Ralf,

Linux supports the traditional MIPS UNIX cacheflush(2) syscall through
a libc interface.  Since I've not seen any other use for the call than
I/D-cache synchronization.  I'd just make cacheflush(3) use SYNCI where
available...

SYNCI just does what's required to execute code you just wrote: that's
a D-cache writeback and an I-cache invalidate.  It doesn't invalidate
the D-cache afterwards, which is required by the definition of
cacheflush(3).

I think it would be better to provide cache manipulation calls defined
top-down (by their purpose); but so long as we are stuck with calls
which are defined as performing particular low-level actions, it's
surely dangerous to guess that we know what they are used for so we
can trim the functions accordingly...

--
Dominic Sweetman
MIPS Technologies