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)

7 files changed, 33 insertions, 7 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 44789eff983f..16a4b9e689be 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -344,6 +344,7 @@ config ARCH_HIGHBANK
         select CPU_V7
         select GENERIC_CLOCKEVENTS
         select HAVE_ARM_SCU
+        select MIGHT_HAVE_CACHE_L2X0
         select USE_OF
         help
           Support for the Calxeda Highbank SoC based boards.
@@ -361,6 +362,7 @@ config ARCH_CNS3XXX
         select CPU_V6K
         select GENERIC_CLOCKEVENTS
         select ARM_GIC
+        select MIGHT_HAVE_CACHE_L2X0
         select MIGHT_HAVE_PCI
         select PCI_DOMAINS if PCI
         help
@@ -381,6 +383,7 @@ config ARCH_PRIMA2
         select GENERIC_CLOCKEVENTS
         select CLKDEV_LOOKUP
         select GENERIC_IRQ_CHIP
+        select MIGHT_HAVE_CACHE_L2X0
         select USE_OF
         select ZONE_DMA
         help
@@ -633,6 +636,7 @@ config ARCH_TEGRA
         select GENERIC_GPIO
         select HAVE_CLK
         select HAVE_SCHED_CLOCK
+        select MIGHT_HAVE_CACHE_L2X0
         select ARCH_HAS_CPUFREQ
         help
           This enables support for NVIDIA Tegra based systems (Tegra APX,
@@ -703,6 +707,7 @@ config ARCH_SHMOBILE
         select CLKDEV_LOOKUP
         select HAVE_MACH_CLKDEV
         select GENERIC_CLOCKEVENTS
+        select MIGHT_HAVE_CACHE_L2X0
         select NO_IOPORT
         select SPARSE_IRQ
         select MULTI_IRQ_HANDLER
@@ -904,6 +909,7 @@ config ARCH_U8500
         select CLKDEV_LOOKUP
         select ARCH_REQUIRE_GPIOLIB
         select ARCH_HAS_CPUFREQ
+        select MIGHT_HAVE_CACHE_L2X0
         help
           Support for ST-Ericsson's Ux500 architecture
 
@@ -914,6 +920,7 @@ config ARCH_NOMADIK
         select CPU_ARM926T
         select CLKDEV_LOOKUP
         select GENERIC_CLOCKEVENTS
+        select MIGHT_HAVE_CACHE_L2X0
         select ARCH_REQUIRE_GPIOLIB
         help
           Support for the Nomadik platform by ST-Ericsson
@@ -973,6 +980,7 @@ config ARCH_ZYNQ
         select ARM_GIC
         select ARM_AMBA
         select ICST
+        select MIGHT_HAVE_CACHE_L2X0
         select USE_OF
         help
           Support for Xilinx Zynq ARM Cortex A9 Platform
diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
index 724ec0f3560d..7f2347bd6ccc 100644
--- a/arch/arm/mach-exynos/Kconfig
+++ b/arch/arm/mach-exynos/Kconfig
@@ -17,6 +17,7 @@ choice
 
 config ARCH_EXYNOS4
         bool "SAMSUNG EXYNOS4"
+        select MIGHT_HAVE_CACHE_L2X0
         help
           Samsung EXYNOS4 SoCs based systems
 
diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
index 503414718905..c8415784e60c 100644
--- a/arch/arm/mach-omap2/Kconfig
+++ b/arch/arm/mach-omap2/Kconfig
@@ -44,6 +44,7 @@ config ARCH_OMAP4
         select CPU_V7
         select ARM_GIC
         select LOCAL_TIMERS if SMP
+        select MIGHT_HAVE_CACHE_L2X0
         select PL310_ERRATA_588369
         select PL310_ERRATA_727915
         select ARM_ERRATA_720789
diff --git a/arch/arm/mach-realview/Kconfig b/arch/arm/mach-realview/Kconfig
index dba6d0c1fc17..3dd620f8dd9b 100644
--- a/arch/arm/mach-realview/Kconfig
+++ b/arch/arm/mach-realview/Kconfig
@@ -12,6 +12,7 @@ config REALVIEW_EB_A9MP
         bool "Support Multicore Cortex-A9 Tile"
         depends on MACH_REALVIEW_EB
         select CPU_V7
+        select MIGHT_HAVE_CACHE_L2X0
         help
           Enable support for the Cortex-A9MPCore tile fitted to the
           Realview(R) Emulation Baseboard platform.
@@ -21,6 +22,7 @@ config REALVIEW_EB_ARM11MP
         depends on MACH_REALVIEW_EB
         select CPU_V6K
         select ARCH_HAS_BARRIERS if SMP
+        select MIGHT_HAVE_CACHE_L2X0
         help
           Enable support for the ARM11MPCore tile fitted to the Realview(R)
           Emulation Baseboard platform.
@@ -39,6 +41,7 @@ config MACH_REALVIEW_PB11MP
         select CPU_V6K
         select ARM_GIC
         select HAVE_PATA_PLATFORM
+        select MIGHT_HAVE_CACHE_L2X0
         select ARCH_HAS_BARRIERS if SMP
         help
           Include support for the ARM(R) RealView(R) Platform Baseboard for
@@ -51,6 +54,7 @@ config MACH_REALVIEW_PB1176
         select CPU_V6
         select ARM_GIC
         select HAVE_TCM
+        select MIGHT_HAVE_CACHE_L2X0
         help
           Include support for the ARM(R) RealView(R) Platform Baseboard for
           ARM1176JZF-S.
@@ -78,6 +82,7 @@ config MACH_REALVIEW_PBX
         bool "Support RealView(R) Platform Baseboard Explore"
         select ARM_GIC
         select HAVE_PATA_PLATFORM
+        select MIGHT_HAVE_CACHE_L2X0
         select ARCH_SPARSEMEM_ENABLE if CPU_V7 && !REALVIEW_HIGH_PHYS_OFFSET
         select ZONE_DMA if SPARSEMEM
         help
diff --git a/arch/arm/mach-vexpress/Kconfig b/arch/arm/mach-vexpress/Kconfig
index 931148487f0b..a8aefc8a6f24 100644
--- a/arch/arm/mach-vexpress/Kconfig
+++ b/arch/arm/mach-vexpress/Kconfig
@@ -8,5 +8,6 @@ config ARCH_VEXPRESS_CA9X4
         select ARM_ERRATA_720789
         select ARM_ERRATA_751472
         select ARM_ERRATA_753970
+        select MIGHT_HAVE_CACHE_L2X0
 
 endmenu
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
diff --git a/arch/arm/plat-mxc/Kconfig b/arch/arm/plat-mxc/Kconfig
index b3a1f2b3ada3..b30708e28c1d 100644
--- a/arch/arm/plat-mxc/Kconfig
+++ b/arch/arm/plat-mxc/Kconfig
@@ -20,6 +20,7 @@ config ARCH_IMX_V6_V7
         bool "i.MX3, i.MX6"
         select AUTO_ZRELADDR if !ZBOOT_ROM
         select ARM_PATCH_PHYS_VIRT
+        select MIGHT_HAVE_CACHE_L2X0
         help
           This enables support for systems based on the Freescale i.MX3 and i.MX6
           family.