1CACHEFLUSH(2)              Linux Programmer's Manual             CACHEFLUSH(2)
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NAME

6       cacheflush - flush contents of instruction and/or data cache
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SYNOPSIS

9       #include <asm/cachectl.h>
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11       int cacheflush(char *addr, int nbytes, int cache);
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DESCRIPTION

14       cacheflush()  flushes  the  contents  of the indicated cache(s) for the
15       user addresses in the range addr to (addr+nbytes-1).  cache may be  one
16       of:
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18       ICACHE Flush the instruction cache.
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20       DCACHE Write  back  to  memory  and invalidate the affected valid cache
21              lines.
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23       BCACHE Same as (ICACHE|DCACHE).
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RETURN VALUE

26       cacheflush() returns 0 on success  or  -1  on  error.   If  errors  are
27       detected, errno will indicate the error.
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ERRORS

30       EFAULT Some  or all of the address range addr to (addr+nbytes-1) is not
31              accessible.
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33       EINVAL cache is not one of ICACHE, DCACHE, or BCACHE (but see BUGS).
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CONFORMING TO

36       Historically, this system call was available on all MIPS UNIX  variants
37       including RISC/os, IRIX, Ultrix, NetBSD, OpenBSD, and FreeBSD (and also
38       on some non-UNIX MIPS operating systems), so that the existence of this
39       call in MIPS operating systems is a de-facto standard.
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41   Caveat
42       cacheflush()  should  not  be used in programs intended to be portable.
43       On Linux, this call first appeared on the MIPS architecture, but  nowa‐
44       days, Linux provides a cacheflush() system call on some other architec‐
45       tures, but with different arguments.
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BUGS

48       Linux kernels older than version 2.6.11  ignore  the  addr  and  nbytes
49       arguments, making this function fairly expensive.  Therefore, the whole
50       cache is always flushed.
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52       This function always behaves as if BCACHE has been passed for the cache
53       argument and does not do any error checking on the cache argument.
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COLOPHON

56       This  page  is  part of release 4.15 of the Linux man-pages project.  A
57       description of the project, information about reporting bugs,  and  the
58       latest     version     of     this    page,    can    be    found    at
59       https://www.kernel.org/doc/man-pages/.
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63Linux                             2017-09-15                     CACHEFLUSH(2)
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