mm/memory_hotplug.c: make register_mem_sect_under_node() a callback of walk_memory_range()

link_mem_sections() and walk_memory_range() share most of the code, so
we can use convert link_mem_sections() into a dummy function that calls
walk_memory_range() with a callback to register_mem_sect_under_node().

This patch converts register_mem_sect_under_node() in order to match a
walk_memory_range's callback, getting rid of the check_nid argument and
checking instead if the system is still boothing, since we only have to
check for the nid if the system is in such state.

Link: http://lkml.kernel.org/r/20180622111839.10071-4-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Suggested-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 38 deletions

diff --git a/drivers/base/node.c b/drivers/base/node.c
index a5e821d09656..845d5523812b 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -399,10 +399,9 @@ static int __ref get_nid_for_pfn(unsigned long pfn)
 }
 
 /* register memory section under specified node if it spans that node */
-int register_mem_sect_under_node(struct memory_block *mem_blk, int nid,
-				 bool check_nid)
+int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg)
 {
-	int ret;
+	int ret, nid = *(int *)arg;
 	unsigned long pfn, sect_start_pfn, sect_end_pfn;
 
 	if (!mem_blk)
@@ -433,7 +432,7 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, int nid,
 		 * case, during hotplug we know that all pages in the memory
 		 * block belong to the same node.
 		 */
-		if (check_nid) {
+		if (system_state == SYSTEM_BOOTING) {
 			page_nid = get_nid_for_pfn(pfn);
 			if (page_nid < 0)
 				continue;
@@ -490,41 +489,10 @@ int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
 	return 0;
 }
 
-int link_mem_sections(int nid, unsigned long start_pfn, unsigned long nr_pages,
-		      bool check_nid)
+int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn)
 {
-	unsigned long end_pfn = start_pfn + nr_pages;
-	unsigned long pfn;
-	struct memory_block *mem_blk = NULL;
-	int err = 0;
-
-	for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
-		unsigned long section_nr = pfn_to_section_nr(pfn);
-		struct mem_section *mem_sect;
-		int ret;
-
-		if (!present_section_nr(section_nr))
-			continue;
-		mem_sect = __nr_to_section(section_nr);
-
-		/* same memblock ? */
-		if (mem_blk)
-			if ((section_nr >= mem_blk->start_section_nr) &&
-			    (section_nr <= mem_blk->end_section_nr))
-				continue;
-
-		mem_blk = find_memory_block_hinted(mem_sect, mem_blk);
-
-		ret = register_mem_sect_under_node(mem_blk, nid, check_nid);
-		if (!err)
-			err = ret;
-
-		/* discard ref obtained in find_memory_block() */
-	}
-
-	if (mem_blk)
-		kobject_put(&mem_blk->dev.kobj);
-	return err;
+	return walk_memory_range(start_pfn, end_pfn, (void *)&nid,
+					register_mem_sect_under_node);
 }
 
 #ifdef CONFIG_HUGETLBFS