Messages in this thread Patch in this message | | | From | David Hildenbrand <> | Subject | [PATCH v3 04/11] arm64/mm: Add temporary arch_remove_memory() implementation | Date | Mon, 27 May 2019 13:11:45 +0200 |
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A proper arch_remove_memory() implementation is on its way, which also cleanly removes page tables in arch_add_memory() in case something goes wrong.
As we want to use arch_remove_memory() in case something goes wrong during memory hotplug after arch_add_memory() finished, let's add a temporary hack that is sufficient enough until we get a proper implementation that cleans up page table entries.
We will remove CONFIG_MEMORY_HOTREMOVE around this code in follow up patches.
Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Jun Yao <yaojun8558363@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: David Hildenbrand <david@redhat.com> --- arch/arm64/mm/mmu.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index a1bfc4413982..e569a543c384 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1084,4 +1084,23 @@ int arch_add_memory(int nid, u64 start, u64 size, return __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT, restrictions); } +#ifdef CONFIG_MEMORY_HOTREMOVE +void arch_remove_memory(int nid, u64 start, u64 size, + struct vmem_altmap *altmap) +{ + unsigned long start_pfn = start >> PAGE_SHIFT; + unsigned long nr_pages = size >> PAGE_SHIFT; + struct zone *zone; + + /* + * FIXME: Cleanup page tables (also in arch_add_memory() in case + * adding fails). Until then, this function should only be used + * during memory hotplug (adding memory), not for memory + * unplug. ARCH_ENABLE_MEMORY_HOTREMOVE must not be + * unlocked yet. + */ + zone = page_zone(pfn_to_page(start_pfn)); + __remove_pages(zone, start_pfn, nr_pages, altmap); +} +#endif #endif -- 2.20.1
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