similar to: [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

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

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

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

From: "Edgar E. Iglesias" <edgar.iglesias at xilinx.com> I'm trying to run rpmsg and remoteproc on the ZynqMP (arm64) but I'm hitting a DMA/mm error. The issue was discussed here: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-March/333050.html Russel King pointed out that the arm64 is not doing anything wrong by returning vmapped memory (which is incompatible

From: "Edgar E. Iglesias" <edgar.iglesias at xilinx.com> I'm trying to run rpmsg and remoteproc on the ZynqMP (arm64) but I'm hitting a DMA/mm error. The issue was discussed here: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-March/333050.html Russel King pointed out that the arm64 is not doing anything wrong by returning vmapped memory (which is incompatible

"Edgar E. Iglesias" <edgar.iglesias at gmail.com> writes: > From: "Edgar E. Iglesias" <edgar.iglesias at xilinx.com> > > Signed-off-by: Edgar E. Iglesias <edgar.iglesias at xilinx.com> First off, I have handed maintainership off to Michael S. Tsirkin, so his word is now law. That said... there's nothing fundamentally *wrong* with this, but

"Edgar E. Iglesias" <edgar.iglesias at gmail.com> writes: > From: "Edgar E. Iglesias" <edgar.iglesias at xilinx.com> > > Signed-off-by: Edgar E. Iglesias <edgar.iglesias at xilinx.com> First off, I have handed maintainership off to Michael S. Tsirkin, so his word is now law. That said... there's nothing fundamentally *wrong* with this, but

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

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

From: "Edgar E. Iglesias" <edgar.iglesias at xilinx.com> Signed-off-by: Edgar E. Iglesias <edgar.iglesias at xilinx.com> --- drivers/rpmsg/virtio_rpmsg_bus.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c index 73354ee..9ae53a0 100644 ---

On Wed, May 06, 2015 at 03:51:48PM +0930, Rusty Russell wrote: > "Edgar E. Iglesias" <edgar.iglesias at gmail.com> writes: > > From: "Edgar E. Iglesias" <edgar.iglesias at xilinx.com> > > > > Signed-off-by: Edgar E. Iglesias <edgar.iglesias at xilinx.com> > > First off, I have handed maintainership off to Michael S. Tsirkin, so >

On Wed, Dec 07, 2016 at 10:59:12PM -0800, Wendy Liang wrote: > If sg is already dma mapped, do not call dma_map_page() in > vring_map_one_sg(). > > In case of rpmsg, rpmsg uses dma_alloc_coherent() to allocate > memory to share with the remote. There is no pages setup > in dma_alloc_coherent(). > > In this case, we cannot convert the virtual address back to the >

On Wed, Dec 07, 2016 at 10:59:12PM -0800, Wendy Liang wrote: > If sg is already dma mapped, do not call dma_map_page() in > vring_map_one_sg(). > > In case of rpmsg, rpmsg uses dma_alloc_coherent() to allocate > memory to share with the remote. There is no pages setup > in dma_alloc_coherent(). > > In this case, we cannot convert the virtual address back to the >

virtio spec requires that all drivers set DRIVER_OK before using devices. While rpmsg isn't yet included in the virtio 1 spec, previous spec versions also required this. virtio rpmsg violates this rule: is calls kick before setting DRIVER_OK. The fix isn't trivial since simply calling virtio_device_ready earlier would mean we might get an interrupt in parallel with adding buffers.

virtio spec requires that all drivers set DRIVER_OK before using devices. While rpmsg isn't yet included in the virtio 1 spec, previous spec versions also required this. virtio rpmsg violates this rule: is calls kick before setting DRIVER_OK. The fix isn't trivial since simply calling virtio_device_ready earlier would mean we might get an interrupt in parallel with adding buffers.

Hi, Next update: v6: - rename include/linux/virtio_rpmsg.h -> include/linux/rpmsg/virtio.h v5: - don't hard-code message layout v4: - add endianness conversions to comply with the VirtIO standard v3: - address several checkpatch warnings - address comments from Mathieu Poirier v2: - update patch #5 with a correct vhost_dev_init() prototype - drop patch #6 - it depends on a different

Hi, Next update: v6: - rename include/linux/virtio_rpmsg.h -> include/linux/rpmsg/virtio.h v5: - don't hard-code message layout v4: - add endianness conversions to comply with the VirtIO standard v3: - address several checkpatch warnings - address comments from Mathieu Poirier v2: - update patch #5 with a correct vhost_dev_init() prototype - drop patch #6 - it depends on a different

checkpatch.pl wants arrays of strings declared as follows: static const char * const names[] = { "vq-1", "vq-2", "vq-3" }; Currently the find_vqs() function takes a const char *names[] argument so passing checkpatch.pl's const char * const names[] results in a compiler error due to losing the second const. This patch adjusts the find_vqs() prototype and

checkpatch.pl wants arrays of strings declared as follows: static const char * const names[] = { "vq-1", "vq-2", "vq-3" }; Currently the find_vqs() function takes a const char *names[] argument so passing checkpatch.pl's const char * const names[] results in a compiler error due to losing the second const. This patch adjusts the find_vqs() prototype and