#include <linux/mmzone.h>
#include <linux/bootmem.h>
#include <linux/module.h>
+#include <linux/spinlock.h>
#include <asm/dma.h>
/*
*
* 1) mem_section - memory sections, mem_map's for valid memory
*/
-#ifdef CONFIG_ARCH_SPARSEMEM_EXTREME
+#ifdef CONFIG_SPARSEMEM_EXTREME
struct mem_section *mem_section[NR_SECTION_ROOTS]
____cacheline_maxaligned_in_smp;
+#else
+struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
+ ____cacheline_maxaligned_in_smp;
+#endif
+EXPORT_SYMBOL(mem_section);
-static void sparse_index_init(unsigned long section, int nid)
+#ifdef CONFIG_SPARSEMEM_EXTREME
+static struct mem_section *sparse_index_alloc(int nid)
{
- unsigned long root = SECTION_TO_ROOT(section);
+ struct mem_section *section = NULL;
+ unsigned long array_size = SECTIONS_PER_ROOT *
+ sizeof(struct mem_section);
+
+ section = alloc_bootmem_node(NODE_DATA(nid), array_size);
+
+ if (section)
+ memset(section, 0, array_size);
+
+ return section;
+}
+
+static int sparse_index_init(unsigned long section_nr, int nid)
+{
+ static spinlock_t index_init_lock = SPIN_LOCK_UNLOCKED;
+ unsigned long root = SECTION_NR_TO_ROOT(section_nr);
+ struct mem_section *section;
+ int ret = 0;
if (mem_section[root])
- return;
- mem_section[root] = alloc_bootmem_node(NODE_DATA(nid), PAGE_SIZE);
- if (mem_section[root])
- memset(mem_section[root], 0, PAGE_SIZE);
- else
- panic("memory_present: NO MEMORY\n");
+ return -EEXIST;
+
+ section = sparse_index_alloc(nid);
+ /*
+ * This lock keeps two different sections from
+ * reallocating for the same index
+ */
+ spin_lock(&index_init_lock);
+
+ if (mem_section[root]) {
+ ret = -EEXIST;
+ goto out;
+ }
+
+ mem_section[root] = section;
+out:
+ spin_unlock(&index_init_lock);
+ return ret;
+}
+#else /* !SPARSEMEM_EXTREME */
+static inline int sparse_index_init(unsigned long section_nr, int nid)
+{
+ return 0;
}
-#else
-struct mem_section mem_section[NR_MEM_SECTIONS]
- ____cacheline_maxaligned_in_smp;
#endif
-EXPORT_SYMBOL(mem_section);
/* Record a memory area against a node. */
void memory_present(int nid, unsigned long start, unsigned long end)