ARM: cache: do not crash when the MMU isn't yet setup

Drivers currently cannot implement explicit cache handling and rely on
running the same code before and after mmu_initcall() without crashing.

Depending on the chosen config options, the cache functions are not yet
setup and using them early on ends in a null pointer dereference.

The RPi's mailbox driver is such a case; it requires cache handling once
the MMU is fully set up and yet the RPi setup needs to use the driver to
get the memory size before mem_initcall() and hence mmu_initcall().

Fix this by checking the cache_fns pointer before dereferencing it.

Signed-off-by: Andre Heider <a.heider@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

0 files changed, 0 insertions, 0 deletions