From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: linuxppc-dev@lists.ozlabs.org
Cc: aneesh.kumar@linux.vnet.ibm.com,
Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: [PATCH 02/24] powerpc/mm: Pre-filter SRR1 bits before do_page_fault()
Date: Wed, 19 Jul 2017 14:49:24 +1000 [thread overview]
Message-ID: <20170719044946.22030-2-benh@kernel.crashing.org> (raw)
In-Reply-To: <20170719044946.22030-1-benh@kernel.crashing.org>
By filtering the relevant SRR1 bits in the assembly rather than
in do_page_fault() itself, we avoid a conditional branch (since we
already come from different path for data and instruction faults).
This will allow more simplifications later
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
arch/powerpc/kernel/head_32.S | 2 +-
arch/powerpc/kernel/head_8xx.S | 4 ++--
arch/powerpc/mm/fault.c | 14 ++------------
3 files changed, 5 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index a5301248b098..f11d1cd6e314 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -409,7 +409,7 @@ InstructionAccess:
mr r4,r12 /* SRR0 is fault address */
bl hash_page
1: mr r4,r12
- mr r5,r9
+ andis. r5,r9,0x4820 /* Filter relevant SRR1 bits */
EXC_XFER_LITE(0x400, handle_page_fault)
/* External interrupt */
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index c032fe8c2d26..da3afa2c1658 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -569,8 +569,8 @@ _ENTRY(DTLBMiss_jmp)
InstructionTLBError:
EXCEPTION_PROLOG
mr r4,r12
- mr r5,r9
- andis. r10,r5,0x4000
+ andis. r5,r9,0x4820 /* Filter relevant SRR1 bits */
+ andis. r10,r9,0x4000
beq+ 1f
tlbie r4
itlbie:
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index faddc87d0205..f04bc9f6b134 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -203,23 +203,13 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
int code = SEGV_MAPERR;
int is_write = 0;
- int trap = TRAP(regs);
- int is_exec = trap == 0x400;
+ int is_exec = TRAP(regs) == 0x400;
int is_user = user_mode(regs);
int fault;
int rc = 0, store_update_sp = 0;
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
- /*
- * Fortunately the bit assignments in SRR1 for an instruction
- * fault and DSISR for a data fault are mostly the same for the
- * bits we are interested in. But there are some bits which
- * indicate errors in DSISR but can validly be set in SRR1.
- */
- if (is_exec)
- error_code &= 0x48200000;
- else
- is_write = error_code & DSISR_ISSTORE;
+ is_write = error_code & DSISR_ISSTORE;
#else
is_write = error_code & ESR_DST;
#endif /* CONFIG_4xx || CONFIG_BOOKE */
--
2.13.3
next prev parent reply other threads:[~2017-07-19 4:50 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-19 4:49 [PATCH 01/24] powerpc/mm: Move exception_enter/exit to a do_page_fault wrapper Benjamin Herrenschmidt
2017-07-19 4:49 ` Benjamin Herrenschmidt [this message]
2017-07-22 16:43 ` [PATCH 02/24] powerpc/mm: Pre-filter SRR1 bits before do_page_fault() LEROY Christophe
2017-07-23 1:10 ` Benjamin Herrenschmidt
2017-07-24 13:48 ` Michael Ellerman
2017-07-19 4:49 ` [PATCH 03/24] powerpc/6xx: Handle DABR match before calling do_page_fault Benjamin Herrenschmidt
2017-08-03 0:19 ` Michael Ellerman
2017-08-03 1:00 ` Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 04/24] powerpc/mm: Update definitions of DSISR bits Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 05/24] powerpc/mm: Update bits used to skip hash_page Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 06/24] powerpc/mm: Use symbolic constants for filtering SRR1 bits on ISIs Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 07/24] powerpc/mm: Move out definition of CPU specific is_write bits Benjamin Herrenschmidt
2017-07-22 16:40 ` LEROY Christophe
2017-07-23 1:06 ` Benjamin Herrenschmidt
2017-07-24 11:58 ` Michael Ellerman
2017-07-19 4:49 ` [PATCH 08/24] powerpc/mm: Move error_code checks for bad faults earlier Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 09/24] powerpc/mm: Overhaul handling of bad page faults Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 10/24] powerpc/mm: Move debugger check to notify_page_fault() Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 11/24] powerpc/mm: Simplify returns from __do_page_fault Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 12/24] powerpc/mm: Fix reporting of kernel execute faults Benjamin Herrenschmidt
2018-11-07 8:35 ` Christophe LEROY
2018-11-07 10:39 ` Benjamin Herrenschmidt
[not found] ` <87zhtr5d1v.fsf@linux.ibm.com>
2018-11-30 6:08 ` Christophe LEROY
2017-07-19 4:49 ` [PATCH 13/24] powerpc/mm: Make bad_area* helper functions Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 14/24] powerpc/mm: Rework mm_fault_error() Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 15/24] powerpc/mm: Move CMO accounting out of do_page_fault into a helper Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 16/24] powerpc/mm: Cosmetic fix to page fault accounting Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 17/24] powerpc/mm: Move the DSISR_PROTFAULT sanity check Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 18/24] powerpc/mm: Move/simplify faulthandler_disabled() and !mm check Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 19/24] powerpc/mm: Add a bunch of (un)likely annotations to do_page_fault Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 20/24] powerpc/mm: Set fault flags earlier Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 21/24] powerpc/mm: Move page fault VMA access checks to a helper Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 22/24] powerpc/mm: Don't lose "major" fault indication on retry Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 23/24] powerpc/mm: Cleanup check for stack expansion Benjamin Herrenschmidt
2017-07-21 16:59 ` LEROY Christophe
2017-07-24 10:47 ` Michael Ellerman
2017-07-24 17:34 ` LEROY Christophe
2017-07-25 11:19 ` Michael Ellerman
2017-07-31 11:37 ` Christophe LEROY
2017-07-19 4:49 ` [PATCH 24/24] powerpc: Remove old unused icswx based coprocessor support Benjamin Herrenschmidt
2017-08-07 10:41 ` [01/24] powerpc/mm: Move exception_enter/exit to a do_page_fault wrapper Michael Ellerman
2017-08-07 16:37 ` Christophe LEROY
2017-08-08 2:16 ` Michael Ellerman
2017-08-08 6:45 ` Christophe LEROY
2017-08-08 10:00 ` Michael Ellerman
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