projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| a3a85a76 RW |
1 | #ifndef _ASM_UM_BARRIER_H_ |
| 2 | #define _ASM_UM_BARRIER_H_ | |
| 3 | ||
| 4 | #include <asm/asm.h> | |
| 5 | #include <asm/segment.h> | |
| 6 | #include <asm/cpufeature.h> | |
| 7 | #include <asm/cmpxchg.h> | |
| 8 | #include <asm/nops.h> | |
| 9 | ||
| 10 | #include <linux/kernel.h> | |
| 11 | #include <linux/irqflags.h> | |
| 12 | ||
| 13 | /* | |
| 14 | * Force strict CPU ordering. | |
| 15 | * And yes, this is required on UP too when we're talking | |
| 16 | * to devices. | |
| 17 | */ | |
| 18 | #ifdef CONFIG_X86_32 | |
| 19 | ||
| 20 | #define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2) | |
| 21 | #define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2) | |
| 22 | #define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM) | |
| 23 | ||
| 24 | #else /* CONFIG_X86_32 */ | |
| 25 | ||
| 26 | #define mb() asm volatile("mfence" : : : "memory") | |
| 27 | #define rmb() asm volatile("lfence" : : : "memory") | |
| 28 | #define wmb() asm volatile("sfence" : : : "memory") | |
| 29 | ||
| 30 | #endif /* CONFIG_X86_32 */ | |
| 31 | ||
| a3a85a76 RW |
32 | #ifdef CONFIG_SMP |
| 33 | ||
| 34 | #define smp_mb() mb() | |
| 35 | #ifdef CONFIG_X86_PPRO_FENCE | |
| 36 | #define smp_rmb() rmb() | |
| 37 | #else /* CONFIG_X86_PPRO_FENCE */ | |
| 38 | #define smp_rmb() barrier() | |
| 39 | #endif /* CONFIG_X86_PPRO_FENCE */ | |
| 40 | ||
| a3a85a76 | 41 | #define smp_wmb() barrier() |
| a3a85a76 | 42 | |
| a3a85a76 RW |
43 | #define set_mb(var, value) do { (void)xchg(&var, value); } while (0) |
| 44 | ||
| 45 | #else /* CONFIG_SMP */ | |
| 46 | ||
| 47 | #define smp_mb() barrier() | |
| 48 | #define smp_rmb() barrier() | |
| 49 | #define smp_wmb() barrier() | |
| a3a85a76 RW |
50 | #define set_mb(var, value) do { var = value; barrier(); } while (0) |
| 51 | ||
| 52 | #endif /* CONFIG_SMP */ | |
| 53 | ||
| 8a449718 AD |
54 | #define read_barrier_depends() do { } while (0) |
| 55 | #define smp_read_barrier_depends() do { } while (0) | |
| 56 | ||
| a3a85a76 RW |
57 | /* |
| 58 | * Stop RDTSC speculation. This is needed when you need to use RDTSC | |
| 59 | * (or get_cycles or vread that possibly accesses the TSC) in a defined | |
| 60 | * code region. | |
| 61 | * | |
| 62 | * (Could use an alternative three way for this if there was one.) | |
| 63 | */ | |
| 64 | static inline void rdtsc_barrier(void) | |
| 65 | { | |
| 66 | alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC); | |
| 67 | alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC); | |
| 68 | } | |
| 69 | ||
| 70 | #endif |