mm: remove sparsemem allocation details from the bootmem allocator

alloc_bootmem_section() derives allocation area constraints from the
specified sparsemem section.  This is a bit specific for a generic memory
allocator like bootmem, though, so move it over to sparsemem.

As __alloc_bootmem_node_nopanic() already retries failed allocations with
relaxed area constraints, the fallback code in sparsemem.c can be removed
and the code becomes a bit more compact overall.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 12 insertions, 57 deletions

diff --git a/mm/bootmem.c b/mm/bootmem.c
index 9d0f26664b3b..d1c7a79d6f3a 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -803,28 +803,6 @@ void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
 
 }
 
-#ifdef CONFIG_SPARSEMEM
-/**
- * alloc_bootmem_section - allocate boot memory from a specific section
- * @size: size of the request in bytes
- * @section_nr: sparse map section to allocate from
- *
- * Return NULL on failure.
- */
-void * __init alloc_bootmem_section(unsigned long size,
-                                    unsigned long section_nr)
-{
-        bootmem_data_t *bdata;
-        unsigned long pfn, goal;
-
-        pfn = section_nr_to_pfn(section_nr);
-        goal = pfn << PAGE_SHIFT;
-        bdata = &bootmem_node_data[early_pfn_to_nid(pfn)];
-
-        return alloc_bootmem_bdata(bdata, size, SMP_CACHE_BYTES, goal, 0);
-}
-#endif
-
 #ifndef ARCH_LOW_ADDRESS_LIMIT
 #define ARCH_LOW_ADDRESS_LIMIT  0xffffffffUL
 #endif
diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index 9f4048149f64..d23415c001bc 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -355,28 +355,6 @@ void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
         return __alloc_bootmem_node(pgdat, size, align, goal);
 }
 
-#ifdef CONFIG_SPARSEMEM
-/**
- * alloc_bootmem_section - allocate boot memory from a specific section
- * @size: size of the request in bytes
- * @section_nr: sparse map section to allocate from
- *
- * Return NULL on failure.
- */
-void * __init alloc_bootmem_section(unsigned long size,
-                                    unsigned long section_nr)
-{
-        unsigned long pfn, goal, limit;
-
-        pfn = section_nr_to_pfn(section_nr);
-        goal = pfn << PAGE_SHIFT;
-        limit = section_nr_to_pfn(section_nr + 1) << PAGE_SHIFT;
-
-        return __alloc_memory_core_early(early_pfn_to_nid(pfn), size,
-                                         SMP_CACHE_BYTES, goal, limit);
-}
-#endif
-
 #ifndef ARCH_LOW_ADDRESS_LIMIT
 #define ARCH_LOW_ADDRESS_LIMIT  0xffffffffUL
 #endif
diff --git a/mm/sparse.c b/mm/sparse.c
index a8bc7d364deb..6a4bf9160e85 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -273,10 +273,10 @@ static unsigned long *__kmalloc_section_usemap(void)
 #ifdef CONFIG_MEMORY_HOTREMOVE
 static unsigned long * __init
 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
-                                         unsigned long count)
+                                         unsigned long size)
 {
-        unsigned long section_nr;
-
+        pg_data_t *host_pgdat;
+        unsigned long goal;
         /*
          * A page may contain usemaps for other sections preventing the
          * page being freed and making a section unremovable while
@@ -287,8 +287,10 @@ sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
          * from the same section as the pgdat where possible to avoid
          * this problem.
          */
-        section_nr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
-        return alloc_bootmem_section(usemap_size() * count, section_nr);
+        goal = __pa(pgdat) & PAGE_SECTION_MASK;
+        host_pgdat = NODE_DATA(early_pfn_to_nid(goal >> PAGE_SHIFT));
+        return __alloc_bootmem_node_nopanic(host_pgdat, size,
+                                            SMP_CACHE_BYTES, goal);
 }
 
 static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
@@ -332,9 +334,9 @@ static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
 #else
 static unsigned long * __init
 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
-                                         unsigned long count)
+                                         unsigned long size)
 {
-        return NULL;
+        return alloc_bootmem_node_nopanic(pgdat, size);
 }
 
 static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
@@ -352,13 +354,10 @@ static void __init sparse_early_usemaps_alloc_node(unsigned long**usemap_map,
         int size = usemap_size();
 
         usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nodeid),
-                                                                 usemap_count);
+                                                          size * usemap_count);
         if (!usemap) {
-                usemap = alloc_bootmem_node(NODE_DATA(nodeid), size * usemap_count);
-                if (!usemap) {
-                        printk(KERN_WARNING "%s: allocation failed\n", __func__);
-                        return;
-                }
+                printk(KERN_WARNING "%s: allocation failed\n", __func__);
+                return;
         }
 
         for (pnum = pnum_begin; pnum < pnum_end; pnum++) {