From 659dc4562c1b15e3401ad15338d2109af7c6d718 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 22 Jan 2019 16:21:47 +0100 Subject: PM: QoS: no need to check return value of debugfs_create functions When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Signed-off-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki --- kernel/power/qos.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'kernel/power') diff --git a/kernel/power/qos.c b/kernel/power/qos.c index b7a82502857a..9d22131afc1e 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -582,10 +582,8 @@ static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d) 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); - } + debugfs_create_file(qos->name, S_IRUGO, d, (void *)qos, + &pm_qos_debug_fops); return misc_register(&qos->pm_qos_power_miscdev); } @@ -685,8 +683,6 @@ static int __init pm_qos_power_init(void) 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], d); -- cgit v1.2.3 From 9cac42d0645ceb2ca8b815cee04810ec9b0d13b3 Mon Sep 17 00:00:00 2001 From: Quentin Perret Date: Tue, 22 Jan 2019 16:42:47 +0000 Subject: PM / EM: Expose the Energy Model in debugfs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The recently introduced Energy Model (EM) framework manages power cost tables of CPUs. These tables are currently only visible from kernel space. However, in order to debug the behaviour of subsystems that use the EM (EAS for example), it is often required to know what the power costs are from userspace. For this reason, introduce under /sys/kernel/debug/energy_model a set of directories representing the performance domains of the system. Each performance domain contains a set of sub-directories representing the different capacity states (cs) and their attributes, as well as a file exposing the related CPUs. The resulting hierarchy is as follows on Arm juno r0 for example: /sys/kernel/debug/energy_model ├── pd0 │   ├── cpus │   ├── cs:450000 │   │   ├── cost │   │   ├── frequency │   │   └── power │   ├── cs:575000 │   │   ├── cost │   │   ├── frequency │   │   └── power │   ├── cs:700000 │   │   ├── cost │   │   ├── frequency │   │   └── power │   ├── cs:775000 │   │   ├── cost │   │   ├── frequency │   │   └── power │   └── cs:850000 │   ├── cost │   ├── frequency │   └── power └── pd1 ├── cpus ├── cs:1100000 │   ├── cost │   ├── frequency │   └── power ├── cs:450000 │   ├── cost │   ├── frequency │   └── power ├── cs:625000 │   ├── cost │   ├── frequency │   └── power ├── cs:800000 │   ├── cost │   ├── frequency │   └── power └── cs:950000 ├── cost ├── frequency └── power Signed-off-by: Quentin Perret Reviewed-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki --- kernel/power/energy_model.c | 57 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) (limited to 'kernel/power') diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index d9dc2c38764a..7d66ee68aaaf 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -10,6 +10,7 @@ #include #include +#include #include #include #include @@ -23,6 +24,60 @@ static DEFINE_PER_CPU(struct em_perf_domain *, em_data); */ static DEFINE_MUTEX(em_pd_mutex); +#ifdef CONFIG_DEBUG_FS +static struct dentry *rootdir; + +static void em_debug_create_cs(struct em_cap_state *cs, struct dentry *pd) +{ + struct dentry *d; + char name[24]; + + snprintf(name, sizeof(name), "cs:%lu", cs->frequency); + + /* Create per-cs directory */ + d = debugfs_create_dir(name, pd); + debugfs_create_ulong("frequency", 0444, d, &cs->frequency); + debugfs_create_ulong("power", 0444, d, &cs->power); + debugfs_create_ulong("cost", 0444, d, &cs->cost); +} + +static int em_debug_cpus_show(struct seq_file *s, void *unused) +{ + seq_printf(s, "%*pbl\n", cpumask_pr_args(to_cpumask(s->private))); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(em_debug_cpus); + +static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) +{ + struct dentry *d; + char name[8]; + int i; + + snprintf(name, sizeof(name), "pd%d", cpu); + + /* Create the directory of the performance domain */ + d = debugfs_create_dir(name, rootdir); + + debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops); + + /* Create a sub-directory for each capacity state */ + for (i = 0; i < pd->nr_cap_states; i++) + em_debug_create_cs(&pd->table[i], d); +} + +static int __init em_debug_init(void) +{ + /* Create /sys/kernel/debug/energy_model directory */ + rootdir = debugfs_create_dir("energy_model", NULL); + + return 0; +} +core_initcall(em_debug_init); +#else /* CONFIG_DEBUG_FS */ +static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) {} +#endif static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, struct em_data_callback *cb) { @@ -102,6 +157,8 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, pd->nr_cap_states = nr_states; cpumask_copy(to_cpumask(pd->cpus), span); + em_debug_create_pd(pd, cpu); + return pd; free_cs_table: -- cgit v1.2.3