x86: Unify NUMA initialization between 32 and 64bit

Now that everything else is unified, NUMA initialization can be
unified too.

* numa_init_array() and init_cpu_to_node() are moved from
  numa_64 to numa.

* numa_32::initmem_init() is updated to call numa_init_array()
  and setup_arch() to call init_cpu_to_node() on 32bit too.

* x86_cpu_to_node_map is now initialized to NUMA_NO_NODE on
  32bit too. This is safe now as numa_init_array() will initialize
  it early during boot.

This makes NUMA mapping fully initialized before
setup_per_cpu_areas() on 32bit too and thus makes the first
percpu chunk which contains all the static variables and some of
dynamic area allocated with NUMA affinity correctly considered.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: yinghai@kernel.org
Cc: brgerst@gmail.com
Cc: gorcunov@gmail.com
Cc: shaohui.zheng@intel.com
Cc: rientjes@google.com
LKML-Reference: <1295789862-25482-17-git-send-email-tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>

3 files changed, 73 insertions, 79 deletions

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 75abecb614c..bf60715bd1b 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -38,11 +38,7 @@ EXPORT_SYMBOL(node_to_cpumask_map);
 /*
  * Map cpu index to node index
  */
-#ifdef CONFIG_X86_32
-DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, 0);
-#else
 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
-#endif
 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
 
 void __cpuinit numa_set_node(int cpu, int node)
@@ -99,6 +95,78 @@ void __init setup_node_to_cpumask_map(void)
         pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
 }
 
+/*
+ * There are unfortunately some poorly designed mainboards around that
+ * only connect memory to a single CPU. This breaks the 1:1 cpu->node
+ * mapping. To avoid this fill in the mapping for all possible CPUs,
+ * as the number of CPUs is not known yet. We round robin the existing
+ * nodes.
+ */
+void __init numa_init_array(void)
+{
+        int rr, i;
+
+        rr = first_node(node_online_map);
+        for (i = 0; i < nr_cpu_ids; i++) {
+                if (early_cpu_to_node(i) != NUMA_NO_NODE)
+                        continue;
+                numa_set_node(i, rr);
+                rr = next_node(rr, node_online_map);
+                if (rr == MAX_NUMNODES)
+                        rr = first_node(node_online_map);
+        }
+}
+
+static __init int find_near_online_node(int node)
+{
+        int n, val;
+        int min_val = INT_MAX;
+        int best_node = -1;
+
+        for_each_online_node(n) {
+                val = node_distance(node, n);
+
+                if (val < min_val) {
+                        min_val = val;
+                        best_node = n;
+                }
+        }
+
+        return best_node;
+}
+
+/*
+ * Setup early cpu_to_node.
+ *
+ * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
+ * and apicid_to_node[] tables have valid entries for a CPU.
+ * This means we skip cpu_to_node[] initialisation for NUMA
+ * emulation and faking node case (when running a kernel compiled
+ * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
+ * is already initialized in a round robin manner at numa_init_array,
+ * prior to this call, and this initialization is good enough
+ * for the fake NUMA cases.
+ *
+ * Called before the per_cpu areas are setup.
+ */
+void __init init_cpu_to_node(void)
+{
+        int cpu;
+        u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
+
+        BUG_ON(cpu_to_apicid == NULL);
+
+        for_each_possible_cpu(cpu) {
+                int node = numa_cpu_node(cpu);
+
+                if (node == NUMA_NO_NODE)
+                        continue;
+                if (!node_online(node))
+                        node = find_near_online_node(node);
+                numa_set_node(cpu, node);
+        }
+}
+
 #ifndef CONFIG_DEBUG_PER_CPU_MAPS
 
 # ifndef CONFIG_NUMA_EMU
diff --git a/arch/x86/mm/numa_32.c b/arch/x86/mm/numa_32.c
index 8d91d227be0..505bb04654b 100644
--- a/arch/x86/mm/numa_32.c
+++ b/arch/x86/mm/numa_32.c
@@ -367,6 +367,7 @@ void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn,
          */
 
         get_memcfg_numa();
+        numa_init_array();
 
         kva_pages = roundup(calculate_numa_remap_pages(), PTRS_PER_PTE);
 
diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index 14664f58a75..f548fbf75f4 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -224,28 +224,6 @@ setup_node_bootmem(int nodeid, unsigned long start, unsigned long end)
         node_set_online(nodeid);
 }
 
-/*
- * There are unfortunately some poorly designed mainboards around that
- * only connect memory to a single CPU. This breaks the 1:1 cpu->node
- * mapping. To avoid this fill in the mapping for all possible CPUs,
- * as the number of CPUs is not known yet. We round robin the existing
- * nodes.
- */
-void __init numa_init_array(void)
-{
-        int rr, i;
-
-        rr = first_node(node_online_map);
-        for (i = 0; i < nr_cpu_ids; i++) {
-                if (early_cpu_to_node(i) != NUMA_NO_NODE)
-                        continue;
-                numa_set_node(i, rr);
-                rr = next_node(rr, node_online_map);
-                if (rr == MAX_NUMNODES)
-                        rr = first_node(node_online_map);
-        }
-}
-
 #ifdef CONFIG_NUMA_EMU
 /* Numa emulation */
 static struct bootnode nodes[MAX_NUMNODES] __initdata;
@@ -664,59 +642,6 @@ unsigned long __init numa_free_all_bootmem(void)
         return pages;
 }
 
-#ifdef CONFIG_NUMA
-
-static __init int find_near_online_node(int node)
-{
-        int n, val;
-        int min_val = INT_MAX;
-        int best_node = -1;
-
-        for_each_online_node(n) {
-                val = node_distance(node, n);
-
-                if (val < min_val) {
-                        min_val = val;
-                        best_node = n;
-                }
-        }
-
-        return best_node;
-}
-
-/*
- * Setup early cpu_to_node.
- *
- * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
- * and apicid_to_node[] tables have valid entries for a CPU.
- * This means we skip cpu_to_node[] initialisation for NUMA
- * emulation and faking node case (when running a kernel compiled
- * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
- * is already initialized in a round robin manner at numa_init_array,
- * prior to this call, and this initialization is good enough
- * for the fake NUMA cases.
- *
- * Called before the per_cpu areas are setup.
- */
-void __init init_cpu_to_node(void)
-{
-        int cpu;
-        u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
-
-        BUG_ON(cpu_to_apicid == NULL);
-
-        for_each_possible_cpu(cpu) {
-                int node = numa_cpu_node(cpu);
-
-                if (node == NUMA_NO_NODE)
-                        continue;
-                if (!node_online(node))
-                        node = find_near_online_node(node);
-                numa_set_node(cpu, node);
-        }
-}
-#endif
-
 int __cpuinit numa_cpu_node(int cpu)
 {
         int apicid = early_per_cpu(x86_cpu_to_apicid, cpu);