exynos: Reinit the L2 cache settings right before jumping to kernel

We've tweaked some L2 cache settings recently which means that RO
U-Boot and RW U-Boot might have different ideas for what the proper
settings are.  The RO settings that we have appear to be good enough
for running U-Boot but they can cause problems for the kernel.
Unfortunately it's not easy for the kernel to reconfigure these
settings since the L2 cache is turned on REALLY early in the kernel
(before it knows anything about what board it's on).  ...and you're
not supposed to change the settings while the L2 cache is in use.

We'll be nice to the kernel and set the L2 cache settings after we've
turned off the cache but before we jump to the kernel.

NOTE: the kernel will still have to have some smarts, since the RO
U-Boot will still be in charge of cache settings when bringing up
secondary CPUs and when coming out of sleep.  It will presumably save
the cache settings of the boot CPU and apply them elsewhere.

BUG=chromium:384034
TEST=Use this as an RW update and see cache settings get updated.

Change-Id: Ifa65bc822c075963f8e3276c714ed0ee5647f950
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/203567
Reviewed-by: Simon Glass <sjg@chromium.org>
1 file changed