[PATCH V2] arm64: optimized copy_to_user and copy_from_user assembly code

Feng Kan fkan at apm.com
Mon Aug 11 11:05:23 PDT 2014


On Sun, Aug 10, 2014 at 8:01 PM, Radha Mohan <mohun106 at gmail.com> wrote:
> Hi Feng,
>
>
>> +
>> +.Lcpy_not_short:
>> +       /*
>> +        * We don't much care about the alignment of DST, but we want SRC
>> +        * to be 128-bit (16 byte) aligned so that we don't cross cache line
>> +        * boundaries on both loads and stores.
>> +        */
>
> Could you please tell why is destination alignment not an issue? Is
> this a generic implementation that you are referring to or specific to
> your platform?
This is per Linaro Cortext String optimization routines.

https://launchpad.net/cortex-strings

Zhichang submitted something similar for the memcpy from the
same optimization.

Sorry resend in text mode.
>
>> --
>> 1.9.1
>>
>>
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