From 4ab215061554ae2a4b78744a5dd3b3c6639f16a7 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Tue, 11 Dec 2018 18:48:48 +0000 Subject: 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 Signed-off-by: Will Deacon --- arch/arm64/mm/mmu.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'arch/arm64/mm/mmu.c') 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 -- cgit v1.2.3