From 91a3f6af430d81c5f855f3f1ff0f3715e064f342 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Tue, 25 Feb 2014 17:11:03 +0000 Subject: [PATCH] arm: 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 Cc: Dave Martin Cc: Marc Zyngier Cc: Nicolas Pitre Cc: Russell King Signed-off-by: Lorenzo Pieralisi Acked-by: Marc Zyngier Reviewed-by: Dave Martin --- arch/arm/include/asm/assembler.h | 2 +- arch/arm/kernel/sleep.S | 5 ++++- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 5c2285160575..1db31af5c966 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -270,7 +270,7 @@ * 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 b907d9b790ab..1b880db2a033 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} ) -- 2.39.5