diff options
author | Ingo Molnar <mingo@kernel.org> | 2012-04-14 13:18:27 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2012-04-14 13:19:04 +0200 |
commit | 6ac1ef482d7ae0c690f1640bf6eb818ff9a2d91e (patch) | |
tree | 021cc9f6b477146fcebe6f3be4752abfa2ba18a9 /arch/ia64/include/asm/barrier.h | |
parent | 682968e0c425c60f0dde37977e5beb2b12ddc4cc (diff) | |
parent | a385ec4f11bdcf81af094c03e2444ee9b7fad2e5 (diff) |
Merge branch 'perf/core' into perf/uprobes
Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/ia64/include/asm/barrier.h')
-rw-r--r-- | arch/ia64/include/asm/barrier.h | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/ia64/include/asm/barrier.h b/arch/ia64/include/asm/barrier.h new file mode 100644 index 00000000000..60576e06b6f --- /dev/null +++ b/arch/ia64/include/asm/barrier.h @@ -0,0 +1,68 @@ +/* + * Memory barrier definitions. This is based on information published + * in the Processor Abstraction Layer and the System Abstraction Layer + * manual. + * + * Copyright (C) 1998-2003 Hewlett-Packard Co + * David Mosberger-Tang <davidm@hpl.hp.com> + * Copyright (C) 1999 Asit Mallick <asit.k.mallick@intel.com> + * Copyright (C) 1999 Don Dugger <don.dugger@intel.com> + */ +#ifndef _ASM_IA64_BARRIER_H +#define _ASM_IA64_BARRIER_H + +#include <linux/compiler.h> + +/* + * Macros to force memory ordering. In these descriptions, "previous" + * and "subsequent" refer to program order; "visible" means that all + * architecturally visible effects of a memory access have occurred + * (at a minimum, this means the memory has been read or written). + * + * wmb(): Guarantees that all preceding stores to memory- + * like regions are visible before any subsequent + * stores and that all following stores will be + * visible only after all previous stores. + * rmb(): Like wmb(), but for reads. + * mb(): wmb()/rmb() combo, i.e., all previous memory + * accesses are visible before all subsequent + * accesses and vice versa. This is also known as + * a "fence." + * + * Note: "mb()" and its variants cannot be used as a fence to order + * accesses to memory mapped I/O registers. For that, mf.a needs to + * be used. However, we don't want to always use mf.a because (a) + * it's (presumably) much slower than mf and (b) mf.a is supported for + * sequential memory pages only. + */ +#define mb() ia64_mf() +#define rmb() mb() +#define wmb() mb() +#define read_barrier_depends() do { } while(0) + +#ifdef CONFIG_SMP +# define smp_mb() mb() +# define smp_rmb() rmb() +# define smp_wmb() wmb() +# define smp_read_barrier_depends() read_barrier_depends() +#else +# define smp_mb() barrier() +# define smp_rmb() barrier() +# define smp_wmb() barrier() +# define smp_read_barrier_depends() do { } while(0) +#endif + +/* + * XXX check on this ---I suspect what Linus really wants here is + * acquire vs release semantics but we can't discuss this stuff with + * Linus just yet. Grrr... + */ +#define set_mb(var, value) do { (var) = (value); mb(); } while (0) + +/* + * The group barrier in front of the rsm & ssm are necessary to ensure + * that none of the previous instructions in the same group are + * affected by the rsm/ssm. + */ + +#endif /* _ASM_IA64_BARRIER_H */ |