ARM: l2x0/pl310: Refactor Kconfig to be more maintainable

Making CACHE_L2X0 depend on (huge list of MACH_ and ARCH_ configs)
is bothersome to maintain and likely to lead to merge conflicts.

This patch moves the knowledge of which platforms have a L2x0 or
PL310 cache controller to the individual machines.  To enable this,
a new MIGHT_HAVE_CACHE_L2X0 config option is introduced to allow
machines to indicate that they may have such a cache controller
independently of each other.

Boards/SoCs which cannot reliably operate without the L2 cache
controller support will need to select CACHE_L2X0 directly from
their own Kconfigs instead.  This applies to some TrustZone-enabled
boards where Linux runs in the Normal World, for example.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
        (for cns3xxx)
Acked-by: Tony Lindgren <tony@atomide.com>
        (for omap)
Acked-by: Shawn Guo <shawn.guo@linaro.org>
        (for imx)
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
        (for exynos)
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
        (for imx)
Acked-by: Olof Johansson <olof@lixom.net>
        (for tegra)

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 0074b8dba793d6b9c54cd0869ab7f40535f7e07d..acb1c36adaddd37dbf54b4fbdb40ac35f867b16e 100644 (file)
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -816,13 +816,23 @@ config CACHE_FEROCEON_L2_WRITETHROUGH
          Say Y here to use the Feroceon L2 cache in writethrough mode.
          Unless you specifically require this, say N for writeback mode.
 
+config MIGHT_HAVE_CACHE_L2X0
+       bool
+       help
+         This option should be selected by machines which have a L2x0
+         or PL310 cache controller, but where its use is optional.
+
+         The only effect of this option is to make CACHE_L2X0 and
+         related options available to the user for configuration.
+
+         Boards or SoCs which always require the cache controller
+         support to be present should select CACHE_L2X0 directly
+         instead of this option, thus preventing the user from
+         inadvertently configuring a broken kernel.
+
 config CACHE_L2X0
-       bool "Enable the L2x0 outer cache controller"
-       depends on REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || MACH_REALVIEW_PB1176 || \
-                  REALVIEW_EB_A9MP || SOC_IMX35 || SOC_IMX31 || MACH_REALVIEW_PBX || \
-                  ARCH_NOMADIK || ARCH_OMAP4 || ARCH_EXYNOS4 || ARCH_TEGRA || \
-                  ARCH_U8500 || ARCH_VEXPRESS_CA9X4 || ARCH_SHMOBILE
-       default y
+       bool "Enable the L2x0 outer cache controller" if MIGHT_HAVE_CACHE_L2X0
+       default MIGHT_HAVE_CACHE_L2X0
        select OUTER_CACHE
        select OUTER_CACHE_SYNC
        help