summaryrefslogtreecommitdiffstats
path: root/drivers/virtio/virtio_pci_modern_dev.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/virtio/virtio_pci_modern_dev.c')
-rw-r--r--drivers/virtio/virtio_pci_modern_dev.c711
1 files changed, 711 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio_pci_modern_dev.c
new file mode 100644
index 000000000..ccdd41935
--- /dev/null
+++ b/drivers/virtio/virtio_pci_modern_dev.c
@@ -0,0 +1,711 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/virtio_pci_modern.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/delay.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);
+
+ /* Check if the BAR may have changed since we requested the region. */
+ if (bar >= PCI_STD_NUM_BARS || !(mdev->modern_bars & (1 << bar))) {
+ dev_err(&dev->dev,
+ "virtio_pci: bar unexpectedly changed to %u\n", bar);
+ return NULL;
+ }
+
+ 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 >= PCI_STD_NUM_BARS)
+ 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();
+
+ /* 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_modern_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),
+ &notify_length);
+
+ pci_read_config_dword(pci_dev,
+ notify + offsetof(struct virtio_pci_notify_cap,
+ cap.offset),
+ &notify_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:
+ pci_release_selected_regions(pci_dev, mdev->modern_bars);
+ return err;
+}
+EXPORT_SYMBOL_GPL(vp_modern_probe);
+
+/*
+ * vp_modern_remove: 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;
+
+ /*
+ * Per memory-barriers.txt, wmb() is not needed to guarantee
+ * that the cache coherent memory writes have completed
+ * before writing to the MMIO region.
+ */
+ vp_iowrite8(status, &cfg->device_status);
+}
+EXPORT_SYMBOL_GPL(vp_modern_set_status);
+
+/*
+ * vp_modern_get_queue_reset - get the queue reset status
+ * @mdev: the modern virtio-pci device
+ * @index: queue index
+ */
+int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
+{
+ struct virtio_pci_modern_common_cfg __iomem *cfg;
+
+ cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
+
+ vp_iowrite16(index, &cfg->cfg.queue_select);
+ return vp_ioread16(&cfg->queue_reset);
+}
+EXPORT_SYMBOL_GPL(vp_modern_get_queue_reset);
+
+/*
+ * vp_modern_set_queue_reset - reset the queue
+ * @mdev: the modern virtio-pci device
+ * @index: queue index
+ */
+void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
+{
+ struct virtio_pci_modern_common_cfg __iomem *cfg;
+
+ cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
+
+ vp_iowrite16(index, &cfg->cfg.queue_select);
+ vp_iowrite16(1, &cfg->queue_reset);
+
+ while (vp_ioread16(&cfg->queue_reset))
+ msleep(1);
+
+ while (vp_ioread16(&cfg->cfg.queue_enable))
+ msleep(1);
+}
+EXPORT_SYMBOL_GPL(vp_modern_set_queue_reset);
+
+/*
+ * 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");