diff options
| author | Will Deacon <willdeacon@google.com> | 2023-03-29 22:25:00 +0800 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2023-04-25 11:53:15 -0400 |
| commit | b0a2fe148a70dc805f1e11702a08a7065418a8dd (patch) | |
| tree | dd96eae340d934015017a673ef06127c49c7a645 /drivers | |
| parent | 37e53db38bdbeb58732e36d1efcdf58f6ce3a138 (diff) | |
| download | u-boot-b0a2fe148a70dc805f1e11702a08a7065418a8dd.tar.gz | |
virtio: Use bounce buffers when VIRTIO_F_IOMMU_PLATFORM is setWIP/2023-04-25-use-bounce-buffers-for-VIRTIO_F_IOMMU_PLATFORM
Devices advertising the VIRTIO_F_IOMMU_PLATFORM feature require
platform-specific handling to configure their DMA transactions.
When handling virtio descriptors for such a device, use bounce
buffers to ensure that the underlying buffers are always aligned
to and padded to PAGE_SIZE in preparation for platform specific
handling at page granularity.
Signed-off-by: Will Deacon <willdeacon@google.com>
[ Paul: pick from the Android tree. Rebase to the upstream ]
Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
Cc: Bin Meng <bmeng.cn@gmail.com>
Link: https://android.googlesource.com/platform/external/u-boot/+/1eff171e613ee67dca71dbe97be7282e2db17011
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 48 |
1 files changed, 47 insertions, 1 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index de75786ca76..c9adcce5c09 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -28,14 +28,51 @@ static void virtio_free_pages(struct udevice *vdev, void *ptr, u32 npages) free(ptr); } +static int __bb_force_page_align(struct bounce_buffer *state) +{ + const ulong align_mask = PAGE_SIZE - 1; + + if ((ulong)state->user_buffer & align_mask) + return 0; + + if (state->len != state->len_aligned) + return 0; + + return 1; +} + static unsigned int virtqueue_attach_desc(struct virtqueue *vq, unsigned int i, struct virtio_sg *sg, u16 flags) { struct vring_desc_shadow *desc_shadow = &vq->vring_desc_shadow[i]; struct vring_desc *desc = &vq->vring.desc[i]; + void *addr; + + if (IS_ENABLED(CONFIG_BOUNCE_BUFFER) && vq->vring.bouncebufs) { + struct bounce_buffer *bb = &vq->vring.bouncebufs[i]; + unsigned int bbflags; + int ret; + + if (flags & VRING_DESC_F_WRITE) + bbflags = GEN_BB_WRITE; + else + bbflags = GEN_BB_READ; + + ret = bounce_buffer_start_extalign(bb, sg->addr, sg->length, + bbflags, PAGE_SIZE, + __bb_force_page_align); + if (ret) { + debug("%s: failed to allocate bounce buffer (length 0x%zx)\n", + vq->vdev->name, sg->length); + } + + addr = bb->bounce_buffer; + } else { + addr = sg->addr; + } /* Update the shadow descriptor. */ - desc_shadow->addr = (u64)(uintptr_t)sg->addr; + desc_shadow->addr = (u64)(uintptr_t)addr; desc_shadow->len = sg->length; desc_shadow->flags = flags; @@ -50,6 +87,15 @@ static unsigned int virtqueue_attach_desc(struct virtqueue *vq, unsigned int i, static void virtqueue_detach_desc(struct virtqueue *vq, unsigned int idx) { + struct vring_desc *desc = &vq->vring.desc[idx]; + struct bounce_buffer *bb; + + if (!IS_ENABLED(CONFIG_BOUNCE_BUFFER) || !vq->vring.bouncebufs) + return; + + bb = &vq->vring.bouncebufs[idx]; + bounce_buffer_stop(bb); + desc->addr = cpu_to_virtio64(vq->vdev, (u64)(uintptr_t)bb->user_buffer); } int virtqueue_add(struct virtqueue *vq, struct virtio_sg *sgs[], |