[PATCH 1/6] virtio-pci: introduce legacy device module
From: Wu Zongyong
Date: Wed Sep 08 2021 - 08:21:18 EST
Split common codes from virtio-pci-legacy so vDPA driver can reuse it
later.
Signed-off-by: Wu Zongyong <wuzongyong@xxxxxxxxxxxxxxxxx>
---
drivers/virtio/Kconfig | 10 ++
drivers/virtio/Makefile | 1 +
drivers/virtio/virtio_pci_common.c | 10 +-
drivers/virtio/virtio_pci_common.h | 9 +-
drivers/virtio/virtio_pci_legacy.c | 101 +++---------
drivers/virtio/virtio_pci_legacy_dev.c | 220 +++++++++++++++++++++++++
include/linux/virtio_pci_legacy.h | 44 +++++
7 files changed, 312 insertions(+), 83 deletions(-)
create mode 100644 drivers/virtio/virtio_pci_legacy_dev.c
create mode 100644 include/linux/virtio_pci_legacy.h
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index ce1b3f6ec325..b14768dc9e04 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -20,6 +20,15 @@ config VIRTIO_PCI_LIB
PCI device with possible vendor specific extensions. Any
module that selects this module must depend on PCI.
+config VIRTIO_PCI_LIB_LEGACY
+ tristate
+ help
+ Legacy PCI device (Virtio PCI Card 0.9.x Draft and older device)
+ implementation.
+ This modules implements the basic probe and control for devices
+ which are based on legacy PCI device. Any module that selects this
+ module must depend on PCI.
+
menuconfig VIRTIO_MENU
bool "Virtio drivers"
default y
@@ -43,6 +52,7 @@ config VIRTIO_PCI_LEGACY
bool "Support for legacy virtio draft 0.9.X and older devices"
default y
depends on VIRTIO_PCI
+ select VIRTIO_PCI_LIB_LEGACY
help
Virtio PCI Card 0.9.X Draft (circa 2014) and older device support.
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index 699bbea0465f..0a82d0873248 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o
obj-$(CONFIG_VIRTIO_PCI_LIB) += virtio_pci_modern_dev.o
+obj-$(CONFIG_VIRTIO_PCI_LIB_LEGACY) += virtio_pci_legacy_dev.o
obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index b35bb2d57f62..d724f676608b 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -549,6 +549,8 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
pci_set_master(pci_dev);
+ vp_dev->is_legacy = vp_dev->ldev.ioaddr ? true : false;
+
rc = register_virtio_device(&vp_dev->vdev);
reg_dev = vp_dev;
if (rc)
@@ -557,10 +559,10 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
return 0;
err_register:
- if (vp_dev->ioaddr)
- virtio_pci_legacy_remove(vp_dev);
+ if (vp_dev->is_legacy)
+ virtio_pci_legacy_remove(vp_dev);
else
- virtio_pci_modern_remove(vp_dev);
+ virtio_pci_modern_remove(vp_dev);
err_probe:
pci_disable_device(pci_dev);
err_enable_device:
@@ -587,7 +589,7 @@ static void virtio_pci_remove(struct pci_dev *pci_dev)
unregister_virtio_device(&vp_dev->vdev);
- if (vp_dev->ioaddr)
+ if (vp_dev->is_legacy)
virtio_pci_legacy_remove(vp_dev);
else
virtio_pci_modern_remove(vp_dev);
diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index beec047a8f8d..eb17a29fc7ef 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -25,6 +25,7 @@
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#include <linux/virtio_pci.h>
+#include <linux/virtio_pci_legacy.h>
#include <linux/virtio_pci_modern.h>
#include <linux/highmem.h>
#include <linux/spinlock.h>
@@ -44,16 +45,14 @@ struct virtio_pci_vq_info {
struct virtio_pci_device {
struct virtio_device vdev;
struct pci_dev *pci_dev;
+ struct virtio_pci_legacy_device ldev;
struct virtio_pci_modern_device mdev;
- /* In legacy mode, these two point to within ->legacy. */
+ bool is_legacy;
+
/* Where to read and clear interrupt */
u8 __iomem *isr;
- /* Legacy only field */
- /* the IO mapping for the PCI config space */
- void __iomem *ioaddr;
-
/* a list of queues so we can dispatch IRQs */
spinlock_t lock;
struct list_head virtqueues;
diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
index d62e9835aeec..82eb437ad920 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -14,6 +14,7 @@
* Michael S. Tsirkin <mst@xxxxxxxxxx>
*/
+#include "linux/virtio_pci_legacy.h"
#include "virtio_pci_common.h"
/* virtio config->get_features() implementation */
@@ -23,7 +24,7 @@ static u64 vp_get_features(struct virtio_device *vdev)
/* When someone needs more than 32 feature bits, we'll need to
