[for,4.19-stable,v3,17/24] mm/memory_hotplug: remove memory block devices before arch_remove_memory()

Commit Message

David Hildenbrand Jan. 28, 2020, 9:50 a.m. UTC

commit 4c4b7f9ba9486c565aead99a198ceeef73ae81f6 upstream.

Let's factor out removing of memory block devices, which is only
necessary for memory added via add_memory() and friends that created
memory block devices.  Remove the devices before calling
arch_remove_memory().

This finishes factoring out memory block device handling from
arch_add_memory() and arch_remove_memory().

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: David Hildenbrand <[e-mail]>
Reviewed-by: Dan Williams <[e-mail]>
Acked-by: Michal Hocko <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: "Rafael J. Wysocki" <[e-mail]>
Cc: David Hildenbrand <[e-mail]>
Cc: "[e-mail]" <[e-mail]>
Cc: Andrew Banman <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Alex Deucher <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Mark Brown <[e-mail]>
Cc: Chris Wilson <[e-mail]>
Cc: Oscar Salvador <[e-mail]>
Cc: Jonathan Cameron <[e-mail]>
Cc: Arun KS <[e-mail]>
Cc: Mathieu Malaterre <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Anshuman Khandual <[e-mail]>
Cc: Ard Biesheuvel <[e-mail]>
Cc: Baoquan He <[e-mail]>
Cc: Benjamin Herrenschmidt <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Chintan Pandya <[e-mail]>
Cc: Christophe Leroy <[e-mail]>
Cc: Dave Hansen <[e-mail]>
Cc: Fenghua Yu <[e-mail]>
Cc: Heiko Carstens <[e-mail]>
Cc: "H. Peter Anvin" <[e-mail]>
Cc: Joonsoo Kim <[e-mail]>
Cc: Jun Yao <[e-mail]>
Cc: "Kirill A. Shutemov" <[e-mail]>
Cc: Logan Gunthorpe <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Masahiro Yamada <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Mike Rapoport <[e-mail]>
Cc: Nicholas Piggin <[e-mail]>
Cc: Oscar Salvador <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Pavel Tatashin <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Qian Cai <[e-mail]>
Cc: Rich Felker <[e-mail]>
Cc: Rob Herring <[e-mail]>
Cc: Robin Murphy <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Tony Luck <[e-mail]>
Cc: Vasily Gorbik <[e-mail]>
Cc: Wei Yang <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: Yoshinori Sato <[e-mail]>
Cc: Yu Zhao <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>
Signed-off-by: David Hildenbrand <[e-mail]>
---
 drivers/base/memory.c  | 37 ++++++++++++++++++-------------------
 drivers/base/node.c    | 11 ++++++-----
 include/linux/memory.h |  2 +-
 include/linux/node.h   |  6 ++----
 mm/memory_hotplug.c    |  5 +++--
 5 files changed, 30 insertions(+), 31 deletions(-)

Patch

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index b89b9c3efa59..fdda7a6d712e 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -768,32 +768,31 @@  int create_memory_block_devices(unsigned long start, unsigned long size)
 	return ret;
 }
 
-void unregister_memory_section(struct mem_section *section)
+/*
+ * Remove memory block devices for the given memory area. Start and size
+ * have to be aligned to memory block granularity. Memory block devices
+ * have to be offline.
+ */
+void remove_memory_block_devices(unsigned long start, unsigned long size)
 {
+	const int start_block_id = pfn_to_block_id(PFN_DOWN(start));
+	const int end_block_id = pfn_to_block_id(PFN_DOWN(start + size));
 	struct memory_block *mem;
+	int block_id;
 
