[PATCH] xen: Don't call panic if ARM TF cpu off returns DENIED

[dmitry.semenets@xxxxxxxxx]

From: Dmytro Semenets <dmytro_semenets@xxxxxxxx>

According to PSCI specification ARM TF can return DENIED on CPU OFF.
This patch brings the hypervisor into compliance with the PSCI
specification.
Refer to "Arm Power State Coordination Interface (DEN0022D.b)"
section 5.5.2

Signed-off-by: Dmytro Semenets <dmytro_semenets@xxxxxxxx>
Reviewed-by: Volodymyr Babchuk <volodymyr_babchuk@xxxxxxxx>
---
 xen/arch/arm/psci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
index 0c90c2305c..55787fde58 100644
--- a/xen/arch/arm/psci.c
+++ b/xen/arch/arm/psci.c
@@ -63,8 +63,9 @@ void call_psci_cpu_off(void)
 
         /* If successfull the PSCI cpu_off call doesn't return */
         arm_smccc_smc(PSCI_0_2_FN32_CPU_OFF, &res);
-        panic("PSCI cpu off failed for CPU%d err=%d\n", smp_processor_id(),
-              PSCI_RET(res));
+        if ( PSCI_RET(res) != PSCI_DENIED )
+            panic("PSCI cpu off failed for CPU%d err=%d\n", smp_processor_id(),
+                PSCI_RET(res));
     }
 }
 
-- 
2.25.1