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authorRobin Murphy <robin.murphy@arm.com>2018-12-11 18:48:48 +0000
committerWill Deacon <will.deacon@arm.com>2018-12-12 14:43:43 +0000
commit4ab215061554ae2a4b78744a5dd3b3c6639f16a7 (patch)
tree47b51d9c71d7c0012c043a7f161c30e9b08fa80a /arch/arm64
parentarm64: percpu: Fix LSE implementation of value-returning pcpu atomics (diff)
downloadlinux-dev-4ab215061554ae2a4b78744a5dd3b3c6639f16a7.tar.xz
linux-dev-4ab215061554ae2a4b78744a5dd3b3c6639f16a7.zip
arm64: Add memory hotplug support
Wire up the basic support for hot-adding memory. Since memory hotplug is fairly tightly coupled to sparsemem, we tweak pfn_valid() to also cross-check the presence of a section in the manner of the generic implementation, before falling back to memblock to check for no-map regions within a present section as before. By having arch_add_memory(() create the linear mapping first, this then makes everything work in the way that __add_section() expects. We expect hotplug to be ACPI-driven, so the swapper_pg_dir updates should be safe from races by virtue of the global device hotplug lock. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to '')
-rw-r--r--arch/arm64/Kconfig3
-rw-r--r--arch/arm64/mm/init.c8
-rw-r--r--arch/arm64/mm/mmu.c17
-rw-r--r--arch/arm64/mm/numa.c10
4 files changed, 38 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 47c1f21e81dc..e9af113c572f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -261,6 +261,9 @@ config ZONE_DMA32
config HAVE_GENERIC_GUP
def_bool y
+config ARCH_ENABLE_MEMORY_HOTPLUG
+ def_bool y
+
config SMP
def_bool y
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 6cde00554e9b..4bfe0fc9edac 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -291,6 +291,14 @@ int pfn_valid(unsigned long pfn)
if ((addr >> PAGE_SHIFT) != pfn)
return 0;
+
+#ifdef CONFIG_SPARSEMEM
+ if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
+ return 0;
+
+ if (!valid_section(__nr_to_section(pfn_to_section_nr(pfn))))
+ return 0;
+#endif
return memblock_is_map_memory(addr);
}
EXPORT_SYMBOL(pfn_valid);
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 674c409a8ce4..da513a1facf4 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1046,3 +1046,20 @@ int pud_free_pmd_page(pud_t *pudp, unsigned long addr)
pmd_free(NULL, table);
return 1;
}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
+ bool want_memblock)
+{
+ int flags = 0;
+
+ if (rodata_full || debug_pagealloc_enabled())
+ flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
+
+ __create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start),
+ size, PAGE_KERNEL, pgd_pgtable_alloc, flags);
+
+ return __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT,
+ altmap, want_memblock);
+}
+#endif
diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
index 27a31efd9e8e..ae34e3a1cef1 100644
--- a/arch/arm64/mm/numa.c
+++ b/arch/arm64/mm/numa.c
@@ -466,3 +466,13 @@ 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;
+}