Files
fjrXTR f0ea57c2d7 S666LN-kernel: Initial Device kernel tree
* Based on S666LN-MA66BABCDEFLMNQ-T-OP-240322V1005
* Imported kernel-headers for dummy

Change-Id: I639796c449784d67edc65d7f38cf7d7119d117d2
Signed-off-by: fjrXTR <fajarslebew31@gmail.com>
2024-11-24 07:52:05 +01:00

74 lines
1.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* 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>
struct page;
/*
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
}
static inline void prefetch_page_address(struct page *page)
{
#if defined(WANT_PAGE_VIRTUAL) || defined(HASHED_PAGE_VIRTUAL)
prefetch(page);
#endif
}
#endif