Russell King <[email protected]> wrote:
> These are the constant versions, where the compiler can optimise the
> mask and word offset itself.
So my inclusion of ARM is correct... Under some circumstances it will write
to the target word when it wouldn't actually make a change:
static inline int
____atomic_test_and_set_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
raw_local_irq_save(flags);
res = *p;
*p = res | mask;
raw_local_irq_restore(flags);
return res & mask;
}
Remember: *p is volatile.
David
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