drm/amdgpu: check if vram is lost v2

backup first 64 byte of gart table as reset magic, check if magic is same
after gpu hw reset.
v2: use memcmp instead of manual innovation.

Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 8274d8e23e98..ec9774c0d1d9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1427,6 +1427,7 @@ typedef void (*amdgpu_wreg_t)(struct amdgpu_device*, uint32_t, uint32_t);
 typedef uint32_t (*amdgpu_block_rreg_t)(struct amdgpu_device*, uint32_t, uint32_t);
 typedef void (*amdgpu_block_wreg_t)(struct amdgpu_device*, uint32_t, uint32_t, uint32_t);
 
+#define AMDGPU_RESET_MAGIC_NUM 64
 struct amdgpu_device {
         struct device                   *dev;
         struct drm_device               *ddev;
@@ -1619,6 +1620,7 @@ struct amdgpu_device {
 
         /* record hw reset is performed */
         bool has_hw_reset;
+        u8                              reset_magic[AMDGPU_RESET_MAGIC_NUM];
 
 };