[PATCH V2] mm/memtest: Add ARCH_USE_MEMTEST

[Catalin Marinas]

On Mon, Mar 01, 2021 at 10:02:06AM +0530, Anshuman Khandual wrote:
> early_memtest() does not get called from all architectures. Hence enabling
> CONFIG_MEMTEST and providing a valid memtest=[1..N] kernel command line
> option might not trigger the memory pattern tests as would be expected in
> normal circumstances. This situation is misleading.
> 
> The change here prevents the above mentioned problem after introducing a
> new config option ARCH_USE_MEMTEST that should be subscribed on platforms
> that call early_memtest(), in order to enable the config CONFIG_MEMTEST.
> Conversely CONFIG_MEMTEST cannot be enabled on platforms where it would
> not be tested anyway.
> 
> Cc: Russell King <linux at armlinux.org.uk>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will at kernel.org>
> Cc: Thomas Bogendoerfer <tsbogend at alpha.franken.de>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> Cc: Paul Mackerras <paulus at samba.org>
> Cc: Thomas Gleixner <tglx at linutronix.de>
> Cc: Ingo Molnar <mingo at redhat.com>
> Cc: Chris Zankel <chris at zankel.net>
> Cc: Max Filippov <jcmvbkbc at gmail.com>
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: linux-mips at vger.kernel.org
> Cc: linuxppc-dev at lists.ozlabs.org
> Cc: linux-xtensa at linux-xtensa.org
> Cc: linux-mm at kvack.org
> Cc: linux-kernel at vger.kernel.org
> Reviewed-by: Max Filippov <jcmvbkbc at gmail.com>
> Signed-off-by: Anshuman Khandual <anshuman.khandual at arm.com>

For arm64:

Acked-by: Catalin Marinas <catalin.marinas at arm.com>