 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
481
482 /*
483 * Per memory-barriers.txt, wmb() is not needed to guarantee
484 * that the cache coherent memory writes have completed
485 * before writing to the MMIO region.
486 */
487 vp_iowrite8(value: status, addr: &cfg->device_status);
488}
489EXPORT_SYMBOL_GPL(vp_modern_set_status);
490
491/*
492 * vp_modern_get_queue_reset - get the queue reset status
493 * @mdev: the modern virtio-pci device
494 * @index: queue index
495 */
496int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
497{
498 struct virtio_pci_modern_common_cfg __iomem *cfg;
499
500 cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
501
502 vp_iowrite16(value: index, addr: &cfg->cfg.queue_select);
503 return vp_ioread16(addr: &cfg->queue_reset);
504}
505EXPORT_SYMBOL_GPL(vp_modern_get_queue_reset);
506
507/*
508 * vp_modern_set_queue_reset - reset the queue
509 * @mdev: the modern virtio-pci device
510 * @index: queue index
511 */
512void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
513{
514 struct virtio_pci_modern_common_cfg __iomem *cfg;
515
516 cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
517
518 vp_iowrite16(value: index, addr: &cfg->cfg.queue_select);
519 vp_iowrite16(value: 1, addr: &cfg->queue_reset);
520
521 while (vp_ioread16(addr: &cfg->queue_reset))
522 msleep(msecs: 1);
523
524 while (vp_ioread16(addr: &cfg->cfg.queue_enable))
525 msleep(msecs: 1);
526}
527EXPORT_SYMBOL_GPL(vp_modern_set_queue_reset);
528
529/*
530 * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
531 * @mdev: the modern virtio-pci device
532 * @index: queue index
533 * @vector: the config vector
534 *
535 * Returns the config vector read from the device
536 */
537u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
538 u16 index, u16 vector)
539{
540 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
541
542 vp_iowrite16(value: index, addr: &cfg->queue_select);
543 vp_iowrite16(value: vector, addr: &cfg->queue_msix_vector);
544 /* Flush the write out to device */
545 return vp_ioread16(addr: &cfg->queue_msix_vector);
546}
547EXPORT_SYMBOL_GPL(vp_modern_queue_vector);
548
549/*
550 * vp_modern_config_vector - set the vector for config interrupt
551 * @mdev: the modern virtio-pci device
552 * @vector: the config vector
553 *
554 * Returns the config vector read from the device
555 */
556u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev,
557 u16 vector)
558{
559 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
560
561 /* Setup the vector used for configuration events */
562 vp_iowrite16(value: vector, addr: &cfg->msix_config);
563 /* Verify we had enough resources to assign the vector */
564 /* Will also flush the write out to device */
565 return vp_ioread16(addr: &cfg->msix_config);
566}
567EXPORT_SYMBOL_GPL(vp_modern_config_vector);
568
569/*
570 * vp_modern_queue_address - set the virtqueue address
571 * @mdev: the modern virtio-pci device
572 * @index: the queue index
573 * @desc_addr: address of the descriptor area
574 * @driver_addr: address of the driver area
575 * @device_addr: address of the device area
576 */
577void vp_modern_queue_address(struct virtio_pci_modern_device *mdev,
578 u16 index, u64 desc_addr, u64 driver_addr,
579 u64 device_addr)
580{
581 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
582
583 vp_iowrite16(value: index, addr: &cfg->queue_select);
584
585 vp_iowrite64_twopart(val: desc_addr, lo: &cfg->queue_desc_lo,
586 hi: &cfg->queue_desc_hi);
587 vp_iowrite64_twopart(val: driver_addr, lo: &cfg->queue_avail_lo,
588 hi: &cfg->queue_avail_hi);
589 vp_iowrite64_twopart(val: device_addr, lo: &cfg->queue_used_lo,
590 hi: &cfg->queue_used_hi);
591}
592EXPORT_SYMBOL_GPL(vp_modern_queue_address);
593
594/*
595 * vp_modern_set_queue_enable - enable a virtqueue
596 * @mdev: the modern virtio-pci device
597 * @index: the queue index
598 * @enable: whether the virtqueue is enable or not
