memory hotplug: make alloc_bootmem_section()

alloc_bootmem_section() can allocate specified section's area.  This is used
for usemap to keep same section with pgdat by later patch.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
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>

diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
index 4e4e340..6a5dbdc 100644 (file)
--- a/include/linux/bootmem.h
+++ b/include/linux/bootmem.h
@@ -101,6 +101,8 @@ extern void reserve_bootmem_node(pg_data_t *pgdat,
 extern void free_bootmem_node(pg_data_t *pgdat,
                              unsigned long addr,
                              unsigned long size);
+extern void *alloc_bootmem_section(unsigned long size,
+                                  unsigned long section_nr);
 
 #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
 #define alloc_bootmem_node(pgdat, x) \

diff --git a/mm/bootmem.c b/mm/bootmem.c
index 369624d..e8fb927 100644 (file)
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -545,6 +545,37 @@ void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
        return __alloc_bootmem(size, align, goal);
 }
 
+#ifdef CONFIG_SPARSEMEM
+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;
+
+       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_core(pgdat->bdata, __pa(ptr), size);
+               ptr = NULL;
+       }
+
+       return ptr;
+}
+#endif
+
 #ifndef ARCH_LOW_ADDRESS_LIMIT
 #define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
 #endif