From b0952977c98affb9054aa5ba6a79291a293c8824 Mon Sep 17 00:00:00 2001
From: Andrew Scull <ascull@google.com>
Date: Mon, 16 May 2022 10:41:30 +0000
Subject: [PATCH] virtio_ring: Add helper to attach vring descriptor
Move the logic for attaching a descriptor to its own function.
Signed-off-by: Andrew Scull <ascull@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
drivers/virtio/virtio_ring.c | 36 +++++++++++++++++-------------------
1 file changed, 17 insertions(+), 19 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index a6922ce1b8..d3fc842f30 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -16,6 +16,18 @@
#include <linux/bug.h>
#include <linux/compat.h>
+static unsigned int virtqueue_attach_desc(struct virtqueue *vq, unsigned int i,
+ struct virtio_sg *sg, u16 flags)
+{
+ struct vring_desc *desc = &vq->vring.desc[i];
+
+ desc->addr = cpu_to_virtio64(vq->vdev, (u64)(uintptr_t)sg->addr);
+ desc->len = cpu_to_virtio32(vq->vdev, sg->length);
+ desc->flags = cpu_to_virtio16(vq->vdev, flags);
+
+ return virtio16_to_cpu(vq->vdev, desc->next);
+}
+
int virtqueue_add(struct virtqueue *vq, struct virtio_sg *sgs[],
unsigned int out_sgs, unsigned int in_sgs)
{
@@ -44,27 +56,13 @@ int virtqueue_add(struct virtqueue *vq, struct virtio_sg *sgs[],
return -ENOSPC;
}
- for (n = 0; n < out_sgs; n++) {
- struct virtio_sg *sg = sgs[n];
-
- desc[i].flags = cpu_to_virtio16(vq->vdev, VRING_DESC_F_NEXT);
- desc[i].addr = cpu_to_virtio64(vq->vdev, (u64)(size_t)sg->addr);
- desc[i].len = cpu_to_virtio32(vq->vdev, sg->length);
-
- prev = i;
- i = virtio16_to_cpu(vq->vdev, desc[i].next);
- }
- for (; n < (out_sgs + in_sgs); n++) {
- struct virtio_sg *sg = sgs[n];
-
- desc[i].flags = cpu_to_virtio16(vq->vdev, VRING_DESC_F_NEXT |
- VRING_DESC_F_WRITE);
- desc[i].addr = cpu_to_virtio64(vq->vdev,
- (u64)(uintptr_t)sg->addr);
- desc[i].len = cpu_to_virtio32(vq->vdev, sg->length);
+ for (n = 0; n < descs_used; n++) {
+ u16 flags = VRING_DESC_F_NEXT;
+ if (n >= out_sgs)
+ flags |= VRING_DESC_F_WRITE;
prev = i;
- i = virtio16_to_cpu(vq->vdev, desc[i].next);
+ i = virtqueue_attach_desc(vq, i, sgs[n], flags);
}
/* Last one doesn't continue */
desc[prev].flags &= cpu_to_virtio16(vq->vdev, ~VRING_DESC_F_NEXT);
--
2.39.5