Re: [PATCH v2 03/10] xen/arm: Implement CPU_OFF PSCI call (physical interface)

[Julien Grall <julien.grall@arm.com>]

On 23/04/18 18:12, Mirela Simonovic wrote:
> On Mon, Apr 23, 2018 at 1:21 PM, Julien Grall <julien.grall@arm.com> wrote:
>> On 20/04/18 13:25, Mirela Simonovic wrote:
>>> +    if ( errno )
>>> +        panic("PSCI cpu off failed for CPU%d err=%d\n",
>>> get_processor_id(),
>>> +              errno);
>>> +}
>>> +
>>>    void call_psci_system_off(void)
>>>    {
>>>        if ( psci_ver > PSCI_VERSION(0, 1) )
>>> diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
>>> index b2116f0d2d..1ca3d63261 100644
>>> --- a/xen/arch/arm/smpboot.c
>>> +++ b/xen/arch/arm/smpboot.c
>>> @@ -395,6 +395,9 @@ void stop_cpu(void)
>>>        /* Make sure the write happens before we sleep forever */
>>>        dsb(sy);
>>>        isb();
>>> +    if ( system_state == SYS_STATE_suspend )
>>
>>
>> I don't think this should be call only on suspend/resume. System shutdown
>> could also benefit of PSCI CPU off. This is also paving the way to more use
>> case of turning off a CPU.
> 
> Ok, but then we do need to check for PSCI version here.

Or inside call_psci_off to match the other psci_* functions. However, 
you still need to check the PSCI version in the suspend code to deny any 
suspend/resume functionally on platform without PSCI CPU off support.

Cheers,
-- 
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel