1 // SPDX-License-Identifier: GPL-2.0-or-later
3 #include <linux/virtio_pci_modern.h>
4 #include <linux/module.h>
6 #include <linux/delay.h>
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
16 * @len: the length that is actually mapped
17 * @pa: physical address of the capability
19 * Returns the io address of for the part of the capability
22 vp_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)
26 struct pci_dev *dev = mdev->pci_dev;
31 pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
34 pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
36 pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
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))) {
42 "virtio_pci: bar unexpectedly changed to %u\n", bar);
46 if (length <= start) {
48 "virtio_pci: bad capability len %u (>%u expected)\n",
53 if (length - start < minlen) {
55 "virtio_pci: bad capability len %u (>=%zu expected)\n",
62 if (start + offset < offset) {
64 "virtio_pci: map wrap-around %u+%u\n",
71 if (offset & (align - 1)) {
73 "virtio_pci: offset %u not aligned to %u\n",
84 if (minlen + offset < minlen ||
85 minlen + offset > pci_resource_len(dev, bar)) {
87 "virtio_pci: map virtio %zu@%u "
88 "out of range on bar %i length %lu\n",
90 bar, (unsigned long)pci_resource_len(dev, bar));
94 p = pci_iomap_range(dev, bar, offset, length);
97 "virtio_pci: unable to map virtio %u@%u on bar %i\n",
100 *pa = pci_resource_start(dev, bar) + offset;
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
112 * Returns offset of the capability, or 0.
114 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
115 u32 ioresource_types, int *bars)
119 for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
121 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
123 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
126 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
130 /* Ignore structures with reserved BAR values */
131 if (bar >= PCI_STD_NUM_BARS)
134 if (type == cfg_type) {
135 if (pci_resource_len(dev, bar) &&
136 pci_resource_flags(dev, bar) & ioresource_types) {
145 /* This is part of the ABI. Don't screw with it. */
146 static inline void check_offsets(void)
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));
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
217 * Return 0 on succeed otherwise fail
219 int vp_modern_probe(struct virtio_pci_modern_device *mdev)
221 struct pci_dev *pci_dev = mdev->pci_dev;
222 int err, common, isr, notify, device;
229 if (mdev->device_id_check) {
230 devid = mdev->device_id_check(pci_dev);
233 mdev->id.device = devid;
235 /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
236 if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
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.
243 mdev->id.device = pci_dev->subsystem_device;
245 /* Modern devices: simply use PCI device id, but start from 0x1040. */
246 mdev->id.device = pci_dev->device - 0x1040;
249 mdev->id.vendor = pci_dev->subsystem_vendor;
251 /* check for a common config: if not, use legacy mode (bar 0). */
252 common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
253 IORESOURCE_IO | IORESOURCE_MEM,
256 dev_info(&pci_dev->dev,
257 "virtio_pci: leaving for legacy driver\n");
261 /* If common is there, these should be too... */
262 isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
263 IORESOURCE_IO | IORESOURCE_MEM,
265 notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
266 IORESOURCE_IO | IORESOURCE_MEM,
268 if (!isr || !notify) {
269 dev_err(&pci_dev->dev,
270 "virtio_pci: missing capabilities %i/%i/%i\n",
271 common, isr, notify);
275 err = dma_set_mask_and_coherent(&pci_dev->dev,
276 mdev->dma_mask ? : DMA_BIT_MASK(64));
278 err = dma_set_mask_and_coherent(&pci_dev->dev,
281 dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
283 /* Device capability is only mandatory for devices that have
284 * device-specific configuration.
286 device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
287 IORESOURCE_IO | IORESOURCE_MEM,
290 err = pci_request_selected_regions(pci_dev, mdev->modern_bars,
291 "virtio-pci-modern");
296 mdev->common = vp_modern_map_capability(mdev, common,
297 sizeof(struct virtio_pci_common_cfg), 4, 0,
298 offsetofend(struct virtio_pci_modern_common_cfg,
300 &mdev->common_len, NULL);
303 mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1,
309 /* Read notify_off_multiplier from config space. */
310 pci_read_config_dword(pci_dev,
311 notify + offsetof(struct virtio_pci_notify_cap,
312 notify_off_multiplier),
313 &mdev->notify_offset_multiplier);
314 /* Read notify length and offset from config space. */
315 pci_read_config_dword(pci_dev,
316 notify + offsetof(struct virtio_pci_notify_cap,
320 pci_read_config_dword(pci_dev,
321 notify + offsetof(struct virtio_pci_notify_cap,
325 /* We don't know how many VQs we'll map, ahead of the time.
326 * If notify length is small, map it all now.
327 * Otherwise, map each VQ individually later.
329 if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
330 mdev->notify_base = vp_modern_map_capability(mdev, notify,
335 if (!mdev->notify_base)
338 mdev->notify_map_cap = notify;
341 /* Again, we don't know how much we should map, but PAGE_SIZE
342 * is more than enough for all existing devices.
