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powerpc: Add irqtrace support for 32-bit powerpc

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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>
This commit is contained in:
Benjamin Herrenschmidt 2009-06-17 17:43:59 +00:00
parent 04a85d1234
commit 5d38902c48
4 changed files with 135 additions and 15 deletions
Download patch file Download diff file Expand all files Collapse all files

20
arch/powerpc/include/asm/hw_irq.h
View file

@ -68,13 +68,13 @@ static inline int irqs_disabled_flags(unsigned long flags)
#if defined(CONFIG_BOOKE)
#define SET_MSR_EE(x) mtmsr(x)
#define local_irq_restore(flags) __asm__ __volatile__("wrtee %0" : : "r" (flags) : "memory")
#define raw_local_irq_restore(flags) __asm__ __volatile__("wrtee %0" : : "r" (flags) : "memory")
#else
#define SET_MSR_EE(x) mtmsr(x)
#define local_irq_restore(flags) mtmsr(flags)
#define raw_local_irq_restore(flags) mtmsr(flags)
#endif
static inline void local_irq_disable(void)
static inline void raw_local_irq_disable(void)
{
#ifdef CONFIG_BOOKE
__asm__ __volatile__("wrteei 0": : :"memory");
@ -86,7 +86,7 @@ static inline void local_irq_disable(void)
#endif
}
static inline void local_irq_enable(void)
static inline void raw_local_irq_enable(void)
{
#ifdef CONFIG_BOOKE
__asm__ __volatile__("wrteei 1": : :"memory");
@ -98,7 +98,7 @@ static inline void local_irq_enable(void)
#endif
}
static inline void local_irq_save_ptr(unsigned long *flags)
static inline void raw_local_irq_save_ptr(unsigned long *flags)
{
unsigned long msr;
msr = mfmsr();
@ -110,12 +110,12 @@ static inline void local_irq_save_ptr(unsigned long *flags)
#endif
}
#define local_save_flags(flags) ((flags) = mfmsr())
#define local_irq_save(flags) local_irq_save_ptr(&flags)
#define irqs_disabled() ((mfmsr() & MSR_EE) == 0)
#define raw_local_save_flags(flags) ((flags) = mfmsr())
#define raw_local_irq_save(flags) raw_local_irq_save_ptr(&flags)
#define raw_irqs_disabled() ((mfmsr() & MSR_EE) == 0)
#define raw_irqs_disabled_flags(flags) (((flags) & MSR_EE) == 0)
#define hard_irq_enable() local_irq_enable()
#define hard_irq_disable() local_irq_disable()
#define hard_irq_disable() raw_local_irq_disable()
static inline int irqs_disabled_flags(unsigned long flags)
{