x86-64, NUMA: Seperate out numa_alloc_distance() from numa_set_distance()

Alloc code is much bigger the distance setting.  Separate it out into
numa_alloc_distance() for readability.

-v2: Let alloc_numa_distance to return -ENOMEM on failing path,
     requested by tj.

-tj: Description update.  Minor tweaks including function name,
     location and return value check.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 40 insertions, 35 deletions

diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index 848381bdd358..cccc01d8415c 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -401,6 +401,44 @@ void __init numa_reset_distance(void)
         numa_distance = NULL;
 }
 
+static int __init numa_alloc_distance(void)
+{
+        nodemask_t nodes_parsed;
+        size_t size;
+        int i, j, cnt = 0;
+        u64 phys;
+
+        /* size the new table and allocate it */
+        nodes_parsed = numa_nodes_parsed;
+        numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
+
+        for_each_node_mask(i, nodes_parsed)
+                cnt = i;
+        size = ++cnt * sizeof(numa_distance[0]);
+
+        phys = memblock_find_in_range(0, (u64)max_pfn_mapped << PAGE_SHIFT,
+                                      size, PAGE_SIZE);
+        if (phys == MEMBLOCK_ERROR) {
+                pr_warning("NUMA: Warning: can't allocate distance table!\n");
+                /* don't retry until explicitly reset */
+                numa_distance = (void *)1LU;
+                return -ENOMEM;
+        }
+        memblock_x86_reserve_range(phys, phys + size, "NUMA DIST");
+
+        numa_distance = __va(phys);
+        numa_distance_cnt = cnt;
+
+        /* fill with the default distances */
+        for (i = 0; i < cnt; i++)
+                for (j = 0; j < cnt; j++)
+                        numa_distance[i * cnt + j] = i == j ?
+                                LOCAL_DISTANCE : REMOTE_DISTANCE;
+        printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
+
+        return 0;
+}
+
 /**
  * numa_set_distance - Set NUMA distance from one NUMA to another
  * @from: the 'from' node to set distance
@@ -413,41 +451,8 @@ void __init numa_reset_distance(void)
  */
 void __init numa_set_distance(int from, int to, int distance)
 {
-        if (!numa_distance) {
-                nodemask_t nodes_parsed;
-                size_t size;
-                int i, j, cnt = 0;
-                u64 phys;
-
-                /* size the new table and allocate it */
-                nodes_parsed = numa_nodes_parsed;
-                numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
-
-                for_each_node_mask(i, nodes_parsed)
-                        cnt = i;
-                size = ++cnt * sizeof(numa_distance[0]);
-
-                phys = memblock_find_in_range(0,
-                                              (u64)max_pfn_mapped << PAGE_SHIFT,
-                                              size, PAGE_SIZE);
-                if (phys == MEMBLOCK_ERROR) {
-                        pr_warning("NUMA: Warning: can't allocate distance table!\n");
-                        /* don't retry until explicitly reset */
-                        numa_distance = (void *)1LU;
-                        return;
-                }
-                memblock_x86_reserve_range(phys, phys + size, "NUMA DIST");
-
-                numa_distance = __va(phys);
-                numa_distance_cnt = cnt;
-
-                /* fill with the default distances */
-                for (i = 0; i < cnt; i++)
-                        for (j = 0; j < cnt; j++)
-                                numa_distance[i * cnt + j] = i == j ?
-                                        LOCAL_DISTANCE : REMOTE_DISTANCE;
-                printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
-        }
+        if (!numa_distance && numa_alloc_distance() < 0)
+                return;
 
         if (from >= numa_distance_cnt || to >= numa_distance_cnt) {
                 printk_once(KERN_DEBUG "NUMA: Debug: distance out of bound, from=%d to=%d distance=%d\n",