Now that modules exec page tables are preallocated, the instruction
TLBmiss handler can use task PGDIR inconditionally.
Also revise the identification of user vs kernel user space by doing
a calculation instead of a comparison: Get the segment number and
subtract the number of the first kernel segment. The result is
positive for kernel addresses and negative for user addresses,
which means that upper 2 bits are 0 for kernel and 3 for user.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_book3s_32.S | 17 +++++------------
1 file changed, 5 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 7995506e7fbd..156304c00ece 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -413,22 +413,15 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
InstructionTLBMiss:
/* Get PTE (linux-style) and check access */
mfspr r0,SPRN_IMISS
-#ifdef CONFIG_EXECMEM
- lis r1, TASK_SIZE@h /* check if kernel address */
- cmplw 0,r1,r0
-#endif
mfspr r2, SPRN_SDR1
li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
rlwinm r2, r2, 28, 0xfffff000
+ rlwimi r2,r0,12,20,29 /* insert top 10 bits of address */
+ lwz r2,0(r2) /* get pmd entry */
#ifdef CONFIG_EXECMEM
- li r3, 3
- bgt- 112f
- lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */
- li r3, 0
- addi r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */
+ rlwinm r3, r0, 4, 0xf
+ subi r3, r3, (TASK_SIZE >> 28) & 0xf
#endif
-112: rlwimi r2,r0,12,20,29 /* insert top 10 bits of address */
- lwz r2,0(r2) /* get pmd entry */
rlwinm. r2,r2,0,0,19 /* extract address of pte page */
beq- InstructionAddressInvalid /* return if no mapping */
rlwimi r2,r0,22,20,29 /* insert next 10 bits of address */
@@ -437,7 +430,7 @@ InstructionTLBMiss:
bne- InstructionAddressInvalid /* return if access not permitted */
/* Convert linux-style PTE to low word of PPC-style PTE */
#ifdef CONFIG_EXECMEM
- rlwimi r2, r3, 0, 31, 31 /* userspace ? -> PP lsb */
+ rlwimi r2, r3, 1, 31, 31 /* userspace ? -> PP lsb */
#endif
ori r1, r1, 0xe06 /* clear out reserved bits */
andc r1, r2, r1 /* PP = user? 1 : 0 */
--
2.44.0