diff options
Diffstat (limited to 'include/asm-sh/system.h')
| -rw-r--r-- | include/asm-sh/system.h | 43 |
1 files changed, 34 insertions, 9 deletions
diff --git a/include/asm-sh/system.h b/include/asm-sh/system.h index eb4902ed920..1630a5411e5 100644 --- a/include/asm-sh/system.h +++ b/include/asm-sh/system.h @@ -67,8 +67,17 @@ static inline void sched_cacheflush(void) { } -#define nop() __asm__ __volatile__ ("nop") - +#ifdef CONFIG_CPU_SH4A +#define __icbi() \ +{ \ + unsigned long __addr; \ + __addr = 0xa8000000; \ + __asm__ __volatile__( \ + "icbi %0\n\t" \ + : /* no output */ \ + : "m" (__m(__addr))); \ +} +#endif #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) @@ -84,15 +93,31 @@ static __inline__ unsigned long tas(volatile int *m) extern void __xchg_called_with_bad_pointer(void); +/* + * A brief note on ctrl_barrier(), the control register write barrier. + * + * Legacy SH cores typically require a sequence of 8 nops after + * modification of a control register in order for the changes to take + * effect. On newer cores (like the sh4a and sh5) this is accomplished + * with icbi. + * + * Also note that on sh4a in the icbi case we can forego a synco for the + * write barrier, as it's not necessary for control registers. + * + * Historically we have only done this type of barrier for the MMUCR, but + * it's also necessary for the CCR, so we make it generic here instead. + */ #ifdef CONFIG_CPU_SH4A -#define mb() __asm__ __volatile__ ("synco": : :"memory") -#define rmb() mb() -#define wmb() __asm__ __volatile__ ("synco": : :"memory") +#define mb() __asm__ __volatile__ ("synco": : :"memory") +#define rmb() mb() +#define wmb() __asm__ __volatile__ ("synco": : :"memory") +#define ctrl_barrier() __icbi() #define read_barrier_depends() do { } while(0) #else -#define mb() __asm__ __volatile__ ("": : :"memory") -#define rmb() mb() -#define wmb() __asm__ __volatile__ ("": : :"memory") +#define mb() __asm__ __volatile__ ("": : :"memory") +#define rmb() mb() +#define wmb() __asm__ __volatile__ ("": : :"memory") +#define ctrl_barrier() __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop") #define read_barrier_depends() do { } while(0) #endif @@ -218,8 +243,8 @@ do { \ #define back_to_P1() \ do { \ unsigned long __dummy; \ + ctrl_barrier(); \ __asm__ __volatile__( \ - "nop;nop;nop;nop;nop;nop;nop\n\t" \ "mov.l 1f, %0\n\t" \ "jmp @%0\n\t" \ " nop\n\t" \ |