s390x/mm: implement arch_remove_memory()

Will come in handy when wanting to handle errors after
arch_add_memory().

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Alex Deucher <[email protected]>
Cc: Andrew Banman <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Arun KS <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Chintan Pandya <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jonathan Cameron <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Jun Yao <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Logan Gunthorpe <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Mathieu Malaterre <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Qian Cai <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Robin Murphy <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: Yu Zhao <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 7 insertions, 6 deletions

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 7d6638c18cb4..5b1ec2f532e0 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -290,12 +290,13 @@ int arch_add_memory(int nid, u64 start, u64 size,
 void arch_remove_memory(int nid, u64 start, u64 size,
 			struct vmem_altmap *altmap)
 {
-	/*
-	 * There is no hardware or firmware interface which could trigger a
-	 * hot memory remove on s390. So there is nothing that needs to be
-	 * implemented.
-	 */
-	BUG();
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long nr_pages = size >> PAGE_SHIFT;
+	struct zone *zone;
+
+	zone = page_zone(pfn_to_page(start_pfn));
+	__remove_pages(zone, start_pfn, nr_pages, altmap);
+	vmem_remove_mapping(start, size);
 }
 #endif
 #endif /* CONFIG_MEMORY_HOTPLUG */