arm: mm: qsd8x50: Fix incorrect permission faults
RFC PATCH 12/12 arm: mm: qsd8x50: Fix incorrect permission faults
From: Dave Estes <[email protected]>
Handle incorrectly reported permission faults for qsd8650. On permission faults, retry MVA to PA conversion. If retry detects translation fault. Report as translation fault.
Cc Jamie Lokier <[email protected]>
Signed-off-by Dave Estes <[email protected]>
Signed-off-by Daniel Walker <[email protected]>
--- arch/arm/mm/Kconfig | 2 ++ arch/arm/mm/abort-ev7.S | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 0 deletions(-)
arch/arm/mm/Kconfig +2 -0
@@ -572,6 +572,8 @@ config CPU_TLB_V6 config CPU_TLB_V7 bool +config VERIFY_PERMISSION_FAULT + bool endif config CPU_HAS_ASID
arch/arm/mm/abort-ev7.S +38 -0
@@ -1,3 +1,20 @@ +/* Copyright (c) 2009, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + #include <linux/linkage.h> #include <asm/assembler.h> /*
@@ -29,5 +46,26 @@ ENTRY(v7_early_abort) * V6 code adjusts the returned DFSR. * New designs should not need to patch up faults. */ + +#if defined(CONFIG_VERIFY_PERMISSION_FAULT) + /* + * Detect erroneous permission failures and fix + */ + ldr r3, =0x40d @ On permission fault + and r3, r1, r3 + cmp r3, #0x0d + movne pc, lr + + mcr p15, 0, r0, c7, c8, 0 @ Retranslate FAR + isb + mrc p15, 0, r2, c7, c4, 0 @ Read the PAR + and r3, r2, #0x7b @ On translation fault + cmp r3, #0x0b + movne pc, lr + bic r1, r1, #0xf @ Fix up FSR FS[5:0] + and r2, r2, #0x7e + orr r1, r1, r2, LSR #1 +#endif + mov pc, lr ENDPROC(v7_early_abort)
Signature · 1 line
1.6.3.3
RFC PATCH 12/12 arm: mm: qsd8x50: Fix incorrect permission faults
Quoted 5 lines
From: Dave Estes <[email protected]>
Handle incorrectly reported permission faults for qsd8650. On permission faults, retry MVA to PA conversion. If retry detects translation fault. Report as translation fault.
...
Quoted 16 lines
arch/arm/mm/abort-ev7.S +12
-0@@ -29,5 +46,26 @@ ENTRY(v7_early_abort) * V6 code adjusts the returned DFSR. * New designs should not need to patch up faults. */ + +#if defined(CONFIG_VERIFY_PERMISSION_FAULT) + /* + * Detect erroneous permission failures and fix + */ + ldr r3, =0x40d @ On permission fault + and r3, r1, r3 + cmp r3, #0x0d + movne pc, lr + + mcr p15, 0, r0, c7, c8, 0 @ Retranslate FAR + isb
arch/arm/mm/abort-ev7.S ENTRY(v7_early_abort) · line 70
Quoted 10 lines
arch/arm/mm/abort-ev7.S +9
-0+ mrc p15, 0, r2, c7, c4, 0 @ Read the PAR + and r3, r2, #0x7b @ On translation fault + cmp r3, #0x0b + movne pc, lr + bic r1, r1, #0xf @ Fix up FSR FS[5:0] + and r2, r2, #0x7e + orr r1, r1, r2, LSR #1 +#endif + mov pc, lr
So you are working around qsd8650 hardware bug? That should probably go to the comment here.
Pavel
Signature · 2 lines
(english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html