ARM: Put target PC for PSCI CPU_ON on per-CPU stack

Use a per-CPU variable for saving the target PC during CPU_ON
operations. This allows us to run this service independently on targets
that have more than 2 cores and also core-local power control.

CC: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Tested-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Tom Warren <twarren@nvidia.com>

diff --git a/arch/arm/cpu/armv7/psci.S b/arch/arm/cpu/armv7/psci.S
index 18d85c4..87c0c0b 100644 (file)
--- a/arch/arm/cpu/armv7/psci.S
+++ b/arch/arm/cpu/armv7/psci.S
@@ -17,6 +17,7 @@
 
 #include <config.h>
 #include <linux/linkage.h>
+#include <asm/macro.h>
 #include <asm/psci.h>
 
        .pushsection ._secure.text, "ax"
@@ -202,6 +203,7 @@ ENTRY(psci_get_cpu_stack_top)
        add     r5, r5, #0x2000                 @ Skip two pages
        lsr     r5, r5, #12                     @ Align to start of page
        lsl     r5, r5, #12
+       sub     r5, r5, #4                      @ reserve 1 word for target PC
        sub     r0, r5, r0                      @ here's our stack!
 
        bx      lr
@@ -212,13 +214,10 @@ ENTRY(psci_cpu_entry)
 
        bl      _nonsec_init
 
-       adr     r0, _psci_target_pc
-       ldr     r0, [r0]
+       bl      psci_get_cpu_id                 @ CPU ID => r0
+       bl      psci_get_cpu_stack_top          @ stack top => r0
+       ldr     r0, [r0]                        @ target PC at stack top
        b       _do_nonsec_entry
 ENDPROC(psci_cpu_entry)
 
-.globl _psci_target_pc
-_psci_target_pc:
-       .word   0
-
        .popsection

diff --git a/arch/arm/cpu/armv7/sunxi/psci.S b/arch/arm/cpu/armv7/sunxi/psci.S
index dd583b2..7ec0500 100644 (file)
--- a/arch/arm/cpu/armv7/sunxi/psci.S
+++ b/arch/arm/cpu/armv7/sunxi/psci.S
@@ -139,8 +139,11 @@ out:       mcr     p15, 0, r7, c1, c1, 0
        @ r2 = target PC
 .globl psci_cpu_on
 psci_cpu_on:
-       ldr     r0, =_psci_target_pc
-       str     r2, [r0]
+       push    {lr}
+
+       mov     r0, r1
+       bl      psci_get_cpu_stack_top  @ get stack top of target CPU
+       str     r2, [r0]                @ store target PC at stack top
        dsb
 
        movw    r0, #(SUN7I_CPUCFG_BASE & 0xffff)
@@ -195,7 +198,7 @@ psci_cpu_on:
        str     r6, [r0, #0x1e4]
 
        mov     r0, #ARM_PSCI_RET_SUCCESS       @ Return PSCI_RET_SUCCESS
-       mov     pc, lr
+       pop     {pc}
 
 .globl psci_cpu_off
 psci_cpu_off: