From: Thierry Reding treding@nvidia.com
If we use the IOMMU API directly to map buffers into host1x' IOVA space, we must make sure that the DMA API doesn't already set up a mapping, or else translation will fail.
The direct DMA API allows us to allocate memory that will not be mapped through an IOMMU automatically.
Reviewed-by: Dmitry Osipenko digetx@gmail.com Signed-off-by: Thierry Reding treding@nvidia.com --- drivers/gpu/host1x/cdma.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/host1x/cdma.c b/drivers/gpu/host1x/cdma.c index e2d106fa3c0b..a96c4dd1e449 100644 --- a/drivers/gpu/host1x/cdma.c +++ b/drivers/gpu/host1x/cdma.c @@ -19,6 +19,7 @@
#include <asm/cacheflush.h> #include <linux/device.h> +#include <linux/dma-direct.h> #include <linux/dma-mapping.h> #include <linux/host1x.h> #include <linux/interrupt.h> @@ -70,6 +71,7 @@ static void host1x_pushbuffer_destroy(struct push_buffer *pb) */ static int host1x_pushbuffer_init(struct push_buffer *pb) { + unsigned long attrs = DMA_ATTR_WRITE_COMBINE; struct host1x_cdma *cdma = pb_to_cdma(pb); struct host1x *host1x = cdma_to_host1x(cdma); struct iova *alloc; @@ -91,8 +93,8 @@ static int host1x_pushbuffer_init(struct push_buffer *pb)
size = iova_align(&host1x->iova, size);
- pb->mapped = dma_alloc_wc(host1x->dev, size, &pb->phys, - GFP_KERNEL); + pb->mapped = dma_direct_alloc(host1x->dev, size, &pb->phys, + GFP_KERNEL, attrs); if (!pb->mapped) return -ENOMEM;
@@ -127,7 +129,10 @@ static int host1x_pushbuffer_init(struct push_buffer *pb) iommu_free_iova: __free_iova(&host1x->iova, alloc); iommu_free_mem: - dma_free_wc(host1x->dev, size, pb->mapped, pb->phys); + if (host1x->domain) + dma_direct_free(host1x->dev, size, pb->mapped, pb->phys, attrs); + else + dma_free_wc(host1x->dev, size, pb->mapped, pb->phys);
return err; }