diff options
| -rw-r--r-- | arch/mips/include/asm/processor.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h index d8a5951433fc..b2fa62922d88 100644 --- a/arch/mips/include/asm/processor.h +++ b/arch/mips/include/asm/processor.h @@ -386,7 +386,20 @@ unsigned long get_wchan(struct task_struct *p); #define KSTK_ESP(tsk) (task_pt_regs(tsk)->regs[29]) #define KSTK_STATUS(tsk) (task_pt_regs(tsk)->cp0_status) +#ifdef CONFIG_CPU_LOONGSON3 +/* + * Loongson-3's SFB (Store-Fill-Buffer) may buffer writes indefinitely when a + * tight read loop is executed, because reads take priority over writes & the + * hardware (incorrectly) doesn't ensure that writes will eventually occur. + * + * Since spin loops of any kind should have a cpu_relax() in them, force an SFB + * flush from cpu_relax() such that any pending writes will become visible as + * expected. + */ +#define cpu_relax() smp_mb() +#else #define cpu_relax() barrier() +#endif /* * Return_address is a replacement for __builtin_return_address(count) |