ARM: Avoid building unsafe kernels on OMAP2 and MX3

OMAP2 (armv6) and MX3 turn off support for the V6K instructions, which
when they include support for SMP kernels means that the resulting
kernel is unsafe on SMP and can result in corrupted filesystems as we
end up using unsafe bitops.

Re-enable the use of V6K instructions on such kernels, and let such
kernels running on V6 CPUs eat undefined instruction faults which will
be much safer than filesystem corruption.  Next merge window we can fix
this properly (as it requires a much bigger set of changes.)

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 9d30c6f804b9de6454c9dc7b8bb16974ed487a16..c9d2d56feced1e92074a8a523e91572cb41e1fa1 100644 (file)
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -405,7 +405,7 @@ config CPU_V6
 config CPU_32v6K
        bool "Support ARM V6K processor extensions" if !SMP
        depends on CPU_V6 || CPU_V7
-       default y if SMP && !(ARCH_MX3 || ARCH_OMAP2)
+       default y if SMP
        help
          Say Y here if your ARMv6 processor supports the 'K' extension.
          This enables the kernel to use some instructions not present
@@ -416,7 +416,7 @@ config CPU_32v6K
 # ARMv7
 config CPU_V7
        bool "Support ARM V7 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
-       select CPU_32v6K if !ARCH_OMAP2
+       select CPU_32v6K
        select CPU_32v7
        select CPU_ABRT_EV7
        select CPU_PABRT_V7