cacheflush - flush contents of instruction and/or data cache
int cacheflush(char *addr, int nbytes, int cache);
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:
- Flush the instruction cache.
- Write back to memory and invalidate the affected valid cache lines.
- Same as (ICACHE|DCACHE).
cacheflush() returns 0 on success or -1 on error. If errors are detected,
errno will indicate the error.
- Some or all of the address range addr to (addr+nbytes-1) is
- cache is not one of ICACHE, DCACHE, or BCACHE
(but see BUGS).
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.
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.
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
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