summaryrefslogtreecommitdiff
path: root/arch/powerpc
diff options
context:
space:
mode:
authorChristophe Leroy <christophe.leroy@csgroup.eu>2020-11-25 10:10:49 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2020-12-03 17:01:31 +0300
commit03d701c2d9b0091cf8e96cb49ab7d2a6a9f19937 (patch)
treefb25935d3fff153e31c5c3334badfadec8b72408 /arch/powerpc
parent7b107a71e732c298d684ee1bafd82f1a2be58d5e (diff)
downloadlinux-03d701c2d9b0091cf8e96cb49ab7d2a6a9f19937.tar.xz
powerpc/32s: Don't use SPRN_SPRG_PGDIR in hash_page
SPRN_SPRG_PGDIR is there mainly to speedup SW TLB miss handlers for powerpc 603. We need to free SPRN_SPRG2 to reduce the mess with CONFIG_VMAP_STACK. In hash_page(), reading PGDIR from thread_struct will be in the noise performance wise. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4adca19b7120cdf619956768ed09e74fc6a558f3.1606285014.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/mm/book3s32/hash_low.S9
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index 48415c857d80..aca353d1c5f4 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -65,13 +65,14 @@ _GLOBAL(hash_page)
/* Get PTE (linux-style) and check access */
lis r0, TASK_SIZE@h /* check if kernel address */
cmplw 0,r4,r0
+ mfspr r8,SPRN_SPRG_THREAD /* current task's THREAD (phys) */
ori r3,r3,_PAGE_USER|_PAGE_PRESENT /* test low addresses as user */
- mfspr r5, SPRN_SPRG_PGDIR /* phys page-table root */
+ lwz r5,PGDIR(r8) /* virt page-table root */
blt+ 112f /* assume user more likely */
- lis r5, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */
- addi r5 ,r5 ,(swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */
+ lis r5,swapper_pg_dir@ha /* if kernel address, use */
+ addi r5,r5,swapper_pg_dir@l /* kernel page table */
rlwimi r3,r9,32-12,29,29 /* MSR_PR -> _PAGE_USER */
-112:
+112: tophys(r5, r5)
#ifndef CONFIG_PTE_64BIT
rlwimi r5,r4,12,20,29 /* insert top 10 bits of address */
lwz r8,0(r5) /* get pmd entry */