* steal a bit to indicate that the rest are somewhere else. */
- return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
+ return vp_legacy_get_features(&vp_dev->ldev);
}
/* virtio config->finalize_features() implementation */
@@ -38,7 +39,7 @@ static int vp_finalize_features(struct virtio_device *vdev)
BUG_ON((u32)vdev->features != vdev->features);
/* We only support 32 feature bits. */
- iowrite32(vdev->features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
+ vp_legacy_set_features(&vp_dev->ldev, vdev->features);
return 0;
}
@@ -48,7 +49,7 @@ static void vp_get(struct virtio_device *vdev, unsigned offset,
void *buf, unsigned len)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- void __iomem *ioaddr = vp_dev->ioaddr +
+ void __iomem *ioaddr = vp_dev->ldev.ioaddr +
VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) +
offset;
u8 *ptr = buf;
@@ -64,7 +65,7 @@ static void vp_set(struct virtio_device *vdev, unsigned offset,
const void *buf, unsigned len)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- void __iomem *ioaddr = vp_dev->ioaddr +
+ void __iomem *ioaddr = vp_dev->ldev.ioaddr +
VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) +
offset;
const u8 *ptr = buf;
@@ -78,7 +79,7 @@ static void vp_set(struct virtio_device *vdev, unsigned offset,
static u8 vp_get_status(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+ return vp_legacy_get_status(&vp_dev->ldev);
}
static void vp_set_status(struct virtio_device *vdev, u8 status)
@@ -86,28 +87,24 @@ static void vp_set_status(struct virtio_device *vdev, u8 status)
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* We should never be setting status to 0. */
BUG_ON(status == 0);
- iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+ vp_legacy_set_status(&vp_dev->ldev, status);
}
static void vp_reset(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* 0 status means a reset. */
- iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+ vp_legacy_set_status(&vp_dev->ldev, 0);
/* Flush out the status write, and flush in device writes,
* including MSi-X interrupts, if any. */
- ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+ vp_legacy_get_status(&vp_dev->ldev);
/* Flush pending VQ/configuration callbacks. */
vp_synchronize_vectors(vdev);
}
static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
{
- /* Setup the vector used for configuration events */
- iowrite16(vector, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
- /* Verify we had enough resources to assign the vector */
- /* Will also flush the write out to device */
- return ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+ return vp_legacy_config_vector(&vp_dev->ldev, vector);
}
static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
@@ -123,12 +120,9 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
int err;
u64 q_pfn;
- /* Select the queue we're interested in */
- iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
-
/* Check if queue is either not available or already active. */
- num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
- if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
+ num = vp_legacy_get_queue_size(&vp_dev->ldev, index);
+ if (!num || vp_legacy_get_queue_enable(&vp_dev->ldev, index))
return ERR_PTR(-ENOENT);
info->msix_vector = msix_vec;
@@ -151,13 +145,12 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
}
/* activate the queue */
- iowrite32(q_pfn, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+ vp_legacy_set_queue_address(&vp_dev->ldev, index, q_pfn);
- vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
+ vq->priv = (void __force *)vp_dev->ldev.ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
- iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
- msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+ msix_vec = vp_legacy_queue_vector(&vp_dev->ldev, index, msix_vec);
if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
err = -EBUSY;
goto out_deactivate;
@@ -167,7 +160,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
return vq;
out_deactivate:
- iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+ vp_legacy_set_queue_address(&vp_dev->ldev, index, 0);
out_del_vq:
vring_del_virtqueue(vq);
return ERR_PTR(err);
