| Message ID | 20200610101223.7152-1-lukasz.luba@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
On Wed, Jun 10, 2020 at 12:12 PM Lukasz Luba <lukasz.luba@arm.com> wrote: > > Add support for other devices than CPUs. The registration function > does not require a valid cpumask pointer and is ready to handle new > devices. Some of the internal structures has been reorganized in order to > keep consistent view (like removing per_cpu pd pointers). > > Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> > --- > Hi all, > > This is just a small change compared to v8 addressing Rafael's > comments an Dan's static analyzes. > Here are the changes: > - added comment about mutex usage in the unregister function > - changed 'dev' into @dev in the kerneldoc comments > - removed 'else' statement from em_create_pd() to calm down static analizers I've applied the series as 5.9 material with patch [4/8] replaced with this one. Sorry for the delays in handling this! Thanks! > include/linux/device.h | 5 + > include/linux/energy_model.h | 29 ++++- > kernel/power/energy_model.c | 244 ++++++++++++++++++++++++----------- > 3 files changed, 194 insertions(+), 84 deletions(-) > > diff --git a/include/linux/device.h b/include/linux/device.h > index ac8e37cd716a..7023d3ea189b 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -13,6 +13,7 @@ > #define _DEVICE_H_ > > #include <linux/dev_printk.h> > +#include <linux/energy_model.h> > #include <linux/ioport.h> > #include <linux/kobject.h> > #include <linux/klist.h> > @@ -559,6 +560,10 @@ struct device { > struct dev_pm_info power; > struct dev_pm_domain *pm_domain; > > +#ifdef CONFIG_ENERGY_MODEL > + struct em_perf_domain *em_pd; > +#endif > + > #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN > struct irq_domain *msi_domain; > #endif > diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h > index 7076cb22b247..2d4689964029 100644 > --- a/include/linux/energy_model.h > +++ b/include/linux/energy_model.h > @@ -12,8 +12,10 @@ > > /** > * em_perf_state - Performance state of a performance domain > - * @frequency: The CPU frequency in KHz, for consistency with CPUFreq > - * @power: The power consumed by 1 CPU at this level, in milli-watts > + * @frequency: The frequency in KHz, for consistency with CPUFreq > + * @power: The power consumed at this level, in milli-watts (by 1 CPU or > + by a registered device). It can be a total power: static and > + dynamic. > * @cost: The cost coefficient associated with this level, used during > * energy calculation. Equal to: power * max_frequency / frequency > */ > @@ -27,12 +29,16 @@ struct em_perf_state { > * em_perf_domain - Performance domain > * @table: List of performance states, in ascending order > * @nr_perf_states: Number of performance states > - * @cpus: Cpumask covering the CPUs of the domain > + * @cpus: Cpumask covering the CPUs of the domain. It's here > + * for performance reasons to avoid potential cache > + * misses during energy calculations in the scheduler > + * and simplifies allocating/freeing that memory region. > * > - * A "performance domain" represents a group of CPUs whose performance is > - * scaled together. All CPUs of a performance domain must have the same > - * micro-architecture. Performance domains often have a 1-to-1 mapping with > - * CPUFreq policies. > + * In case of CPU device, a "performance domain" represents a group of CPUs > + * whose performance is scaled together. All CPUs of a performance domain > + * must have the same micro-architecture. Performance domains often have > + * a 1-to-1 mapping with CPUFreq policies. In case of other devices the @cpus > + * field is unused. > */ > struct em_perf_domain { > struct em_perf_state *table; > @@ -71,10 +77,12 @@ struct em_data_callback { > #define EM_DATA_CB(_active_power_cb) { .active_power = &_active_power_cb } > > struct em_perf_domain *em_cpu_get(int cpu); > +struct em_perf_domain *em_pd_get(struct device *dev); > int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, > struct em_data_callback *cb); > int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, > struct em_data_callback *cb, cpumask_t *span); > +void em_dev_unregister_perf_domain(struct device *dev); > > /** > * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. domain > @@ -184,10 +192,17 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, > { > return -EINVAL; > } > +static inline void em_dev_unregister_perf_domain(struct device *dev) > +{ > +} > static inline struct em_perf_domain *em_cpu_get(int cpu) > { > return NULL; > } > +static inline struct em_perf_domain *em_pd_get(struct device *dev) > +{ > + return NULL; > +} > static inline unsigned long em_pd_energy(struct em_perf_domain *pd, > unsigned long max_util, unsigned long sum_util) > { > diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c > index 5b8a1566526a..32d76e78f992 100644 > --- a/kernel/power/energy_model.c > +++ b/kernel/power/energy_model.c > @@ -1,9 +1,10 @@ > // SPDX-License-Identifier: GPL-2.0 > /* > - * Energy Model of CPUs > + * Energy Model of devices > * > - * Copyright (c) 2018, Arm ltd. > + * Copyright (c) 2018-2020, Arm ltd. > * Written by: Quentin Perret, Arm ltd. > + * Improvements provided by: Lukasz Luba, Arm ltd. > */ > > #define pr_fmt(fmt) "energy_model: " fmt > @@ -15,15 +16,17 @@ > #include <linux/sched/topology.h> > #include <linux/slab.h> > > -/* Mapping of each CPU to the performance domain to which it belongs. */ > -static DEFINE_PER_CPU(struct em_perf_domain *, em_data); > - > /* > * Mutex serializing the registrations of performance domains and letting > * callbacks defined by drivers sleep. > */ > static DEFINE_MUTEX(em_pd_mutex); > > +static bool _is_cpu_device(struct device *dev) > +{ > + return (dev->bus == &cpu_subsys); > +} > + > #ifdef CONFIG_DEBUG_FS > static struct dentry *rootdir; > > @@ -49,22 +52,30 @@ static int em_debug_cpus_show(struct seq_file *s, void *unused) > } > DEFINE_SHOW_ATTRIBUTE(em_debug_cpus); > > -static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) > +static void em_debug_create_pd(struct device *dev) > { > 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); > + d = debugfs_create_dir(dev_name(dev), rootdir); > > - debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops); > + if (_is_cpu_device(dev)) > + debugfs_create_file("cpus", 0444, d, dev->em_pd->cpus, > + &em_debug_cpus_fops); > > /* Create a sub-directory for each performance state */ > - for (i = 0; i < pd->nr_perf_states; i++) > - em_debug_create_ps(&pd->table[i], d); > + for (i = 0; i < dev->em_pd->nr_perf_states; i++) > + em_debug_create_ps(&dev->em_pd->table[i], d); > + > +} > + > +static void em_debug_remove_pd(struct device *dev) > +{ > + struct dentry *debug_dir; > + > + debug_dir = debugfs_lookup(dev_name(dev), rootdir); > + debugfs_remove_recursive(debug_dir); > } > > static int __init em_debug_init(void) > @@ -76,40 +87,34 @@ static int __init em_debug_init(void) > } > core_initcall(em_debug_init); > #else /* CONFIG_DEBUG_FS */ > -static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) {} > +static void em_debug_create_pd(struct device *dev) {} > +static void em_debug_remove_pd(struct device *dev) {} > #endif > -static struct em_perf_domain * > -em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, > - cpumask_t *span) > + > +static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd, > + int nr_states, struct em_data_callback *cb) > { > unsigned long opp_eff, prev_opp_eff = ULONG_MAX; > unsigned long power, freq, prev_freq = 0; > - int i, ret, cpu = cpumask_first(span); > struct em_perf_state *table; > - struct em_perf_domain *pd; > + int i, ret; > u64 fmax; > > - if (!cb->active_power) > - return NULL; > - > - pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL); > - if (!pd) > - return NULL; > - > table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL); > if (!table) > - goto free_pd; > + return -ENOMEM; > > /* Build the list of performance states for this performance domain */ > for (i = 0, freq = 0; i < nr_states; i++, freq++) { > /* > * active_power() is a driver callback which ceils 'freq' to > - * lowest performance state of 'cpu' above 'freq' and updates > + * lowest performance state of 'dev' above 'freq' and updates > * 'power' and 'freq' accordingly. > */ > ret = cb->active_power(&power, &freq, dev); > if (ret) { > - pr_err("pd%d: invalid perf. state: %d\n", cpu, ret); > + dev_err(dev, "EM: invalid perf. state: %d\n", > + ret); > goto free_ps_table; > } > > @@ -118,7 +123,8 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, > * higher performance states. > */ > if (freq <= prev_freq) { > - pr_err("pd%d: non-increasing freq: %lu\n", cpu, freq); > + dev_err(dev, "EM: non-increasing freq: %lu\n", > + freq); > goto free_ps_table; > } > > @@ -127,7 +133,8 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, > * positive, in milli-watts and to fit into 16 bits. > */ > if (!power || power > EM_MAX_POWER) { > - pr_err("pd%d: invalid power: %lu\n", cpu, power); > + dev_err(dev, "EM: invalid power: %lu\n", > + power); > goto free_ps_table; > } > > @@ -142,8 +149,8 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, > */ > opp_eff = freq / power; > if (opp_eff >= prev_opp_eff) > - pr_warn("pd%d: hertz/watts ratio non-monotonically decreasing: em_perf_state %d >= em_perf_state%d\n", > - cpu, i, i - 1); > + dev_dbg(dev, "EM: hertz/watts ratio non-monotonically decreasing: em_perf_state %d >= em_perf_state%d\n", > + i, i - 1); > prev_opp_eff = opp_eff; > } > > @@ -156,30 +163,82 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, > > pd->table = table; > pd->nr_perf_states = nr_states; > - cpumask_copy(to_cpumask(pd->cpus), span); > > - em_debug_create_pd(pd, cpu); > - > - return pd; > + return 0; > > free_ps_table: > kfree(table); > -free_pd: > - kfree(pd); > + return -EINVAL; > +} > + > +static int em_create_pd(struct device *dev, int nr_states, > + struct em_data_callback *cb, cpumask_t *cpus) > +{ > + struct em_perf_domain *pd; > + struct device *cpu_dev; > + int cpu, ret; > + > + if (_is_cpu_device(dev)) { > + pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL); > + if (!pd) > + return -ENOMEM; > + > + cpumask_copy(em_span_cpus(pd), cpus); > + } else { > + pd = kzalloc(sizeof(*pd), GFP_KERNEL); > + if (!pd) > + return -ENOMEM; > + } > + > + ret = em_create_perf_table(dev, pd, nr_states, cb); > + if (ret) { > + kfree(pd); > + return ret; > + } > + > + if (_is_cpu_device(dev)) > + for_each_cpu(cpu, cpus) { > + cpu_dev = get_cpu_device(cpu); > + cpu_dev->em_pd = pd; > + } > + > + dev->em_pd = pd; > + > + return 0; > +} > + > +/** > + * em_pd_get() - Return the performance domain for a device > + * @dev : Device to find the performance domain for > + * > + * Returns the performance domain to which @dev belongs, or NULL if it doesn't > + * exist. > + */ > +struct em_perf_domain *em_pd_get(struct device *dev) > +{ > + if (IS_ERR_OR_NULL(dev)) > + return NULL; > > - return NULL; > + return dev->em_pd; > } > +EXPORT_SYMBOL_GPL(em_pd_get); > > /** > * em_cpu_get() - Return the performance domain for a CPU > * @cpu : CPU to find the performance domain for > * > - * Return: the performance domain to which 'cpu' belongs, or NULL if it doesn't > + * Returns the performance domain to which @cpu belongs, or NULL if it doesn't > * exist. > */ > struct em_perf_domain *em_cpu_get(int cpu) > { > - return READ_ONCE(per_cpu(em_data, cpu)); > + struct device *cpu_dev; > + > + cpu_dev = get_cpu_device(cpu); > + if (!cpu_dev) > + return NULL; > + > + return em_pd_get(cpu_dev); > } > EXPORT_SYMBOL_GPL(em_cpu_get); > > @@ -188,7 +247,7 @@ EXPORT_SYMBOL_GPL(em_cpu_get); > * @dev : Device for which the EM is to register > * @nr_states : Number of performance states to register > * @cb : Callback functions providing the data of the Energy Model > - * @span : Pointer to cpumask_t, which in case of a CPU device is > + * @cpus : Pointer to cpumask_t, which in case of a CPU device is > * obligatory. It can be taken from i.e. 