提交 febe4296 编写于 作者: J John David Anglin 提交者: Helge Deller

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: NJohn David Anglin  <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: NHelge Deller <deller@gmx.de>
上级 c78e710c
......@@ -892,19 +892,10 @@ ENTRY_CFI(flush_dcache_page_asm)
fdc,m r31(%r28)
fdc,m r31(%r28)
fdc,m r31(%r28)
cmpb,COND(<<) %r28, %r25,1b
cmpb,COND(<<) %r28, %r25,1b
fdc,m r31(%r28)
sync
#ifdef CONFIG_PA20
pdtlb,l %r0(%r25)
#else
tlb_lock %r20,%r21,%r22
pdtlb %r0(%r25)
tlb_unlock %r20,%r21,%r22
#endif
bv %r0(%r2)
nop
.exit
......@@ -979,17 +970,6 @@ ENTRY_CFI(flush_icache_page_asm)
fic,m %r31(%sr4,%r28)
sync
#ifdef CONFIG_PA20
pdtlb,l %r0(%r28)
pitlb,l %r0(%sr4,%r25)
#else
tlb_lock %r20,%r21,%r22
pdtlb %r0(%r28)
pitlb %r0(%sr4,%r25)
tlb_unlock %r20,%r21,%r22
#endif
bv %r0(%r2)
nop
.exit
......
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