1 files changed, 89 insertions, 2 deletions

diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index 5f4c006c4b1e..97b0df71303e 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -41,6 +41,8 @@
 #include <linux/platform_device.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
 
 #include <linux/uaccess.h>
 #include <linux/export.h>
@@ -182,6 +184,81 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
         c->target_value = value;
 }
 
+static inline int pm_qos_get_value(struct pm_qos_constraints *c);
+static int pm_qos_dbg_show_requests(struct seq_file *s, void *unused)
+{
+        struct pm_qos_object *qos = (struct pm_qos_object *)s->private;
+        struct pm_qos_constraints *c;
+        struct pm_qos_request *req;
+        char *type;
+        unsigned long flags;
+        int tot_reqs = 0;
+        int active_reqs = 0;
+
+        if (IS_ERR_OR_NULL(qos)) {
+                pr_err("%s: bad qos param!\n", __func__);
+                return -EINVAL;
+        }
+        c = qos->constraints;
+        if (IS_ERR_OR_NULL(c)) {
+                pr_err("%s: Bad constraints on qos?\n", __func__);
+                return -EINVAL;
+        }
+
+        /* Lock to ensure we have a snapshot */
+        spin_lock_irqsave(&pm_qos_lock, flags);
+        if (plist_head_empty(&c->list)) {
+                seq_puts(s, "Empty!\n");
+                goto out;
+        }
+
+        switch (c->type) {
+        case PM_QOS_MIN:
+                type = "Minimum";
+                break;
+        case PM_QOS_MAX:
+                type = "Maximum";
+                break;
+        case PM_QOS_SUM:
+                type = "Sum";
+                break;
+        default:
+                type = "Unknown";
+        }
+
+        plist_for_each_entry(req, &c->list, node) {
+                char *state = "Default";
+
+                if ((req->node).prio != c->default_value) {
+                        active_reqs++;
+                        state = "Active";
+                }
+                tot_reqs++;
+                seq_printf(s, "%d: %d: %s\n", tot_reqs,
+                           (req->node).prio, state);
+        }
+
+        seq_printf(s, "Type=%s, Value=%d, Requests: active=%d / total=%d\n",
+                   type, pm_qos_get_value(c), active_reqs, tot_reqs);
+
+out:
+        spin_unlock_irqrestore(&pm_qos_lock, flags);
+        return 0;
+}
+
+static int pm_qos_dbg_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, pm_qos_dbg_show_requests,
+                           inode->i_private);
+}
+
+static const struct file_operations pm_qos_debug_fops = {
+        .open           = pm_qos_dbg_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
 /**
  * pm_qos_update_target - manages the constraints list and calls the notifiers
  *  if needed
@@ -509,12 +586,17 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
 EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
 
 /* User space interface to PM QoS classes via misc devices */
-static int register_pm_qos_misc(struct pm_qos_object *qos)
+static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d)
 {
         qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR;
         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);
+        }
+
         return misc_register(&qos->pm_qos_power_miscdev);
 }
 
@@ -608,11 +690,16 @@ static int __init pm_qos_power_init(void)
 {
         int ret = 0;
         int i;
+        struct dentry *d;
 
         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]);
+                ret = register_pm_qos_misc(pm_qos_array[i], d);
                 if (ret < 0) {
                         printk(KERN_ERR "pm_qos_param: %s setup failed\n",
                                pm_qos_array[i]->name);