345 mdev->device = vp_modern_map_capability(mdev, device, 0, 4,
356 if (mdev->notify_base)
357 pci_iounmap(pci_dev, mdev->notify_base);
359 pci_iounmap(pci_dev, mdev->isr);
361 pci_iounmap(pci_dev, mdev->common);
363 pci_release_selected_regions(pci_dev, mdev->modern_bars);
366 EXPORT_SYMBOL_GPL(vp_modern_probe);
369 * vp_modern_remove: remove and cleanup the modern virtio pci device
370 * @mdev: the modern virtio-pci device
372 void vp_modern_remove(struct virtio_pci_modern_device *mdev)
374 struct pci_dev *pci_dev = mdev->pci_dev;
377 pci_iounmap(pci_dev, mdev->device);
378 if (mdev->notify_base)
379 pci_iounmap(pci_dev, mdev->notify_base);
380 pci_iounmap(pci_dev, mdev->isr);
381 pci_iounmap(pci_dev, mdev->common);
382 pci_release_selected_regions(pci_dev, mdev->modern_bars);
384 EXPORT_SYMBOL_GPL(vp_modern_remove);
387 * vp_modern_get_features - get features from device
388 * @mdev: the modern virtio-pci device
390 * Returns the features read from the device
392 u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)
394 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
398 vp_iowrite32(0, &cfg->device_feature_select);
399 features = vp_ioread32(&cfg->device_feature);
400 vp_iowrite32(1, &cfg->device_feature_select);
401 features |= ((u64)vp_ioread32(&cfg->device_feature) << 32);
405 EXPORT_SYMBOL_GPL(vp_modern_get_features);
408 * vp_modern_get_driver_features - get driver features from device
409 * @mdev: the modern virtio-pci device
411 * Returns the driver features read from the device
413 u64 vp_modern_get_driver_features(struct virtio_pci_modern_device *mdev)
415 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
419 vp_iowrite32(0, &cfg->guest_feature_select);
420 features = vp_ioread32(&cfg->guest_feature);
421 vp_iowrite32(1, &cfg->guest_feature_select);
422 features |= ((u64)vp_ioread32(&cfg->guest_feature) << 32);
426 EXPORT_SYMBOL_GPL(vp_modern_get_driver_features);
429 * vp_modern_set_features - set features to device
430 * @mdev: the modern virtio-pci device
431 * @features: the features set to device
433 void vp_modern_set_features(struct virtio_pci_modern_device *mdev,
436 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
438 vp_iowrite32(0, &cfg->guest_feature_select);
439 vp_iowrite32((u32)features, &cfg->guest_feature);
440 vp_iowrite32(1, &cfg->guest_feature_select);
441 vp_iowrite32(features >> 32, &cfg->guest_feature);
443 EXPORT_SYMBOL_GPL(vp_modern_set_features);
446 * vp_modern_generation - get the device genreation
447 * @mdev: the modern virtio-pci device
449 * Returns the genreation read from device
451 u32 vp_modern_generation(struct virtio_pci_modern_device *mdev)
453 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
455 return vp_ioread8(&cfg->config_generation);
457 EXPORT_SYMBOL_GPL(vp_modern_generation);
460 * vp_modern_get_status - get the device status
461 * @mdev: the modern virtio-pci device
463 * Returns the status read from device
465 u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
467 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
469 return vp_ioread8(&cfg->device_status);
471 EXPORT_SYMBOL_GPL(vp_modern_get_status);
474 * vp_modern_set_status - set status to device
475 * @mdev: the modern virtio-pci device
476 * @status: the status set to device
478 void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
481 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
484 * Per memory-barriers.txt, wmb() is not needed to guarantee
485 * that the cache coherent memory writes have completed
486 * before writing to the MMIO region.
488 vp_iowrite8(status, &cfg->device_status);
490 EXPORT_SYMBOL_GPL(vp_modern_set_status);
493 * vp_modern_get_queue_reset - get the queue reset status
494 * @mdev: the modern virtio-pci device
495 * @index: queue index
497 int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
499 struct virtio_pci_modern_common_cfg __iomem *cfg;
501 cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
503 vp_iowrite16(index, &cfg->cfg.queue_select);
504 return vp_ioread16(&cfg->queue_reset);
506 EXPORT_SYMBOL_GPL(vp_modern_get_queue_reset);
509 * vp_modern_set_queue_reset - reset the queue
510 * @mdev: the modern virtio-pci device
511 * @index: queue index
513 void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
515 struct virtio_pci_modern_common_cfg __iomem *cfg;
517 cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
519 vp_iowrite16(index, &cfg->cfg.queue_select);
520 vp_iowrite16(1, &cfg->queue_reset);
522 while (vp_ioread16(&cfg->queue_reset))
525 while (vp_ioread16(&cfg->cfg.queue_enable))
528 EXPORT_SYMBOL_GPL(vp_modern_set_queue_reset);
531 * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
532 * @mdev: the modern virtio-pci device
533 * @index: queue index
534 * @vector: the config vector
536 * Returns the config vector read from the device
538 u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
539 u16 index, u16 vector)
541 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
543 vp_iowrite16(index, &cfg->queue_select);
544 vp_iowrite16(vector, &cfg->queue_msix_vector);
