This is a note to let you know that I've just added the patch titled
parisc: Remove unnecessary TLB purges from flush_dcache_page_asm and flush_icache_page_asm
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
parisc-remove-unnecessary-tlb-purges-from-flush_dcache_page_asm-and-flush_icache_page_asm.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From febe42964fe182281859b3d43d844bb25ca49367 Mon Sep 17 00:00:00 2001
From: John David Anglin <dave.anglin@xxxxxxxx>
Date: Tue, 6 Dec 2016 22:02:01 -0500
Subject: parisc: Remove unnecessary TLB purges from flush_dcache_page_asm and flush_icache_page_asm
From: John David Anglin <dave.anglin@xxxxxxxx>
commit febe42964fe182281859b3d43d844bb25ca49367 upstream.
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@xxxxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/parisc/kernel/pacache.S | 22 +---------------------
1 file changed, 1 insertion(+), 21 deletions(-)
--- a/arch/parisc/kernel/pacache.S
+++ b/arch/parisc/kernel/pacache.S
@@ -886,19 +886,10 @@ ENTRY(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
@@ -973,17 +964,6 @@ ENTRY(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
Patches currently in stable-queue which might be from dave.anglin@xxxxxxxx are
queue-4.4/parisc-remove-unnecessary-tlb-purges-from-flush_dcache_page_asm-and-flush_icache_page_asm.patch
queue-4.4/parisc-purge-tlb-before-setting-pte.patch
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