[PATCH v2 06/10] powerpc/603: Don't handle kernel page TLB misses when not need
From: Christophe Leroy <hidden>
Date: 2019-02-21 10:38:29
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
ITLB miss on kernel pages only occur with CONFIG_MODULES and CONFIG_DEBUG_PAGEALLOC. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/kernel/head_32.S | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 4c2cc42399aa..e4338d785a94 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S@@ -498,15 +498,19 @@ InstructionTLBMiss: */ /* Get PTE (linux-style) and check access */ mfspr r3,SPRN_IMISS +#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC) lis r1,PAGE_OFFSET@h /* check if kernel address */ cmplw 0,r1,r3 +#endif mfspr r2, SPRN_SPRG_PGDIR li r1,_PAGE_USER|_PAGE_PRESENT|_PAGE_EXEC /* low addresses tested as user */ +#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC) bge- 112f mfspr r2,SPRN_SRR1 /* and MSR_PR bit from SRR1 */ rlwimi r1,r2,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */ lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */ addi r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */ +#endif 112: rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */ lwz r2,0(r2) /* get pmd entry */ rlwinm. r2,r2,0,0,19 /* extract address of pte page */
--
2.13.3