Subject: [Xen-devel] [PATCH v3 20/62] arm/acpi: Add ACPI support for SMP initialization

From: [email-masked] (Shannon Zhao)
Date: Wed, 30 Dec 2015 11:11:08 +0800

On 2015/11/30 22:57, Julien Grall wrote:
> Hi Shannon,
> 
> On 17/11/15 09:40, shannon.zhao at linaro.org wrote:
>> > diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
>> > index d800cb6..dede0e1 100644
>> > --- a/xen/arch/arm/psci.c
>> > +++ b/xen/arch/arm/psci.c
>> > @@ -22,6 +22,7 @@
>> >  #include <xen/mm.h>
>> >  #include <xen/smp.h>
>> >  #include <asm/psci.h>
>> > +#include <asm/acpi.h>
>> >  
>> >  /*
>> >   * While a 64-bit OS can make calls with SMC32 calling conventions, for
>> > @@ -86,6 +87,9 @@ int __init psci_init_0_1(void)
>> >      int ret;
>> >      const struct dt_device_node *psci;
>> >  
>> > +    if ( !acpi_disabled )
>> > +        return -EINVAL;
> Please explain in the commit message why PSCI 0.1 is not supported on ACPI.

Hi,

I check this again. There are not limitations of supporting PSCI version
in ACPI SPEC. It should support PSCI 0.1 as well. But look at the code
of linux kernel, it says it only supports PSCI 0.2+.

#define ACPI_FADT_PSCI_COMPLIANT    (1)	/* 00: [V5+] PSCI 0.2+ is
implemented */

So does it need to be consistent with Linux or support PSCI 0.1 in Xen
as well?

Thanks,
-- 
Shannon