Re: [PATCH v2 2/2] io: prevent compiler reordering on the default readX() implementation

Sinan Kaya
2018-04-04T15:57:37Z

On 4/4/2018 11:55 AM, Arnd Bergmann wrote:
> On Wed, Apr 4, 2018 at 5:52 PM, Sinan Kaya <okaya@codeaurora.org> wrote:
>> On 4/3/2018 6:29 PM, Palmer Dabbelt wrote:
>>>
>>
>> Are we looking for something like this?
>
> Yes, exactly, plus the same for write and in/out of course.
>

OK. I just wanted to double check first.

>> diff --git a/inc
>> #ifndef readb
>> #define readb readb
>> -static inline u8 readb(const volatile void __iomem *addr)
>> -{
>> - return __raw_readb(addr);
>> -}
>> +#define readb(c) \
>> + ({ u8 __v; \
>> + __io_br(); \
>> + __v = __raw_readb(c); \
>> + __io_ar(); \
>> + __v; })
>> #endif
>
> I would prefer leaving these as inline functions, but that's only
> a cosmetic difference.

sure, I'll leave these as inline functions.

>
> Arnd
>

--
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.