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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/ia64/include/asm/barrier.h | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/ia64/include/asm/barrier.h')
-rw-r--r-- | kernel/arch/ia64/include/asm/barrier.h | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/kernel/arch/ia64/include/asm/barrier.h b/kernel/arch/ia64/include/asm/barrier.h new file mode 100644 index 000000000..f6769eb2b --- /dev/null +++ b/kernel/arch/ia64/include/asm/barrier.h @@ -0,0 +1,93 @@ +/* + * 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 dma_rmb() mb() +#define dma_wmb() mb() + +#ifdef CONFIG_SMP +# define smp_mb() mb() +#else +# define smp_mb() barrier() +#endif + +#define smp_rmb() smp_mb() +#define smp_wmb() smp_mb() + +#define read_barrier_depends() do { } while (0) +#define smp_read_barrier_depends() do { } while (0) + +#define smp_mb__before_atomic() barrier() +#define smp_mb__after_atomic() barrier() + +/* + * IA64 GCC turns volatile stores into st.rel and volatile loads into ld.acq no + * need for asm trickery! + */ + +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + barrier(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + barrier(); \ + ___p1; \ +}) + +/* + * 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 */ |