linux hardware spinlock framework for heterogeneous processor SOCs?

linux hardware spinlock framework for heterogeneous processor SOCs?

[Nishanth Menon]

Changing subject, the original thread is at [1], looping in lkml for a 
wider audience for advice.

Que, Simon had written, on 08/11/2010 05:03 PM, the following:
>> just a curious question:
>>
>> Is there no h/w spinlock implementation for other architectures in
>> linux? I mean the concept does not seem unique for a heterogenous
>> processor environments now a days.. if it does exist, maybe we have two
>> options:
>> * extend standard spinlock architecture to handle h/w spinlocks as well
>> * establish a new framework for h/w spinlocks..
>>
> 
> Thank you for bringing that to my attention.  I did a quick search and
 > haven't found any hwspinlock module elsewhere.  But should there be
 > hwspinlocks over multiple architectures in the future, we can definitely
 > consider something like the two solutions that you suggested, so that
 > they can be used from platform-independent kernel code.  However, right
 > now we can develop OMAP hwspinlock independently of that.

I did glance through the kernel commit log, and nothing remotely seems 
to match up at least in my opinion (closest seemed to be [2] 
drivers/gpu/drm/ - but it did not seem relevant here). If this concept 
is unique to OMAP family alone, then I guess it makes sense to introduce 
SOC specific API library for usage. hoping for some suggestions to 
enlighten us.

Ref:
[1] http://marc.info/?t=127955774200003&r=1&w=2
[2] http://dri.sourceforge.net/doc/hardware_locking_low_level.html

-- 
Regards,
Nishanth Menon