'policy->cpus'. For other > * type of devices this should be set to NULL. > * > @@ -201,13 +260,12 @@ EXPORT_SYMBOL_GPL(em_cpu_get); > * Return 0 on success > */ > int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, > - struct em_data_callback *cb, cpumask_t *span) > + struct em_data_callback *cb, cpumask_t *cpus) > { > unsigned long cap, prev_cap = 0; > - struct em_perf_domain *pd; > - int cpu, ret = 0; > + int cpu, ret; > > - if (!dev || !span || !nr_states || !cb) > + if (!dev || !nr_states || !cb) > return -EINVAL; > > /* > @@ -216,47 +274,50 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, > */ > mutex_lock(&em_pd_mutex); > > - for_each_cpu(cpu, span) { > - /* Make sure we don't register again an existing domain. */ > - if (READ_ONCE(per_cpu(em_data, cpu))) { > - ret = -EEXIST; > - goto unlock; > - } > + if (dev->em_pd) { > + ret = -EEXIST; > + goto unlock; > + } > > - /* > - * All CPUs of a domain must have the same micro-architecture > - * since they all share the same table. > - */ > - cap = arch_scale_cpu_capacity(cpu); > - if (prev_cap && prev_cap != cap) { > - pr_err("CPUs of %*pbl must have the same capacity\n", > - cpumask_pr_args(span)); > + if (_is_cpu_device(dev)) { > + if (!cpus) { > + dev_err(dev, "EM: invalid CPU mask\n"); > ret = -EINVAL; > goto unlock; > } > - prev_cap = cap; > + > + for_each_cpu(cpu, cpus) { > + if (em_cpu_get(cpu)) { > + dev_err(dev, "EM: exists for CPU%d\n", cpu); > + ret = -EEXIST; > + goto unlock; > + } > + /* > + * All CPUs of a domain must have the same > + * micro-architecture since they all share the same > + * table. > + */ > + cap = arch_scale_cpu_capacity(cpu); > + if (prev_cap && prev_cap != cap) { > + dev_err(dev, "EM: CPUs of %*pbl must have the same capacity\n", > + cpumask_pr_args(cpus)); > + > + ret = -EINVAL; > + goto unlock; > + } > + prev_cap = cap; > + } > } > > - /* Create the performance domain and add it to the Energy Model. */ > - pd = em_create_pd(dev, nr_states, cb, span); > - if (!pd) { > - ret = -EINVAL; > + ret = em_create_pd(dev, nr_states, cb, cpus); > + if (ret) > goto unlock; > - } > > - for_each_cpu(cpu, span) { > - /* > - * The per-cpu array can be read concurrently from em_cpu_get(). > - * The barrier enforces the ordering needed to make sure readers > - * can only access well formed em_perf_domain structs. > - */ > - smp_store_release(per_cpu_ptr(&em_data, cpu), pd); > - } > + em_debug_create_pd(dev); > + dev_info(dev, "EM: created perf domain\n"); > > - pr_debug("Created perf domain %*pbl\n", cpumask_pr_args(span)); > unlock: > mutex_unlock(&em_pd_mutex); > - > return ret; > } > EXPORT_SYMBOL_GPL(em_dev_register_perf_domain); > @@ -285,3 +346,32 @@ int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, > return em_dev_register_perf_domain(cpu_dev, nr_states, cb, span); > } > EXPORT_SYMBOL_GPL(em_register_perf_domain); > + > +/** > + * em_dev_unregister_perf_domain() - Unregister Energy Model (EM) for a device > + * @dev : Device for which the EM is registered > + * > + * Unregister the EM for the specified @dev (but not a CPU device). > + */ > +void em_dev_unregister_perf_domain(struct device *dev) > +{ > + if (IS_ERR_OR_NULL(dev) || !dev->em_pd) > + return; > + > + if (_is_cpu_device(dev)) > + return; > + > + /* > + * The mutex separates all register/unregister requests and protects > + * from potential clean-up/setup issues in the debugfs directories. > + * The debugfs directory name is the same as device's name. > + */ > + mutex_lock(&em_pd_mutex); > + em_debug_remove_pd(dev); > + > + kfree(dev->em_pd->table); > + kfree(dev->em_pd); > + dev->em_pd = NULL; > + mutex_unlock(&em_pd_mutex); > +} > +EXPORT_SYMBOL_GPL(em_dev_unregister_perf_domain); > -- > 2.17.1 >
