gpu: nvgpu: Always allocate zeroed DMA mem

Always allocate explicitly zeroed DMA memory and remove the
unnecessary memset() from the alloc path for memory with a
kernel mapping.

JIRA NVGPU-418

Change-Id: I5a3df6e6969e2586df41b72325d1bff1e40206e6
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1598933
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/dma.c b/drivers/gpu/nvgpu/common/linux/dma.c
index 22f2cefb..d0b6c8a8 100644
--- a/drivers/gpu/nvgpu/common/linux/dma.c
+++ b/drivers/gpu/nvgpu/common/linux/dma.c
@@ -231,8 +231,9 @@ int nvgpu_dma_alloc_flags_sys(struct gk20a *g, unsigned long flags,
 
         nvgpu_dma_flags_to_attrs(&dma_attrs, flags);
 
-        alloc_ret = dma_alloc_attrs(d, size, &iova, GFP_KERNEL,
-                                        __DMA_ATTR(dma_attrs));
+        alloc_ret = dma_alloc_attrs(d, size, &iova,
+                                    GFP_KERNEL|__GFP_ZERO,
+                                    __DMA_ATTR(dma_attrs));
         if (!alloc_ret)
                 return -ENOMEM;
 
@@ -245,7 +246,6 @@ int nvgpu_dma_alloc_flags_sys(struct gk20a *g, unsigned long flags,
                 mem->cpu_va = alloc_ret;
                 err = nvgpu_get_sgtable_attrs(g, &mem->priv.sgt, mem->cpu_va,
                                         iova, size, flags);
-                memset(mem->cpu_va, 0, size);
         }
         if (err)
                 goto fail_free;