2 files changed, 59 insertions, 6 deletions

diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
index d9dc2c38764a..7d66ee68aaaf 100644
--- a/kernel/power/energy_model.c
+++ b/kernel/power/energy_model.c
@@ -10,6 +10,7 @@
 
 #include <linux/cpu.h>
 #include <linux/cpumask.h>
+#include <linux/debugfs.h>
 #include <linux/energy_model.h>
 #include <linux/sched/topology.h>
 #include <linux/slab.h>
@@ -23,6 +24,60 @@ static DEFINE_PER_CPU(struct em_perf_domain *, em_data);
  */
 static DEFINE_MUTEX(em_pd_mutex);
 
+#ifdef CONFIG_DEBUG_FS
+static struct dentry *rootdir;
+
+static void em_debug_create_cs(struct em_cap_state *cs, struct dentry *pd)
+{
+        struct dentry *d;
+        char name[24];
+
+        snprintf(name, sizeof(name), "cs:%lu", cs->frequency);
+
+        /* Create per-cs directory */
+        d = debugfs_create_dir(name, pd);
+        debugfs_create_ulong("frequency", 0444, d, &cs->frequency);
+        debugfs_create_ulong("power", 0444, d, &cs->power);
+        debugfs_create_ulong("cost", 0444, d, &cs->cost);
+}
+
+static int em_debug_cpus_show(struct seq_file *s, void *unused)
+{
+        seq_printf(s, "%*pbl\n", cpumask_pr_args(to_cpumask(s->private)));
+
+        return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(em_debug_cpus);
+
+static void em_debug_create_pd(struct em_perf_domain *pd, int cpu)
+{
+        struct dentry *d;
+        char name[8];
+        int i;
+
+        snprintf(name, sizeof(name), "pd%d", cpu);
+
+        /* Create the directory of the performance domain */
+        d = debugfs_create_dir(name, rootdir);
+
+        debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops);
+
+        /* Create a sub-directory for each capacity state */
+        for (i = 0; i < pd->nr_cap_states; i++)
+                em_debug_create_cs(&pd->table[i], d);
+}
+
+static int __init em_debug_init(void)
+{
+        /* Create /sys/kernel/debug/energy_model directory */
+        rootdir = debugfs_create_dir("energy_model", NULL);
+
+        return 0;
+}
+core_initcall(em_debug_init);
+#else /* CONFIG_DEBUG_FS */
+static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) {}
+#endif
 static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states,
                                                 struct em_data_callback *cb)
 {
@@ -102,6 +157,8 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states,
         pd->nr_cap_states = nr_states;
         cpumask_copy(to_cpumask(pd->cpus), span);
 
+        em_debug_create_pd(pd, cpu);
+
         return pd;
 
 free_cs_table:
diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index b7a82502857a..9d22131afc1e 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -582,10 +582,8 @@ static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d)
         qos->pm_qos_power_miscdev.name = qos->name;
         qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops;
 
-        if (d) {
-                (void)debugfs_create_file(qos->name, S_IRUGO, d,
-                                          (void *)qos, &pm_qos_debug_fops);
-        }
+        debugfs_create_file(qos->name, S_IRUGO, d, (void *)qos,
+                            &pm_qos_debug_fops);
 
         return misc_register(&qos->pm_qos_power_miscdev);
 }
@@ -685,8 +683,6 @@ static int __init pm_qos_power_init(void)
         BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES);
 
         d = debugfs_create_dir("pm_qos", NULL);
-        if (IS_ERR_OR_NULL(d))
-                d = NULL;
 
         for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) {
                 ret = register_pm_qos_misc(pm_qos_array[i], d);