mm/memory_hotplug: move and simplify walk_memory_blocks()

Let's move walk_memory_blocks() to the place where memory block logic
resides and simplify it.  While at it, add a type for the callback
function.

Link: http://lkml.kernel.org/r/20190614100114.311-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Qian Cai <cai@lca.pw>
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 c54e80fd25a84642d4fac619b321ee23522cd246..0204384b4d1dc7215542f94a2ba4f7a8c51970b6 100644 (file)
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -44,6 +44,11 @@ static inline unsigned long pfn_to_block_id(unsigned long pfn)
        return base_memory_block_id(pfn_to_section_nr(pfn));
 }
 
+static inline unsigned long phys_to_block_id(unsigned long phys)
+{
+       return pfn_to_block_id(PFN_DOWN(phys));
+}
+
 static int memory_subsys_online(struct device *dev);
 static int memory_subsys_offline(struct device *dev);
 
@@ -851,3 +856,40 @@ out:
                printk(KERN_ERR "%s() failed: %d\n", __func__, ret);
        return ret;
 }
+
+/**
+ * walk_memory_blocks - walk through all present memory blocks overlapped
+ *                     by the range [start, start + size)
+ *
+ * @start: start address of the memory range
+ * @size: size of the memory range
+ * @arg: argument passed to func
+ * @func: callback for each memory section walked
+ *
+ * This function walks through all present memory blocks overlapped by the
+ * range [start, start + size), calling func on each memory block.
+ *
+ * In case func() returns an error, walking is aborted and the error is
+ * returned.
+ */
+int walk_memory_blocks(unsigned long start, unsigned long size,
+                      void *arg, walk_memory_blocks_func_t func)
+{
+       const unsigned long start_block_id = phys_to_block_id(start);
+       const unsigned long end_block_id = phys_to_block_id(start + size - 1);
+       struct memory_block *mem;
+       unsigned long block_id;
+       int ret = 0;
+
+       for (block_id = start_block_id; block_id <= end_block_id; block_id++) {
+               mem = find_memory_block_by_id(block_id, NULL);
+               if (!mem)
+                       continue;
+
+               ret = func(mem, arg);
+               put_device(&mem->dev);
+               if (ret)
+                       break;
+       }
+       return ret;
+}

diff --git a/include/linux/memory.h b/include/linux/memory.h
index f26a5417ec5d6fad42b0b6f3e9c7af1255cbf3e5..b3b388775a308fe795d90c1cc8ebda46dae86d85 100644 (file)
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -119,6 +119,9 @@ extern int memory_isolate_notify(unsigned long val, void *v);
 extern struct memory_block *find_memory_block_hinted(struct mem_section *,
                                                        struct memory_block *);
 extern struct memory_block *find_memory_block(struct mem_section *);
+typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
+extern int walk_memory_blocks(unsigned long start, unsigned long size,
+                             void *arg, walk_memory_blocks_func_t func);
 #define CONFIG_MEM_BLOCK_SIZE  (PAGES_PER_SECTION<<PAGE_SHIFT)
 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 

diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index d9fffc34949f0ba25a2d4d28d0ecdc160c1f8c0b..475aff8efbf8bec24a4feebaeafe6fefee1c8327 100644 (file)
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -340,8 +340,6 @@ static inline void __remove_memory(int nid, u64 start, u64 size) {}
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
 extern void __ref free_area_init_core_hotplug(int nid);
-extern int walk_memory_blocks(unsigned long start, unsigned long size,
-               void *arg, int (*func)(struct memory_block *, void *));
 extern int __add_memory(int nid, u64 start, u64 size);
 extern int add_memory(int nid, u64 start, u64 size);
 extern int add_memory_resource(int nid, struct resource *resource);

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index b3ef84e408fade3b3900c8947511d9a32674406b..fafee5f13ef23ce3ba10226225d5e8f260f542b7 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1659,62 +1659,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
 {
        return __offline_pages(start_pfn, start_pfn + nr_pages);
 }
-#endif /* CONFIG_MEMORY_HOTREMOVE */
 
-/**
- * walk_memory_blocks - walk through all present memory blocks overlapped
- *                     by the range [start, start + size)
- *
- * @start: start address of the memory range
- * @size: size of the memory range
- * @arg: argument passed to func
- * @func: callback for each memory block walked
- *
- * This function walks through all present memory blocks overlapped by the
- * range [start, start + size), calling func on each memory block.
- *
- * Returns the return value of func.
- */
-int walk_memory_blocks(unsigned long start, unsigned long size,
-               void *arg, int (*func)(struct memory_block *, void *))
-{
-       const unsigned long start_pfn = PFN_DOWN(start);
-       const unsigned long end_pfn = PFN_UP(start + size - 1);
-       struct memory_block *mem = NULL;
-       struct mem_section *section;
-       unsigned long pfn, section_nr;
-       int ret;
-
-       for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
-               section_nr = pfn_to_section_nr(pfn);
-               if (!present_section_nr(section_nr))
-                       continue;
-
-               section = __nr_to_section(section_nr);
-               /* same memblock? */
-               if (mem)
-                       if ((section_nr >= mem->start_section_nr) &&
-                           (section_nr <= mem->end_section_nr))
-                               continue;
-
-               mem = find_memory_block_hinted(section, mem);
-               if (!mem)
-                       continue;
-
-               ret = func(mem, arg);
-               if (ret) {
-                       kobject_put(&mem->dev.kobj);
-                       return ret;
-               }
-       }
-
-       if (mem)
-               kobject_put(&mem->dev.kobj);
-
-       return 0;
-}
-
-#ifdef CONFIG_MEMORY_HOTREMOVE
 static int check_memblock_offlined_cb(struct memory_block *mem, void *arg)
 {
        int ret = !is_memblock_offlined(mem);