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authorLorenzo Pieralisi <lorenzo.pieralisi@arm.com>2014-05-08 17:31:40 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2014-05-25 23:49:27 +0100
commit0e0779da2233f2dfc85e9c3a6ea142476d326811 (patch)
tree8222330d72936e63a8cec7d45956cb669bed6d14 /arch/arm
parent72e6ae285a1dbff553734985bedadf409d99c02d (diff)
downloadop-kernel-dev-0e0779da2233f2dfc85e9c3a6ea142476d326811.zip
op-kernel-dev-0e0779da2233f2dfc85e9c3a6ea142476d326811.tar.gz
ARM: 8053/1: kernel: sleep: restore HYP mode configuration in cpu_resume
On CPUs with virtualization extensions the kernel installs HYP mode configuration on both primary and secondary cpus upon cold boot. On platforms where CPUs are shutdown in idle paths (ie CPU core gating), when a CPU resumes from low-power states it currently does not execute code that reinstalls the HYP configuration, which means that the kernel cannot run eg KVM properly on such machines. This patch, mirroring cold-boot behaviour, executes position independent code that reinstalls HYP configuration and drops to SVC mode safely on warmboot, so that deep idle states can be enabled in kernel running as hosts on platforms with power management HW. Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Dave Martin <dave.martin@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Nicolas Pitre <nico@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/assembler.h2
-rw-r--r--arch/arm/kernel/sleep.S5
2 files changed, 5 insertions, 2 deletions
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index b974184..57f0584 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -312,7 +312,7 @@
* you cannot return to the original mode.
*/
.macro safe_svcmode_maskall reg:req
-#if __LINUX_ARM_ARCH__ >= 6
+#if __LINUX_ARM_ARCH__ >= 6 && !defined(CONFIG_CPU_V7M)
mrs \reg , cpsr
eor \reg, \reg, #HYP_MODE
tst \reg, #MODE_MASK
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S
index b907d9b..1b880db 100644
--- a/arch/arm/kernel/sleep.S
+++ b/arch/arm/kernel/sleep.S
@@ -127,6 +127,10 @@ ENDPROC(cpu_resume_after_mmu)
.align
ENTRY(cpu_resume)
ARM_BE8(setend be) @ ensure we are in BE mode
+#ifdef CONFIG_ARM_VIRT_EXT
+ bl __hyp_stub_install_secondary
+#endif
+ safe_svcmode_maskall r1
mov r1, #0
ALT_SMP(mrc p15, 0, r0, c0, c0, 5)
ALT_UP_B(1f)
@@ -144,7 +148,6 @@ ARM_BE8(setend be) @ ensure we are in BE mode
ldr r0, [r0, #SLEEP_SAVE_SP_PHYS]
ldr r0, [r0, r1, lsl #2]
- setmode PSR_I_BIT | PSR_F_BIT | SVC_MODE, r1 @ set SVC, irqs off
@ load phys pgd, stack, resume fn
ARM( ldmia r0!, {r1, sp, pc} )
THUMB( ldmia r0!, {r1, r2, r3} )
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