@@ -178,17 +171,15 @@ static void del_vq(struct virtio_pci_vq_info *info)
struct virtqueue *vq = info->vq;
struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
- iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
-
if (vp_dev->msix_enabled) {
- iowrite16(VIRTIO_MSI_NO_VECTOR,
- vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+ vp_legacy_queue_vector(&vp_dev->ldev, vq->index,
+ VIRTIO_MSI_NO_VECTOR);
/* Flush the write out to device */
- ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
+ ioread8(vp_dev->ldev.ioaddr + VIRTIO_PCI_ISR);
}
/* Select and deactivate the queue */
- iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+ vp_legacy_set_queue_address(&vp_dev->ldev, vq->index, 0);
vring_del_virtqueue(vq);
}
@@ -211,51 +202,18 @@ static const struct virtio_config_ops virtio_pci_config_ops = {
/* the PCI probing function */
int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
{
+ struct virtio_pci_legacy_device *ldev = &vp_dev->ldev;
struct pci_dev *pci_dev = vp_dev->pci_dev;
int rc;
- /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
- if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
- return -ENODEV;
-
- if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
- printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
- VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
- return -ENODEV;
- }
-
- rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64));
- if (rc) {
- rc = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32));
- } else {
- /*
- * The virtio ring base address is expressed as a 32-bit PFN,
- * with a page size of 1 << VIRTIO_PCI_QUEUE_ADDR_SHIFT.
- */
- dma_set_coherent_mask(&pci_dev->dev,
- DMA_BIT_MASK(32 + VIRTIO_PCI_QUEUE_ADDR_SHIFT));
- }
-
- if (rc)
- dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
+ ldev->pci_dev = pci_dev;
- rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy");
+ rc = vp_legacy_probe(ldev);
if (rc)
return rc;
- rc = -ENOMEM;
- vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
- if (!vp_dev->ioaddr)
- goto err_iomap;
-
- vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR;
-
- /* we use the subsystem vendor/device id as the virtio vendor/device
- * id. this allows us to use the same PCI vendor/device id for all
- * virtio devices and to identify the particular virtio driver by
- * the subsystem ids */
- vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
- vp_dev->vdev.id.device = pci_dev->subsystem_device;
+ vp_dev->isr = ldev->isr;
+ vp_dev->vdev.id = ldev->id;
vp_dev->vdev.config = &virtio_pci_config_ops;
@@ -264,16 +222,11 @@ int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
vp_dev->del_vq = del_vq;
return 0;
-
-err_iomap:
- pci_release_region(pci_dev, 0);
- return rc;
}
void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
{
- struct pci_dev *pci_dev = vp_dev->pci_dev;
+ struct virtio_pci_legacy_device *ldev = &vp_dev->ldev;
- pci_iounmap(pci_dev, vp_dev->ioaddr);
- pci_release_region(pci_dev, 0);
+ vp_legacy_remove(ldev);
}
diff --git a/drivers/virtio/virtio_pci_legacy_dev.c b/drivers/virtio/virtio_pci_legacy_dev.c
new file mode 100644
index 000000000000..9b97680dd02b
--- /dev/null
+++ b/drivers/virtio/virtio_pci_legacy_dev.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "linux/virtio_pci.h"
+#include <linux/virtio_pci_legacy.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+
+/*
+ * vp_legacy_probe: probe the legacy virtio pci device, note that the
+ * caller is required to enable PCI device before calling this function.
+ * @ldev: the legacy virtio-pci device
+ *
+ * Return 0 on succeed otherwise fail
+ */
+int vp_legacy_probe(struct virtio_pci_legacy_device *ldev)
+{
+ struct pci_dev *pci_dev = ldev->pci_dev;
+ int rc;
+
+ /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
+ if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
+ return -ENODEV;
+
+ if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION)
+ return -ENODEV;
+
+ rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64));
+ if (rc) {
+ rc = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32));
+ } else {
+ /*
+ * The virtio ring base address is expressed as a 32-bit PFN,
+ * with a page size of 1 << VIRTIO_PCI_QUEUE_ADDR_SHIFT.
