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Date: Fri, 05 Jul 2013 17:46:36 +0900
From: Chanwoo Choi <cw00.choi@...sung.com>
To: viresh.kumar@...aro.org, rjw@...k.pl, linux-kernel@...r.kernel.org
Cc: linux-pm@...r.kernel.org, cpufreq@...r.kernel.org,
kyungmin.park@...sung.com, myungjoo.ham@...sung.com,
cw00.choi@...sung.com
Subject: [PATCH 1/6] cpufreq: Add debugfs directory for cpufreq
This patch create debugfs root directory and child directory according to
the number of CPUs for CPUFreq as below debugfs directory path:
- /sys/kernel/debug/cpufreq/cpuX
If many CPUs share only one cpufreq policy, other CPU(except for CPU0) create
a link for debugfs directory of CPU0.
- /sys/kernel/debug/cpufreq/cpu0
- /sys/kernel/debug/cpufreq/cpu[1-(N-1)] -> /sys/kernel/debug/cpufreq/cpu0
And then cpufreq may need to create debugfs specific file below of debugfs
directory of cpufreq. (e.g., /sys/kernel/debug/cpufreq/cpu0/load_table)
Signed-off-by: Chanwoo Choi <cw00.choi@...sung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@...sung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@...sung.com>
---
drivers/cpufreq/cpufreq.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/cpufreq.h | 1 +
2 files changed, 58 insertions(+)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 2d53f47..bc01c8e 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -23,6 +23,7 @@
#include <linux/notifier.h>
#include <linux/cpufreq.h>
#include <linux/delay.h>
+#include <linux/debugfs.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/device.h>
@@ -47,6 +48,10 @@ static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);
#endif
static DEFINE_RWLOCK(cpufreq_driver_lock);
+/* The cpufreq_debugfs is used to create debugfs root directory for CPUFreq. */
+#define MAX_DEBUGFS_NAME_LEN CPUFREQ_NAME_LEN
+static struct dentry *cpufreq_debugfs;
+
/*
* cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure
* all cpufreq/hotplug/workqueue/etc related lock issues.
@@ -726,6 +731,20 @@ static int cpufreq_add_dev_symlink(unsigned int cpu,
cpufreq_cpu_put(managed_policy);
return ret;
}
+
+ if (cpufreq_debugfs) {
+ char symlink_name[MAX_DEBUGFS_NAME_LEN];
+ char target_name[MAX_DEBUGFS_NAME_LEN];
+
+ sprintf(symlink_name, "cpu%d", j);
+ sprintf(target_name, "./cpu%d", cpu);
+ managed_policy->cpu_debugfs[j] = debugfs_create_symlink(
+ symlink_name,
+ cpufreq_debugfs,
+ target_name);
+ if (!managed_policy->cpu_debugfs[j])
+ pr_debug("creating debugfs symlink failed\n");
+ }
}
return ret;
}
@@ -746,6 +765,22 @@ static int cpufreq_add_dev_interface(unsigned int cpu,
if (ret)
return ret;
+ /* prepare interface data for debugfs */
+ if (cpufreq_debugfs) {
+ char name[MAX_DEBUGFS_NAME_LEN];
+ int size, i;
+
+ sprintf(name, "cpu%d", policy->cpu);
+ size = sizeof(struct dentry*) * NR_CPUS;
+ i = cpu;
+
+ policy->cpu_debugfs = devm_kzalloc(dev, size, GFP_KERNEL);
+ policy->cpu_debugfs[i] = debugfs_create_dir(name,
+ cpufreq_debugfs);
+ if (!policy->cpu_debugfs[i])
+ pr_debug("creating debugfs directory failed\n");
+ }
+
/* set up files for this cpu device */
drv_attr = cpufreq_driver->attr;
while ((drv_attr) && (*drv_attr)) {
@@ -839,6 +874,20 @@ static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling,
return ret;
}
+ if (cpufreq_debugfs) {
+ char symlink_name[MAX_DEBUGFS_NAME_LEN];
+ char target_name[MAX_DEBUGFS_NAME_LEN];
+
+ sprintf(symlink_name, "cpu%d", cpu);
+ sprintf(target_name, "./cpu%d", sibling);
+ policy->cpu_debugfs[cpu] = debugfs_create_symlink(
+ symlink_name,
+ cpufreq_debugfs,
+ target_name);
+ if (!policy->cpu_debugfs[cpu])
+ pr_debug("creating debugfs symlink failed\n");
+ }
+
return 0;
}
#endif
@@ -1046,6 +1095,7 @@ static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif
if (cpu != data->cpu) {
sysfs_remove_link(&dev->kobj, "cpufreq");
+ debugfs_remove(data->cpu_debugfs[cpu]);
} else if (cpus > 1) {
/* first sibling now owns the new sysfs dir */
cpu_dev = get_cpu_device(cpumask_first(data->cpus));
@@ -1068,6 +1118,9 @@ static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif
return -EINVAL;
}
+ debugfs_remove_recursive(data->cpu_debugfs[cpu]);
+ debugfs_remove(cpufreq_debugfs);
+
WARN_ON(lock_policy_rwsem_write(cpu));
update_policy_cpu(data, cpu_dev->id);
unlock_policy_rwsem_write(cpu);
@@ -1976,6 +2029,10 @@ static int __init cpufreq_core_init(void)
BUG_ON(!cpufreq_global_kobject);
register_syscore_ops(&cpufreq_syscore_ops);
+ cpufreq_debugfs = debugfs_create_dir("cpufreq", NULL);
+ if (!cpufreq_debugfs)
+ pr_debug("creating debugfs root failed\n");
+
return 0;
}
core_initcall(cpufreq_core_init);
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 037d36a..825f379 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -115,6 +115,7 @@ struct cpufreq_policy {
struct kobject kobj;
struct completion kobj_unregister;
+ struct dentry **cpu_debugfs;
};
#define CPUFREQ_ADJUST (0)
--
1.8.0
--
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