diff options
Diffstat (limited to 'arch/mips/include/asm/barrier.h')
-rw-r--r-- | arch/mips/include/asm/barrier.h | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/arch/mips/include/asm/barrier.h b/arch/mips/include/asm/barrier.h new file mode 100644 index 000000000..49ff172a7 --- /dev/null +++ b/arch/mips/include/asm/barrier.h @@ -0,0 +1,142 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2006 by Ralf Baechle (ralf@linux-mips.org) + */ +#ifndef __ASM_BARRIER_H +#define __ASM_BARRIER_H + +#include <asm/addrspace.h> +#include <asm/sync.h> + +static inline void __sync(void) +{ + asm volatile(__SYNC(full, always) ::: "memory"); +} + +static inline void rmb(void) +{ + asm volatile(__SYNC(rmb, always) ::: "memory"); +} +#define rmb rmb + +static inline void wmb(void) +{ + asm volatile(__SYNC(wmb, always) ::: "memory"); +} +#define wmb wmb + +#define fast_mb() __sync() + +#define __fast_iob() \ + __asm__ __volatile__( \ + ".set push\n\t" \ + ".set noreorder\n\t" \ + "lw $0,%0\n\t" \ + "nop\n\t" \ + ".set pop" \ + : /* no output */ \ + : "m" (*(int *)CKSEG1) \ + : "memory") +#ifdef CONFIG_CPU_CAVIUM_OCTEON +# define fast_iob() do { } while (0) +#else /* ! CONFIG_CPU_CAVIUM_OCTEON */ +# ifdef CONFIG_SGI_IP28 +# define fast_iob() \ + __asm__ __volatile__( \ + ".set push\n\t" \ + ".set noreorder\n\t" \ + "lw $0,%0\n\t" \ + "sync\n\t" \ + "lw $0,%0\n\t" \ + ".set pop" \ + : /* no output */ \ + : "m" (*(int *)CKSEG1ADDR(0x1fa00004)) \ + : "memory") +# else +# define fast_iob() \ + do { \ + __sync(); \ + __fast_iob(); \ + } while (0) +# endif +#endif /* CONFIG_CPU_CAVIUM_OCTEON */ + +#ifdef CONFIG_CPU_HAS_WB + +#include <asm/wbflush.h> + +#define mb() wbflush() +#define iob() wbflush() + +#else /* !CONFIG_CPU_HAS_WB */ + +#define mb() fast_mb() +#define iob() fast_iob() + +#endif /* !CONFIG_CPU_HAS_WB */ + +#if defined(CONFIG_WEAK_ORDERING) +# define __smp_mb() __sync() +# define __smp_rmb() rmb() +# define __smp_wmb() wmb() +#else +# define __smp_mb() barrier() +# define __smp_rmb() barrier() +# define __smp_wmb() barrier() +#endif + +/* + * When LL/SC does imply order, it must also be a compiler barrier to avoid the + * compiler from reordering where the CPU will not. When it does not imply + * order, the compiler is also free to reorder across the LL/SC loop and + * ordering will be done by smp_llsc_mb() and friends. + */ +#if defined(CONFIG_WEAK_REORDERING_BEYOND_LLSC) && defined(CONFIG_SMP) +# define __WEAK_LLSC_MB sync +# define smp_llsc_mb() \ + __asm__ __volatile__(__stringify(__WEAK_LLSC_MB) : : :"memory") +# define __LLSC_CLOBBER +#else +# define __WEAK_LLSC_MB +# define smp_llsc_mb() do { } while (0) +# define __LLSC_CLOBBER "memory" +#endif + +#ifdef CONFIG_CPU_CAVIUM_OCTEON +#define smp_mb__before_llsc() smp_wmb() +#define __smp_mb__before_llsc() __smp_wmb() +/* Cause previous writes to become visible on all CPUs as soon as possible */ +#define nudge_writes() __asm__ __volatile__(".set push\n\t" \ + ".set arch=octeon\n\t" \ + "syncw\n\t" \ + ".set pop" : : : "memory") +#else +#define smp_mb__before_llsc() smp_llsc_mb() +#define __smp_mb__before_llsc() smp_llsc_mb() +#define nudge_writes() mb() +#endif + +/* + * In the Loongson3 LL/SC workaround case, all of our LL/SC loops already have + * a completion barrier immediately preceding the LL instruction. Therefore we + * can skip emitting a barrier from __smp_mb__before_atomic(). + */ +#ifdef CONFIG_CPU_LOONGSON3_WORKAROUNDS +# define __smp_mb__before_atomic() +#else +# define __smp_mb__before_atomic() __smp_mb__before_llsc() +#endif + +#define __smp_mb__after_atomic() smp_llsc_mb() + +static inline void sync_ginv(void) +{ + asm volatile(__SYNC(ginv, always)); +} + +#include <asm-generic/barrier.h> + +#endif /* __ASM_BARRIER_H */ |