545 /* Flush the write out to device */
546 return vp_ioread16(&cfg->queue_msix_vector);
548 EXPORT_SYMBOL_GPL(vp_modern_queue_vector);
551 * vp_modern_config_vector - set the vector for config interrupt
552 * @mdev: the modern virtio-pci device
553 * @vector: the config vector
555 * Returns the config vector read from the device
557 u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev,
560 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
562 /* Setup the vector used for configuration events */
563 vp_iowrite16(vector, &cfg->msix_config);
564 /* Verify we had enough resources to assign the vector */
565 /* Will also flush the write out to device */
566 return vp_ioread16(&cfg->msix_config);
568 EXPORT_SYMBOL_GPL(vp_modern_config_vector);
571 * vp_modern_queue_address - set the virtqueue address
572 * @mdev: the modern virtio-pci device
573 * @index: the queue index
574 * @desc_addr: address of the descriptor area
575 * @driver_addr: address of the driver area
576 * @device_addr: address of the device area
578 void vp_modern_queue_address(struct virtio_pci_modern_device *mdev,
579 u16 index, u64 desc_addr, u64 driver_addr,
582 struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
584 vp_iowrite16(index, &cfg->queue_select);
586 vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo,
587 &cfg->queue_desc_hi);
588 vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo,
589 &cfg->queue_avail_hi);
590 vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo,
591 &cfg->queue_used_hi);
593 EXPORT_SYMBOL_GPL(vp_modern_queue_address);
596 * vp_modern_set_queue_enable - enable a virtqueue
597 * @mdev: the modern virtio-pci device
598 * @index: the queue index
599 * @enable: whether the virtqueue is enable or not
601 void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev,
602 u16 index, bool enable)
604 vp_iowrite16(index, &mdev->common->queue_select);
605 vp_iowrite16(enable, &mdev->common->queue_enable);
607 EXPORT_SYMBOL_GPL(vp_modern_set_queue_enable);
610 * vp_modern_get_queue_enable - enable a virtqueue
611 * @mdev: the modern virtio-pci device
612 * @index: the queue index
614 * Returns whether a virtqueue is enabled or not
616 bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev,
619 vp_iowrite16(index, &mdev->common->queue_select);
621 return vp_ioread16(&mdev->common->queue_enable);
623 EXPORT_SYMBOL_GPL(vp_modern_get_queue_enable);
626 * vp_modern_set_queue_size - set size for a virtqueue
627 * @mdev: the modern virtio-pci device
628 * @index: the queue index
629 * @size: the size of the virtqueue
631 void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev,
634 vp_iowrite16(index, &mdev->common->queue_select);
635 vp_iowrite16(size, &mdev->common->queue_size);
638 EXPORT_SYMBOL_GPL(vp_modern_set_queue_size);
641 * vp_modern_get_queue_size - get size for a virtqueue
642 * @mdev: the modern virtio-pci device
643 * @index: the queue index
645 * Returns the size of the virtqueue
647 u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
650 vp_iowrite16(index, &mdev->common->queue_select);
652 return vp_ioread16(&mdev->common->queue_size);
655 EXPORT_SYMBOL_GPL(vp_modern_get_queue_size);
658 * vp_modern_get_num_queues - get the number of virtqueues
659 * @mdev: the modern virtio-pci device
661 * Returns the number of virtqueues
663 u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev)
665 return vp_ioread16(&mdev->common->num_queues);
667 EXPORT_SYMBOL_GPL(vp_modern_get_num_queues);
670 * vp_modern_get_queue_notify_off - get notification offset for a virtqueue
671 * @mdev: the modern virtio-pci device
672 * @index: the queue index
674 * Returns the notification offset for a virtqueue
676 static u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev,
679 vp_iowrite16(index, &mdev->common->queue_select);
681 return vp_ioread16(&mdev->common->queue_notify_off);
685 * vp_modern_map_vq_notify - map notification area for a
687 * @mdev: the modern virtio-pci device
688 * @index: the queue index
689 * @pa: the pointer to the physical address of the nofity area
691 * Returns the address of the notification area
693 void __iomem *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
694 u16 index, resource_size_t *pa)
696 u16 off = vp_modern_get_queue_notify_off(mdev, index);
698 if (mdev->notify_base) {
699 /* offset should not wrap */
700 if ((u64)off * mdev->notify_offset_multiplier + 2
701 > mdev->notify_len) {
702 dev_warn(&mdev->pci_dev->dev,
703 "bad notification offset %u (x %u) "
704 "for queue %u > %zd",
705 off, mdev->notify_offset_multiplier,
706 index, mdev->notify_len);
710 *pa = mdev->notify_pa +
711 off * mdev->notify_offset_multiplier;
712 return mdev->notify_base + off * mdev->notify_offset_multiplier;
714 return vp_modern_map_capability(mdev,
715 mdev->notify_map_cap, 2, 2,
716 off * mdev->notify_offset_multiplier, 2,
720 EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify);
722 MODULE_VERSION("0.1");
723 MODULE_DESCRIPTION("Modern Virtio PCI Device");
724 MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
725 MODULE_LICENSE("GPL");