ARM: 6188/1: Add a config option for the ARM11MPCore DMA cache maintenance workaround
authorCatalin Marinas <catalin.marinas@arm.com>
Mon, 21 Jun 2010 14:10:07 +0000 (15:10 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Thu, 1 Jul 2010 09:12:31 +0000 (10:12 +0100)
commitad642d9f58f1af6e96efccb5f84e52c6d01db5c4
tree4319ed1e81f50c7035457cc0fa1cf4bcdf760abb
parentca57926d53580f7c950496cb7ef6d7930610e1dd
ARM: 6188/1: Add a config option for the ARM11MPCore DMA cache maintenance workaround

Commit f4d6477f introduced a workaround for the lack of hardware
broadcasting of the cache maintenance operations on ARM11MPCore.
However, the workaround is only valid on CPUs that do not do speculative
loads into the D-cache.

This patch adds a Kconfig option with the corresponding help to make the
above clear. When the DMA_CACHE_RWFO option is disabled, the kernel
behaviour is that prior to the f4d6477f commit. This also allows ARMv6
UP processors with speculative loads to work correctly.

For other processors, a different workaround may be needed.

Cc: Ronen Shitrit <rshitrit@marvell.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/mm/Kconfig
arch/arm/mm/cache-v6.S