// SPDX-License-Identifier: GPL-2.0-or-later #include <linux/virtio_pci_modern.h> #include <linux/module.h> #include <linux/pci.h> /* * vp_modern_map_capability - map a part of virtio pci capability * @mdev: the modern virtio-pci device * @off: offset of the capability * @minlen: minimal length of the capability * @align: align requirement * @start: start from the capability * @size: map size * @len: the length that is actually mapped * @pa: physical address of the capability * * Returns the io address of for the part of the capability */ static void __iomem * vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off, size_t minlen, u32 align, u32 start, u32 size, size_t *len, resource_size_t *pa) { struct pci_dev *dev = mdev->pci_dev; u8 bar; u32 offset, length; void __iomem *p; pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap, bar), &bar); pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset), &offset); pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length), &length); if (length <= start) { dev_err(&dev->dev, "virtio_pci: bad capability len %u (>%u expected)\n", length, start); return NULL; } if (length - start < minlen) { dev_err(&dev->dev, "virtio_pci: bad capability len %u (>=%zu expected)\n", length, minlen); return NULL; } length -= start; if (start + offset < offset) { dev_err(&dev->dev, "virtio_pci: map wrap-around %u+%u\n", start, offset); return NULL; } offset += start; if (offset & (align - 1)) { dev_err(&dev->dev, "virtio_pci: offset %u not aligned to %u\n", offset, align); return NULL; } if (length > size) length = size; if (len) *len = length; if (minlen + offset < minlen || minlen + offset > pci_resource_len(dev, bar)) { dev_err(&dev->dev, "virtio_pci: map virtio %zu@%u " "out of range on bar %i length %lu\n", minlen, offset, bar, (unsigned long)pci_resource_len(dev, bar)); return NULL; } p = pci_iomap_range(dev, bar, offset, length); if (!p) dev_err(&dev->dev, "virtio_pci: unable to map virtio %u@%u on bar %i\n", length, offset, bar); else if (pa) *pa = pci_resource_start(dev, bar) + offset; return p; } /** * virtio_pci_find_capability - walk capabilities to find device info. * @dev: the pci device * @cfg_type: the VIRTIO_PCI_CAP_* value we seek * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO. * @bars: the bitmask of BARs * * Returns offset of the capability, or 0. */ static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type, u32 ioresource_types, int *bars) { int pos; for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); pos > 0; pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) { u8 type, bar; pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, cfg_type), &type); pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, bar), &bar); /* Ignore structures with reserved BAR values */ if (bar > 0x5) continue; if (type == cfg_type) { if (pci_resource_len(dev, bar) && pci_resource_flags(dev, bar) & ioresource_types) { *bars |= (1 << bar); return pos; } } } return 0; } /* This is part of the ABI. Don't screw with it. */ static inline void check_offsets(void) { /* Note: disk space was harmed in compilation of this function. */ BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR != offsetof(struct virtio_pci_cap, cap_vndr)); BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT != offsetof(struct virtio_pci_cap, cap_next)); BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN != offsetof(struct virtio_pci_cap, cap_len)); BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE != offsetof(struct virtio_pci_cap, cfg_type)); BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR != offsetof(struct virtio_pci_cap, bar)); BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET != offsetof(struct virtio_pci_cap, offset)); BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH != offsetof(struct virtio_pci_cap, length)); BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT != offsetof(struct virtio_pci_notify_cap, notify_off_multiplier)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT != offsetof(struct virtio_pci_common_cfg, device_feature_select)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF != offsetof(struct virtio_pci_common_cfg, device_feature)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT != offsetof(struct virtio_pci_common_cfg, guest_feature_select)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF != offsetof(struct virtio_pci_common_cfg, guest_feature)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX != offsetof(struct virtio_pci_common_cfg, msix_config)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ != offsetof(struct