NetBSD master CVS tree commits

[source%NetBSD.ORG@localhost]

pk
Thu Mar 20 15:48:39 PST 1997
Update of /cvsroot/src/sys/arch/sparc/sparc
In directory netbsd1:/var/slash-tmp/cvs-serv15716

Modified Files:
        pmap.c 
Log Message:
Replace many setpte4m() calls with a simpler helper function because
the address of the desired PTE location is readily available in the
callers context (setpte4m() retraces the entire 3-level structure
to arrive at the PTE location).

Also, in many cases we can do away with the distinction between pmaps
that have or have not allocated a context. This is really only useful
in cases where we're interested in the REF or MOD bits which can differ
in the TLB version of a PTE.  By doing this, we avoid getpte()'s which
in many cases instruct the MMU to start a table walk only to find out
that there's nothing there after going 2/3 of the way, or waste a TLB
entry because of TLB flushing soon after getpte() completes.

In addition, there's a hook to flush the cache line corresponding to
the (kernel virtual) location of a PTE entry when it gets altered.