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SubjectRe: [PATCH] virtio-mmio: read[wl]()/write[wl] are already little-endian
On Tue, Mar 09, 2021 at 11:43:13PM +0100, Laurent Vivier wrote:
> read[wl]()/write[wl] already access memory in little-endian mode.

But then they convert it to CPU right? We just convert it back ...

> No need to convert the value with cpu_to_leXX()/leXX_to_cpu()
>
> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
> ---
> drivers/virtio/virtio_mmio.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
> index a286d22b6551..3f6a5588f77d 100644
> --- a/drivers/virtio/virtio_mmio.c
> +++ b/drivers/virtio/virtio_mmio.c
> @@ -168,17 +168,17 @@ static void vm_get(struct virtio_device *vdev, unsigned offset,
> memcpy(buf, &b, sizeof b);
> break;
> case 2:
> - w = cpu_to_le16(readw(base + offset));
> + w = readw(base + offset);
> memcpy(buf, &w, sizeof w);
> break;
> case 4:
> - l = cpu_to_le32(readl(base + offset));
> + l = readl(base + offset);
> memcpy(buf, &l, sizeof l);
> break;
> case 8:
> - l = cpu_to_le32(readl(base + offset));
> + l = readl(base + offset);
> memcpy(buf, &l, sizeof l);
> - l = cpu_to_le32(ioread32(base + offset + sizeof l));
> + l = ioread32(base + offset + sizeof l);
> memcpy(buf + sizeof l, &l, sizeof l);
> break;
> default:
> @@ -212,17 +212,17 @@ static void vm_set(struct virtio_device *vdev, unsigned offset,
> break;
> case 2:
> memcpy(&w, buf, sizeof w);
> - writew(le16_to_cpu(w), base + offset);
> + writew(w, base + offset);
> break;
> case 4:
> memcpy(&l, buf, sizeof l);
> - writel(le32_to_cpu(l), base + offset);
> + writel(l, base + offset);
> break;
> case 8:
> memcpy(&l, buf, sizeof l);
> - writel(le32_to_cpu(l), base + offset);
> + writel(l, base + offset);
> memcpy(&l, buf + sizeof l, sizeof l);
> - writel(le32_to_cpu(l), base + offset + sizeof l);
> + writel(l, base + offset + sizeof l);
> break;
> default:
> BUG();
> --
> 2.29.2

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