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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/mm/mmu.c
parent6e4ede698d1c17102e42c6f734f7d8cf60df28d5 (diff)
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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 'arch/arm64/mm/mmu.c')
-rw-r--r--arch/arm64/mm/mmu.c17
1 files changed, 17 insertions, 0 deletions
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