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.

Signed-off-by: Jia He <justin.he@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
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: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Chuhong Yuan <hslester96@gmail.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Cc: Kaly Xin <Kaly.Xin@arm.com>
Link: http://lkml.kernel.org/r/20200710031619.18762-2-justin.he@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
index aafcee3..73f8b49 100644 (file)
--- a/arch/arm64/mm/numa.c
+++ b/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;
-}

diff --git a/arch/ia64/mm/numa.c b/arch/ia64/mm/numa.c
index 5e1015e..f349642 100644 (file)
--- a/arch/ia64/mm/numa.c
+++ b/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

diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 613de80..cd13793 100644 (file)
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -425,15 +425,6 @@ int arch_add_memory(int nid, u64 start, u64 size,
        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)
 {

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index b05f45e..aa76ec2 100644 (file)
--- a/arch/x86/mm/numa.c
+++ b/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

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index ac6961a..6289a90 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -350,6 +350,16 @@ int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages,
        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,