ACPI/NUMA: Do not map pxm to node when NUMA is turned off

acpi_map_pxm_to_node() unconditially maps nodes even when NUMA is turned
off. So acpi_get_node() might return a node > 0, which is fatal when NUMA
is disabled as the rest of the kernel assumes that only node 0 exists.

Expose numa_off to the acpi code and return NUMA_NO_NODE when it's set.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: linux-ia64@vger.kernel.org
Cc: catalin.marinas@arm.com
Cc: rjw@rjwysocki.net
Cc: will.deacon@arm.com
Cc: linux-acpi@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: lenb@kernel.org
Link: http://lkml.kernel.org/r/1481602709-18260-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/arm64/include/asm/numa.h

@@ -15,6 +15,8 @@ int __node_distance(int from, int to);
 
 extern nodemask_t numa_nodes_parsed __initdata;
 
+extern bool numa_off;
+
 /* Mappings between node number and cpus on that node. */
 extern cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
 void numa_clear_node(unsigned int cpu);

arch/arm64/mm/numa.c

@@ -35,7 +35,7 @@ static int cpu_to_node_map[NR_CPUS] = { [0 ... NR_CPUS-1] = NUMA_NO_NODE };
 
 static int numa_distance_cnt;
 static u8 *numa_distance;
-static bool numa_off;
+bool numa_off;
 
 static __init int numa_parse_early_param(char *opt)
 {

arch/ia64/include/asm/numa.h

@@ -65,6 +65,8 @@ extern int paddr_to_nid(unsigned long paddr);
 
 #define local_nodeid (cpu_to_node_map[smp_processor_id()])
 
+#define numa_off     0
+
 extern void map_cpu_to_node(int cpu, int nid);
 extern void unmap_cpu_from_node(int cpu, int nid);
 extern void numa_clear_node(int cpu);

arch/x86/mm/numa.c

@@ -19,7 +19,7 @@
 
 #include "numa_internal.h"
 
-int __initdata numa_off;
+int numa_off;
 nodemask_t numa_nodes_parsed __initdata;
 
 struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;

drivers/acpi/numa.c

@@ -70,7 +70,7 @@ int acpi_map_pxm_to_node(int pxm)
 {
 	int node;
 
-	if (pxm < 0 || pxm >= MAX_PXM_DOMAINS)
+	if (pxm < 0 || pxm >= MAX_PXM_DOMAINS || numa_off)
 		return NUMA_NO_NODE;
 
 	node = pxm_to_node_map[pxm];