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/x86/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/x86/include/asm/barrier.h')
-rw-r--r-- | kernel/arch/x86/include/asm/barrier.h | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/kernel/arch/x86/include/asm/barrier.h b/kernel/arch/x86/include/asm/barrier.h new file mode 100644 index 000000000..959e45b81 --- /dev/null +++ b/kernel/arch/x86/include/asm/barrier.h @@ -0,0 +1,105 @@ +#ifndef _ASM_X86_BARRIER_H +#define _ASM_X86_BARRIER_H + +#include <asm/alternative.h> +#include <asm/nops.h> + +/* + * Force strict CPU ordering. + * And yes, this is required on UP too when we're talking + * to devices. + */ + +#ifdef CONFIG_X86_32 +/* + * Some non-Intel clones support out of order store. wmb() ceases to be a + * nop for these. + */ +#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2) +#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2) +#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM) +#else +#define mb() asm volatile("mfence":::"memory") +#define rmb() asm volatile("lfence":::"memory") +#define wmb() asm volatile("sfence" ::: "memory") +#endif + +#ifdef CONFIG_X86_PPRO_FENCE +#define dma_rmb() rmb() +#else +#define dma_rmb() barrier() +#endif +#define dma_wmb() barrier() + +#ifdef CONFIG_SMP +#define smp_mb() mb() +#define smp_rmb() dma_rmb() +#define smp_wmb() barrier() +#define set_mb(var, value) do { (void)xchg(&var, value); } while (0) +#else /* !SMP */ +#define smp_mb() barrier() +#define smp_rmb() barrier() +#define smp_wmb() barrier() +#define set_mb(var, value) do { var = value; barrier(); } while (0) +#endif /* SMP */ + +#define read_barrier_depends() do { } while (0) +#define smp_read_barrier_depends() do { } while (0) + +#if defined(CONFIG_X86_PPRO_FENCE) + +/* + * For this option x86 doesn't have a strong TSO memory + * model and we should fall back to full barriers. + */ + +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ___p1; \ +}) + +#else /* regular x86 TSO memory ordering */ + +#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; \ +}) + +#endif + +/* Atomic operations are already serializing on x86 */ +#define smp_mb__before_atomic() barrier() +#define smp_mb__after_atomic() barrier() + +/* + * Stop RDTSC speculation. This is needed when you need to use RDTSC + * (or get_cycles or vread that possibly accesses the TSC) in a defined + * code region. + */ +static __always_inline void rdtsc_barrier(void) +{ + alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC, + "lfence", X86_FEATURE_LFENCE_RDTSC); +} + +#endif /* _ASM_X86_BARRIER_H */ |