diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2013-07-18 17:20:33 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-07-26 12:01:17 +0100 |
| commit | 8fbac214e5c594a0c2fe78c14adf2cdbb1febc92 (patch) | |
| tree | 0f331dcd30fb4110f10afe7cde11bc40b8f83ada | |
| parent | ab8d46c0609843a83aef3f486365ca5e7c21d537 (diff) | |
ARM: 7787/1: virt: ensure visibility of __boot_cpu_mode
Secondary CPUs write to __boot_cpu_mode with caches disabled, and thus a
cached value of __boot_cpu_mode may be incoherent with that in memory.
This could lead to a failure to detect mismatched boot modes.
This patch adds flushing to ensure that writes by secondaries to
__boot_cpu_mode are made visible before we test against it.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/include/asm/virt.h | 12 | ||||
| -rw-r--r-- | arch/arm/kernel/setup.c | 2 |
2 files changed, 14 insertions, 0 deletions
diff --git a/arch/arm/include/asm/virt.h b/arch/arm/include/asm/virt.h index 50af92bac73..4371f45c578 100644 --- a/arch/arm/include/asm/virt.h +++ b/arch/arm/include/asm/virt.h @@ -29,6 +29,7 @@ #define BOOT_CPU_MODE_MISMATCH PSR_N_BIT #ifndef __ASSEMBLY__ +#include <asm/cacheflush.h> #ifdef CONFIG_ARM_VIRT_EXT /* @@ -41,10 +42,21 @@ */ extern int __boot_cpu_mode; +static inline void sync_boot_mode(void) +{ + /* + * As secondaries write to __boot_cpu_mode with caches disabled, we + * must flush the corresponding cache entries to ensure the visibility + * of their writes. + */ + sync_cache_r(&__boot_cpu_mode); +} + void __hyp_set_vectors(unsigned long phys_vector_base); unsigned long __hyp_get_vectors(void); #else #define __boot_cpu_mode (SVC_MODE) +#define sync_boot_mode() #endif #ifndef ZIMAGE diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 96286cb383b..afc2489ee13 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -836,6 +836,8 @@ static int __init meminfo_cmp(const void *_a, const void *_b) void __init hyp_mode_check(void) { #ifdef CONFIG_ARM_VIRT_EXT + sync_boot_mode(); + if (is_hyp_mode_available()) { pr_info("CPU: All CPU(s) started in HYP mode.\n"); pr_info("CPU: Virtualization extensions available.\n"); |