On 09/26/2013 12:07 AM, Will Deacon wrote:

On Wed, Sep 25, 2013 at 03:25:19AM +0100, Chen Gang wrote:

quoted

atomic* value is signed value, and atomic* functions need also process
signed value (parameter value, and return value), so 32-bit arm need
use 'long long' instead of 'u64'.

After replacement, it will also fix a bug for atomic64_add_negative():
"u64 is never less than 0".

The modifications are:

  in vim, use "1,% s/\<u64\>/long long/g" command.
  remove '__aligned(8)' which is useless for 64-bit.
  be sure of 80 column limitation after replacement.


Signed-off-by: Chen Gang <redacted>

Looks better to me, thanks. While you're here, we could also replace the use
of `unsigned long' with `int' for the 32-bit atomics, then the whole header
is consistent with the generic types.

Will

Hmm... at least, it seems we can let "use 'int' for 32-bit atomics" in
another patch.


Firstly, this 'fix' is not belong to API, and either, it has no related
'standard' 'demo' in "asm-generic/" (it is architecture independent, so
no related inline assembly code).

After a random check, another 3 architectures (maybe more) are also may
using 'unsigned long': "arm64/include/asm/atomic.h",
"sh/include/asm/atomic-llsc.h", and "xtensa/include/asm/atomic.h".

And as far as I know, for a register related variable, 'unsigned long'
is also a common using way for both 32-bit and 64-bit (at least, it is a
simple way to prevent issues).


Thanks.
-- 
Chen Gang