From febe42964fe182281859b3d43d844bb25ca49367 Mon Sep 17 00:00:00 2001 From: John David Anglin <dave.anglin@bell.net> Date: Tue, 6 Dec 2016 22:02:01 -0500 Subject: [PATCH] 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 | 22 +--------------------- 1 file changed, 1 insertion(+), 21 deletions(-) diff --git a/arch/parisc/kernel/pacache.S b/arch/parisc/kernel/pacache.S index 1b39a2acaadf4..adf7187f89515 100644 --- a/arch/parisc/kernel/pacache.S +++ b/arch/parisc/kernel/pacache.S @@ -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 -- GitLab