This patch introduces a transport specific methods to set or get the
coalescing parameters and implement the pci methods.

Signed-off-by: Jason Wang <jasow...@redhat.com>
---
 drivers/virtio/virtio_pci_modern.c | 15 +++++++++++++++
 include/linux/virtio_config.h      |  8 ++++++++
 include/uapi/linux/virtio_pci.h    |  4 ++++
 3 files changed, 27 insertions(+)

diff --git a/drivers/virtio/virtio_pci_modern.c 
b/drivers/virtio/virtio_pci_modern.c
index e88e099..ce801ae 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -266,6 +266,16 @@ static void vp_set_status(struct virtio_device *vdev, u8 
status)
        vp_iowrite8(status, &vp_dev->common->device_status);
 }
 
+static void vp_set_coalesce(struct virtio_device *vdev, int n,
+                           u32 coalesce_count, u32 coalesce_us)
+{
+       struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+       iowrite16(n, &vp_dev->common->queue_select);
+       iowrite32(coalesce_count, &vp_dev->common->queue_coalesce_count);
+       iowrite32(coalesce_us, &vp_dev->common->queue_coalesce_us);
+}
+
 static void vp_reset(struct virtio_device *vdev)
 {
        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
@@ -481,6 +491,7 @@ static const struct virtio_config_ops virtio_pci_config_ops 
= {
        .generation     = vp_generation,
        .get_status     = vp_get_status,
        .set_status     = vp_set_status,
+       .set_coalesce   = vp_set_coalesce,
        .reset          = vp_reset,
        .find_vqs       = vp_modern_find_vqs,
        .del_vqs        = vp_del_vqs,
@@ -588,6 +599,10 @@ static inline void check_offsets(void)
                     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));
+       BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_COALESCE_C !=
+               offsetof(struct virtio_pci_common_cfg, queue_coalesce_count));
+       BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_COALESCE_U !=
+               offsetof(struct virtio_pci_common_cfg, queue_coalesce_us));
 }
 
 /* the PCI probing function */
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 1e306f7..d100c32 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -28,6 +28,12 @@
  * @set_status: write the status byte
  *     vdev: the virtio_device
  *     status: the new status byte
+ * @set_coalesce: set coalescing parameters
+ *     vdev: the virtio_device
+ *     n: the queue index
+ *     coalesce_count: maximum coalesced count before issuing interrupt
+ *      coalesce_count: maximum micro seconds to wait if there's a
+ *      pending buffer
  * @reset: reset the device
  *     vdev: the virtio device
  *     After this, status and feature negotiation must be done again
@@ -66,6 +72,8 @@ struct virtio_config_ops {
        u32 (*generation)(struct virtio_device *vdev);
        u8 (*get_status)(struct virtio_device *vdev);
        void (*set_status)(struct virtio_device *vdev, u8 status);
+       void (*set_coalesce)(struct virtio_device *vdev, int n,
+                            u32 coalesce_count, u32 coalesce_us);
        void (*reset)(struct virtio_device *vdev);
        int (*find_vqs)(struct virtio_device *, unsigned nvqs,
                        struct virtqueue *vqs[],
diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index 7530146..3396026 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -155,6 +155,8 @@ struct virtio_pci_common_cfg {
        __le32 queue_avail_hi;          /* read-write */
        __le32 queue_used_lo;           /* read-write */
        __le32 queue_used_hi;           /* read-write */
+       __le32 queue_coalesce_count;    /* read-write */
+       __le32 queue_coalesce_us;       /* read-write */
 };
 
 /* Macro versions of offsets for the Old Timers! */
@@ -187,6 +189,8 @@ struct virtio_pci_common_cfg {
 #define VIRTIO_PCI_COMMON_Q_AVAILHI    44
 #define VIRTIO_PCI_COMMON_Q_USEDLO     48
 #define VIRTIO_PCI_COMMON_Q_USEDHI     52
+#define VIRTIO_PCI_COMMON_Q_COALESCE_C  56
+#define VIRTIO_PCI_COMMON_Q_COALESCE_U  60
 
 #endif /* VIRTIO_PCI_NO_MODERN */
 
-- 
1.8.3.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to