599 */
600void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev,
601 u16 index, bool enable)
602{
603 vp_iowrite16(value: index, addr: &mdev->common->queue_select);
604 vp_iowrite16(value: enable, addr: &mdev->common->queue_enable);
605}
606EXPORT_SYMBOL_GPL(vp_modern_set_queue_enable);
607
608/*
609 * vp_modern_get_queue_enable - enable a virtqueue
610 * @mdev: the modern virtio-pci device
611 * @index: the queue index
612 *
613 * Returns whether a virtqueue is enabled or not
614 */
615bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev,
616 u16 index)
617{
618 vp_iowrite16(value: index, addr: &mdev->common->queue_select);
619
620 return vp_ioread16(addr: &mdev->common->queue_enable);
621}
622EXPORT_SYMBOL_GPL(vp_modern_get_queue_enable);
623
624/*
625 * vp_modern_set_queue_size - set size for a virtqueue
626 * @mdev: the modern virtio-pci device
627 * @index: the queue index
628 * @size: the size of the virtqueue
629 */
630void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev,
631 u16 index, u16 size)
632{
633 vp_iowrite16(value: index, addr: &mdev->common->queue_select);
634 vp_iowrite16(value: size, addr: &mdev->common->queue_size);
635
636}
637EXPORT_SYMBOL_GPL(vp_modern_set_queue_size);
638
639/*
640 * vp_modern_get_queue_size - get size for a virtqueue
641 * @mdev: the modern virtio-pci device
642 * @index: the queue index
643 *
644 * Returns the size of the virtqueue
645 */
646u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
647 u16 index)
648{
649 vp_iowrite16(value: index, addr: &mdev->common->queue_select);
650
651 return vp_ioread16(addr: &mdev->common->queue_size);
652
653}
654EXPORT_SYMBOL_GPL(vp_modern_get_queue_size);
655
656/*
657 * vp_modern_get_num_queues - get the number of virtqueues
658 * @mdev: the modern virtio-pci device
659 *
660 * Returns the number of virtqueues
661 */
662u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev)
663{
664 return vp_ioread16(addr: &mdev->common->num_queues);
665}
666EXPORT_SYMBOL_GPL(vp_modern_get_num_queues);
667
668/*
669 * vp_modern_get_queue_notify_off - get notification offset for a virtqueue
670 * @mdev: the modern virtio-pci device
671 * @index: the queue index
672 *
673 * Returns the notification offset for a virtqueue
674 */
675static u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev,
676 u16 index)
677{
678 vp_iowrite16(value: index, addr: &mdev->common->queue_select);
679
680 return vp_ioread16(addr: &mdev->common->queue_notify_off);
681}
682
683/*
684 * vp_modern_map_vq_notify - map notification area for a
685 * specific virtqueue
686 * @mdev: the modern virtio-pci device
687 * @index: the queue index
688 * @pa: the pointer to the physical address of the nofity area
689 *
690 * Returns the address of the notification area
691 */
692void __iomem *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
693 u16 index, resource_size_t *pa)
694{
695 u16 off = vp_modern_get_queue_notify_off(mdev, index);
696
697 if (mdev->notify_base) {
698 /* offset should not wrap */
699 if ((u64)off * mdev->notify_offset_multiplier + 2
700 > mdev->notify_len) {
701 dev_warn(&mdev->pci_dev->dev,
702 "bad notification offset %u (x %u) "
703 "for queue %u > %zd",
704 off, mdev->notify_offset_multiplier,
705 index, mdev->notify_len);
706 return NULL;
707 }
708 if (pa)
709 *pa = mdev->notify_pa +
710 off * mdev->notify_offset_multiplier;
711 return mdev->notify_base + off * mdev->notify_offset_multiplier;
712 } else {
713 return vp_modern_map_capability(mdev,
714 off: mdev->notify_map_cap, minlen: 2, align: 2,
715 start: off * mdev->notify_offset_multiplier, size: 2,
716 NULL, pa);
717 }
718}
719EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify);
720
721MODULE_VERSION("0.1");
722MODULE_DESCRIPTION("Modern Virtio PCI Device");
723MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
724MODULE_LICENSE("GPL");
725

source code of linux/drivers/virtio/virtio_pci_modern_dev.c