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author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-06-17 17:43:59 +0000 |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-06-26 14:37:27 +1000 |
commit | 5d38902c483881645ba16058cffaa478b81e5cfa (patch) | |
tree | 1ed21b6a245c772a6d86cac7cd8ebe566dd970bb /arch/powerpc/kernel/setup_32.c | |
parent | 04a85d1234d7e1682a612565e663e6b760918643 (diff) | |
download | linux-5d38902c483881645ba16058cffaa478b81e5cfa.tar.bz2 |
powerpc: Add irqtrace support for 32-bit powerpc
Based on initial work from: Dale Farnsworth <dale@farnsworth.org>
Add the low level irq tracing hooks for 32-bit powerpc needed
to enable full lockdep functionality.
The approach taken to deal with the code in entry_32.S is that
we don't trace all the transitions of MSR:EE when we just turn
it off to peek at TI_FLAGS without races. Only when we are
calling into C code or returning from exceptions with a state
that have changed from what lockdep thinks.
There's a little bugger though: If we take an exception that
keeps interrupts enabled (such as an alignment exception) while
interrupts are enabled, we will call trace_hardirqs_on() on the
way back spurriously. Not a big deal, but to get rid of it would
require remembering in pt_regs that the exception was one of the
type that kept interrupts enabled which we don't know at this
stage. (Well, we could test all cases for regs->trap but that
sucks too much).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/setup_32.c')
-rw-r--r-- | arch/powerpc/kernel/setup_32.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c index 1d154248cf40..e1e3059cf34b 100644 --- a/arch/powerpc/kernel/setup_32.c +++ b/arch/powerpc/kernel/setup_32.c @@ -119,6 +119,8 @@ notrace unsigned long __init early_init(unsigned long dt_ptr) */ notrace void __init machine_init(unsigned long dt_ptr) { + lockdep_init(); + /* Enable early debugging if any specified (see udbg.h) */ udbg_early_init(); |