diff options
Diffstat (limited to 'arch/arm/include/asm/cputype.h')
| -rw-r--r-- | arch/arm/include/asm/cputype.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h index 8c25dc4e9851..9672e978d50d 100644 --- a/arch/arm/include/asm/cputype.h +++ b/arch/arm/include/asm/cputype.h @@ -89,13 +89,18 @@ extern unsigned int processor_id; __val; \ }) +/* + * The memory clobber prevents gcc 4.5 from reordering the mrc before + * any is_smp() tests, which can cause undefined instruction aborts on + * ARM1136 r0 due to the missing extended CP15 registers. + */ #define read_cpuid_ext(ext_reg) \ ({ \ unsigned int __val; \ asm("mrc p15, 0, %0, c0, " ext_reg \ : "=r" (__val) \ : \ - : "cc"); \ + : "memory"); \ __val; \ }) |