When scheduling an mm on a CPU where it hasn't previously been used, we
flush the icache on that CPU so that any code loaded previously on
a different core can be safely executed.

For cores with hardware broadcasting of cache maintenance operations,
this is clearly unnecessary, since the inner-shareable invalidation in
__sync_icache_dcache will affect all CPUs.

This patch conditionalises the icache flush in switch_mm based on
cache_ops_need_broadcast().

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Albin Tonnerre <albin.tonnerre@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>