1 files changed, 20 insertions, 10 deletions

diff --git a/arch/powerpc/kernel/cacheinfo.c b/arch/powerpc/kernel/cacheinfo.c
index 65ab9fcebd31..6f903e9aa20b 100644
--- a/arch/powerpc/kernel/cacheinfo.c
+++ b/arch/powerpc/kernel/cacheinfo.c
@@ -655,11 +655,27 @@ static unsigned int index_dir_to_cpu(struct cache_index_dir *index)
  * On big-core systems, each core has two groups of CPUs each of which
  * has its own L1-cache. The thread-siblings which share l1-cache with
  * @cpu can be obtained via cpu_smallcore_mask().
+ *
+ * On some big-core systems, the L2 cache is shared only between some
+ * groups of siblings. This is already parsed and encoded in
+ * cpu_l2_cache_mask().
+ *
+ * TODO: cache_lookup_or_instantiate() needs to be made aware of the
+ *       "ibm,thread-groups" property so that cache->shared_cpu_map
+ *       reflects the correct siblings on platforms that have this
+ *       device-tree property. This helper function is only a stop-gap
+ *       solution so that we report the correct siblings to the
+ *       userspace via sysfs.
  */
-static const struct cpumask *get_big_core_shared_cpu_map(int cpu, struct cache *cache)
+static const struct cpumask *get_shared_cpu_map(struct cache_index_dir *index, struct cache *cache)
 {
-	if (cache->level == 1)
-		return cpu_smallcore_mask(cpu);
+	if (has_big_cores) {
+		int cpu = index_dir_to_cpu(index);
+		if (cache->level == 1)
+			return cpu_smallcore_mask(cpu);
+		if (cache->level == 2 && thread_group_shares_l2)
+			return cpu_l2_cache_mask(cpu);
+	}
 
 	return &cache->shared_cpu_map;
 }
@@ -670,17 +686,11 @@ show_shared_cpumap(struct kobject *k, struct kobj_attribute *attr, char *buf, bo
 	struct cache_index_dir *index;
 	struct cache *cache;
 	const struct cpumask *mask;
-	int cpu;
 
 	index = kobj_to_cache_index_dir(k);
 	cache = index->cache;
 
-	if (has_big_cores) {
-		cpu = index_dir_to_cpu(index);
-		mask = get_big_core_shared_cpu_map(cpu, cache);
-	} else {
-		mask  = &cache->shared_cpu_map;
-	}
+	mask = get_shared_cpu_map(index, cache);
 
 	return cpumap_print_to_pagebuf(list, buf, mask);
 }