[PATCH 52/74] ST SPEAr13xx: Adding CPU hotplug support added for SMP platforms

Shiraz Hashim shiraz.hashim at st.com
Thu Sep 30 05:37:08 EDT 2010


Hello Sundar,

Sorry for replying so late :).

On 9/3/2010 11:30 AM, Sundar wrote:
> Hi,
> 
> On Mon, Aug 30, 2010 at 4:09 PM, Viresh KUMAR <viresh.kumar at st.com> wrote:
>> From: Deepak Sikri <deepak.sikri at st.com>
>>
>> Signed-off-by: Deepak Sikri <deepak.sikri at st.com>
>> Signed-off-by: shiraz hashim <shiraz.hashim at st.com>
>> Signed-off-by: Viresh Kumar <viresh.kumar at st.com>
>> ---
> 
>> +       flush_cache_all();
>> +       asm volatile(
>> +       "       mcr     p15, 0, %1, c7, c5, 0\n"
>> +       "       mcr     p15, 0, %1, c7, c10, 4\n"
> 
> Isnt this a Cortex-A9 platform? If yes, then this is not implemented
> on the Cortex-A9 if I am right.
> You should use a dsb() here.

yes, I would place dsb here.

>> +               /*
>> +                * here's the WFI
>> +                */
>> +               asm(".word      0xe320f003\n"
>> +                   :
> 
> Also, why not a simple asm volatile("wfi" : : : "memory"); instead of
> hard coded values.

Would add a wfi() macro in asm/system.h including sev() as suggested by
Russell. This statement would be replaced by a simple wfi().

regards
Shiraz



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