CACHEFLUSH(2) Linux Programmer's Manual CACHEFLUSH(2)
NAME
cacheflush - flush contents of instruction and/or data cache
SYNOPSIS
#include <asm/cachectl.h>
int cacheflush(char *addr, int nbytes, int cache);
DESCRIPTION
cacheflush() flushes the contents of the indicated cache(s) for the
user addresses in the range addr to (addr+nbytes-1). cache may be one
of:
ICACHE Flush the instruction cache.
DCACHE Write back to memory and invalidate the affected valid cache
lines.
BCACHE Same as (ICACHE|DCACHE).
RETURN VALUE
cacheflush() returns 0 on success or -1 on error. If errors are de-
tected, errno will indicate the error.
ERRORS
EFAULT Some or all of the address range addr to (addr+nbytes-1) is not
accessible.
EINVAL cache is not one of ICACHE, DCACHE, or BCACHE (but see BUGS).
CONFORMING TO
Historically, this system call was available on all MIPS UNIX variants
including RISC/os, IRIX, Ultrix, NetBSD, OpenBSD, and FreeBSD (and also
on some non-UNIX MIPS operating systems), so that the existence of this
call in MIPS operating systems is a de-facto standard.
Caveat
cacheflush() should not be used in programs intended to be portable.
On Linux, this call first appeared on the MIPS architecture, but nowa-
days, Linux provides a cacheflush() system call on some other architec-
tures, but with different arguments.
BUGS
Linux kernels older than version 2.6.11 ignore the addr and nbytes ar-
guments, making this function fairly expensive. Therefore, the whole
cache is always flushed.
This function always behaves as if BCACHE has been passed for the cache
argument and does not do any error checking on the cache argument.
COLOPHON
This page is part of release 5.07 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
Linux 2017-09-15 CACHEFLUSH(2)