Viewing file:  barrier.h (2.16 KB) -rw-r--r--
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/*
* Copyright IBM Corp. 1999, 2009
*
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
#ifndef __ASM_BARRIER_H
#define __ASM_BARRIER_H
#include <asm/alternative.h>
/*
* Force strict CPU ordering.
* And yes, this is required on UP too when we're talking
* to devices.
*/
#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
/* Fast-BCR without checkpoint synchronization */
#define __ASM_BARRIER "bcr 14,0\n"
#else
#define __ASM_BARRIER "bcr 15,0\n"
#endif
#define mb() do { asm volatile(__ASM_BARRIER : : : "memory"); } while (0)
/* Prevent speculative execution past this barrier. */
#define barrier_nospec() \
do { \
asm volatile(ALTERNATIVE("", ".long 0xb2e8f000", 81) \
: : : "memory"); \
} while (0)
#define rmb() barrier()
#define wmb() barrier()
#define dma_rmb() mb()
#define dma_wmb() mb()
#define smp_mb() mb()
#define smp_rmb() rmb()
#define smp_wmb() wmb()
#define read_barrier_depends() do { } while (0)
#define smp_read_barrier_depends() do { } while (0)
#define smp_mb__before_atomic() smp_mb()
#define smp_mb__after_atomic() smp_mb()
#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0)
#define smp_store_release(p, v) \
do { \
compiletime_assert_atomic_type(*p); \
barrier(); \
WRITE_ONCE(*p, v); \
} while (0)
#define smp_load_acquire(p) \
({ \
typeof(*p) ___p1 = READ_ONCE(*p); \
compiletime_assert_atomic_type(*p); \
barrier(); \
___p1; \
})
/**
* array_index_mask_nospec - generate a mask for array_idx() that is
* ~0UL when the bounds check succeeds and 0 otherwise
* @index: array element index
* @size: number of elements in array
*/
#define array_index_mask_nospec array_index_mask_nospec
static inline unsigned long array_index_mask_nospec(unsigned long index,
unsigned long size)
{
unsigned long mask;
if (__builtin_constant_p(size) && size > 0) {
asm(" clgr %2,%1\n"
" slbgr %0,%0\n"
:"=d" (mask) : "d" (size-1), "d" (index) :"cc");
return mask;
}
asm(" clgr %1,%2\n"
" slbgr %0,%0\n"
:"=d" (mask) : "d" (size), "d" (index) :"cc");
return ~mask;
}
#endif /* __ASM_BARRIER_H */
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