+ */
+ dma_set_coherent_mask(&pci_dev->dev,
+ DMA_BIT_MASK(32 + VIRTIO_PCI_QUEUE_ADDR_SHIFT));
+ }
+
+ if (rc)
+ dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
+
+ rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy");
+ if (rc)
+ return rc;
+
+ ldev->ioaddr = pci_iomap(pci_dev, 0, 0);
+ if (!ldev->ioaddr)
+ goto err_iomap;
+
+ ldev->isr = ldev->ioaddr + VIRTIO_PCI_ISR;
+
+ ldev->id.vendor = pci_dev->subsystem_vendor;
+ ldev->id.device = pci_dev->subsystem_device;
+
+ return 0;
+err_iomap:
+ pci_release_region(pci_dev, 0);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(vp_legacy_probe);
+
+/*
+ * vp_legacy_probe: remove and cleanup the legacy virtio pci device
+ * @ldev: the legacy virtio-pci device
+ */
+void vp_legacy_remove(struct virtio_pci_legacy_device *ldev)
+{
+ struct pci_dev *pci_dev = ldev->pci_dev;
+
+ pci_iounmap(pci_dev, ldev->ioaddr);
+ pci_release_region(pci_dev, 0);
+}
+EXPORT_SYMBOL_GPL(vp_legacy_remove);
+
+/*
+ * vp_legacy_get_features - get features from device
+ * @ldev: the legacy virtio-pci device
+ *
+ * Returns the features read from the device
+ */
+u64 vp_legacy_get_features(struct virtio_pci_legacy_device *ldev)
+{
+
+ return ioread32(ldev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
+}
+EXPORT_SYMBOL_GPL(vp_legacy_get_features);
+
+/*
+ * vp_legacy_get_driver_features - get driver features from device
+ * @ldev: the legacy virtio-pci device
+ *
+ * Returns the driver features read from the device
+ */
+u64 vp_legacy_get_driver_features(struct virtio_pci_legacy_device *ldev)
+{
+ return ioread32(ldev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
+}
+EXPORT_SYMBOL_GPL(vp_legacy_get_driver_features);
+
+/*
+ * vp_legacy_set_features - set features to device
+ * @ldev: the legacy virtio-pci device
+ * @features: the features set to device
+ */
+void vp_legacy_set_features(struct virtio_pci_legacy_device *ldev,
+ u32 features)
+{
+ iowrite32(features, ldev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
+}
+EXPORT_SYMBOL_GPL(vp_legacy_set_features);
+
+/*
+ * vp_legacy_get_status - get the device status
+ * @ldev: the legacy virtio-pci device
+ *
+ * Returns the status read from device
+ */
+u8 vp_legacy_get_status(struct virtio_pci_legacy_device *ldev)
+{
+ return ioread8(ldev->ioaddr + VIRTIO_PCI_STATUS);
+}
+EXPORT_SYMBOL_GPL(vp_legacy_get_status);
+
+/*
+ * vp_legacy_set_status - set status to device
+ * @ldev: the legacy virtio-pci device
+ * @status: the status set to device
+ */
+void vp_legacy_set_status(struct virtio_pci_legacy_device *ldev,
+ u8 status)
+{
+ iowrite8(status, ldev->ioaddr + VIRTIO_PCI_STATUS);
+}
+EXPORT_SYMBOL_GPL(vp_legacy_set_status);
+
+/*
+ * vp_legacy_queue_vector - set the MSIX vector for a specific virtqueue
+ * @ldev: the legacy virtio-pci device
+ * @index: queue index
+ * @vector: the config vector
+ *
+ * Returns the config vector read from the device
+ */
+u16 vp_legacy_queue_vector(struct virtio_pci_legacy_device *ldev,
+ u16 index, u16 vector)
+{
+ iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
+ iowrite16(vector, ldev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+ /* Flush the write out to device */
+ return ioread16(ldev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+}
+EXPORT_SYMBOL_GPL(vp_legacy_queue_vector);
+
+/*
+ * vp_legacy_config_vector - set the vector for config interrupt
+ * @ldev: the legacy virtio-pci device
+ * @vector: the config vector
+ *
+ * Returns the config vector read from the device
+ */
+u16 vp_legacy_config_vector(struct virtio_pci_legacy_device *ldev,
+ u16 vector)
+{
+ /* Setup the vector used for configuration events */
