Re: [parisc-linux] Untested port of parisc_device to generic device

[J.E.J. Bottomley]

[e-mail] said:
> 
> 	I'd like to know more about what these machines look like in the real
> world.  Specifically, I am interested in the trade-off of having a
> parameter to wback_fake_consistent so that it could be enabled or
> disabled on an individual basis.

Actually, so would I.  I can suspect why there might exist machines like this 
(say the consistent attribute is settable at the pgd level)

> 	I suspect that the parameter is not worth the clutter because these
> "partially consistent" machines either have a large amount of
> consistent memory, so the case of the allocation failing in the is not
> worth supporting, or it is easy to check for consistent memory on them
> with something like "if ((unsigned long) vaddr < 0xwhatever)", but I'm
> just guessing. 

Well, if it has to be done, it can be done by making alloc_consistent return a 
handle rather than an address and making wback/invalidate take the handle (but 
it's certainly not ideal).

James