diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/powerpc/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/powerpc/include/asm/barrier.h')
-rw-r--r-- | kernel/arch/powerpc/include/asm/barrier.h | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/include/asm/barrier.h b/kernel/arch/powerpc/include/asm/barrier.h new file mode 100644 index 000000000..a3bf5be11 --- /dev/null +++ b/kernel/arch/powerpc/include/asm/barrier.h @@ -0,0 +1,93 @@ +/* + * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu> + */ +#ifndef _ASM_POWERPC_BARRIER_H +#define _ASM_POWERPC_BARRIER_H + +/* + * Memory barrier. + * The sync instruction guarantees that all memory accesses initiated + * by this processor have been performed (with respect to all other + * mechanisms that access memory). The eieio instruction is a barrier + * providing an ordering (separately) for (a) cacheable stores and (b) + * loads and stores to non-cacheable memory (e.g. I/O devices). + * + * mb() prevents loads and stores being reordered across this point. + * rmb() prevents loads being reordered across this point. + * wmb() prevents stores being reordered across this point. + * read_barrier_depends() prevents data-dependent loads being reordered + * across this point (nop on PPC). + * + * *mb() variants without smp_ prefix must order all types of memory + * operations with one another. sync is the only instruction sufficient + * to do this. + * + * For the smp_ barriers, ordering is for cacheable memory operations + * only. We have to use the sync instruction for smp_mb(), since lwsync + * doesn't order loads with respect to previous stores. Lwsync can be + * used for smp_rmb() and smp_wmb(). + * + * However, on CPUs that don't support lwsync, lwsync actually maps to a + * heavy-weight sync, so smp_wmb() can be a lighter-weight eieio. + */ +#define mb() __asm__ __volatile__ ("sync" : : : "memory") +#define rmb() __asm__ __volatile__ ("sync" : : : "memory") +#define wmb() __asm__ __volatile__ ("sync" : : : "memory") + +#define set_mb(var, value) do { var = value; mb(); } while (0) + +#ifdef __SUBARCH_HAS_LWSYNC +# define SMPWMB LWSYNC +#else +# define SMPWMB eieio +#endif + +#define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") +#define dma_rmb() __lwsync() +#define dma_wmb() __asm__ __volatile__ (stringify_in_c(SMPWMB) : : :"memory") + +#ifdef CONFIG_SMP +#define smp_lwsync() __lwsync() + +#define smp_mb() mb() +#define smp_rmb() __lwsync() +#define smp_wmb() __asm__ __volatile__ (stringify_in_c(SMPWMB) : : :"memory") +#else +#define smp_lwsync() barrier() + +#define smp_mb() barrier() +#define smp_rmb() barrier() +#define smp_wmb() barrier() +#endif /* CONFIG_SMP */ + +#define read_barrier_depends() do { } while (0) +#define smp_read_barrier_depends() do { } while (0) + +/* + * This is a barrier which prevents following instructions from being + * started until the value of the argument x is known. For example, if + * x is a variable loaded from memory, this prevents following + * instructions from being executed until the load has been performed. + */ +#define data_barrier(x) \ + asm volatile("twi 0,%0,0; isync" : : "r" (x) : "memory"); + +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + smp_lwsync(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + smp_lwsync(); \ + ___p1; \ +}) + +#define smp_mb__before_atomic() smp_mb() +#define smp_mb__after_atomic() smp_mb() + +#endif /* _ASM_POWERPC_BARRIER_H */ |