powerpc-e500-dont-pre-check-write-access-on-data-tlb-error.patch removed from -mm tree
The quilt patch titled
Subject: powerpc/e500: don't pre-check write access on data TLB error
has been removed from the -mm tree. Its filename was
powerpc-e500-dont-pre-check-write-access-on-data-tlb-error.patch
This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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From: Christophe Leroy <[email protected]>
Subject: powerpc/e500: don't pre-check write access on data TLB error
Date: Tue, 2 Jul 2024 15:51:30 +0200
Don't pre-check write access on read-only pages on data TLB error.
Load the TLB anyway and take a DSI exception when it happens. This avoids reading SPRN_ESR at every data TLB error exception.
---
arch/powerpc/kernel/head_85xx.S | 15 --------------- 1 file changed, 15 deletions(-)
arch/powerpc/kernel/head_85xx.S renamed from arch/powerpc/kernel/head_85xx.S~powerpc-e500-dont-pre-check-write-access-on-data-tlb-error +0 -15
@@ -472,27 +472,12 @@ END_BTB_FLUSH_SECTION #endif 4: - /* Mask of required permission bits. Note that while we - * do copy ESR:ST to _PAGE_WRITE position as trying to write - * to an RO page is pretty common, we don't do it with - * _PAGE_DIRTY. We could do it, but it's a fairly rare - * event so I'd rather take the overhead when it happens - * rather than adding an instruction here. We should measure - * whether the whole thing is worth it in the first place - * as we could avoid loading SPRN_ESR completely in the first - * place... - * - * TODO: Is it worth doing that mfspr & rlwimi in the first - * place or can we save a couple of instructions here ? - */ - mfspr r12,SPRN_ESR #ifdef CONFIG_PTE_64BIT li r13,_PAGE_PRESENT|_PAGE_BAP_SR oris r13,r13,_PAGE_ACCESSED@h #else li r13,_PAGE_PRESENT|_PAGE_READ|_PAGE_ACCESSED #endif - rlwimi r13,r12,11,29,29 FIND_PTE andc. r13,r13,r11 /* Check permission */
_
Patches currently in -mm which might be from [email protected] are