tree 5740df4815666c3920da2fccca790de706b16062
parent c07380beafabee343a7f298bacd22598d72c7c87
author James Hogan <james.hogan@imgtec.com> 1338373403 +0100
committer James Hogan <james.hogan@imgtec.com> 1362254955 +0000

Add HAVE_64BIT_ALIGNED_ACCESS

On 64 bit architectures with no efficient unaligned access, padding and
explicit alignment must be added in various places to prevent unaligned
64bit accesses (such as taskstats and trace ring buffer).

However this also needs to apply to 32 bit architectures with 64 bit
accesses requiring alignment such as metag.

This is solved by adding a new Kconfig symbol HAVE_64BIT_ALIGNED_ACCESS
which defaults to 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS, and can be
explicitly selected by METAG and any other relevant architectures. This
can be used in various places to determine whether 64bit alignment is
required.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Will Drewry <wad@chromium.org>