This is a note to let you know that I've just added the patch titled arm64: mm: update max_pfn after memory hotplug to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm64-mm-update-max_pfn-after-memory-hotplug.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit beac69a4f9052956f9a6af44e0c5f34299be3fdd Author: Sudarshan Rajagopalan <quic_sudaraja@xxxxxxxxxxx> Date: Tue Sep 28 11:51:49 2021 -0700 arm64: mm: update max_pfn after memory hotplug [ Upstream commit 8fac67ca236b961b573355e203dbaf62a706a2e5 ] After new memory blocks have been hotplugged, max_pfn and max_low_pfn needs updating to reflect on new PFNs being hot added to system. Without this patch, debug-related functions that use max_pfn such as get_max_dump_pfn() or read_page_owner() will not work with any page in memory that is hot-added after boot. Fixes: 4ab215061554 ("arm64: Add memory hotplug support") Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@xxxxxxxxxxx> Signed-off-by: Chris Goldsworthy <quic_cgoldswo@xxxxxxxxxxx> Acked-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Florian Fainelli <f.fainelli@xxxxxxxxx> Cc: Georgi Djakov <quic_c_gdjako@xxxxxxxxxxx> Tested-by: Georgi Djakov <quic_c_gdjako@xxxxxxxxxxx> Link: https://lore.kernel.org/r/a51a27ee7be66024b5ce626310d673f24107bcb8.1632853776.git.quic_cgoldswo@xxxxxxxxxxx Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 9ff0de1b2b93c..90d185853e341 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size, if (ret) __remove_pgd_mapping(swapper_pg_dir, __phys_to_virt(start), size); + else { + max_pfn = PFN_UP(start + size); + max_low_pfn = max_pfn; + } + return ret; }