From 1e5d8e1e47afde23e3249aed25d7d124feff5c1c Mon Sep 17 00:00:00 2001
From: Dan Williams
Date: Sun, 16 Feb 2020 12:01:04 -0800
Subject: x86/mm: Introduce CONFIG_NUMA_KEEP_MEMINFO

Currently x86 numa_meminfo is marked __initdata in the
CONFIG_MEMORY_HOTPLUG=n case. In support of a new facility to allow
drivers to map reserved memory to a 'target_node'
(phys_to_target_node()), add support for removing the __initdata
designation for those users. Both memory hotplug and
phys_to_target_node() users select CONFIG_NUMA_KEEP_MEMINFO to tell the
arch to maintain its physical address to NUMA mapping infrastructure
post init.

Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <x86@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/158188326422.894464.15742054998046628934.stgit@dwillia2-desk3.amr.corp.intel.com
---
 mm/Kconfig | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'mm/Kconfig')

diff --git a/mm/Kconfig b/mm/Kconfig
index ab80933be65f..328268473fec 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -139,6 +139,10 @@ config HAVE_FAST_GUP
 config ARCH_KEEP_MEMBLOCK
 	bool
 
+# Keep arch NUMA mapping infrastructure post-init.
+config NUMA_KEEP_MEMINFO
+	bool
+
 config MEMORY_ISOLATION
 	bool
 
@@ -154,6 +158,7 @@ config MEMORY_HOTPLUG
 	bool "Allow for memory hot-add"
 	depends on SPARSEMEM || X86_64_ACPI_NUMA
 	depends on ARCH_ENABLE_MEMORY_HOTPLUG
+	select NUMA_KEEP_MEMINFO if NUMA
 
 config MEMORY_HOTPLUG_SPARSE
 	def_bool y
-- 
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