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Diffstat (limited to 'arch/blackfin/include/asm/barrier.h')
-rw-r--r-- | arch/blackfin/include/asm/barrier.h | 86 |
1 files changed, 0 insertions, 86 deletions
diff --git a/arch/blackfin/include/asm/barrier.h b/arch/blackfin/include/asm/barrier.h deleted file mode 100644 index 7cca51cae5ff..000000000000 --- a/arch/blackfin/include/asm/barrier.h +++ /dev/null @@ -1,86 +0,0 @@ -/* - * Copyright 2004-2009 Analog Devices Inc. - * Tony Kou (tonyko@lineo.ca) - * - * Licensed under the GPL-2 or later - */ - -#ifndef _BLACKFIN_BARRIER_H -#define _BLACKFIN_BARRIER_H - -#include <asm/cache.h> - -#define nop() __asm__ __volatile__ ("nop;\n\t" : : ) - -/* - * Force strict CPU ordering. - */ -#ifdef CONFIG_SMP - -#ifdef __ARCH_SYNC_CORE_DCACHE -/* Force Core data cache coherence */ -# define mb() do { barrier(); smp_check_barrier(); smp_mark_barrier(); } while (0) -# define rmb() do { barrier(); smp_check_barrier(); } while (0) -# define wmb() do { barrier(); smp_mark_barrier(); } while (0) -/* - * read_barrier_depends - Flush all pending reads that subsequents reads - * depend on. - * - * No data-dependent reads from memory-like regions are ever reordered - * over this barrier. All reads preceding this primitive are guaranteed - * to access memory (but not necessarily other CPUs' caches) before any - * reads following this primitive that depend on the data return by - * any of the preceding reads. This primitive is much lighter weight than - * rmb() on most CPUs, and is never heavier weight than is - * rmb(). - * - * These ordering constraints are respected by both the local CPU - * and the compiler. - * - * Ordering is not guaranteed by anything other than these primitives, - * not even by data dependencies. See the documentation for - * memory_barrier() for examples and URLs to more information. - * - * For example, the following code would force ordering (the initial - * value of "a" is zero, "b" is one, and "p" is "&a"): - * - * <programlisting> - * CPU 0 CPU 1 - * - * b = 2; - * memory_barrier(); - * p = &b; q = p; - * read_barrier_depends(); - * d = *q; - * </programlisting> - * - * because the read of "*q" depends on the read of "p" and these - * two reads are separated by a read_barrier_depends(). However, - * the following code, with the same initial values for "a" and "b": - * - * <programlisting> - * CPU 0 CPU 1 - * - * a = 2; - * memory_barrier(); - * b = 3; y = b; - * read_barrier_depends(); - * x = a; - * </programlisting> - * - * does not enforce ordering, since there is no data dependency between - * the read of "a" and the read of "b". Therefore, on some CPUs, such - * as Alpha, "y" could be set to 3 and "x" to 0. Use rmb() - * in cases like this where there are no data dependencies. - */ -# define read_barrier_depends() do { barrier(); smp_check_barrier(); } while (0) -#endif - -#endif /* !CONFIG_SMP */ - -#define __smp_mb__before_atomic() barrier() -#define __smp_mb__after_atomic() barrier() - -#include <asm-generic/barrier.h> - -#endif /* _BLACKFIN_BARRIER_H */ |