On 07/12/2013 11:57 AM, Benjamin Herrenschmidt wrote:
On Fri, 2013-07-12 at 10:13 +0800, tiejun.chen wrote:
#define hard_irq_disable() do { \
u8 _was_enabled = get_paca()->soft_enabled; \
Current problem I met is issued from the above line.
__hard_irq_disable(); \
- get_paca()->soft_enabled = 0; \
Not here.
If I'm misunderstanding what you guys means, please correct me since this is a
long discussion thread. I have to reread that carefully.
Then make it
u8 _was_enabled;
__hard_irq_disable();
was_enabled = local_paca->....
Once you have hard disabled, using local_paca directly *should* be safe
(minus that gcc problem I mentioned).
Is the following fine?
powerpc: to access local paca after hard irq disabled
We can access paca directly after hard interrupt disabled, and
this can avoid accessing wrong paca when using get_paca() in
preempt case.
Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxxxxxx>
---
arch/powerpc/include/asm/hw_irq.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index ba713f1..10be1dd 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -96,10 +96,11 @@ static inline bool arch_irqs_disabled(void)
#endif
#define hard_irq_disable() do { \
- u8 _was_enabled = get_paca()->soft_enabled; \
+ u8 _was_enabled; \
__hard_irq_disable(); \
- get_paca()->soft_enabled = 0; \
- get_paca()->irq_happened |= PACA_IRQ_HARD_DIS; \
+ _was_enabled = local_paca->soft_enabled; \
+ local_paca->soft_enabled = 0; \
+ local_paca->irq_happened |= PACA_IRQ_HARD_DIS; \
if (_was_enabled) \
trace_hardirqs_off(); \
} while(0)
--
1.7.9.5
Or what about that change to call SOFT_DISABLE_INTS only in KVM scenario? Which
better?
Then I can send to review?
Thanks,
Tiejun
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