Commit 035b19a1 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/32s: Always map kernel text and rodata with BATs 



Since commit 2b279c03 ("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: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/da51f7ec632825a4ce43290a904aad61648408c0.1606285013.git.christophe.leroy@csgroup.eu
parent 98f5559a

arch/powerpc/kernel/head_book3s_32.S

+2 −2
Original line number Diff line number Diff line
@@ -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 */

arch/powerpc/mm/book3s32/mmu.c

+3 −5
Original line number Diff line number Diff line
@@ -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)