linux/arch/sh/include/asm/atomic-irq.h
Matt Fleming 0c50f6f383 sh: Make the atomic functions safe for irqsoff tracing
The irqsoff tracer uses the atomic_* functions internally, but the
implementations of those functions in arch/sh/include/asm/atomic-irq.h
disable irqs to achieve atomicity. A continuous loop ensues where we
disable interrupts, trace the interrupt disabling, call atomic_*
functions, disable interrupts, trace the interrupt disabling, etc..

The simplest solution to all this is to just convert uses of
local_irq_save()/local_irq_restore() the raw_* equivalents because the
raw_* equivalents don't call trace_hardirqs_on()/trace_hardirqs_off().

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-06-15 00:31:17 +09:00

72 lines
1.3 KiB
C

#ifndef __ASM_SH_ATOMIC_IRQ_H
#define __ASM_SH_ATOMIC_IRQ_H
/*
* To get proper branch prediction for the main line, we must branch
* forward to code at the end of this object's .text section, then
* branch back to restart the operation.
*/
static inline void atomic_add(int i, atomic_t *v)
{
unsigned long flags;
raw_local_irq_save(flags);
v->counter += i;
raw_local_irq_restore(flags);
}
static inline void atomic_sub(int i, atomic_t *v)
{
unsigned long flags;
raw_local_irq_save(flags);
v->counter -= i;
raw_local_irq_restore(flags);
}
static inline int atomic_add_return(int i, atomic_t *v)
{
unsigned long temp, flags;
raw_local_irq_save(flags);
temp = v->counter;
temp += i;
v->counter = temp;
raw_local_irq_restore(flags);
return temp;
}
static inline int atomic_sub_return(int i, atomic_t *v)
{
unsigned long temp, flags;
raw_local_irq_save(flags);
temp = v->counter;
temp -= i;
v->counter = temp;
raw_local_irq_restore(flags);
return temp;
}
static inline void atomic_clear_mask(unsigned int mask, atomic_t *v)
{
unsigned long flags;
raw_local_irq_save(flags);
v->counter &= ~mask;
raw_local_irq_restore(flags);
}
static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
{
unsigned long flags;
raw_local_irq_save(flags);
v->counter |= mask;
raw_local_irq_restore(flags);
}
#endif /* __ASM_SH_ATOMIC_IRQ_H */