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powerpc/32: Set an IBAT covering up to _einittext during init

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Always set an IBAT covering up to _einittext during init because when
CONFIG_MODULES is not selected there is no reason to have an exception
handler for kernel instruction TLB misses.

It implies DBAT and IBAT are now totaly independent, IBATs are set
by setibat() and DBAT by setbat().

This allows to revert commit 9bb162fa26 ("powerpc/603: Fix
boot failure with DEBUG_PAGEALLOC and KFENCE")

Reported-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ce7f04a39593934d9b1ee68c69144ccd3d4da4a1.1655202804.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2022-06-14 12:34:09 +02:00 committed by Michael Ellerman
parent 980bbf7ca7
commit 2a0fb3c155
2 changed files with 6 additions and 8 deletions
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4
arch/powerpc/kernel/head_book3s_32.S
View File

@ -418,14 +418,14 @@ InstructionTLBMiss:
*/
/* Get PTE (linux-style) and check access */
mfspr r3,SPRN_IMISS
#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
#ifdef CONFIG_MODULES
lis r1, TASK_SIZE@h /* check if kernel address */
cmplw 0,r1,r3
#endif
mfspr r2, SPRN_SDR1
li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC | _PAGE_USER
rlwinm r2, r2, 28, 0xfffff000
#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
#ifdef CONFIG_MODULES
bgt- 112f
lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */
li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC

10
arch/powerpc/mm/book3s32/mmu.c
View File

@ -159,7 +159,10 @@ unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
{
unsigned long done;
unsigned long border = (unsigned long)__init_begin - PAGE_OFFSET;
unsigned long size;
size = roundup_pow_of_two((unsigned long)_einittext - PAGE_OFFSET);
setibat(0, PAGE_OFFSET, 0, size, PAGE_KERNEL_X);
if (debug_pagealloc_enabled_or_kfence()) {
pr_debug_once("Read-Write memory mapped without BATs\n");
@ -245,10 +248,9 @@ void mmu_mark_rodata_ro(void)
}
/*
* Set up one of the I/D BAT (block address translation) register pairs.
* Set up one of the D BAT (block address translation) register pairs.
* The parameters are not checked; in particular size must be a power
* of 2 between 128k and 256M.
* On 603+, only set IBAT when _PAGE_EXEC is set
*/
void __init setbat(int index, unsigned long virt, phys_addr_t phys,
unsigned int size, pgprot_t prot)
@ -284,10 +286,6 @@ void __init setbat(int index, unsigned long virt, phys_addr_t phys,
/* G bit must be zero in IBATs */
flags &= ~_PAGE_EXEC;
}
if (flags & _PAGE_EXEC)
bat[0] = bat[1];
else
bat[0].batu = bat[0].batl = 0;
bat_addrs[index].start = virt;
bat_addrs[index].limit = virt + ((bl + 1) << 17) - 1;