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 4.09 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/.

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