parisc: Remove unnecessary TLB purges from flush_dcache_page_asm and flush_icache_pag...
authorJohn David Anglin <dave.anglin@bell.net>
Wed, 7 Dec 2016 03:02:01 +0000 (22:02 -0500)
committerHelge Deller <deller@gmx.de>
Wed, 7 Dec 2016 08:01:21 +0000 (09:01 +0100)
commitfebe42964fe182281859b3d43d844bb25ca49367
tree5747f9ba180c5b7f530d0b0ad5b8d3a945004177
parentc78e710c1c9fbeff43dddc0aa3d0ff458e70b0cc
parisc: Remove unnecessary TLB purges from flush_dcache_page_asm and flush_icache_page_asm

We have four routines in pacache.S that use temporary alias pages:
copy_user_page_asm(), clear_user_page_asm(), flush_dcache_page_asm() and
flush_icache_page_asm().  copy_user_page_asm() and clear_user_page_asm()
don't purge the TLB entry used for the operation.
flush_dcache_page_asm() and flush_icache_page_asm do purge the entry.

Presumably, this was thought to optimize TLB use.  However, the
operation is quite heavy weight on PA 1.X processors as we need to take
the TLB lock and a TLB broadcast is sent to all processors.

This patch removes the purges from flush_dcache_page_asm() and
flush_icache_page_asm.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: Helge Deller <deller@gmx.de>
arch/parisc/kernel/pacache.S