diff options
| -rw-r--r-- | arch/arm/include/asm/compiler.h | 32 | ||||
| -rw-r--r-- | arch/arm/include/asm/percpu.h | 15 |
2 files changed, 34 insertions, 13 deletions
diff --git a/arch/arm/include/asm/compiler.h b/arch/arm/include/asm/compiler.h index 8155db2f7fa..009eafa2ea0 100644 --- a/arch/arm/include/asm/compiler.h +++ b/arch/arm/include/asm/compiler.h @@ -11,5 +11,37 @@ */ #define __asmeq(x, y) ".ifnc " x "," y " ; .err ; .endif\n\t" +#if defined(CONFIG_SMP) && !defined(CONFIG_CPU_V6) +/* + * Read TPIDRPRW. + * GCC requires a workaround as it does not treat a "memory" clobber on a + * non-volatile asm block as a side-effect. + * We want to allow caching the value, so for GCC avoid using volatile and + * instead use a fake stack read to hazard against barrier(). + */ +#if defined(__clang__) +static inline unsigned long read_TPIDRPRW(void) +{ + unsigned long off; + + /* + * Read TPIDRPRW. + */ + asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off) : : "memory"); + + return off; +} +#else +static inline unsigned long read_TPIDRPRW(void) +{ + unsigned long off; + register unsigned long *sp asm ("sp"); + + asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off) : "Q" (*sp)); + + return off; +} +#endif +#endif #endif /* __ASM_ARM_COMPILER_H */ diff --git a/arch/arm/include/asm/percpu.h b/arch/arm/include/asm/percpu.h index 209e6504922..208c7e5fa7d 100644 --- a/arch/arm/include/asm/percpu.h +++ b/arch/arm/include/asm/percpu.h @@ -27,21 +27,10 @@ static inline void set_my_cpu_offset(unsigned long off) asm volatile("mcr p15, 0, %0, c13, c0, 4" : : "r" (off) : "memory"); } -static inline unsigned long __my_cpu_offset(void) -{ - unsigned long off; - register unsigned long *sp asm ("sp"); +#include "asm/compiler.h" - /* - * Read TPIDRPRW. - * We want to allow caching the value, so avoid using volatile and - * instead use a fake stack read to hazard against barrier(). - */ - asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off) : "Q" (*sp)); +#define __my_cpu_offset read_TPIDRPRW() - return off; -} -#define __my_cpu_offset __my_cpu_offset() #else #define set_my_cpu_offset(x) do {} while(0) |