[U-Boot] [PATCH v6 06/15] ARM: Put target PC for PSCI CPU_ON on per-CPU stack

Jan Kiszka
2015-04-13T04:48:11Z

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>
---
arch/arm/cpu/armv7/psci.S | 11 +++++------
arch/arm/cpu/armv7/sunxi/psci.S | 9 ++++++---
2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/arm/cpu/armv7/psci.S b/arch/arm/cpu/armv7/psci.S
index 18d85c4..87c0c0b 100644
--- 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
--- 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:
--
2.1.4