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 <[email protected]> Signed-off-by: Kyungmin Park <[email protected]> Signed-off-by: Myungjoo Ham <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
