tree 912270f479798397ecbe45f2972c74f62ebd8748
parent 8945e37e103b165f12c403cc412740718969f811
author David Daney <david.daney@cavium.com> 1425565889 +0300
committer Ralf Baechle <ralf@linux-mips.org> 1427901702 +0200

MIPS: OCTEON: Add semaphore to serialize bootbus accesses.

Some hardware blocks attached to the OCTEON bootbus run asynchronously
to accesses from the CPUs.  These include MMC/SD host, CF(when using
DMA), and NAND controller.  A bus error, or corrupt data may occur if
a CPU is trying to access a bootbus connected device at the same time
the bus is running asynchronous operations.

To work around these problems we add this semaphore that must be
acquired before initiating bootbus activity.  Subsequent patches will
add users for this.

Signed-off-by: David Daney <david.daney@cavium.com>
[aleksey.makarov@auriga.com: combine the patches]
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Signed-off-by: Chandrakala Chavva <cchavva@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9459/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>