diff options
Diffstat (limited to 'arch/arm/include/asm/system.h')
| -rw-r--r-- | arch/arm/include/asm/system.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h index 811be55f338e..9eeda3c177de 100644 --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h @@ -13,6 +13,7 @@ #define CPU_ARCH_ARMv5TEJ 7 #define CPU_ARCH_ARMv6 8 #define CPU_ARCH_ARMv7 9 +#define CPU_ARCH_ARMv7M 10 /* * CR1 bits (CP#15 CR1) @@ -198,7 +199,9 @@ static inline void set_copro_access(unsigned int val) * so enable interrupts over the context switch to avoid high * latency. */ +#ifndef CONFIG_CPU_V7M #define __ARCH_WANT_INTERRUPTS_ON_CTXSW +#endif /* * switch_to(prev, next) should switch from task `prev' to `next' @@ -321,6 +324,56 @@ extern void enable_hlt(void); #ifndef CONFIG_SMP #include <asm-generic/cmpxchg.h> +#elif __LINUX_ARM_ARCH__ >= 6 +extern void __bad_cmpxchg(volatile void *ptr, int size); + +static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, + unsigned long new, int size) +{ + unsigned long oldval, res; + + switch (size) { + case 1: + do { + asm volatile("@ __cmpxchg1\n" + " ldrexb %1, [%2]\n" + " mov %0, #0\n" + " teq %1, %3\n" + " it eq\n" + " strexeqb %0, %4, [%2]\n" + : "=&r" (res), "=&r" (oldval) + : "r" (ptr), "Ir" (old), "r" (new) + : "cc"); + } while (res); + break; + + case 4: + do { + asm volatile("@ __cmpxchg4\n" + " ldrex %1, [%2]\n" + " mov %0, #0\n" + " teq %1, %3\n" + " it eq\n" + " strexeq %0, %4, [%2]\n" + : "=&r" (res), "=&r" (oldval) + : "r" (ptr), "Ir" (old), "r" (new) + : "cc"); + } while (res); + break; + + default: + __bad_cmpxchg(ptr, size); + oldval = 0; + } + + return oldval; +} + +#define cmpxchg(ptr,o,n) \ + ((__typeof__(*(ptr)))__cmpxchg((ptr), \ + (unsigned long)(o), \ + (unsigned long)(n), \ + sizeof(*(ptr)))) #endif #endif /* __ASSEMBLY__ */ |