bootmem: revisit alloc_bootmem_section

Since alloc_bootmem_core does no goal-fallback anymore and just returns
NULL if the allocation fails, we might now use it in alloc_bootmem_section
without all the fixup code for a misplaced allocation.

Also, the limit can be the first PFN of the next section as the semantics
is that the limit is _above_ the allocated region, not within.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 21 deletions

diff --git a/mm/bootmem.c b/mm/bootmem.c
index 459da4710b8f..282b786c2b15 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -632,30 +632,15 @@ void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
 void * __init alloc_bootmem_section(unsigned long size,
                                     unsigned long section_nr)
 {
-        void *ptr;
-        unsigned long limit, goal, start_nr, end_nr, pfn;
-        struct pglist_data *pgdat;
+        bootmem_data_t *bdata;
+        unsigned long pfn, goal, limit;
 
         pfn = section_nr_to_pfn(section_nr);
-        goal = PFN_PHYS(pfn);
-        limit = PFN_PHYS(section_nr_to_pfn(section_nr + 1)) - 1;
-        pgdat = NODE_DATA(early_pfn_to_nid(pfn));
-        ptr = alloc_bootmem_core(pgdat->bdata, size, SMP_CACHE_BYTES, goal,
-                                limit);
-
-        if (!ptr)
-                return NULL;
-
-        start_nr = pfn_to_section_nr(PFN_DOWN(__pa(ptr)));
-        end_nr = pfn_to_section_nr(PFN_DOWN(__pa(ptr) + size));
-        if (start_nr != section_nr || end_nr != section_nr) {
-                printk(KERN_WARNING "alloc_bootmem failed on section %ld.\n",
-                       section_nr);
-                free_bootmem_node(pgdat, __pa(ptr), size);
-                ptr = NULL;
-        }
+        goal = pfn << PAGE_SHIFT;
+        limit = section_nr_to_pfn(section_nr + 1) << PAGE_SHIFT;
+        bdata = &bootmem_node_data[early_pfn_to_nid(pfn)];
 
-        return ptr;
+        return alloc_bootmem_core(bdata, size, SMP_CACHE_BYTES, goal, limit);
 }
 #endif