Re: [PATCH v12 3/5] dt, numa: Add NUMA dt binding implementation.

From: David Daney
Date: Mon Feb 29 2016 - 13:14:04 EST

On 02/29/2016 09:29 AM, Robert Richter wrote:
On 22.02.16 17:58:21, David Daney wrote:
From: Ganapatrao Kulkarni <gkulkarni@xxxxxxxxxxxxxxxxxx>

ADD device tree node parsing for NUMA topology using device
"numa-node-id" property distance-map.

Reviewed-by: Robert Richter <rrichter@xxxxxxxxxx>
Signed-off-by: Ganapatrao Kulkarni <gkulkarni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
drivers/of/Kconfig | 3 +
drivers/of/Makefile | 1 +
drivers/of/of_numa.c | 211 +++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of.h | 9 +++
4 files changed, 224 insertions(+)
create mode 100644 drivers/of/of_numa.c

diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index e2a4841..b3bec3a 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -112,4 +112,7 @@ config OF_OVERLAY
While this option is selected automatically when needed, you can
enable it manually to improve device tree unit test coverage.

+config OF_NUMA

In arch/arm64/Kconfig you now need to:

select OF_NUMA if NUMA && OF

This should depend here on OF and NUMA and enabled in that case. Why
moving that to arch code?

The dependency on of_numa.o is in the architecture specific code, so that is where the Kconfig select should be too.

For new code, we try to avoid putting architecture specific things into the core Kconfig files.

Since arm64 is the only architecture that is currently using this, we don't want to select it for non-arm64 kernels that happen to select NUMA && OF.

I will restore the depends, as it is guard against errors in the architecture specific Kconfig select statements, but I am going to leave the NUMA && OF in the arm64/Kconfig for clarity.

This duplicates code as the same needs to be
implemented for every arch.

Better to duplicate a single Kconfig select statement a few times in architecture specific Kconfig files, than force people to continuously modify the depends in drivers/of/Kconfig