Re: [PATCH 3/3] WorkStruct: Use direct assignment rather than cmpxchg()

[David Howells <dhowells@redhat.com>]

Russell King <rmk+lkml@arm.linux.org.uk> wrote:

> Incorrect.  pre-v6 ARM bitops for test_and_xxx_bit() all do:
> 
> 	save and disable irqs
> 	load value
> 	test bit
> 	if not in desired state, alter bit and write it back
> 	restore irqs

Hmmm...  ARM has two implementations.  One in the header files which is what I
consulted when writing that email:

static inline void ____atomic_set_bit(unsigned int bit, volatile unsigned long *p)
{
	unsigned long flags;
	unsigned long mask = 1UL << (bit & 31);

	p += bit >> 5;

	raw_local_irq_save(flags);
	*p |= mask;
	raw_local_irq_restore(flags);
}

And the other in the libs which does as you say.  Why the one in the header
file at all?

David