1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 2006 by Ralf Baechle (ralf@linux-mips.org) 7 */ 8 #ifndef __ASM_BARRIER_H 9 #define __ASM_BARRIER_H 10 11 #include <asm/addrspace.h> 12 #include <asm/sync.h> 13 __sync(void)14 static inline void __sync(void) 15 { 16 asm volatile(__SYNC(full, always) ::: "memory"); 17 } 18 rmb(void)19 static inline void rmb(void) 20 { 21 asm volatile(__SYNC(rmb, always) ::: "memory"); 22 } 23 #define rmb rmb 24 wmb(void)25 static inline void wmb(void) 26 { 27 asm volatile(__SYNC(wmb, always) ::: "memory"); 28 } 29 #define wmb wmb 30 31 #define fast_mb() __sync() 32 33 #define __fast_iob() \ 34 __asm__ __volatile__( \ 35 ".set push\n\t" \ 36 ".set noreorder\n\t" \ 37 "lw $0,%0\n\t" \ 38 "nop\n\t" \ 39 ".set pop" \ 40 : /* no output */ \ 41 : "m" (*(int *)CKSEG1) \ 42 : "memory") 43 #ifdef CONFIG_CPU_CAVIUM_OCTEON 44 # define fast_iob() do { } while (0) 45 #else /* ! CONFIG_CPU_CAVIUM_OCTEON */ 46 # ifdef CONFIG_SGI_IP28 47 # define fast_iob() \ 48 __asm__ __volatile__( \ 49 ".set push\n\t" \ 50 ".set noreorder\n\t" \ 51 "lw $0,%0\n\t" \ 52 "sync\n\t" \ 53 "lw $0,%0\n\t" \ 54 ".set pop" \ 55 : /* no output */ \ 56 : "m" (*(int *)CKSEG1ADDR(0x1fa00004)) \ 57 : "memory") 58 # else 59 # define fast_iob() \ 60 do { \ 61 __sync(); \ 62 __fast_iob(); \ 63 } while (0) 64 # endif 65 #endif /* CONFIG_CPU_CAVIUM_OCTEON */ 66 67 #ifdef CONFIG_CPU_HAS_WB 68 69 #include <asm/wbflush.h> 70 71 #define mb() wbflush() 72 #define iob() wbflush() 73 74 #else /* !CONFIG_CPU_HAS_WB */ 75 76 #define mb() fast_mb() 77 #define iob() fast_iob() 78 79 #endif /* !CONFIG_CPU_HAS_WB */ 80 81 #if defined(CONFIG_WEAK_ORDERING) 82 # define __smp_mb() __sync() 83 # define __smp_rmb() rmb() 84 # define __smp_wmb() wmb() 85 #else 86 # define __smp_mb() barrier() 87 # define __smp_rmb() barrier() 88 # define __smp_wmb() barrier() 89 #endif 90 91 /* 92 * When LL/SC does imply order, it must also be a compiler barrier to avoid the 93 * compiler from reordering where the CPU will not. When it does not imply 94 * order, the compiler is also free to reorder across the LL/SC loop and 95 * ordering will be done by smp_llsc_mb() and friends. 96 */ 97 #if defined(CONFIG_WEAK_REORDERING_BEYOND_LLSC) && defined(CONFIG_SMP) 98 # define __WEAK_LLSC_MB sync 99 # define smp_llsc_mb() \ 100 __asm__ __volatile__(__stringify(__WEAK_LLSC_MB) : : :"memory") 101 # define __LLSC_CLOBBER 102 #else 103 # define __WEAK_LLSC_MB 104 # define smp_llsc_mb() do { } while (0) 105 # define __LLSC_CLOBBER "memory" 106 #endif 107 108 #ifdef CONFIG_CPU_CAVIUM_OCTEON 109 #define smp_mb__before_llsc() smp_wmb() 110 #define __smp_mb__before_llsc() __smp_wmb() 111 /* Cause previous writes to become visible on all CPUs as soon as possible */ 112 #define nudge_writes() __asm__ __volatile__(".set push\n\t" \ 113 ".set arch=octeon\n\t" \ 114 "syncw\n\t" \ 115 ".set pop" : : : "memory") 116 #else 117 #define smp_mb__before_llsc() smp_llsc_mb() 118 #define __smp_mb__before_llsc() smp_llsc_mb() 119 #define nudge_writes() mb() 120 #endif 121 122 /* 123 * In the Loongson3 LL/SC workaround case, all of our LL/SC loops already have 124 * a completion barrier immediately preceding the LL instruction. Therefore we 125 * can skip emitting a barrier from __smp_mb__before_atomic(). 126 */ 127 #ifdef CONFIG_CPU_LOONGSON3_WORKAROUNDS 128 # define __smp_mb__before_atomic() 129 #else 130 # define __smp_mb__before_atomic() __smp_mb__before_llsc() 131 #endif 132 133 #define __smp_mb__after_atomic() smp_llsc_mb() 134 sync_ginv(void)135 static inline void sync_ginv(void) 136 { 137 asm volatile(__SYNC(ginv, always)); 138 } 139 140 #include <asm-generic/barrier.h> 141 142 #endif /* __ASM_BARRIER_H */ 143