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-rw-r--r--arch/powerpc/mm/numa.c96
1 files changed, 91 insertions, 5 deletions
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 5a944f25e94f..86a63de072c6 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -31,6 +31,8 @@
#include <asm/sparsemem.h>
#include <asm/prom.h>
#include <asm/smp.h>
+#include <asm/cputhreads.h>
+#include <asm/topology.h>
#include <asm/firmware.h>
#include <asm/paca.h>
#include <asm/hvcall.h>
@@ -152,9 +154,22 @@ static void __init get_node_active_region(unsigned long pfn,
}
}
-static void map_cpu_to_node(int cpu, int node)
+static void reset_numa_cpu_lookup_table(void)
+{
+ unsigned int cpu;
+
+ for_each_possible_cpu(cpu)
+ numa_cpu_lookup_table[cpu] = -1;
+}
+
+static void update_numa_cpu_lookup_table(unsigned int cpu, int node)
{
numa_cpu_lookup_table[cpu] = node;
+}
+
+static void map_cpu_to_node(int cpu, int node)
+{
+ update_numa_cpu_lookup_table(cpu, node);
dbg("adding cpu %d to node %d\n", cpu, node);
@@ -522,11 +537,24 @@ static int of_drconf_to_nid_single(struct of_drconf_cell *drmem,
*/
static int numa_setup_cpu(unsigned long lcpu)
{
- int nid = 0;
- struct device_node *cpu = of_get_cpu_node(lcpu, NULL);
+ int nid;
+ struct device_node *cpu;
+
+ /*
+ * If a valid cpu-to-node mapping is already available, use it
+ * directly instead of querying the firmware, since it represents
+ * the most recent mapping notified to us by the platform (eg: VPHN).
+ */
+ if ((nid = numa_cpu_lookup_table[lcpu]) >= 0) {
+ map_cpu_to_node(lcpu, nid);
+ return nid;
+ }
+
+ cpu = of_get_cpu_node(lcpu, NULL);
if (!cpu) {
WARN_ON(1);
+ nid = 0;
goto out;
}
@@ -542,16 +570,38 @@ out:
return nid;
}
+static void verify_cpu_node_mapping(int cpu, int node)
+{
+ int base, sibling, i;
+
+ /* Verify that all the threads in the core belong to the same node */
+ base = cpu_first_thread_sibling(cpu);
+
+ for (i = 0; i < threads_per_core; i++) {
+ sibling = base + i;
+
+ if (sibling == cpu || cpu_is_offline(sibling))
+ continue;
+
+ if (cpu_to_node(sibling) != node) {
+ WARN(1, "CPU thread siblings %d and %d don't belong"
+ " to the same node!\n", cpu, sibling);
+ break;
+ }
+ }
+}
+
static int cpu_numa_callback(struct notifier_block *nfb, unsigned long action,
void *hcpu)
{
unsigned long lcpu = (unsigned long)hcpu;
- int ret = NOTIFY_DONE;
+ int ret = NOTIFY_DONE, nid;
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- numa_setup_cpu(lcpu);
+ nid = numa_setup_cpu(lcpu);
+ verify_cpu_node_mapping((int)lcpu, nid);
ret = NOTIFY_OK;
break;
#ifdef CONFIG_HOTPLUG_CPU
@@ -1069,6 +1119,7 @@ void __init do_init_bootmem(void)
*/
setup_node_to_cpumask_map();
+ reset_numa_cpu_lookup_table();
register_cpu_notifier(&ppc64_numa_nb);
cpu_numa_callback(&ppc64_numa_nb, CPU_UP_PREPARE,
(void *)(unsigned long)boot_cpuid);
@@ -1447,6 +1498,33 @@ static int update_cpu_topology(void *data)
return 0;
}
+static int update_lookup_table(void *data)
+{
+ struct topology_update_data *update;
+
+ if (!data)
+ return -EINVAL;
+
+ /*
+ * Upon topology update, the numa-cpu lookup table needs to be updated
+ * for all threads in the core, including offline CPUs, to ensure that
+ * future hotplug operations respect the cpu-to-node associativity
+ * properly.
+ */
+ for (update = data; update; update = update->next) {
+ int nid, base, j;
+
+ nid = update->new_nid;
+ base = cpu_first_thread_sibling(update->cpu);
+
+ for (j = 0; j < threads_per_core; j++) {
+ update_numa_cpu_lookup_table(base + j, nid);
+ }
+ }
+
+ return 0;
+}
+
/*
* Update the node maps and sysfs entries for each cpu whose home node
* has changed. Returns 1 when the topology has changed, and 0 otherwise.
@@ -1515,6 +1593,14 @@ int arch_update_cpu_topology(void)
stop_machine(update_cpu_topology, &updates[0], &updated_cpus);
+ /*
+ * Update the numa-cpu lookup table with the new mappings, even for
+ * offline CPUs. It is best to perform this update from the stop-
+ * machine context.
+ */
+ stop_machine(update_lookup_table, &updates[0],
+ cpumask_of(raw_smp_processor_id()));
+
for (ud = &updates[0]; ud; ud = ud->next) {
unregister_cpu_under_node(ud->cpu, ud->old_nid);
register_cpu_under_node(ud->cpu, ud->new_nid);