EDAC, skx: Fix randconfig builds in a better way

It was previously noted that Kconfig complained about unmet dependencies
when trying to configure skx_edac together with CONFIG_ACPI=n. First fix
for this checked for ACPI when doing

select ACPI_ADXL

but this required stub functions for the case where ACPI wasn't
selected. It also allowed building a driver that didn't actually work
for a system that has non-volatile DIMMs.

Arnd Bergmann pointed out that the right fix is to make EDAC_SKX
"depend on ACPI".

Fixes: a324e9396ca3 ("EDAC, skx: Fix randconfig builds")
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
CC: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Mauro Carvalho Chehab <mchehab@kernel.org>
CC: linux-edac <linux-edac@vger.kernel.org>
CC: qiuxu.zhuo@intel.com
Link: http://lkml.kernel.org/r/20181106183914.GA26731@agluck-desk

EDAC, skx: Fix randconfig builds

The driver depends on the ADXL component glue and selects it. However,
ADXL itself implicitly depends on ACPI and in nonsensical randconfig
builds like this:

# CONFIG_ACPI is not set
CONFIG_ACPI_ADXL=y

where ACPI is not enabled, the build fails with:

drivers/edac/skx_edac.o: In function `skx_mce_check_error':
skx_edac.c:(.text+0xab): undefined reference to `adxl_decode'
drivers/edac/skx_edac.o: In function `skx_init':
skx_edac.c:(.init.text+0x8bf): undefined reference to `adxl_get_component_names'
make: *** [vmlinux] Error 1

Add stubs for that case so that the build succeeds. CONFIG_ACPI=n
doesn't make any sense for real configurations but this fix will at
least silence randconfig builds.

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>

ACPI/ADXL: Add address translation interface using an ACPI DSM

Some new Intel servers provide an interface so that the OS can ask the
BIOS to translate a system physical address to a memory address (socket,
memory controller, channel, rank, dimm, etc.). This is useful for EDAC
drivers that want to take the address of an error reported in a machine
check bank and let the user know which DIMM may need to be replaced.

Specification for this interface is available at:

https://cdrdv2.intel.com/v1/dl/getContent/603354

[ Based on earlier code by Qiuxu Zhuo <qiuxu.zhuo@intel.com>. ]

[ bp: Make the first pr_info() in adxl_init() pr_debug() so that it
doesn't pollute every dmesg. ]

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
CC: Len Brown <lenb@kernel.org>
CC: linux-acpi@vger.kernel.org
CC: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/20181015202620.23610-1-tony.luck@intel.com