Re: [PATCH 03/22] s390: introduce little endian bitops

From: Arnd Bergmann
Date: Fri Oct 15 2010 - 07:12:00 EST


On Friday 15 October 2010, Akinobu Mita wrote:
> +#define __set_le_bit(nr, addr) \
> + __set_bit((nr)^(__BITOPS_WORDSIZE - 8), (addr))
> +#define __clear_le_bit(nr, addr) \
> + __clear_bit((nr)^(__BITOPS_WORDSIZE - 8), (addr))
> +#define __test_and_set_le_bit(nr, addr) \
> + __test_and_set_bit((nr)^(__BITOPS_WORDSIZE - 8), (addr))
> +#define test_and_set_le_bit(lock, nr, addr) \
> + test_and_set_bit((nr)^(__BITOPS_WORDSIZE - 8), (addr))
> +#define __test_and_clear_le_bit(nr, addr) \
> + __test_and_clear_bit((nr)^(__BITOPS_WORDSIZE - 8), (addr))
> +#define test_and_clear_le_bit(lock, nr, addr) \
> + test_and_clear_bit((nr)^(__BITOPS_WORDSIZE - 8), (addr))
> +#define test_le_bit(nr, addr) \
> + test_bit((nr)^(__BITOPS_WORDSIZE - 8), (addr))

The test_and_clear_le_bit and test_and_set_le_bit calling conventions
are a little surprising here. I would not pass the lock argument
here but leave that to the ext2 wrapper:

#define test_and_set_le_bit(nr, addr) \
test_and_set_bit((nr)^(__BITOPS_WORDSIZE - 8), (addr))
#define test_and_clear_le_bit(nr, addr) \
test_and_clear_bit((nr)^(__BITOPS_WORDSIZE - 8), (addr))

#define ext2_set_bit_atomic(lock, nr, addr) \
test_and_set_le_bit((nr), (unsigned long *)(addr))
#define ext2_clear_bit_atomic(lock, nr, addr) \
test_and_clear_le_bit((nr), (unsigned long *)(addr))

Same thing on arm and m68k.

Arnd
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