Wendy Liang
2016-Dec-06 18:21 UTC
[RFC LINUX PATCH 0/2] Virtio ring works with DMA coherent memory
RPMsg uses dma_alloc_coherent() to allocate memory to shared with the remote. In this case, as there is no pages setup in the dma_alloc_coherent(), we cannot get the physical address back from the virtual address, and thus, we can set the sg_dma_addr to store the DMA address and mark it already DMA mapped. When virtio vring sees the sg_dma_addr is ready set, do not call dma_map_page(). The issue was once discussed here: http://virtualization.linux-foundation.narkive.com/CfVP32Vy/rfc-0-4-rpmsg-fix-init-of-dma-able-virtqueues Edgar E. Iglesias (1): rpmsg: DMA map sgs passed to virtio Wendy Liang (1): virtio_ring: Do not call dma_map_page if sg is already mapped. drivers/rpmsg/virtio_rpmsg_bus.c | 22 +++++++++++++++++++--- drivers/virtio/virtio_ring.c | 6 ++++++ 2 files changed, 25 insertions(+), 3 deletions(-) -- 1.9.1
Jason Wang
2016-Dec-08 03:18 UTC
[RFC LINUX PATCH 0/2] Virtio ring works with DMA coherent memory
On 2016?12?07? 02:21, Wendy Liang wrote:> RPMsg uses dma_alloc_coherent() to allocate memory to shared with the remote. > In this case, as there is no pages setup in the dma_alloc_coherent(), > we cannot get the physical address back from the virtual address, and thus, > we can set the sg_dma_addr to store the DMA address and mark it already DMA > mapped. > > When virtio vring sees the sg_dma_addr is ready set, do not call dma_map_page(). > > The issue was once discussed here: > http://virtualization.linux-foundation.narkive.com/CfVP32Vy/rfc-0-4-rpmsg-fix-init-of-dma-able-virtqueues > > Edgar E. Iglesias (1): > rpmsg: DMA map sgs passed to virtio > > Wendy Liang (1): > virtio_ring: Do not call dma_map_page if sg is already mapped. > > drivers/rpmsg/virtio_rpmsg_bus.c | 22 +++++++++++++++++++--- > drivers/virtio/virtio_ring.c | 6 ++++++ > 2 files changed, 25 insertions(+), 3 deletions(-) >Looks good to me. I think you can send a formal patch (without RFC prefix). Thanks
Jiaying Liang
2016-Dec-08 05:57 UTC
[RFC LINUX PATCH 0/2] Virtio ring works with DMA coherent memory
Thanks Jason, I will resend it as a formal patch. Wendy> -----Original Message----- > From: Jason Wang [mailto:jasowang at redhat.com] > Sent: Wednesday, December 07, 2016 7:18 PM > To: Jiaying Liang; ohad at wizery.com; bjorn.andersson at linaro.org; linux- > remoteproc at vger.kernel.org; mst at redhat.com; virtualization at lists.linux- > foundation.org > Cc: Jiaying Liang > Subject: Re: [RFC LINUX PATCH 0/2] Virtio ring works with DMA coherent > memory > > > > On 2016?12?07? 02:21, Wendy Liang wrote: > > RPMsg uses dma_alloc_coherent() to allocate memory to shared with the > remote. > > In this case, as there is no pages setup in the dma_alloc_coherent(), > > we cannot get the physical address back from the virtual address, and > > thus, we can set the sg_dma_addr to store the DMA address and mark it > > already DMA mapped. > > > > When virtio vring sees the sg_dma_addr is ready set, do not call > dma_map_page(). > > > > The issue was once discussed here: > > http://virtualization.linux-foundation.narkive.com/CfVP32Vy/rfc-0-4-rp > > msg-fix-init-of-dma-able-virtqueues > > > > Edgar E. Iglesias (1): > > rpmsg: DMA map sgs passed to virtio > > > > Wendy Liang (1): > > virtio_ring: Do not call dma_map_page if sg is already mapped. > > > > drivers/rpmsg/virtio_rpmsg_bus.c | 22 +++++++++++++++++++--- > > drivers/virtio/virtio_ring.c | 6 ++++++ > > 2 files changed, 25 insertions(+), 3 deletions(-) > > > > Looks good to me. > > I think you can send a formal patch (without RFC prefix). > > ThanksThis email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately.
Possibly Parallel Threads
- [RFC LINUX PATCH 0/2] Virtio ring works with DMA coherent memory
- [PATCH 0/2] Virtio ring works with DMA coherent memory
- [PATCH 0/2] Virtio ring works with DMA coherent memory
- [RFC LINUX PATCH 0/2] Virtio ring works with DMA coherent memory
- [RFC LINUX PATCH 0/2] Virtio ring works with DMA coherent memory