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| author | Mark Rutland <mark.rutland@arm.com> | 2013-07-09 15:16:06 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2013-07-23 11:00:24 +0100 |
| commit | 82b2f495fba338d1e3098dde1df54944a9c19751 (patch) | |
| tree | 866012a9d6b7bb010d8ea6fcde80da1954549f52 /arch | |
| parent | 3b2f64d00c46e1e4e9bd0bb9bb12619adac27a4b (diff) | |
| download | linux-82b2f495fba338d1e3098dde1df54944a9c19751.tar.bz2 | |
arm64: 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>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/include/asm/virt.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 439827271e3d..26e310c54344 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -21,6 +21,7 @@ #define BOOT_CPU_MODE_EL2 (0x0e12b007) #ifndef __ASSEMBLY__ +#include <asm/cacheflush.h> /* * __boot_cpu_mode records what mode CPUs were booted in. @@ -36,9 +37,20 @@ extern u32 __boot_cpu_mode[2]; void __hyp_set_vectors(phys_addr_t phys_vector_base); phys_addr_t __hyp_get_vectors(void); +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. + */ + __flush_dcache_area(__boot_cpu_mode, sizeof(__boot_cpu_mode)); +} + /* Reports the availability of HYP mode */ static inline bool is_hyp_mode_available(void) { + sync_boot_mode(); return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 && __boot_cpu_mode[1] == BOOT_CPU_MODE_EL2); } @@ -46,6 +58,7 @@ static inline bool is_hyp_mode_available(void) /* Check if the bootloader has booted CPUs in different modes */ static inline bool is_hyp_mode_mismatched(void) { + sync_boot_mode(); return __boot_cpu_mode[0] != __boot_cpu_mode[1]; } |