From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hildenbrand Date: Mon, 27 May 2019 11:11:45 +0000 Subject: [PATCH v3 04/11] arm64/mm: Add temporary arch_remove_memory() implementation Message-Id: <20190527111152.16324-5-david@redhat.com> List-Id: References: <20190527111152.16324-1-david@redhat.com> In-Reply-To: <20190527111152.16324-1-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-mm@kvack.org Cc: Mark Rutland , linux-s390@vger.kernel.org, Ard Biesheuvel , linux-ia64@vger.kernel.org, Yu Zhao , Anshuman Khandual , linux-sh@vger.kernel.org, Catalin Marinas , David Hildenbrand , Will Deacon , linux-kernel@vger.kernel.org, Wei Yang , Jun Yao , Chintan Pandya , Igor Mammedov , akpm@linux-foundation.org, Mike Rapoport , linuxppc-dev@lists.ozlabs.org, Dan Williams , linux-arm-kernel@lists.infradead.org, Robin Murphy 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 Cc: Will Deacon Cc: Mark Rutland Cc: Andrew Morton Cc: Ard Biesheuvel Cc: Chintan Pandya Cc: Mike Rapoport Cc: Jun Yao Cc: Yu Zhao Cc: Robin Murphy Cc: Anshuman Khandual Signed-off-by: David Hildenbrand --- 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