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

On Wed, Dec 30, 2015 at 11:11:08AM +0800, Shannon Zhao wrote:

On 2015/11/30 22:57, Julien Grall wrote:

quoted

Hi Shannon,

On 17/11/15 09:40, shannon.zhao at linaro.org wrote:

quoted

quoted

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.

I believe that's an oversight in the ACPI documentation, which should
state 0.2+.

There was a deliberate decision that the FADT PSCI flag implied PSCI
0.2+, since prior to PSCI 0.2 function IDs were not well-defined, and
functions crticial for some uses cases did not exist (e.g. AFFINITY_INFO
for kexec-type things).

I don't know why that did not make it into the documentation.

Charles, thoughts?

Mark.