mm: move memtest under mm

Memtest is a simple feature which fills the memory with a given set of
patterns and validates memory contents, if bad memory regions is detected
it reserves them via memblock API.  Since memblock API is widely used by
other architectures this feature can be enabled outside of x86 world.

This patch set promotes memtest to live under generic mm umbrella and
enables memtest feature for arm/arm64.

It was reported that this patch set was useful for tracking down an issue
with some errant DMA on an arm64 platform.

This patch (of 6):

There is nothing platform dependent in the core memtest code, so other
platforms might benefit from this feature too.

[linux@roeck-us.net: MEMTEST depends on MEMBLOCK]
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 36b6fa88ce5b..5c7a3183423b 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1745,6 +1745,18 @@ config TEST_UDELAY
 
 	  If unsure, say N.
 
+config MEMTEST
+	bool "Memtest"
+	depends on HAVE_MEMBLOCK
+	---help---
+	  This option adds a kernel parameter 'memtest', which allows memtest
+	  to be set.
+	        memtest=0, mean disabled; -- default
+	        memtest=1, mean do 1 test pattern;
+	        ...
+	        memtest=4, mean do 4 test patterns.
+	  If you are unsure how to answer this question, answer N.
+
 source "samples/Kconfig"
 
 source "lib/Kconfig.kgdb"