x86: Unify CPU -> NUMA node mapping between 32 and 64bit

Unlike 64bit, 32bit has been using its own cpu_to_node_map[] for
CPU -> NUMA node mapping.  Replace it with early_percpu variable
x86_cpu_to_node_map and share the mapping code with 64bit.

* USE_PERCPU_NUMA_NODE_ID is now enabled for 32bit too.

* x86_cpu_to_node_map and numa_set/clear_node() are moved from
  numa_64 to numa.  For now, on 32bit, x86_cpu_to_node_map is initialized
  with 0 instead of NUMA_NO_NODE.  This is to avoid introducing unexpected
  behavior change and will be updated once init path is unified.

* srat_detect_node() is now enabled for x86_32 too.  It calls
  numa_set_node() and initializes the mapping making explicit
  cpu_to_node_map[] updates from map/unmap_cpu_to_node() unnecessary.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: eric.dumazet@gmail.com
Cc: yinghai@kernel.org
Cc: brgerst@gmail.com
Cc: gorcunov@gmail.com
Cc: penberg@kernel.org
Cc: shaohui.zheng@intel.com
Cc: rientjes@google.com
LKML-Reference: <1295789862-25482-15-git-send-email-tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: David Rientjes <rientjes@google.com>

5 files changed, 5 insertions, 16 deletions

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index a7bca59ec595..a2c512175395 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -590,12 +590,7 @@ static void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
 	if (nid == -1 || !node_online(nid))
 		return;
 	set_apicid_to_node(physid, nid);
-#ifdef CONFIG_X86_64
 	numa_set_node(cpu, nid);
-#else /* CONFIG_X86_32 */
-	cpu_to_node_map[cpu] = nid;
-#endif
-
 #endif
 }
 
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 3cce8f2bb2e1..77858fd64620 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -233,7 +233,7 @@ static void __cpuinit init_amd_k7(struct cpuinfo_x86 *c)
 }
 #endif
 
-#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
+#ifdef CONFIG_NUMA
 /*
  * To workaround broken NUMA config.  Read the comment in
  * srat_detect_node().
@@ -338,7 +338,7 @@ EXPORT_SYMBOL_GPL(amd_get_nb_id);
 
 static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
 {
-#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
+#ifdef CONFIG_NUMA
 	int cpu = smp_processor_id();
 	int node;
 	unsigned apicid = c->apicid;
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 6052004bf4f4..df86bc8c859d 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -276,7 +276,7 @@ static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
 
 static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
 {
-#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
+#ifdef CONFIG_NUMA
 	unsigned node;
 	int cpu = smp_processor_id();
 
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index b5147f00f0ef..71f4727da373 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -233,6 +233,7 @@ void __init setup_per_cpu_areas(void)
 		per_cpu(irq_stack_ptr, cpu) =
 			per_cpu(irq_stack_union.irq_stack, cpu) +
 			IRQ_STACK_SIZE - 64;
+#endif
 #ifdef CONFIG_NUMA
 		per_cpu(x86_cpu_to_node_map, cpu) =
 			early_per_cpu_map(x86_cpu_to_node_map, cpu);
@@ -246,7 +247,6 @@ void __init setup_per_cpu_areas(void)
 		 */
 		set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
 #endif
-#endif
 		/*
 		 * Up to this point, the boot CPU has been using .init.data
 		 * area.  Reload any changed state for the boot CPU.
@@ -263,7 +263,7 @@ void __init setup_per_cpu_areas(void)
 #ifdef CONFIG_X86_32
 	early_per_cpu_ptr(x86_cpu_to_logical_apicid) = NULL;
 #endif
-#if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
+#ifdef CONFIG_NUMA
 	early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
 #endif
 
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index b7cfce535cb0..2c203822424f 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -133,16 +133,11 @@ EXPORT_PER_CPU_SYMBOL(cpu_info);
 atomic_t init_deasserted;
 
 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_32)
-/* which node each logical CPU is on */
-int cpu_to_node_map[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = 0 };
-EXPORT_SYMBOL(cpu_to_node_map);
-
 /* set up a mapping between cpu and node. */
 static void map_cpu_to_node(int cpu, int node)
 {
 	printk(KERN_INFO "Mapping cpu %d to node %d\n", cpu, node);
 	cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
-	cpu_to_node_map[cpu] = node;
 }
 
 /* undo a mapping between cpu and node. */
@@ -153,7 +148,6 @@ static void unmap_cpu_to_node(int cpu)
 	printk(KERN_INFO "Unmapping cpu %d from all nodes\n", cpu);
 	for (node = 0; node < MAX_NUMNODES; node++)
 		cpumask_clear_cpu(cpu, node_to_cpumask_map[node]);
-	cpu_to_node_map[cpu] = 0;
 }
 #else /* !(CONFIG_NUMA && CONFIG_X86_32) */
 #define map_cpu_to_node(cpu, node)	({})