drm/amdgpu/gfx: create a common bitmask function (v2)

The same function was duplicated in all the gfx IPs. Use
a single implementation for all.

v2: use static inline (Alex Xie)

Reviewed-by: Alex Xie <AlexBin.Xie@amd.com>
Suggested-by: Andres Rodriguez <andresx7@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
index e02044086445..2d846ef1c033 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
@@ -30,4 +30,17 @@ void amdgpu_gfx_scratch_free(struct amdgpu_device *adev, uint32_t reg);
 void amdgpu_gfx_parse_disable_cu(unsigned *mask, unsigned max_se,
                 unsigned max_sh);
 
+/**
+ * amdgpu_gfx_create_bitmask - create a bitmask
+ *
+ * @bit_width: length of the mask
+ *
+ * create a variable length bit mask.
+ * Returns the bitmask.
+ */
+static inline u32 amdgpu_gfx_create_bitmask(u32 bit_width)
+{
+        return (u32)((1ULL << bit_width) - 1);
+}
+
 #endif