12 Mar
2015
12 Mar
'15
3:27 a.m.
On Wed, Mar 11, 2015 at 10:04 PM, Russell King - ARM Linux linux@arm.linux.org.uk wrote:
No, this is wrong. They do not. CMA remaps pages to be non-cacheable rather than the old technique where the above statement was true.
There's some corner cases which make that less effective than it once was, and as I've already said, those need to be fixed. The reason that these were missed is because all the ARM CMA work bypassed me - CMA on ARM has had zero review from the point of view of the ARM architecture, so it's not surprising it gets stuff like this wrong.
Once that's fixed, setting bit 22 is not necessary.
Understood. Thanks for the clarification.