[PATCH] drm/amdgpu: Replace ternary operator with min() in 'amdgpu_iomem_read'

[PATCH] drm/amdgpu: Replace ternary operator with min() in 'amdgpu_iomem_read'

[Srinivasan Shanmugam]

Fixes the following coccicheck:

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c:2427:16-17: WARNING opportunity for min()

min() macro is defined in include/linux/minmax.h. It avoids multiple
evaluations of the arguments when non-constant and performs strict
type-checking.

Cc: Guchun Chen <guchun.chen@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index df32785a8b36..c03fe7ee555b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -2424,7 +2424,7 @@ static ssize_t amdgpu_iomem_read(struct file *f, char __user *buf,
 		struct page *p;
 		void *ptr;
 
-		bytes = bytes < size ? bytes : size;
+		bytes = min(bytes, size);
 
 		/* Translate the bus address to a physical address.  If
 		 * the domain is NULL it means there is no IOMMU active
-- 
2.25.1

Re: [PATCH] drm/amdgpu: Replace ternary operator with min() in 'amdgpu_iomem_read'

[Christian König]

Am 12.08.23 um 16:47 schrieb Srinivasan Shanmugam:
> Fixes the following coccicheck:
>
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c:2427:16-17: WARNING opportunity for min()
>
> min() macro is defined in include/linux/minmax.h. It avoids multiple
> evaluations of the arguments when non-constant and performs strict
> type-checking.
>
> Cc: Guchun Chen <guchun.chen@amd.com>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>

Please double check that we don't need min_t() here.

With that done this patch and the _write variant are Reviewed-by: 
Christian König <christian.koenig@amd.com>.

Regards,
Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index df32785a8b36..c03fe7ee555b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -2424,7 +2424,7 @@ static ssize_t amdgpu_iomem_read(struct file *f, char __user *buf,
>   		struct page *p;
>   		void *ptr;
>   
> -		bytes = bytes < size ? bytes : size;
> +		bytes = min(bytes, size);
>   
>   		/* Translate the bus address to a physical address.  If
>   		 * the domain is NULL it means there is no IOMMU active

Re: [PATCH] drm/amdgpu: Replace ternary operator with min() in 'amdgpu_iomem_read'

[SHANMUGAM, SRINIVASAN]

On 8/14/2023 2:45 PM, Christian König wrote:
> Am 12.08.23 um 16:47 schrieb Srinivasan Shanmugam:
>> Fixes the following coccicheck:
>>
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c:2427:16-17: WARNING 
>> opportunity for min()
>>
>> min() macro is defined in include/linux/minmax.h. It avoids multiple
>> evaluations of the arguments when non-constant and performs strict
>> type-checking.
>>
>> Cc: Guchun Chen <guchun.chen@amd.com>
>> Cc: Christian König <christian.koenig@amd.com>
>> Cc: Alex Deucher <alexander.deucher@amd.com>
>> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
>> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
>
> Please double check that we don't need min_t() here.

Thanks a lot Christian for your reviews! Highly appreciate for your help!

min_t() is needed if there is any explict typecasting for any of the 
variables passed to min() please.

For ex: some references pls:

1.

commit 3434392da74953727f6c27bcf24aa7d8ae789c80
Author: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Date:   Sun Jul 23 12:29:14 2023 +0530

     drm/amdgpu: Update min() to min_t() in 'amdgpu_info_ioctl'

2.

https://patchwork.kernel.org/project/linux-omap/patch/1307877290-26672-1-git-send-email-tlinder@codeaurora.org/#1917462

Best regards,

Srini

>
> With that done this patch and the _write variant are Reviewed-by: 
> Christian König <christian.koenig@amd.com>.
>
> Regards,
> Christian.
>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> index df32785a8b36..c03fe7ee555b 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> @@ -2424,7 +2424,7 @@ static ssize_t amdgpu_iomem_read(struct file 
>> *f, char __user *buf,
>>           struct page *p;
>>           void *ptr;
>>   -        bytes = bytes < size ? bytes : size;
>> +        bytes = min(bytes, size);
>>             /* Translate the bus address to a physical address. If
>>            * the domain is NULL it means there is no IOMMU active
>