[038/165] mm/memory_hotplug: introduce default dummy memory_add_physaddr_to_nid()

Commit Message

Andrew Morton Aug. 12, 2020, 1:32 a.m. UTC

From: Jia He <[e-mail]>
Subject: mm/memory_hotplug: introduce default dummy memory_add_physaddr_to_nid()

This is to introduce a general dummy helper.  memory_add_physaddr_to_nid()
is a fallback option to get the nid in case NUMA_NO_NID is detected.

After this patch, arm64/sh/s390 can simply use the general dummy version. 
PowerPC/x86/ia64 will still use their specific version.

This is the preparation to set a fallback value for dev_dax->target_node.

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Jia He <[e-mail]>
Reviewed-by: David Hildenbrand <[e-mail]>
Cc: Dan Williams <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: Tony Luck <[e-mail]>
Cc: Fenghua Yu <[e-mail]>
Cc: Yoshinori Sato <[e-mail]>
Cc: Rich Felker <[e-mail]>
Cc: Dave Hansen <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: "H. Peter Anvin" <[e-mail]>
Cc: Vishal Verma <[e-mail]>
Cc: Dave Jiang <[e-mail]>
Cc: Baoquan He <[e-mail]>
Cc: Chuhong Yuan <[e-mail]>
Cc: Mike Rapoport <[e-mail]>
Cc: Logan Gunthorpe <[e-mail]>
Cc: Masahiro Yamada <[e-mail]>
Cc: Jonathan Cameron <[e-mail]>
Cc: Kaly Xin <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 arch/arm64/mm/numa.c |   10 ----------
 arch/ia64/mm/numa.c  |    2 --
 arch/sh/mm/init.c    |    9 ---------
 arch/x86/mm/numa.c   |    1 -
 mm/memory_hotplug.c  |   10 ++++++++++
 5 files changed, 10 insertions(+), 22 deletions(-)

Patch

--- a/arch/arm64/mm/numa.c~mm-memory_hotplug-introduce-default-dummy-memory_add_physaddr_to_nid
+++ a/arch/arm64/mm/numa.c
@@ -461,13 +461,3 @@  void __init arm64_numa_init(void)
 
 	numa_init(dummy_numa_init);
 }
-
-/*
- * We hope that we will be hotplugging memory on nodes we already know about,
- * such that acpi_get_node() succeeds and we never fall back to this...
- */
-int memory_add_physaddr_to_nid(u64 addr)
-{
-	pr_warn("Unknown node for memory at 0x%llx, assuming node 0\n", addr);
-	return 0;
-}
--- a/arch/ia64/mm/numa.c~mm-memory_hotplug-introduce-default-dummy-memory_add_physaddr_to_nid
+++ a/arch/ia64/mm/numa.c
@@ -106,7 +106,5 @@  int memory_add_physaddr_to_nid(u64 addr)
 		return 0;
 	return nid;
 }
-
-EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 #endif
 #endif
--- a/arch/sh/mm/init.c~mm-memory_hotplug-introduce-default-dummy-memory_add_physaddr_to_nid
+++ a/arch/sh/mm/init.c
@@ -425,15 +425,6 @@  int arch_add_memory(int nid, u64 start,
 	return ret;
 }
 
-#ifdef CONFIG_NUMA
-int memory_add_physaddr_to_nid(u64 addr)
-{
-	/* Node 0 for now.. */
-	return 0;
-}
-EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
-#endif
-
 void arch_remove_memory(int nid, u64 start, u64 size,
 			struct vmem_altmap *altmap)
 {
--- a/arch/x86/mm/numa.c~mm-memory_hotplug-introduce-default-dummy-memory_add_physaddr_to_nid
+++ a/arch/x86/mm/numa.c
@@ -929,5 +929,4 @@  int memory_add_physaddr_to_nid(u64 start
 		nid = numa_meminfo.blk[0].nid;
 	return nid;
 }
-EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 #endif
--- a/mm/memory_hotplug.c~mm-memory_hotplug-introduce-default-dummy-memory_add_physaddr_to_nid
+++ a/mm/memory_hotplug.c
@@ -350,6 +350,16 @@  int __ref __add_pages(int nid, unsigned
 	return err;
 }
 
+#ifdef CONFIG_NUMA
+int __weak memory_add_physaddr_to_nid(u64 start)
+{
+	pr_info_once("Unknown target node for memory at 0x%llx, assuming node 0\n",
+			start);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
+#endif
+
 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
 static unsigned long find_smallest_section_pfn(int nid, struct zone *zone,
 				     unsigned long start_pfn,