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 detected, 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
       nowadays, Linux provides a cacheflush() system call on some other architectures, but with different arguments.

BUGS

       Linux kernels older than version 2.6.11 ignore the addr and nbytes arguments, 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 4.15 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)