arm64: mm: Make icache synchronisation logic huge page aware

arm64: mm: Make icache synchronisation logic huge page aware

The __sync_icache_dcache routine will only flush the dcache for the
first page of a compound page, potentially leading to stale icache
data residing further on in a hugetlb page.

This patch addresses this issue by taking into consideration the
order of the page when flushing the dcache.

Reported-by: Mark Brown <[email protected]>
Tested-by: Mark Brown <[email protected]>
Signed-off-by: Steve Capper <[email protected]>
Acked-by: Will Deacon <[email protected]>
Signed-off-by: Catalin Marinas <[email protected]>
Cc: <[email protected]> # v3.11+