From: Hongbo Zhang <hongbo.zh...@nxp.com>

For the robustness of codes, while powering on a CPU, it is better to check
if the target CPU is already on or in the process of power on, if yes the
power on routine shouldn't be executed further and should return with the
corresponding status immediately.

Signed-off-by: Hongbo Zhang <hongbo.zh...@nxp.com>
---
 arch/arm/cpu/armv7/ls102xa/psci.S | 29 +++++++++++++++++++++++++++++
 arch/arm/include/asm/psci.h       |  5 +++++
 2 files changed, 34 insertions(+)

diff --git a/arch/arm/cpu/armv7/ls102xa/psci.S 
b/arch/arm/cpu/armv7/ls102xa/psci.S
index a4482e4..0188ade 100644
--- a/arch/arm/cpu/armv7/ls102xa/psci.S
+++ b/arch/arm/cpu/armv7/ls102xa/psci.S
@@ -66,6 +66,22 @@ psci_cpu_on:
        beq     out_psci_cpu_on
        mov     r1, r0
 
+       bl      psci_get_cpu_stack_top
+       sub     r0, r0, #PSCI_CPU_STATUS_OFFSET
+       ldr     r5, [r0]
+
+       cmp     r5, #PSCI_CPU_STATUS_ON
+       moveq   r0, #ARM_PSCI_RET_ALREADY_ON
+       beq     out_psci_cpu_on
+
+       cmp     r5, #PSCI_CPU_STATUS_ON_PENDING
+       moveq   r0, #ARM_PSCI_RET_ON_PENDING
+       beq     out_psci_cpu_on
+
+       mov     r5, #PSCI_CPU_STATUS_ON_PENDING
+       str     r5, [r0]
+       dsb
+
        bl      psci_cpu_on_common
 
        @ Get DCFG base address
@@ -123,6 +139,12 @@ holdoff_release:
        rev     r6, r6
        str     r6, [r4, #DCFG_CCSR_SCRATCHRW1]
 
+       mov     r0, r1
+       bl      psci_get_cpu_stack_top
+       sub     r0, r0, #PSCI_CPU_STATUS_OFFSET
+       mov     r5, #PSCI_CPU_STATUS_ON
+       str     r5, [r0]
+
        isb
        dsb
 
@@ -137,6 +159,13 @@ out_psci_cpu_on:
 psci_cpu_off:
        bl      psci_cpu_off_common
 
+       bl      psci_get_cpu_id
+       bl      psci_get_cpu_stack_top
+       sub     r0, r0, #PSCI_CPU_STATUS_OFFSET
+       mov     r5, #PSCI_CPU_STATUS_OFF
+       str     r5, [r0]
+       dsb
+
 1:     wfi
        b       1b
 
diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
index bedcd30..89a1ba5 100644
--- a/arch/arm/include/asm/psci.h
+++ b/arch/arm/include/asm/psci.h
@@ -67,6 +67,11 @@
 #define PSCI_PERCPU_STACK_SIZE         0x400
 #define PSCI_TARGET_PC_OFFSET          (PSCI_PERCPU_STACK_SIZE - 4)
 #define PSCI_CONTEXT_ID_OFFSET         (PSCI_PERCPU_STACK_SIZE - 8)
+#define PSCI_CPU_STATUS_OFFSET         (PSCI_PERCPU_STACK_SIZE - 12)
+
+#define PSCI_CPU_STATUS_OFF            0
+#define PSCI_CPU_STATUS_ON             1
+#define PSCI_CPU_STATUS_ON_PENDING     2
 
 #ifndef __ASSEMBLY__
 int psci_update_dt(void *fdt);
-- 
2.1.4

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