Signed-off-by: Shannon Nelson <snelson@xxxxxxxxxxx>
---
drivers/vdpa/pds/Makefile | 3 +-
drivers/vdpa/pds/pci_drv.c | 10 ++
drivers/vdpa/pds/pci_drv.h | 2 +
drivers/vdpa/pds/virtio_pci.c | 283 ++++++++++++++++++++++++++++++++++
4 files changed, 297 insertions(+), 1 deletion(-)
create mode 100644 drivers/vdpa/pds/virtio_pci.c
diff --git a/drivers/vdpa/pds/Makefile b/drivers/vdpa/pds/Makefile
index 3ba28a875574..b8376ab165bc 100644
--- a/drivers/vdpa/pds/Makefile
+++ b/drivers/vdpa/pds/Makefile
@@ -4,4 +4,5 @@
obj-$(CONFIG_PDS_VDPA) := pds_vdpa.o
pds_vdpa-y := pci_drv.o \
- debugfs.o
+ debugfs.o \
+ virtio_pci.o
diff --git a/drivers/vdpa/pds/pci_drv.c b/drivers/vdpa/pds/pci_drv.c
index 369e11153f21..10491e22778c 100644
--- a/drivers/vdpa/pds/pci_drv.c
+++ b/drivers/vdpa/pds/pci_drv.c
@@ -44,6 +44,14 @@ pds_vdpa_pci_probe(struct pci_dev *pdev,
goto err_out_free_mem;
}
+ vdpa_pdev->vd_mdev.pci_dev = pdev;
+ err = pds_vdpa_probe_virtio(&vdpa_pdev->vd_mdev);
+ if (err) {
+ dev_err(dev, "Unable to probe for virtio configuration: %pe\n",
+ ERR_PTR(err));
+ goto err_out_free_mem;
+ }
+
pci_enable_pcie_error_reporting(pdev);
/* Use devres management */
@@ -74,6 +82,7 @@ pds_vdpa_pci_probe(struct pci_dev *pdev,
err_out_pci_release_device:
pci_disable_device(pdev);
err_out_free_mem:
+ pds_vdpa_remove_virtio(&vdpa_pdev->vd_mdev);
pci_disable_pcie_error_reporting(pdev);
kfree(vdpa_pdev);
return err;
@@ -88,6 +97,7 @@ pds_vdpa_pci_remove(struct pci_dev *pdev)
pci_clear_master(pdev);
pci_disable_pcie_error_reporting(pdev);
pci_disable_device(pdev);
+ pds_vdpa_remove_virtio(&vdpa_pdev->vd_mdev);
kfree(vdpa_pdev);
dev_info(&pdev->dev, "Removed\n");
diff --git a/drivers/vdpa/pds/pci_drv.h b/drivers/vdpa/pds/pci_drv.h
index 747809e0df9e..15f3b34fafa9 100644
--- a/drivers/vdpa/pds/pci_drv.h
+++ b/drivers/vdpa/pds/pci_drv.h
@@ -43,4 +43,6 @@ struct pds_vdpa_pci_device {
struct virtio_pci_modern_device vd_mdev;
};
+int pds_vdpa_probe_virtio(struct virtio_pci_modern_device *mdev);
+void pds_vdpa_remove_virtio(struct virtio_pci_modern_device *mdev);
#endif /* _PCI_DRV_H */
diff --git a/drivers/vdpa/pds/virtio_pci.c b/drivers/vdpa/pds/virtio_pci.c
new file mode 100644
index 000000000000..0f4ac9467199
--- /dev/null
+++ b/drivers/vdpa/pds/virtio_pci.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/*
+ * adapted from drivers/virtio/virtio_pci_modern_dev.c, v6.0-rc1
+ */
+
+#include <linux/virtio_pci_modern.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+
+#include "pci_drv.h"
+
+/*
+ * pds_vdpa_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 *
+pds_vdpa_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;
+}
+
+/*
+ * pds_vdpa_probe_virtio: 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 pds_vdpa_probe_virtio(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 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: missing common config\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;
+ }
+
+ /* 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 = pds_vdpa_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 = pds_vdpa_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 = pds_vdpa_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 = pds_vdpa_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;
+}
+
+void pds_vdpa_remove_virtio(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);
+}