virtio_pci_common_cfg, num_queues)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS != offsetof(struct virtio_pci_common_cfg, device_status)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION != offsetof(struct virtio_pci_common_cfg, config_generation)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT != offsetof(struct virtio_pci_common_cfg, queue_select)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE != offsetof(struct virtio_pci_common_cfg, queue_size)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX != offsetof(struct virtio_pci_common_cfg, queue_msix_vector)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE != offsetof(struct virtio_pci_common_cfg, queue_enable)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF != offsetof(struct virtio_pci_common_cfg, queue_notify_off)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO != offsetof(struct virtio_pci_common_cfg, queue_desc_lo)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI != offsetof(struct virtio_pci_common_cfg, queue_desc_hi)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO != offsetof(struct virtio_pci_common_cfg, queue_avail_lo)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI != offsetof(struct virtio_pci_common_cfg, queue_avail_hi)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO != offsetof(struct virtio_pci_common_cfg, queue_used_lo)); BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI != offsetof(struct virtio_pci_common_cfg, queue_used_hi)); } /* * vp_modern_probe: probe the modern virtio pci device, note that the * caller is required to enable PCI device before calling this function. * @mdev: the modern virtio-pci device * * Return 0 on succeed otherwise fail */ int vp_modern_probe(struct virtio_pci_modern_device *mdev) { struct pci_dev *pci_dev = mdev->pci_dev; int err, common, isr, notify, device; u32 notify_length; u32 notify_offset; check_offsets(); mdev->pci_dev = pci_dev; /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */ if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f) return -ENODEV; if (pci_dev->device < 0x1040) { /* Transitional devices: use the PCI subsystem device id as * virtio device id, same as legacy driver always did. */ mdev->id.device = pci_dev->subsystem_device; } else { /* Modern devices: simply use PCI device id, but start from 0x1040. */ mdev->id.device = pci_dev->device - 0x1040; } mdev->id.vendor = pci_dev->subsystem_vendor; /* check for a common config: if not, use legacy mode (bar 0). */ common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG, IORESOURCE_IO | IORESOURCE_MEM, &mdev->modern_bars); if (!common) { dev_info(&pci_dev->dev, "virtio_pci: leaving for legacy driver\n"); return -ENODEV; } /* If common is there, these should be too... */ isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG, IORESOURCE_IO | IORESOURCE_MEM, &mdev->modern_bars); notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG, IORESOURCE_IO | IORESOURCE_MEM, &mdev->modern_bars); if (!isr || !notify) { dev_err(&pci_dev->dev, "virtio_pci: missing capabilities %i/%i/%i\n", common, isr, notify); return -EINVAL; } err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64)); if (err) err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32)); if (err) dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); /* Device capability is only mandatory for devices that have * device-specific configuration. */ device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG, IORESOURCE_IO | IORESOURCE_MEM, &mdev->modern_bars); err = pci_request_selected_regions(pci_dev, mdev->modern_bars, "virtio-pci-modern"); if (err) return err; err = -EINVAL; mdev->common = vp_modern_map_capability(mdev, common, sizeof(struct virtio_pci_common_cfg), 4, 0, sizeof(struct virtio_pci_common_cfg), NULL, NULL); if (!mdev->common) goto err_map_common; mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1, 0, 1, NULL, NULL); if (!mdev->isr) goto err_map_isr; /* Read notify_off_multiplier from config space. */ pci_read_config_dword(pci_dev, notify + offsetof(struct virtio_pci_notify_cap, notify_off_multiplier), &mdev->notify_offset_multiplier); /* Read notify length and offset from config space. */ pci_read_config_dword(pci_dev, notify + offsetof(struct virtio_pci_notify_cap, cap.length), ¬ify_length); pci_read_config_dword(pci_dev, notify + offsetof(struct virtio_pci_notify_cap, cap.offset), ¬ify_offset); /* We don't know how many VQs we'll map, ahead of the time. * If notify length is small, map it all now. * Otherwise, map each VQ individually later. */ if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) { mdev->notify_base = vp_modern_map_capability(mdev, notify, 2, 2, 0, notify_length, &mdev->notify_len, &mdev->notify_pa); if (!mdev->notify_base) goto err_map_notify; } else { mdev->notify_map_cap = notify; } /* Again, we don't know how much we should map, but PAGE_SIZE * is more than enough for all existing devices. */ if (device) { mdev->device = vp_modern_map_capability(mdev, device, 0, 4, 0, PAGE_SIZE, &mdev->device_len, NULL); if (!mdev->device) goto err_map_device; } return 0; err_map_device: if (mdev->notify_base) pci_iounmap(pci_dev, mdev->notify_base); err_map_notify: pci_iounmap(pci_dev, mdev->isr); err_map_isr: pci_iounmap(pci_dev, mdev->common); err_map_common: return err; } EXPORT_SYMBOL_GPL(vp_modern_probe); /* * vp_modern_probe: remove and cleanup the modern virtio pci device * @mdev: the modern virtio-pci device */ void vp_modern_remove(struct virtio_pci_modern_device *mdev) { struct pci_dev *pci_dev = mdev->pci_dev; if (mdev->device) pci_iounmap(pci_dev, mdev->device); if (mdev->notify_base) pci_iounmap(pci_dev, mdev->notify_base); pci_iounmap(pci_dev, mdev->isr); pci_iounmap(pci_dev, mdev->common); pci_release_selected_regions(pci_dev, mdev->modern_bars); } EXPORT_SYMBOL_GPL(vp_modern_remove); /* * vp_modern_get_features - get features from device * @mdev: the modern virtio-pci device * * Returns the features read from the device */ u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev) { struct virtio_pci_common_cfg __iomem *cfg = mdev->common; u64 features; vp_iowrite32(0, &cfg->device_feature_select); features = vp_ioread32(&cfg->device_feature); vp_iowrite32(1, &cfg->device_feature_select); features |= ((u64)vp_ioread32(&cfg->device_feature) << 32); return features; } EXPORT_SYMBOL_GPL(vp_modern_get_features); /* * vp_modern_get_driver_features - get driver features from device * @mdev: the modern virtio-pci device * * Returns the driver features read from the device */ u64 vp_modern_get_driver_features(struct virtio_pci_modern_device *mdev) { struct virtio_pci_common_cfg __iomem *cfg = mdev->common; u64 features; vp_iowrite32(0, &cfg->guest_feature_select); features = vp_ioread32(&cfg->guest_feature); vp_iowrite32(1, &cfg->guest_feature_select); features |= ((u64)vp_ioread32(&cfg->guest_feature) << 32); return features; } EXPORT_SYMBOL_GPL(vp_modern_get_driver_features); /* * vp_modern_set_features - set features to device * @mdev: the modern virtio-pci device * @features: the features set to device */ void vp_modern_set_features(struct virtio_pci_modern_device *mdev, u64 features) { struct virtio_pci_common_cfg __iomem *cfg = mdev->common; vp_iowrite32(0, &cfg->guest_feature_select); vp_iowrite32((u32)features, &cfg->guest_feature); vp_iowrite32(1, &cfg->guest_feature_select); vp_iowrite32(features >> 32, &cfg->guest_feature); } EXPORT_SYMBOL_GPL(vp_modern_set_features); /* * vp_modern_generation - get the device genreation * @mdev: the modern virtio-pci device * * Returns the genreation read from device */ u32 vp_modern_generation(struct virtio_pci_modern_device *mdev) { struct virtio_pci_common_cfg __iomem *cfg = mdev->common; return vp_ioread8(&cfg->config_generation); } EXPORT_SYMBOL_GPL(vp_modern_generation); /* * vp_modern_get_status - get the device status * @mdev: the modern virtio-pci device * * Returns the status read from device */ u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev) { struct virtio_pci_common_cfg __iomem *cfg = mdev->common; return vp_ioread8(&cfg->device_status); } EXPORT_SYMBOL_GPL(vp_modern_get_status); /* * vp_modern_set_status - set status to device * @mdev: the modern virtio-pci device * @status: the status set to device */ void vp_modern_set_status(struct virtio_pci_modern_device *mdev, u8 status) { struct virtio_pci_common_cfg __iomem *cfg = mdev->common; vp_iowrite8(status, &cfg->device_status); } EXPORT_SYMBOL_GPL(vp_modern_set_status); /* * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue * @mdev: the modern virtio-pci device * @index: queue index * @vector: the config vector * * Returns the config vector read from the device */ u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev, u16 index, u16 vector) { struct virtio_pci_common_cfg __iomem *cfg = mdev->common; vp_iowrite16(index, &cfg->queue_select); vp_iowrite16(vector, &cfg->queue_msix_vector); /* Flush the write out to device */ return vp_ioread16(&cfg->queue_msix_vector); } EXPORT_SYMBOL_GPL(vp_modern_queue_vector); /* * vp_modern_config_vector - set the vector for config interrupt * @mdev: the modern virtio-pci device * @vector: the config vector * * Returns the config vector read from the device */ u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev, u16 vector) { struct virtio_pci_common_cfg __iomem *cfg = mdev->common; /* Setup the vector used for configuration events */ vp_iowrite16(vector, &cfg->msix_config); /* Verify we had enough resources to assign the vector */ /* Will also flush the write out to device */ return vp_ioread16(&cfg->msix_config); } EXPORT_SYMBOL_GPL(vp_modern_config_vector); /* * vp_modern_queue_address - set the virtqueue address * @mdev: the modern virtio-pci device * @index: the queue index * @desc_addr: address of the descriptor area * @driver_addr: address of the driver area * @device_addr: address of the device area */ void vp_modern_queue_address(struct virtio_pci_modern_device *mdev, u16 index, u64 desc_addr, u64 driver_addr, u64 device_addr) { struct virtio_pci_common_cfg __iomem *cfg = mdev->common; vp_iowrite16(index, &cfg->queue_select); vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo, &cfg->queue_desc_hi); vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo, &cfg->queue_avail_hi); vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo, &cfg->queue_used_hi); } EXPORT_SYMBOL_GPL(vp_modern_queue_address); /* * vp_modern_set_queue_enable - enable a virtqueue * @mdev: the modern virtio-pci device * @index: the queue index * @enable: whether the virtqueue is enable or not */ void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev, u16 index, bool enable) { vp_iowrite16(index, &mdev->common->queue_select); vp_iowrite16(enable, &mdev->common->queue_enable); } EXPORT_SYMBOL_GPL(vp_modern_set_queue_enable); /* * vp_modern_get_queue_enable - enable a virtqueue * @mdev: the modern virtio-pci device * @index: the queue index * * Returns whether a virtqueue is enabled or not */ bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev, u16 index) { vp_iowrite16(index, &mdev->common->queue_select); return vp_ioread16(&mdev->common->queue_enable); } EXPORT_SYMBOL_GPL(vp_modern_get_queue_enable); /* * vp_modern_set_queue_size - set size for a virtqueue * @mdev: the modern virtio-pci device * @index: the queue index * @size: the size of the virtqueue */ void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev, u16 index, u16 size) { vp_iowrite16(index, &mdev->common->queue_select); vp_iowrite16(size, &mdev->common->queue_size); } EXPORT_SYMBOL_GPL(vp_modern_set_queue_size); /* * vp_modern_get_queue_size - get size for a virtqueue * @mdev: the modern virtio-pci device * @index: the queue index * * Returns the size of the virtqueue */ u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev, u16 index) { vp_iowrite16(index, &mdev->common->queue_select); return vp_ioread16(&mdev->common->queue_size); } EXPORT_SYMBOL_GPL(vp_modern_get_queue_size); /* * vp_modern_get_num_queues - get the number of virtqueues * @mdev: the modern virtio-pci device * * Returns the number of virtqueues */ u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev) { return vp_ioread16(&mdev->common->num_queues); } EXPORT_SYMBOL_GPL(vp_modern_get_num_queues); /* * vp_modern_get_queue_notify_off - get notification offset for a virtqueue * @mdev: the modern virtio-pci device * @index: the queue index * * Returns the notification offset for a virtqueue */ static u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev, u16 index) { vp_iowrite16(index, &mdev->common->queue_select); return vp_ioread16(&mdev->common->queue_notify_off); } /* * vp_modern_map_vq_notify - map notification area for a * specific virtqueue * @mdev: the modern virtio-pci device * @index: the queue index * @pa: the pointer to the physical address of the nofity area * * Returns the address of the notification area */ void __iomem *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev, u16 index, resource_size_t *pa) { u16 off = vp_modern_get_queue_notify_off(mdev, index); if (mdev->notify_base) { /* offset should not wrap */ if ((u64)off * mdev->notify_offset_multiplier + 2 > mdev->notify_len) { dev_warn(&mdev->pci_dev->dev, "bad notification offset %u (x %u) " "for queue %u > %zd", off, mdev->notify_offset_multiplier, index, mdev->notify_len); return NULL; } if (pa) *pa = mdev->notify_pa + off * mdev->notify_offset_multiplier; return mdev->notify_base + off * mdev->notify_offset_multiplier; } else { return vp_modern_map_capability(mdev, mdev->notify_map_cap, 2, 2, off * mdev->notify_offset_multiplier, 2, NULL, pa); } } EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify); MODULE_VERSION("0.1"); MODULE_DESCRIPTION("Modern Virtio PCI Device"); MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>"); MODULE_LICENSE("GPL");