[PATCH 2/2] ARM: include: asm: use 'int' instead of 'unsigned long' for normal register variables within atomic.h

[Will Deacon]

On Tue, Oct 08, 2013 at 12:29:14PM +0100, Chen Gang wrote:
> On 10/08/2013 06:33 PM, Will Deacon wrote:
> > On Sat, Oct 05, 2013 at 12:55:18AM +0100, Chen Gang wrote:
> >> Hmm... in my opinion, we need divide atomic_*_mask() into 32-bit and
> >> 64-bit versions. We already have demands to only use 32-bit value to
> >> express mask (can save size), and may have demands to use 64-bit too.
> > 
> > Right, but isn't this code only used by that s390 SCSI driver? Why do other
> > architectures even need to bother implementing it?
> > 
> Hmm... for atomic_set_mask(), "drivers/gpu/drm/i915/i915_irq.c" also
> uses it (it is about Intel Graphics).

I don't think we care too much about the Intel graphics driver on ARM at the
moment.

> For some architectures (e.g. frv, mn10300, mr32r, blackfin, and of cause
> s390), still use atomic_[set/clear]_mask().

We don't care about those either.

> And they are inline functions in atomic.h, individual kernel modules may
> use them (which source code is not merged into kernel). Can we skip
> these individual modules? (I guess we can, but need think of carefully).

or those. If somebody starts complaining, then we can add things back.

> >> And also, excuse me, I am not quite familiar with "exclusive monitor",
> >> could you please provide more details about it?
> > 
> > You'll need to take a look at the ARM ARM, in particular the section about
> > `Synchronisation and Semaphores'.
> > 
> 
> Do you mean "ARM ARM" is a book name? (at least, I really need read more
> things to familiar with ARM)

Yes, the hilariouly titled "ARM Architecture Reference Manual". You can find
it on arm.com, but you have to register:

ARMv7: https://silver.arm.com/download/download.tm?pv=1299246
ARMv8 (beta): https://silver.arm.com/download/download.tm?pv=1448511

Enjoy!

Will