Release 4.12 include/linux/prefetch.h

/*
 *  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
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
50
100.00%
1
100.00%
Total
50
100.00%
1
100.00%

#endif
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
54
47.37%
2
40.00%
Andrew Morton
53
46.49%
1
20.00%
Andi Kleen
6
5.26%
1
20.00%
Lucas De Marchi
1
0.88%
1
20.00%
Total
114
100.00%
5
100.00%
Directory: include/linux

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.