thermal: convert devfreq_cooling to use an IDA

thermal devfreq cooling does not use the ability to look up pointers by
ID, so convert it from using an IDR to the more space-efficient IDA.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
index 5a737fd..a667ba7 100644 (file)
--- a/drivers/thermal/devfreq_cooling.c
+++ b/drivers/thermal/devfreq_cooling.c
@@ -21,14 +21,14 @@
 #include <linux/devfreq.h>
 #include <linux/devfreq_cooling.h>
 #include <linux/export.h>
+#include <linux/idr.h>
 #include <linux/slab.h>
 #include <linux/pm_opp.h>
 #include <linux/thermal.h>
 
 #include <trace/events/thermal.h>
 
-static DEFINE_MUTEX(devfreq_lock);
-static DEFINE_IDR(devfreq_idr);
+static DEFINE_IDA(devfreq_ida);
 
 /**
  * struct devfreq_cooling_device - Devfreq cooling device
@@ -57,42 +57,6 @@ struct devfreq_cooling_device {
        struct devfreq_cooling_power *power_ops;
 };
 
-/**
- * get_idr - function to get a unique id.
- * @idr: struct idr * handle used to create a id.
- * @id: int * value generated by this function.
- *
- * This function will populate @id with an unique
- * id, using the idr API.
- *
- * Return: 0 on success, an error code on failure.
- */
-static int get_idr(struct idr *idr, int *id)
-{
-       int ret;
-
-       mutex_lock(&devfreq_lock);
-       ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL);
-       mutex_unlock(&devfreq_lock);
-       if (unlikely(ret < 0))
-               return ret;
-       *id = ret;
-
-       return 0;
-}
-
-/**
- * release_idr - function to free the unique id.
- * @idr: struct idr * handle used for creating the id.
- * @id: int value representing the unique id.
- */
-static void release_idr(struct idr *idr, int id)
-{
-       mutex_lock(&devfreq_lock);
-       idr_remove(idr, id);
-       mutex_unlock(&devfreq_lock);
-}
-
 /**
  * partition_enable_opps() - disable all opps above a given state
  * @dfc:       Pointer to devfreq we are operating on
@@ -496,9 +460,10 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
        if (err)
                goto free_dfc;
 
-       err = get_idr(&devfreq_idr, &dfc->id);
-       if (err)
+       err = ida_simple_get(&devfreq_ida, 0, 0, GFP_KERNEL);
+       if (err < 0)
                goto free_tables;
+       dfc->id = err;
 
        snprintf(dev_name, sizeof(dev_name), "thermal-devfreq-%d", dfc->id);
 
@@ -509,15 +474,15 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
                dev_err(df->dev.parent,
                        "Failed to register devfreq cooling device (%d)\n",
                        err);
-               goto release_idr;
+               goto release_ida;
        }
 
        dfc->cdev = cdev;
 
        return cdev;
 
-release_idr:
-       release_idr(&devfreq_idr, dfc->id);
+release_ida:
+       ida_simple_remove(&devfreq_ida, dfc->id);
 free_tables:
        kfree(dfc->power_table);
        kfree(dfc->freq_table);
@@ -565,7 +530,7 @@ void devfreq_cooling_unregister(struct thermal_cooling_device *cdev)
        dfc = cdev->devdata;
 
        thermal_cooling_device_unregister(dfc->cdev);
-       release_idr(&devfreq_idr, dfc->id);
+       ida_simple_remove(&devfreq_ida, dfc->id);
        kfree(dfc->power_table);
        kfree(dfc->freq_table);