[PATCH v3 RESEND 05/17] ARM: LPAE: support 64-bit virt_to_phys patching

Catalin Marinas catalin.marinas at arm.com
Mon Sep 24 11:13:05 EDT 2012

On Fri, Sep 21, 2012 at 04:56:03PM +0100, Cyril Chemparathy wrote:
> This patch adds support for 64-bit physical addresses in virt_to_phys()
> patching.  This does not do real 64-bit add/sub, but instead patches in the
> upper 32-bits of the phys_offset directly into the output of virt_to_phys.

So this assumes that for the kernel linear mapping, all the physical
addresses have the same upper 32-bit. That's a good optimisation but I
haven't seen this check when calculating lowmem in sanity_check_meminfo.
Someone may build platform with memory starting at 3GB and going across
the 4GB limit.


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