Merge branch 'for-linus-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

[linux.git] / mm / memory_hotplug.c

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 7e6509a53d79facc47bcf0b5f0d5e37de32f3ad6..61972da38d93cb54d6f1088df186ed20bb0f98bb 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -33,7 +33,6 @@
 #include <linux/stop_machine.h>
 #include <linux/hugetlb.h>
 #include <linux/memblock.h>
-#include <linux/bootmem.h>
 #include <linux/compaction.h>
 
 #include <asm/tlbflush.h>
@@ -839,7 +838,6 @@ static struct zone * __meminit move_pfn_range(int online_type, int nid,
        return zone;
 }
 
-/* Must be protected by mem_hotplug_begin() or a device_lock */
 int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
 {
        unsigned long flags;
@@ -851,6 +849,8 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
        struct memory_notify arg;
        struct memory_block *mem;
 
+       mem_hotplug_begin();
+
        /*
         * We can't use pfn_to_nid() because nid might be stored in struct page
         * which is not yet initialized. Instead, we find nid from memory block.
@@ -915,6 +915,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
 
        if (onlined_pages)
                memory_notify(MEM_ONLINE, &arg);
+       mem_hotplug_done();
        return 0;
 
 failed_addition:
@@ -922,6 +923,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
                 (unsigned long long) pfn << PAGE_SHIFT,
                 (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1);
        memory_notify(MEM_CANCEL_ONLINE, &arg);
+       mem_hotplug_done();
        return ret;
 }
 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
@@ -1069,7 +1071,12 @@ static int online_memory_block(struct memory_block *mem, void *arg)
        return device_online(&mem->dev);
 }
 
-/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
+/*
+ * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
+ * and online/offline operations (triggered e.g. by sysfs).
+ *
+ * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG
+ */
 int __ref add_memory_resource(int nid, struct resource *res, bool online)
 {
        u64 start, size;
@@ -1121,26 +1128,26 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
        /* create new memmap entry */
        firmware_map_add_hotplug(start, start + size, "System RAM");
 
+       /* device_online() will take the lock when calling online_pages() */
+       mem_hotplug_done();
+
        /* online pages if requested */
        if (online)
                walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1),
                                  NULL, online_memory_block);
 
-       goto out;
-
+       return ret;
 error:
        /* rollback pgdat allocation and others */
        if (new_node)
                rollback_node_hotadd(nid);
        memblock_remove(start, size);
-
-out:
        mem_hotplug_done();
        return ret;
 }
-EXPORT_SYMBOL_GPL(add_memory_resource);
 
-int __ref add_memory(int nid, u64 start, u64 size)
+/* requires device_hotplug_lock, see add_memory_resource() */
+int __ref __add_memory(int nid, u64 start, u64 size)
 {
        struct resource *res;
        int ret;
@@ -1154,6 +1161,17 @@ int __ref add_memory(int nid, u64 start, u64 size)
                release_memory_resource(res);
        return ret;
 }
+
+int add_memory(int nid, u64 start, u64 size)
+{
+       int rc;
+
+       lock_device_hotplug();
+       rc = __add_memory(nid, start, size);
+       unlock_device_hotplug();
+
+       return rc;
+}
 EXPORT_SYMBOL_GPL(add_memory);
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
@@ -1540,10 +1558,16 @@ static int __ref __offline_pages(unsigned long start_pfn,
                return -EINVAL;
        if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
                return -EINVAL;
+
+       mem_hotplug_begin();
+
        /* This makes hotplug much easier...and readable.
           we assume this for now. .*/
-       if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start, &valid_end))
+       if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start,
+                                 &valid_end)) {
+               mem_hotplug_done();
                return -EINVAL;
+       }
 
        zone = page_zone(pfn_to_page(valid_start));
        node = zone_to_nid(zone);
@@ -1552,8 +1576,10 @@ static int __ref __offline_pages(unsigned long start_pfn,
        /* set above range as isolated */
        ret = start_isolate_page_range(start_pfn, end_pfn,
                                       MIGRATE_MOVABLE, true);
-       if (ret)
+       if (ret) {
+               mem_hotplug_done();
                return ret;
+       }
 
        arg.start_pfn = start_pfn;
        arg.nr_pages = nr_pages;
@@ -1624,6 +1650,7 @@ static int __ref __offline_pages(unsigned long start_pfn,
        writeback_set_ratelimit();
 
        memory_notify(MEM_OFFLINE, &arg);
+       mem_hotplug_done();
        return 0;
 
 failed_removal:
@@ -1633,10 +1660,10 @@ static int __ref __offline_pages(unsigned long start_pfn,
        memory_notify(MEM_CANCEL_OFFLINE, &arg);
        /* pushback to free area */
        undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
+       mem_hotplug_done();
        return ret;
 }
 
-/* Must be protected by mem_hotplug_begin() or a device_lock */
 int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
 {
        return __offline_pages(start_pfn, start_pfn + nr_pages);
@@ -1807,7 +1834,7 @@ EXPORT_SYMBOL(try_offline_node);
  * and online/offline operations before this call, as required by
  * try_offline_node().
  */
-void __ref remove_memory(int nid, u64 start, u64 size)
+void __ref __remove_memory(int nid, u64 start, u64 size)
 {
        int ret;
 
@@ -1836,5 +1863,12 @@ void __ref remove_memory(int nid, u64 start, u64 size)
 
        mem_hotplug_done();
 }
+
+void remove_memory(int nid, u64 start, u64 size)
+{
+       lock_device_hotplug();
+       __remove_memory(nid, start, size);
+       unlock_device_hotplug();
+}
 EXPORT_SYMBOL_GPL(remove_memory);
 #endif /* CONFIG_MEMORY_HOTREMOVE */