1 files changed, 20 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/nvgpu_mem.c b/drivers/gpu/nvgpu/common/linux/nvgpu_mem.c
index c859520d..69897694 100644
--- a/drivers/gpu/nvgpu/common/linux/nvgpu_mem.c
+++ b/drivers/gpu/nvgpu/common/linux/nvgpu_mem.c
@@ -45,6 +45,14 @@ int nvgpu_mem_begin(struct gk20a *g, struct nvgpu_mem *mem)
                 return 0;
 
         /*
+         * WAR for bug 2040115: we already will always have a coherent vmap()
+         * for all sysmem buffers. The prot settings are left alone since
+         * eventually this should be deleted.
+         */
+        if (nvgpu_is_enabled(g, NVGPU_USE_COHERENT_SYSMEM))
+                return 0;
+
+        /*
          * A CPU mapping is implicitly made for all SYSMEM DMA allocations that
          * don't have NVGPU_DMA_NO_KERNEL_MAPPING. Thus we don't need to make
          * another CPU mapping.
@@ -74,6 +82,13 @@ void nvgpu_mem_end(struct gk20a *g, struct nvgpu_mem *mem)
                 return;
 
         /*
+         * WAR for bug 2040115: skip this since the map will be taken care of
+         * during the free in the DMA API.
+         */
+        if (nvgpu_is_enabled(g, NVGPU_USE_COHERENT_SYSMEM))
+                return;
+
+        /*
          * Similar to nvgpu_mem_begin() we don't need to unmap the CPU mapping
          * already made by the DMA API.
          */
@@ -393,8 +408,12 @@ int nvgpu_mem_create_from_mem(struct gk20a *g,
 
         /*
          * Re-use the CPU mapping only if the mapping was made by the DMA API.
+         *
+         * Bug 2040115: the DMA API wrapper makes the mapping that we should
+         * re-use.
          */
-        if (!(src->priv.flags & NVGPU_DMA_NO_KERNEL_MAPPING))
+        if (!(src->priv.flags & NVGPU_DMA_NO_KERNEL_MAPPING) ||
+            nvgpu_is_enabled(g, NVGPU_USE_COHERENT_SYSMEM))
                 dest->cpu_va = src->cpu_va + (PAGE_SIZE * start_page);
 
         dest->priv.pages = src->priv.pages + start_page;