[U-Boot] [PATCH v2 04/12] ARM: Put target PC for PSCI CPU_ON on per-CPU stack

Jan Kiszka
2015-02-16T12:54:41Z

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.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
arch/arm/cpu/armv7/psci.S | 8 ++------
arch/arm/cpu/armv7/sunxi/psci.S | 9 ++++++---
2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/arm/cpu/armv7/psci.S b/arch/arm/cpu/armv7/psci.S
index da47934..9674503 100644
--- a/arch/arm/cpu/armv7/psci.S
+++ b/arch/arm/cpu/armv7/psci.S
@@ -179,6 +179,7 @@ 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 r5, r5, r4 @ here's our stack!

bx lr
@@ -194,13 +195,8 @@ ENTRY(psci_cpu_entry)
bl _nonsec_init
bl psci_arch_init

- adr r0, _psci_target_pc
- ldr r0, [r0]
+ ldr r0, [sp] @ 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 4372022..8d964d0 100644
--- a/arch/arm/cpu/armv7/sunxi/psci.S
+++ b/arch/arm/cpu/armv7/sunxi/psci.S
@@ -138,8 +138,11 @@ 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 r4, r1
+ bl psci_get_cpu_stack_top @ get stack top of target CPU
+ str r2, [r5] @ store target PC at stack top
dsb

movw r0, #(SUN7I_CPUCFG_BASE & 0xffff)
@@ -194,7 +197,7 @@ 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:
--
2.1.4