NVMe: use split lo_hi_{read,write}q

Some controllers may require ordered split transfers even on 64bit
machines, e.g. Apple's NVMe controller as found in the MacBook8,1 and
MacBookAir7,1 (256/512GB models).

This patch enforces ordered split transfers on 64bit platforms, which
works around that issue for all controllers. As pointed out by Christoph
[1] there should be no performance impact due to that modification.

[1] http://lists.infradead.org/pipermail/linux-nvme/2015-November/002965.html

Signed-off-by: Stephan Guenther <[email protected]>
Signed-off-by: Maurice Leclaire <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>

Updated by me to explicitly use lo_hi_read/writeq instead of playing
define tricks.

Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions