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/include/linux/prefetch.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/include/linux/prefetch.h')
-rw-r--r-- | kernel/include/linux/prefetch.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/kernel/include/linux/prefetch.h b/kernel/include/linux/prefetch.h new file mode 100644 index 000000000..a3bfbdf63 --- /dev/null +++ b/kernel/include/linux/prefetch.h @@ -0,0 +1,64 @@ +/* + * Generic cache management functions. Everything is arch-specific, + * but this header exists to make sure the defines/functions can be + * used in a generic way. + * + * 2000-11-13 Arjan van de Ven <arjan@fenrus.demon.nl> + * + */ + +#ifndef _LINUX_PREFETCH_H +#define _LINUX_PREFETCH_H + +#include <linux/types.h> +#include <asm/processor.h> +#include <asm/cache.h> + +/* + prefetch(x) attempts to pre-emptively get the memory pointed to + by address "x" into the CPU L1 cache. + prefetch(x) should not cause any kind of exception, prefetch(0) is + specifically ok. + + prefetch() should be defined by the architecture, if not, the + #define below provides a no-op define. + + There are 3 prefetch() macros: + + prefetch(x) - prefetches the cacheline at "x" for read + prefetchw(x) - prefetches the cacheline at "x" for write + spin_lock_prefetch(x) - prefetches the spinlock *x for taking + + there is also PREFETCH_STRIDE which is the architecure-preferred + "lookahead" size for prefetching streamed operations. + +*/ + +#ifndef ARCH_HAS_PREFETCH +#define prefetch(x) __builtin_prefetch(x) +#endif + +#ifndef ARCH_HAS_PREFETCHW +#define prefetchw(x) __builtin_prefetch(x,1) +#endif + +#ifndef ARCH_HAS_SPINLOCK_PREFETCH +#define spin_lock_prefetch(x) prefetchw(x) +#endif + +#ifndef PREFETCH_STRIDE +#define PREFETCH_STRIDE (4*L1_CACHE_BYTES) +#endif + +static inline void prefetch_range(void *addr, size_t len) +{ +#ifdef ARCH_HAS_PREFETCH + char *cp; + char *end = addr + len; + + for (cp = addr; cp < end; cp += PREFETCH_STRIDE) + prefetch(cp); +#endif +} + +#endif |