lkml.org 
[lkml]   [2012]   [Feb]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[ 19/72] ARM: 7325/1: fix v7 boot with lockdep enabled
3.2-stable review patch.  If anyone has any objections, please let me know.

------------------
From: Rabin Vincent <rabin@rab.in>

commit 8e43a905dd574f54c5715d978318290ceafbe275 upstream.

Bootup with lockdep enabled has been broken on v7 since b46c0f74657d
("ARM: 7321/1: cache-v7: Disable preemption when reading CCSIDR").

This is because v7_setup (which is called very early during boot) calls
v7_flush_dcache_all, and the save_and_disable_irqs added by that patch
ends up attempting to call into lockdep C code (trace_hardirqs_off())
when we are in no position to execute it (no stack, MMU off).

Fix this by using a notrace variant of save_and_disable_irqs. The code
already uses the notrace variant of restore_irqs.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/arm/include/asm/assembler.h | 5 +++++
arch/arm/mm/cache-v7.S | 2 +-
2 files changed, 6 insertions(+), 1 deletion(-)
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -137,6 +137,11 @@
disable_irq
.endm

+ .macro save_and_disable_irqs_notrace, oldcpsr
+ mrs \oldcpsr, cpsr
+ disable_irq_notrace
+ .endm
+
/*
* Restore interrupt state previously stored in a register. We don't
* guarantee that this will preserve the flags.
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -55,7 +55,7 @@ loop1:
cmp r1, #2 @ see what cache we have at this level
blt skip @ skip if no cache, or just i-cache
#ifdef CONFIG_PREEMPT
- save_and_disable_irqs r9 @ make cssr&csidr read atomic
+ save_and_disable_irqs_notrace r9 @ make cssr&csidr read atomic
#endif
mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
isb @ isb to sych the new cssr&csidr



\
 
 \ /
  Last update: 2012-02-28 02:27    [from the cache]
©2003-2011 Jasper Spaans