[PATCH 1/2] arm/mm: L2CC shared mutex with ARM TZ

[Will Deacon]

On Wed, Nov 14, 2012 at 09:18:31AM +0000, Etienne CARRIERE ST wrote:
> This is why the mutex added for TZ shared of L2 cache maintenance is a "arch_spinlock". It assumes linux handles the spinlock as a native ARM native mutex DDR cell, handled from the ARMv7-A LDREX/STREX.
> I think this is the weakest part of the driver since they is no insurance that linux pristine arch_spinlock will not evolve into something else (i.e features in raw_spinclock).

How does this work with our ticket lock approach? Can you swizzle your
locking implementation by inspecting the kernel version of the code running
on the non-secure side? (I sincerely hope not...)

Will