[PATCH 00/22] Introducing the TI Keystone platform

On Sun, Aug 05, 2012 at 04:10:34PM +0100, Cyril Chemparathy wrote:

On 8/4/2012 4:39 AM, Russell King - ARM Linux wrote:

quoted

On Tue, Jul 31, 2012 at 07:04:36PM -0400, Cyril Chemparathy wrote:

quoted

This series is a follow on to the RFC series posted earlier (archived at [1]).
The major change introduced here is the modification to the kernel patching
mechanism for phys_to_virt/virt_to_phys, in order to support LPAE platforms
that require late patching.  In addition to these changes, we've updated the
series based on feedback from the earlier posting.

Most of the patches in this series are fixes and extensions to LPAE support on
ARM. The last three patches in this series are specific to the TI Keystone
platform, and are being provided here for the sake of completeness.  These
three patches are dependent on the smpops patch set (see [2]), and are not
ready to be merged in as yet.

Can you explain why you want the kernel loaded above the 4GB watermark?
This seems silly to me, as the kernel needs to run at points with a 1:1
physical to virtual mapping, and you can't do that if the kernel is
stored in physical memory above the 4GB watermark.

[...]

We are well aware of the fact that we are barely scratching the surface 
of the problem space here, and we'd be very thankful for a heads up on 
issues that we may have missed so far.

Another thing to be aware is that apart from a virtual alias between the
kernel mapping and the idmap, you now introduce a physical alias as well
and the caches (physically tagged) get confused.

-- 
Catalin