mm/memory_hotplug: remove memory block devices before arch_remove_memory()

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/20190527111152.16324-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 18a30c3ac0ef34da2c130b98ed82d6d77de5d13a..826dd76f662e53b60fe63a705995c87b3b5208dc 100644 (file)
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -759,32 +759,31 @@ 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 aa878fbcf7051452c1f12cffdca121abe741c70c..0b0f38c2c7cd4716fd11916404a709c891ce7b27 100644 (file)
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -802,9 +802,10 @@ 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;
@@ -817,8 +818,8 @@ 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 db3e8567f900a6f40b0fb9b20b55729902639ce9..f26a5417ec5d6fad42b0b6f3e9c7af1255cbf3e5 100644 (file)
--- 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 1a557c589ecb9772a63214e2c5e2c39f1211a95e..02a29e71b175905f103f91b1ef8a43f7afd4efa1 100644 (file)
--- a/include/linux/node.h
+++ b/include/linux/node.h
@@ -139,8 +139,7 @@ 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);
 
 extern int register_memory_node_under_compute_node(unsigned int mem_nid,
                                                   unsigned int cpu_nid,
@@ -176,8 +175,7 @@ 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 fb9dc3fa1138aecdde42677d7663a419d0d8cfe3..37c861e7a71750dd93f631c492502b4cc0ed118b 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -520,8 +520,6 @@ 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);
@@ -1834,6 +1832,9 @@ static int __ref try_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);