Add a helper function for updating the per-cpu core and sibling thread
cpumasks. This helper just sets (or clears) the relevant bit in the
cpumasks each CPU. This is open-coded in several places inside the
mask setup code so moving it into a seperate function is a sensible
cleanup.
Signed-off-by: Oliver O'Halloran <ooh...@gmail.com>
---
arch/powerpc/kernel/smp.c | 61 ++++++++++++++++++++++++-----------------------
1 file changed, 31 insertions(+), 30 deletions(-)
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index dfe0e1d9cd06..1c531887ca51 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -377,6 +377,25 @@ static void smp_store_cpu_info(int id)
#endif
}
+/*
+ * Relationships between CPUs are maintained in a set of per-cpu cpumasks. We
+ * need to ensure that they are kept consistant between CPUs when they are
+ * changed.
+ *
+ * This is slightly tricky since the core mask must be a strict superset of
+ * the sibling mask.
+ */
+static void set_cpus_related(int i, int j, bool related, struct cpumask
*(*relation_fn)(int))
+{
+ if (related) {
+ cpumask_set_cpu(i, relation_fn(j));
+ cpumask_set_cpu(j, relation_fn(i));
+ } else {
+ cpumask_clear_cpu(i, relation_fn(j));
+ cpumask_clear_cpu(j, relation_fn(i));
+ }
+}
+
void __init smp_prepare_cpus(unsigned int max_cpus)
{
unsigned int cpu;
@@ -616,17 +635,9 @@ static void traverse_siblings_chip_id(int cpu, bool add,
int chipid)
const struct cpumask *mask = add ? cpu_online_mask : cpu_present_mask;
int i;
- for_each_cpu(i, mask) {
- if (cpu_to_chip_id(i) == chipid) {
- if (add) {
- cpumask_set_cpu(cpu, cpu_core_mask(i));
- cpumask_set_cpu(i, cpu_core_mask(cpu));
- } else {
- cpumask_clear_cpu(cpu, cpu_core_mask(i));
- cpumask_clear_cpu(i, cpu_core_mask(cpu));
- }
- }
- }
+ for_each_cpu(i, mask)
+ if (cpu_to_chip_id(i) == chipid)
+ set_cpus_related(cpu, i, add, cpu_core_mask);
}
/* Must be called when no change can occur to cpu_present_mask,
@@ -666,23 +677,17 @@ static void traverse_core_siblings(int cpu, bool add)
return;
}
- /* if the chip-id fails then threads which share L2 cache are */
-
+ /* if the chip-id fails then group siblings by the L2 cache */
l2_cache = cpu_to_l2cache(cpu);
mask = add ? cpu_online_mask : cpu_present_mask;
for_each_cpu(i, mask) {
np = cpu_to_l2cache(i);
if (!np)
continue;
- if (np == l2_cache) {
- if (add) {
- cpumask_set_cpu(cpu, cpu_core_mask(i));
- cpumask_set_cpu(i, cpu_core_mask(cpu));
- } else {
- cpumask_clear_cpu(cpu, cpu_core_mask(i));
- cpumask_clear_cpu(i, cpu_core_mask(cpu));
- }
- }
+
+ if (np == l2_cache)
+ set_cpus_related(cpu, i, add, cpu_core_mask);
+
of_node_put(np);
}
of_node_put(l2_cache);
@@ -720,15 +725,13 @@ void start_secondary(void *unused)
for (i = 0; i < threads_per_core; i++) {
if (cpu_is_offline(base + i) && (cpu != base + i))
continue;
- cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
- cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
+ set_cpus_related(cpu, base + i, true, cpu_sibling_mask);
/* cpu_core_map should be a superset of
* cpu_sibling_map even if we don't have cache
* information, so update the former here, too.
*/
- cpumask_set_cpu(cpu, cpu_core_mask(base + i));
- cpumask_set_cpu(base + i, cpu_core_mask(cpu));
+ set_cpus_related(cpu, base + i, true, cpu_core_mask);
}
traverse_core_siblings(cpu, true);
@@ -818,10 +821,8 @@ int __cpu_disable(void)
/* Update sibling maps */
base = cpu_first_thread_sibling(cpu);
for (i = 0; i < threads_per_core && base + i < nr_cpu_ids; i++) {
- cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
- cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
- cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
- cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
+ set_cpus_related(cpu, base + i, false, cpu_sibling_mask);
+ set_cpus_related(cpu, base + i, false, cpu_core_mask);
}
traverse_core_siblings(cpu, false);
--
2.9.3
