mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-08-31 11:41:29 -04:00
Code Issues Packages Projects Releases Wiki Activity

virtio-mmio: add support for transport version 3

Browse Source 
Virtio MMIO transport version 3 allows device reset to complete
asynchronously. Unlike version 2, where writing zero to Status must
complete the reset before the write returns, version 3 requires the
driver to poll Status until it reads back zero before considering reset
complete.

Update virtio-mmio accordingly: accept transport version 3 and, during
reset, wait for Status to become zero. Keep the polling loop unbounded,
consistent with virtio-pci, since the reset callback does not return an
error code.

Signed-off-by: Peter Hilber <peter.hilber@oss.qualcomm.com>
Link: bb1dd2e1fe
Message-ID: <20260605142921.2824-1-peter.hilber@oss.qualcomm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Peter Hilber
2026-06-05 16:29:21 +02:00
committed by Michael S. Tsirkin
parent 8d3ae59288
commit fa8833c085
1 changed files with 10 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/virtio/virtio_mmio.c
View File

@@ -55,6 +55,7 @@
#define pr_fmt(fmt) "virtio-mmio: " fmt
#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/highmem.h>
#include <linux/interrupt.h>
@@ -114,9 +115,9 @@ static int vm_finalize_features(struct virtio_device *vdev)
vring_transport_features(vdev);
/* Make sure there are no mixed devices */
if (vm_dev->version == 2 &&
if (vm_dev->version >= 2 &&
!__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n");
dev_err(&vdev->dev, "New virtio-mmio devices (version >= 2) must provide VIRTIO_F_VERSION_1 feature!\n");
return -EINVAL;
}
@@ -254,6 +255,12 @@ static void vm_reset(struct virtio_device *vdev)
/* 0 status means a reset. */
writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
if (vm_dev->version >= 3) {
/* Wait for reset to complete. */
while (vm_get_status(vdev))
fsleep(1000);
}
}
@@ -600,7 +607,7 @@ static int virtio_mmio_probe(struct platform_device *pdev)
/* Check device version */
vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
if (vm_dev->version < 1 || vm_dev->version > 2) {
if (vm_dev->version < 1 || vm_dev->version > 3) {
dev_err(&pdev->dev, "Version %ld not supported!\n",
vm_dev->version);
rc = -ENXIO;