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)

1 files changed, 16 insertions, 7 deletions

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 67f75a0b66d6..acb1c36adadd 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -816,14 +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 || ARCH_IMX_V6_V7 || MACH_REALVIEW_PBX || \
-                   ARCH_NOMADIK || ARCH_OMAP4 || ARCH_EXYNOS4 || ARCH_TEGRA || \
-                   ARCH_U8500 || ARCH_VEXPRESS_CA9X4 || ARCH_SHMOBILE || \
-                   ARCH_PRIMA2 || ARCH_ZYNQ || ARCH_CNS3XXX || ARCH_HIGHBANK
-        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