[PATCH] drm/radeon: Use hweight32

[PATCH] drm/radeon: Use hweight32

[Akinobu Mita]

Use hweight32 instead of counting for each bit

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
---
 drivers/gpu/drm/radeon/r600.c    | 8 +-------
 drivers/gpu/drm/radeon/r600_cp.c | 7 +------
 2 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index cda280d..169ecc9 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -1424,13 +1424,7 @@ u32 r6xx_remap_render_backend(struct radeon_device *rdev,
 
 int r600_count_pipe_bits(uint32_t val)
 {
-	int i, ret = 0;
-
-	for (i = 0; i < 32; i++) {
-		ret += val & 1;
-		val >>= 1;
-	}
-	return ret;
+	return hweight32(val);
 }
 
 static void r600_gpu_init(struct radeon_device *rdev)
diff --git a/drivers/gpu/drm/radeon/r600_cp.c b/drivers/gpu/drm/radeon/r600_cp.c
index 2514123..be85f75 100644
--- a/drivers/gpu/drm/radeon/r600_cp.c
+++ b/drivers/gpu/drm/radeon/r600_cp.c
@@ -721,12 +721,7 @@ static u32 r600_get_tile_pipe_to_backend_map(u32 num_tile_pipes,
 
 static int r600_count_pipe_bits(uint32_t val)
 {
-	int i, ret = 0;
-	for (i = 0; i < 32; i++) {
-		ret += val & 1;
-		val >>= 1;
-	}
-	return ret;
+	return hweight32(val);
 }
 
 static void r600_gfx_init(struct drm_device *dev,
-- 
1.7.11.7

[PATCH] drm: use memchr_inv()

[Akinobu Mita]

Use memchr_inv() to check the specified memory region is filled with zero.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
---
 drivers/gpu/drm/drm_edid.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index fadcd44..59260bf 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -307,12 +307,9 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
 
 static bool drm_edid_is_zero(u8 *in_edid, int length)
 {
-	int i;
-	u32 *raw_edid = (u32 *)in_edid;
+	if (memchr_inv(in_edid, 0, length))
+		return false;
 
-	for (i = 0; i < length / 4; i++)
-		if (*(raw_edid + i) != 0)
-			return false;
 	return true;
 }
 
-- 
1.7.11.7

[PATCH] drm/ttm: remove unneeded preempt_disable/enable

[Akinobu Mita]

It is unnecessary to disable preemption explicitly while calling
copy_highpage().  Because copy_highpage() will do it again through
kmap_atomic/kunmap_atomic.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
---
 drivers/gpu/drm/ttm/ttm_tt.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index bf82601..7d759a4 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -308,9 +308,7 @@ int ttm_tt_swapin(struct ttm_tt *ttm)
 		if (unlikely(to_page == NULL))
 			goto out_err;
 
-		preempt_disable();
 		copy_highpage(to_page, from_page);
-		preempt_enable();
 		page_cache_release(from_page);
 	}
 
@@ -358,9 +356,7 @@ int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistent_swap_storage)
 			ret = PTR_ERR(to_page);
 			goto out_err;
 		}
-		preempt_disable();
 		copy_highpage(to_page, from_page);
-		preempt_enable();
 		set_page_dirty(to_page);
 		mark_page_accessed(to_page);
 		page_cache_release(to_page);
-- 
1.7.11.7

Re: [PATCH] drm/ttm: remove unneeded preempt_disable/enable

[Thomas Hellstrom]

On 11/09/2012 01:10 PM, Akinobu Mita wrote:
> It is unnecessary to disable preemption explicitly while calling
> copy_highpage().  Because copy_highpage() will do it again through
> kmap_atomic/kunmap_atomic.
>
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: David Airlie <airlied@linux.ie>
> ---
>   drivers/gpu/drm/ttm/ttm_tt.c | 4 ----
>   1 file changed, 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
> index bf82601..7d759a4 100644
> --- a/drivers/gpu/drm/ttm/ttm_tt.c
> +++ b/drivers/gpu/drm/ttm/ttm_tt.c
> @@ -308,9 +308,7 @@ int ttm_tt_swapin(struct ttm_tt *ttm)
>   		if (unlikely(to_page == NULL))
>   			goto out_err;
>   
> -		preempt_disable();
>   		copy_highpage(to_page, from_page);
> -		preempt_enable();
>   		page_cache_release(from_page);
>   	}
>   
> @@ -358,9 +356,7 @@ int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistent_swap_storage)
>   			ret = PTR_ERR(to_page);
>   			goto out_err;
>   		}
> -		preempt_disable();
>   		copy_highpage(to_page, from_page);
> -		preempt_enable();
>   		set_page_dirty(to_page);
>   		mark_page_accessed(to_page);
>   		page_cache_release(to_page);

Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>