mm/sparsemem: use PAGES_PER_SECTION to remove redundant nr_pages parameter

For below functions,

- sparse_add_one_section()
- kmalloc_section_memmap()
- __kmalloc_section_memmap()
- __kfree_section_memmap()

they are always invoked to operate on one memory section, so it is
redundant to always pass a nr_pages parameter, which is the page numbers
in one section.  So we can directly use predefined macro PAGES_PER_SECTION
instead of passing the parameter.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 17 insertions, 22 deletions

diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 22203c293f07..4ca3d951fe91 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -268,8 +268,7 @@ extern int arch_add_memory(int nid, u64 start, u64 size);
 extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
 extern bool is_memblock_offlined(struct memory_block *mem);
 extern void remove_memory(int nid, u64 start, u64 size);
-extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
-                                                                int nr_pages);
+extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn);
 extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms);
 extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
                                           unsigned long pnum);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 8285346be663..1b6fe8ca71e6 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -401,13 +401,12 @@ static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
 static int __meminit __add_section(int nid, struct zone *zone,
                                         unsigned long phys_start_pfn)
 {
-        int nr_pages = PAGES_PER_SECTION;
         int ret;
 
         if (pfn_valid(phys_start_pfn))
                 return -EEXIST;
 
-        ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
+        ret = sparse_add_one_section(zone, phys_start_pfn);
 
         if (ret < 0)
                 return ret;
diff --git a/mm/sparse.c b/mm/sparse.c
index 4ac1d7ef548f..fbb9dbc6aca9 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -590,16 +590,15 @@ void __init sparse_init(void)
 
 #ifdef CONFIG_MEMORY_HOTPLUG
 #ifdef CONFIG_SPARSEMEM_VMEMMAP
-static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
-                                                 unsigned long nr_pages)
+static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid)
 {
         /* This will make the necessary allocations eventually. */
         return sparse_mem_map_populate(pnum, nid);
 }
-static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
+static void __kfree_section_memmap(struct page *memmap)
 {
         unsigned long start = (unsigned long)memmap;
-        unsigned long end = (unsigned long)(memmap + nr_pages);
+        unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
 
         vmemmap_free(start, end);
 }
@@ -613,10 +612,10 @@ static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
 }
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 #else
-static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
+static struct page *__kmalloc_section_memmap(void)
 {
         struct page *page, *ret;
-        unsigned long memmap_size = sizeof(struct page) * nr_pages;
+        unsigned long memmap_size = sizeof(struct page) * PAGES_PER_SECTION;
 
         page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
         if (page)
@@ -634,19 +633,18 @@ got_map_ptr:
         return ret;
 }
 
-static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
-                                                  unsigned long nr_pages)
+static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid)
 {
-        return __kmalloc_section_memmap(nr_pages);
+        return __kmalloc_section_memmap();
 }
 
-static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
+static void __kfree_section_memmap(struct page *memmap)
 {
         if (is_vmalloc_addr(memmap))
                 vfree(memmap);
         else
                 free_pages((unsigned long)memmap,
-                           get_order(sizeof(struct page) * nr_pages));
+                           get_order(sizeof(struct page) * PAGES_PER_SECTION));
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
@@ -684,8 +682,7 @@ static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
  * set.  If this is <=0, then that means that the passed-in
  * map was not consumed and must be freed.
  */
-int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
-                           int nr_pages)
+int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn)
 {
         unsigned long section_nr = pfn_to_section_nr(start_pfn);
         struct pglist_data *pgdat = zone->zone_pgdat;
@@ -702,12 +699,12 @@ int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
         ret = sparse_index_init(section_nr, pgdat->node_id);
         if (ret < 0 && ret != -EEXIST)
                 return ret;
-        memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, nr_pages);
+        memmap = kmalloc_section_memmap(section_nr, pgdat->node_id);
         if (!memmap)
                 return -ENOMEM;
         usemap = __kmalloc_section_usemap();
         if (!usemap) {
-                __kfree_section_memmap(memmap, nr_pages);
+                __kfree_section_memmap(memmap);
                 return -ENOMEM;
         }
 
@@ -719,7 +716,7 @@ int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
                 goto out;
         }
 
-        memset(memmap, 0, sizeof(struct page) * nr_pages);
+        memset(memmap, 0, sizeof(struct page) * PAGES_PER_SECTION);
 
         ms->section_mem_map |= SECTION_MARKED_PRESENT;
 
@@ -729,7 +726,7 @@ out:
         pgdat_resize_unlock(pgdat, &flags);
         if (ret <= 0) {
                 kfree(usemap);
-                __kfree_section_memmap(memmap, nr_pages);
+                __kfree_section_memmap(memmap);
         }
         return ret;
 }
@@ -771,7 +768,7 @@ static void free_section_usemap(struct page *memmap, unsigned long *usemap)
         if (PageSlab(usemap_page) || PageCompound(usemap_page)) {
                 kfree(usemap);
                 if (memmap)
-                        __kfree_section_memmap(memmap, PAGES_PER_SECTION);
+                        __kfree_section_memmap(memmap);
                 return;
         }