CACHE(3) BSD Library Functions Manual CACHE(3)NAME
sys_cache_control, sys_icache_invalidate, sys_dcache_flush — cache con‐
trol
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <libkern/OSCacheControl.h>
int
sys_cache_control(int function, void *start, size_t len);
void
sys_icache_invalidate(void *start, size_t len);
void
sys_dcache_flush(void *start, size_t len);
DESCRIPTION
These functions operate on every cache line containing one of the len
bytes of memory pointed to by start. Normally the operations apply to
every processor in the system, but the exact semantics of these opera‐
tions is platform dependent. They should be used with caution.
sys_cache_control() performs the operation specified by function. Refer
to the header file for a list of currently supported functions.
sys_icache_invalidate() prepares memory for execution, typically by
invalidating the instruction cache for the indicated range. This should
be called after writing machine instructions to memory, and before exe‐
cuting them. On IA32 processors this function is a NOP, because their
instruction caches are coherent.
sys_dcache_flush() writes modified data cache lines to main memory, and
then invalidates all lines in the range being operated on. It can be
useful when dealing with cache incoherent devices or DMA.
RETURN VALUESsys_cache_control() returns zero on success, ENOTSUP if function is not
valid.
SEE ALSOatomic(3), barrier(3)HISTORY
These functions first appeared in Mac OS 10.5 (Leopard).
Darwin September 21, 2006 Darwin
