From 312df4186ad8f7e135ea29e911c9d37a1915494f Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Wed, 19 Jul 2017 14:49:27 +1000
Subject: [PATCH 03/45] powerpc/mm: Update bits used to skip hash_page
References: FATE#322447, bsc#1078248
Patch-mainline: v4.14-rc1
Git-commit: 398a719d34a1b65f9fb1e26f999c197a1446ce48
We test a number of bits from DSISR/SRR1 before deciding
to call hash_page(). If any of these is set, we go directly
to do_page_fault() as the bit indicate a fault that needs
to be handled there (no hashing needed).
This updates the current open-coded masks to use the new
DSISR definitions.
This *does* change the masks actually used in two ways:
- We used to test various bits that were defined as "always 0"
in the architecture and could be repurposed for something
else. From now on, we just ignore such bits.
- We were missing some new bits defined on P9
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kernel/exceptions-64s.S | 6 ++++--
arch/powerpc/kernel/head_32.S | 2 +-
2 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 8fbf009ff216..b26940e8a94a 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1609,8 +1609,10 @@ USE_TEXT_SECTION()
*/
.balign IFETCH_ALIGN_BYTES
do_hash_page:
-#ifdef CONFIG_PPC_STD_MMU_64
- andis. r0,r4,0xa450 /* weird error? */
+ #ifdef CONFIG_PPC_STD_MMU_64
+ lis r0,DSISR_BAD_FAULT_64S@h
+ ori r0,r0,DSISR_BAD_FAULT_64S@l
+ and. r0,r4,r0 /* weird error? */
bne- handle_page_fault /* if not, try to insert a HPTE */
CURRENT_THREAD_INFO(r11, r1)
lwz r0,TI_PREEMPT(r11) /* If we're in an "NMI" */
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index e22734278458..a43f0a5c5f45 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -388,7 +388,7 @@ DataAccess:
EXCEPTION_PROLOG
mfspr r10,SPRN_DSISR
stw r10,_DSISR(r11)
- andis. r0,r10,0xa470 /* weird error? */
+ andis. r0,r10,DSISR_BAD_FAULT_32S@h
bne 1f /* if not, try to put a PTE */
mfspr r4,SPRN_DAR /* into the hash table */
rlwinm r3,r10,32-15,21,21 /* DSISR_STORE -> _PAGE_RW */
--
2.13.6