alpha: select ARCH_USE_MEMTEST

Wire up the generic early memtest from arch_mm_preinit(), which runs
after parse_early_param() has picked up the memtest= command line option
and before memblock_free_all() hands the memory to the buddy allocator.
paging_init() would be the natural place, but Alpha calls it from
setup_arch(), before the option is parsed, so the test would never run.

The test range starts at the first DRAM address rather than physical zero
because low memory on Alpha is owned by the console and PALcode.

Tested under QEMU with memtest=4: all four patterns pass over the free
memblock ranges, with no bad memory reserved.

Also add ALPHA to the memtest= parameter's architecture list.

Assisted-by: Claude:claude-opus-5
Signed-off-by: Matt Turner <mattst88@gmail.com>
Tested-by: Magnus Lindholm <linmag7@gmail.com>
Reviewed-by: Magnus Lindholm <linmag7@gmail.com>
Link: https://lore.kernel.org/r/20260905-arch-kconfig-options-v2-v2-16-83e8245761a2@gmail.com
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>

0 files changed, 0 insertions, 0 deletions