+ iowrite16(vector, ldev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+ /* Verify we had enough resources to assign the vector */
+ /* Will also flush the write out to device */
+ return ioread16(ldev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+}
+EXPORT_SYMBOL_GPL(vp_legacy_config_vector);
+
+/*
+ * vp_legacy_set_queue_address - set the virtqueue address
+ * @ldev: the legacy virtio-pci device
+ * @index: the queue index
+ * @queue_pfn: pfn of the virtqueue
+ */
+void vp_legacy_set_queue_address(struct virtio_pci_legacy_device *ldev,
+ u16 index, u32 queue_pfn)
+{
+ iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
+ iowrite32(queue_pfn, ldev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+}
+EXPORT_SYMBOL_GPL(vp_legacy_set_queue_address);
+
+/*
+ * vp_legacy_get_queue_enable - enable a virtqueue
+ * @ldev: the legacy virtio-pci device
+ * @index: the queue index
+ *
+ * Returns whether a virtqueue is enabled or not
+ */
+bool vp_legacy_get_queue_enable(struct virtio_pci_legacy_device *ldev,
+ u16 index)
+{
+ iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
+ return ioread32(ldev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+}
+EXPORT_SYMBOL_GPL(vp_legacy_get_queue_enable);
+
+/*
+ * vp_legacy_get_queue_size - get size for a virtqueue
+ * @ldev: the legacy virtio-pci device
+ * @index: the queue index
+ *
+ * Returns the size of the virtqueue
+ */
+u16 vp_legacy_get_queue_size(struct virtio_pci_legacy_device *ldev,
+ u16 index)
+{
+ iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
+ return ioread16(ldev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
+}
+EXPORT_SYMBOL_GPL(vp_legacy_get_queue_size);
+
+MODULE_VERSION("0.1");
+MODULE_DESCRIPTION("Legacy Virtio PCI Device");
+MODULE_AUTHOR("Wu Zongyong <wuzongyong@xxxxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/virtio_pci_legacy.h b/include/linux/virtio_pci_legacy.h
new file mode 100644
index 000000000000..ee2c6157215f
--- /dev/null
+++ b/include/linux/virtio_pci_legacy.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_VIRTIO_PCI_LEGACY_H
+#define _LINUX_VIRTIO_PCI_LEGACY_H
+
+#include "linux/mod_devicetable.h"
+#include <linux/pci.h>
+#include <linux/virtio_pci.h>
+
+struct virtio_pci_legacy_device {
+ struct pci_dev *pci_dev;
+
+ /* Where to read and clear interrupt */
+ u8 __iomem *isr;
+ /* The IO mapping for the PCI config space (legacy mode only) */
+ void __iomem *ioaddr;
+
+ struct virtio_device_id id;
+};
+
+u64 vp_legacy_get_features(struct virtio_pci_legacy_device *ldev);
+u64 vp_legacy_get_driver_features(struct virtio_pci_legacy_device *ldev);
+void vp_legacy_set_features(struct virtio_pci_legacy_device *ldev,
+ u32 features);
+u8 vp_legacy_get_status(struct virtio_pci_legacy_device *ldev);
+void vp_legacy_set_status(struct virtio_pci_legacy_device *ldev,
+ u8 status);
+u16 vp_legacy_queue_vector(struct virtio_pci_legacy_device *ldev,
+ u16 idx, u16 vector);
+u16 vp_legacy_config_vector(struct virtio_pci_legacy_device *ldev,
+ u16 vector);
+void vp_legacy_set_queue_address(struct virtio_pci_legacy_device *ldev,
+ u16 index, u32 queue_pfn);
+void vp_legacy_set_queue_enable(struct virtio_pci_legacy_device *ldev,
+ u16 idx, bool enable);
+bool vp_legacy_get_queue_enable(struct virtio_pci_legacy_device *ldev,
+ u16 idx);
+void vp_legacy_set_queue_size(struct virtio_pci_legacy_device *ldev,
+ u16 idx, u16 size);
+u16 vp_legacy_get_queue_size(struct virtio_pci_legacy_device *ldev,
+ u16 idx);
+int vp_legacy_probe(struct virtio_pci_legacy_device *ldev);
+void vp_legacy_remove(struct virtio_pci_legacy_device *ldev);
+
+#endif
--
2.31.1