2023-11-04 09:07:06

by wuqiang.matt

Subject: [PATCH v1] locking/atomic: xtensa: define arch_cmpxchg_local as __cmpxchg_local

The xtensa architecture already has __cmpxchg_local defined upon the
native __cmpxchg_u32 and __generic_cmpxchg_local

Signed-off-by: wuqiang.matt <[email protected]>
---
arch/xtensa/include/asm/cmpxchg.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h
index 675a11ea8de7..956c9925df1c 100644
--- a/arch/xtensa/include/asm/cmpxchg.h
+++ b/arch/xtensa/include/asm/cmpxchg.h
@@ -108,7 +108,7 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr,
* them available.
*/
#define arch_cmpxchg_local(ptr, o, n) \
- ((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o),\
+ ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))))
#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
#define arch_cmpxchg64(ptr, o, n) arch_cmpxchg64_local((ptr), (o), (n))
--
2.40.1

2023-11-04 09:33:18

by Max Filippov

Subject: Re: [PATCH v1] locking/atomic: xtensa: define arch_cmpxchg_local as __cmpxchg_local

On Sat, Nov 4, 2023 at 2:06 AM wuqiang.matt <[email protected]> wrote:
>
> The xtensa architecture already has __cmpxchg_local defined upon the
> native __cmpxchg_u32 and __generic_cmpxchg_local

This description does not make clear why this change is needed. Could you
please expand it to cover the 'why' part?

> Signed-off-by: wuqiang.matt <[email protected]>
> ---
> arch/xtensa/include/asm/cmpxchg.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h
> index 675a11ea8de7..956c9925df1c 100644
> --- a/arch/xtensa/include/asm/cmpxchg.h
> +++ b/arch/xtensa/include/asm/cmpxchg.h
> @@ -108,7 +108,7 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr,
> * them available.
> */
> #define arch_cmpxchg_local(ptr, o, n) \
> - ((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o),\
> + ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
> (unsigned long)(n), sizeof(*(ptr))))
> #define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
> #define arch_cmpxchg64(ptr, o, n) arch_cmpxchg64_local((ptr), (o), (n))
> --
> 2.40.1
>


--
Thanks.
-- Max

2023-11-04 10:39:55

by wuqiang.matt

Subject: Re: [PATCH v1] locking/atomic: xtensa: define arch_cmpxchg_local as __cmpxchg_local

On 2023/11/4 17:31, Max Filippov wrote:
> On Sat, Nov 4, 2023 at 2:06 AM wuqiang.matt <[email protected]> wrote:
>>
>> The xtensa architecture already has __cmpxchg_local defined upon the
>> native __cmpxchg_u32 and __generic_cmpxchg_local
>
> This description does not make clear why this change is needed. Could you
> please expand it to cover the 'why' part?

The purpose of __cmpxchg_local() should be for arch_cmpxchg_local(), similarly
for other architectures like x86/arm/powerpc.

I noticed that arc/hexagon/openrisc/sh don't have arch_cmpxchg_local defined
because my patch triggered an error in kernel building. Then found xtensa's
definition of arch_cmpxchg_local() is not reasonable, so proposed this patch
to improve.

This change is not a must, but an improvement to simply make the codes of
arch_cmpxchg_local() more reasonable.

The patch link that introduced try_cmpxchg_local and triggered building error:
https://lore.kernel.org/all/[email protected]/

>> Signed-off-by: wuqiang.matt <[email protected]>
>> ---
>> arch/xtensa/include/asm/cmpxchg.h | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h
>> index 675a11ea8de7..956c9925df1c 100644
>> --- a/arch/xtensa/include/asm/cmpxchg.h
>> +++ b/arch/xtensa/include/asm/cmpxchg.h
>> @@ -108,7 +108,7 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr,
>> * them available.
>> */
>> #define arch_cmpxchg_local(ptr, o, n) \
>> - ((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o),\
>> + ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
>> (unsigned long)(n), sizeof(*(ptr))))
>> #define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
>> #define arch_cmpxchg64(ptr, o, n) arch_cmpxchg64_local((ptr), (o), (n))
>> --
>> 2.40.1
>>
>
>

2023-11-04 10:58:51

by wuqiang.matt

Subject: [PATCH v2] locking/atomic: xtensa: define arch_cmpxchg_local as __cmpxchg_local

The xtensa architecture already has __cmpxchg_local defined, which makes
arch_cmpxchg_local's definition as __generic_cmpxchg_local unreasonable.

Signed-off-by: wuqiang.matt <[email protected]>
---
arch/xtensa/include/asm/cmpxchg.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h
index 675a11ea8de7..956c9925df1c 100644
--- a/arch/xtensa/include/asm/cmpxchg.h
+++ b/arch/xtensa/include/asm/cmpxchg.h
@@ -108,7 +108,7 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr,
* them available.
*/
#define arch_cmpxchg_local(ptr, o, n) \
- ((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o),\
+ ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))))
#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
#define arch_cmpxchg64(ptr, o, n) arch_cmpxchg64_local((ptr), (o), (n))
--
2.40.1