b92b8b35a2
Since set_mb() is really about an smp_mb() -- not a IO/DMA barrier like mb() rename it to match the recent smp_load_acquire() and smp_store_release(). Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
62 lines
1.6 KiB
C
62 lines
1.6 KiB
C
#ifndef _ASM_UM_BARRIER_H_
|
|
#define _ASM_UM_BARRIER_H_
|
|
|
|
#include <asm/asm.h>
|
|
#include <asm/segment.h>
|
|
#include <asm/cpufeature.h>
|
|
#include <asm/cmpxchg.h>
|
|
#include <asm/nops.h>
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/irqflags.h>
|
|
|
|
/*
|
|
* Force strict CPU ordering.
|
|
* And yes, this is required on UP too when we're talking
|
|
* to devices.
|
|
*/
|
|
#ifdef CONFIG_X86_32
|
|
|
|
#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
|
|
#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
|
|
#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
|
|
|
|
#else /* CONFIG_X86_32 */
|
|
|
|
#define mb() asm volatile("mfence" : : : "memory")
|
|
#define rmb() asm volatile("lfence" : : : "memory")
|
|
#define wmb() asm volatile("sfence" : : : "memory")
|
|
|
|
#endif /* CONFIG_X86_32 */
|
|
|
|
#ifdef CONFIG_X86_PPRO_FENCE
|
|
#define dma_rmb() rmb()
|
|
#else /* CONFIG_X86_PPRO_FENCE */
|
|
#define dma_rmb() barrier()
|
|
#endif /* CONFIG_X86_PPRO_FENCE */
|
|
#define dma_wmb() barrier()
|
|
|
|
#define smp_mb() barrier()
|
|
#define smp_rmb() barrier()
|
|
#define smp_wmb() barrier()
|
|
|
|
#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); barrier(); } while (0)
|
|
|
|
#define read_barrier_depends() do { } while (0)
|
|
#define smp_read_barrier_depends() do { } while (0)
|
|
|
|
/*
|
|
* Stop RDTSC speculation. This is needed when you need to use RDTSC
|
|
* (or get_cycles or vread that possibly accesses the TSC) in a defined
|
|
* code region.
|
|
*
|
|
* (Could use an alternative three way for this if there was one.)
|
|
*/
|
|
static inline void rdtsc_barrier(void)
|
|
{
|
|
alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC,
|
|
"lfence", X86_FEATURE_LFENCE_RDTSC);
|
|
}
|
|
|
|
#endif
|