[PATCH 06/30] drm/amdgpu: Use kmemdup rather than duplicating its implementation

[PATCH 06/30] drm/amdgpu: Use kmemdup rather than duplicating its implementation

[Fuqian Huang]

kmemdup is introduced to duplicate a region of memory in a neat way.
Rather than kmalloc/kzalloc + memset, which the programmer needs to
write the size twice (sometimes lead to mistakes), kmemdup improves
readability, leads to smaller code and also reduce the chances of mistakes.
Suggestion to use kmemdup rather than using kmalloc/kzalloc + memset.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c           | 5 ++---
 drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c           | 5 ++---
 drivers/gpu/drm/amd/display/dc/core/dc.c        | 6 ++----
 drivers/gpu/drm/amd/display/dc/core/dc_stream.c | 4 +---
 4 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
index 02955e6e9dd9..48e38479d634 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -3925,11 +3925,10 @@ static int gfx_v8_0_init_save_restore_list(struct amdgpu_device *adev)
 
 	int list_size;
 	unsigned int *register_list_format =
-		kmalloc(adev->gfx.rlc.reg_list_format_size_bytes, GFP_KERNEL);
+		kmemdup(adev->gfx.rlc.register_list_format,
+			adev->gfx.rlc.reg_list_format_size_bytes, GFP_KERNEL);
 	if (!register_list_format)
 		return -ENOMEM;
-	memcpy(register_list_format, adev->gfx.rlc.register_list_format,
-			adev->gfx.rlc.reg_list_format_size_bytes);
 
 	gfx_v8_0_parse_ind_reg_list(register_list_format,
 				RLC_FormatDirectRegListLength,
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index b610e3b30d95..09d901ef216d 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -2092,11 +2092,10 @@ static int gfx_v9_1_init_rlc_save_restore_list(struct amdgpu_device *adev)
 	u32 tmp = 0;
 
 	u32 *register_list_format =
-		kmalloc(adev->gfx.rlc.reg_list_format_size_bytes, GFP_KERNEL);
+		kmemdup(adev->gfx.rlc.register_list_format,
+			adev->gfx.rlc.reg_list_format_size_bytes, GFP_KERNEL);
 	if (!register_list_format)
 		return -ENOMEM;
-	memcpy(register_list_format, adev->gfx.rlc.register_list_format,
-		adev->gfx.rlc.reg_list_format_size_bytes);
 
 	/* setup unique_indirect_regs array and indirect_start_offsets array */
 	unique_indirect_reg_count = ARRAY_SIZE(unique_indirect_regs);
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 18c775a950cc..6ced3b9cdce2 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -1263,14 +1263,12 @@ struct dc_state *dc_create_state(struct dc *dc)
 struct dc_state *dc_copy_state(struct dc_state *src_ctx)
 {
 	int i, j;
-	struct dc_state *new_ctx = kzalloc(sizeof(struct dc_state),
-					   GFP_KERNEL);
+	struct dc_state *new_ctx = kmemdup(src_ctx,
+			sizeof(struct dc_state), GFP_KERNEL);
 
 	if (!new_ctx)
 		return NULL;
 
-	memcpy(new_ctx, src_ctx, sizeof(struct dc_state));
-
 	for (i = 0; i < MAX_PIPES; i++) {
 			struct pipe_ctx *cur_pipe = &new_ctx->res_ctx.pipe_ctx[i];
 
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
index 96e97d25d639..d4b563a2e220 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
@@ -167,12 +167,10 @@ struct dc_stream_state *dc_copy_stream(const struct dc_stream_state *stream)
 {
 	struct dc_stream_state *new_stream;
 
-	new_stream = kzalloc(sizeof(struct dc_stream_state), GFP_KERNEL);
+	new_stream = kzalloc(stream, sizeof(struct dc_stream_state), GFP_KERNEL);
 	if (!new_stream)
 		return NULL;
 
-	memcpy(new_stream, stream, sizeof(struct dc_stream_state));
-
 	if (new_stream->sink)
 		dc_sink_retain(new_stream->sink);
 
-- 
2.11.0

Re: [PATCH 06/30] drm/amdgpu: Use kmemdup rather than duplicating its implementation

[Emil Velikov]

On Wed, 3 Jul 2019 at 14:15, Fuqian Huang <huangfq.daxian@gmail.com> wrote:
>
> kmemdup is introduced to duplicate a region of memory in a neat way.
> Rather than kmalloc/kzalloc + memset, which the programmer needs to
> write the size twice (sometimes lead to mistakes), kmemdup improves
> readability, leads to smaller code and also reduce the chances of mistakes.
> Suggestion to use kmemdup rather than using kmalloc/kzalloc + memset.
>
> Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Fuqian please add reviewed-by and other tags when sending new revisions.

Fwiw the patch is:
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

-Emil