-	if (WARN_ON_ONCE(!present_section(section)))
+	if (WARN_ON_ONCE(!IS_ALIGNED(start, memory_block_size_bytes()) ||
+			 !IS_ALIGNED(size, memory_block_size_bytes())))
 		return;
 
 	mutex_lock(&mem_sysfs_mutex);
-
-	/*
-	 * Some users of the memory hotplug do not want/need memblock to
-	 * track all sections. Skip over those.
-	 */
-	mem = find_memory_block(section);
-	if (!mem)
-		goto out_unlock;
-
-	unregister_mem_sect_under_nodes(mem, __section_nr(section));
-
-	mem->section_count--;
-	if (mem->section_count == 0)
+	for (block_id = start_block_id; block_id != end_block_id; block_id++) {
+		mem = find_memory_block_by_id(block_id, NULL);
+		if (WARN_ON_ONCE(!mem))
+			continue;
+		mem->section_count = 0;
+		unregister_memory_block_under_nodes(mem);
 		unregister_memory(mem);
-	else
-		put_device(&mem->dev);
-
-out_unlock:
+	}
 	mutex_unlock(&mem_sysfs_mutex);
 }
 
diff --git a/drivers/base/node.c b/drivers/base/node.c
index c3968e2d0a98..1211794d658c 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -453,9 +453,10 @@  int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg)
 	return 0;
 }
 
-/* unregister memory section under all nodes that it spans */
-int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
-				    unsigned long phys_index)
+/*
+ * Unregister memory block device under all nodes that it spans.
+ */
+int unregister_memory_block_under_nodes(struct memory_block *mem_blk)
 {
 	NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
 	unsigned long pfn, sect_start_pfn, sect_end_pfn;
@@ -468,8 +469,8 @@  int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
 		return -ENOMEM;
 	nodes_clear(*unlinked_nodes);
 
-	sect_start_pfn = section_nr_to_pfn(phys_index);
-	sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
+	sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
+	sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
 	for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
 		int nid;
 
diff --git a/include/linux/memory.h b/include/linux/memory.h
index db3e8567f900..f26a5417ec5d 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -112,7 +112,7 @@  extern void unregister_memory_notifier(struct notifier_block *nb);
 extern int register_memory_isolate_notifier(struct notifier_block *nb);
 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 int create_memory_block_devices(unsigned long start, unsigned long size);
-extern void unregister_memory_section(struct mem_section *);
+void remove_memory_block_devices(unsigned long start, unsigned long size);
 extern int memory_dev_init(void);
 extern int memory_notify(unsigned long val, void *v);
 extern int memory_isolate_notify(unsigned long val, void *v);
diff --git a/include/linux/node.h b/include/linux/node.h
index 257bb3d6d014..9a6db437f2d1 100644
--- a/include/linux/node.h
+++ b/include/linux/node.h
@@ -72,8 +72,7 @@  extern int register_cpu_under_node(unsigned int cpu, unsigned int nid);
 extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid);
 extern int register_mem_sect_under_node(struct memory_block *mem_blk,
 						void *arg);
-extern int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
-					   unsigned long phys_index);
+extern int unregister_memory_block_under_nodes(struct memory_block *mem_blk);
 
 #ifdef CONFIG_HUGETLBFS
 extern void register_hugetlbfs_with_node(node_registration_func_t doregister,
@@ -105,8 +104,7 @@  static inline int register_mem_sect_under_node(struct memory_block *mem_blk,
 {
 	return 0;
 }
-static inline int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
-						  unsigned long phys_index)
+static inline int unregister_memory_block_under_nodes(struct memory_block *mem_blk)
 {
 	return 0;
 }
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 414771114685..7a1c9fbf9f41 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -481,8 +481,6 @@  static void __remove_section(struct zone *zone, struct mem_section *ms,
 	if (WARN_ON_ONCE(!valid_section(ms)))
 		return;
 
-	unregister_memory_section(ms);
-
 	scn_nr = __section_nr(ms);
 	start_pfn = section_nr_to_pfn((unsigned long)scn_nr);
 	__remove_zone(zone, start_pfn);
@@ -1914,6 +1912,9 @@  void __ref __remove_memory(int nid, u64 start, u64 size)
 	memblock_free(start, size);
 	memblock_remove(start, size);
 
+	/* remove memory block devices before removing memory */
+	remove_memory_block_devices(start, size);
+
 	arch_remove_memory(nid, start, size, NULL);
 	__release_memory_resource(start, size);