thermal/drivers/cpuidle_cooling: Use device name instead of auto-numbering

Currently the naming of a cooling device is just a cooling technique
followed by a number. When there are multiple cooling devices using
the same technique, it is impossible to clearly identify the related
device as this one is just a number.

For instance:

 thermal-idle-0
 thermal-idle-1
 thermal-idle-2
 thermal-idle-3
 etc ...

The 'thermal' prefix is redundant with the subsystem namespace. This
patch removes the 'thermal prefix and changes the number by the device
name. So the naming above becomes:

 idle-cpu0
 idle-cpu1
 idle-cpu2
 idle-cpu3
 etc ...

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20210314111333.16551-4-daniel.lezcano@linaro.org

diff --git a/drivers/thermal/cpuidle_cooling.c b/drivers/thermal/cpuidle_cooling.c
index 7ecab4b..f329761 100644 (file)
--- a/drivers/thermal/cpuidle_cooling.c
+++ b/drivers/thermal/cpuidle_cooling.c
@@ -9,9 +9,9 @@
 
 #include <linux/cpu_cooling.h>
 #include <linux/cpuidle.h>
+#include <linux/device.h>
 #include <linux/err.h>
 #include <linux/idle_inject.h>
-#include <linux/idr.h>
 #include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/thermal.h>
@@ -26,8 +26,6 @@ struct cpuidle_cooling_device {
        unsigned long state;
 };
 
-static DEFINE_IDA(cpuidle_ida);
-
 /**
  * cpuidle_cooling_runtime - Running time computation
  * @idle_duration_us: CPU idle time to inject in microseconds
@@ -174,10 +172,11 @@ static int __cpuidle_cooling_register(struct device_node *np,
        struct idle_inject_device *ii_dev;
        struct cpuidle_cooling_device *idle_cdev;
        struct thermal_cooling_device *cdev;
+       struct device *dev;
        unsigned int idle_duration_us = TICK_USEC;
        unsigned int latency_us = UINT_MAX;
-       char dev_name[THERMAL_NAME_LENGTH];
-       int id, ret;
+       char *name;
+       int ret;
 
        idle_cdev = kzalloc(sizeof(*idle_cdev), GFP_KERNEL);
        if (!idle_cdev) {
@@ -185,16 +184,10 @@ static int __cpuidle_cooling_register(struct device_node *np,
                goto out;
        }
 
-       id = ida_simple_get(&cpuidle_ida, 0, 0, GFP_KERNEL);
-       if (id < 0) {
-               ret = id;
-               goto out_kfree;
-       }
-
        ii_dev = idle_inject_register(drv->cpumask);
        if (!ii_dev) {
                ret = -EINVAL;
-               goto out_id;
+               goto out_kfree;
        }
 
        of_property_read_u32(np, "duration-us", &idle_duration_us);
@@ -205,24 +198,30 @@ static int __cpuidle_cooling_register(struct device_node *np,
 
        idle_cdev->ii_dev = ii_dev;
 
-       snprintf(dev_name, sizeof(dev_name), "thermal-idle-%d", id);
+       dev = get_cpu_device(cpumask_first(drv->cpumask));
 
-       cdev = thermal_of_cooling_device_register(np, dev_name, idle_cdev,
+       name = kasprintf(GFP_KERNEL, "idle-%s", dev_name(dev));
+       if (!name) {
+               ret = -ENOMEM;
+               goto out_unregister;
+       }
+
+       cdev = thermal_of_cooling_device_register(np, name, idle_cdev,
                                                  &cpuidle_cooling_ops);
+       kfree(name);
+
        if (IS_ERR(cdev)) {
                ret = PTR_ERR(cdev);
                goto out_unregister;
        }
 
        pr_debug("%s: Idle injection set with idle duration=%u, latency=%u\n",
-                dev_name, idle_duration_us, latency_us);
+                name, idle_duration_us, latency_us);
 
        return 0;
 
 out_unregister:
        idle_inject_unregister(ii_dev);
-out_id:
-       ida_simple_remove(&cpuidle_ida, id);
 out_kfree:
        kfree(idle_cdev);
 out: