From 035b19a15a98907916a42a6b1d025877c42f10ad Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 25 Nov 2020 07:10:46 +0000 Subject: [PATCH] powerpc/32s: Always map kernel text and rodata with BATs Since commit 2b279c0348af ("powerpc/32s: Allow mapping with BATs with DEBUG_PAGEALLOC"), there is no real situation where mapping without BATs is required. In order to simplify memory handling, always map kernel text and rodata with BATs even when "nobats" kernel parameter is set. Also fix the 603 TLB miss exceptions that don't require anymore kernel page table if DEBUG_PAGEALLOC. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/da51f7ec632825a4ce43290a904aad61648408c0.1606285013.git.christophe.leroy@csgroup.eu --- arch/powerpc/kernel/head_book3s_32.S | 4 ++-- arch/powerpc/mm/book3s32/mmu.c | 8 +++----- 2 files changed, 5 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S index bbcc84c..757aed0 100644 --- a/arch/powerpc/kernel/head_book3s_32.S +++ b/arch/powerpc/kernel/head_book3s_32.S @@ -457,13 +457,13 @@ InstructionTLBMiss: */ /* Get PTE (linux-style) and check access */ mfspr r3,SPRN_IMISS -#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC) +#ifdef CONFIG_MODULES lis r1, TASK_SIZE@h /* check if kernel address */ cmplw 0,r1,r3 #endif mfspr r2, SPRN_SPRG_PGDIR li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC -#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC) +#ifdef CONFIG_MODULES bgt- 112f lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */ addi r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */ diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c index a59e7ec..5c60dca 100644 --- a/arch/powerpc/mm/book3s32/mmu.c +++ b/arch/powerpc/mm/book3s32/mmu.c @@ -157,11 +157,9 @@ unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top) unsigned long done; unsigned long border = (unsigned long)__init_begin - PAGE_OFFSET; - if (__map_without_bats) { - pr_debug("RAM mapped without BATs\n"); - return base; - } - if (debug_pagealloc_enabled()) { + + if (debug_pagealloc_enabled() || __map_without_bats) { + pr_debug_once("Read-Write memory mapped without BATs\n"); if (base >= border) return base; if (top >= border) -- 2.7.4