Thread (1 message) 1 message, 1 author, 2021-03-11

Re: [PATCH] virtio-mmio: read[wl]()/write[wl] are already little-endian

From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2021-03-11 15:45:39
Also in: lkml

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 ...
quoted hunk
No need to convert the value with cpu_to_leXX()/leXX_to_cpu()

Signed-off-by: Laurent Vivier <redacted>
---
 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
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help