On 6/24/20 4:21 PM, Rafael J. Wysocki wrote: > On Wed, Jun 10, 2020 at 12:12 PM Lukasz Luba <lukasz.luba@arm.com> wrote: >> >> Add support for other devices than CPUs. The registration function >> does not require a valid cpumask pointer and is ready to handle new >> devices. Some of the internal structures has been reorganized in order to >> keep consistent view (like removing per_cpu pd pointers). >> >> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> >> --- >> Hi all, >> >> This is just a small change compared to v8 addressing Rafael's >> comments an Dan's static analyzes. >> Here are the changes: >> - added comment about mutex usage in the unregister function >> - changed 'dev' into @dev in the kerneldoc comments >> - removed 'else' statement from em_create_pd() to calm down static analizers > > I've applied the series as 5.9 material with patch [4/8] replaced with this one. > > Sorry for the delays in handling this! No worries. Thank you very much! Regards, Lukasz > > Thanks! > >> include/linux/device.h | 5 + >> include/linux/energy_model.h | 29 ++++- >> kernel/power/energy_model.c | 244 ++++++++++++++++++++++++----------- >> 3 files changed, 194 insertions(+), 84 deletions(-) >> >> diff --git a/include/linux/device.h b/include/linux/device.h >> index ac8e37cd716a..7023d3ea189b 100644 >> --- a/include/linux/device.h >> +++ b/include/linux/device.h >> @@ -13,6 +13,7 @@ >> #define _DEVICE_H_ >> >> #include <linux/dev_printk.h> >> +#include <linux/energy_model.h> >> #include <linux/ioport.h> >> #include <linux/kobject.h> >> #include <linux/klist.h> >> @@ -559,6 +560,10 @@ struct device { >> struct dev_pm_info power; >> struct dev_pm_domain *pm_domain; >> >> +#ifdef CONFIG_ENERGY_MODEL >> + struct em_perf_domain *em_pd; >> +#endif >> + >> #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN >> struct irq_domain *msi_domain; >> #endif >> diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h >> index 7076cb22b247..2d4689964029 100644 >> --- a/include/linux/energy_model.h >> +++ b/include/linux/energy_model.h >> @@ -12,8 +12,10 @@ >> >> /** >> * em_perf_state - Performance state of a performance domain >> - * @frequency: The CPU frequency in KHz, for consistency with CPUFreq >> - * @power: The power consumed by 1 CPU at this level, in milli-watts >> + * @frequency: The frequency in KHz, for consistency with CPUFreq >> + * @power: The power consumed at this level, in milli-watts (by 1 CPU or >> + by a registered device). It can be a total power: static and >> + dynamic. >> * @cost: The cost coefficient associated with this level, used during >> * energy calculation. Equal to: power * max_frequency / frequency >> */ >> @@ -27,12 +29,16 @@ struct em_perf_state { >> * em_perf_domain - Performance domain >> * @table: List of performance states, in ascending order >> * @nr_perf_states: Number of performance states >> - * @cpus: Cpumask covering the CPUs of the domain >> + * @cpus: Cpumask covering the CPUs of the domain. It's here >> + * for performance reasons to avoid potential cache >> + * misses during energy calculations in the scheduler >> + * and simplifies allocating/freeing that memory region. >> * >> - * A "performance domain" represents a group of CPUs whose performance is >> - * scaled together. All CPUs of a performance domain must have the same >> - * micro-architecture. Performance domains often have a 1-to-1 mapping with >> - * CPUFreq policies. >> + * In case of CPU device, a "performance domain" represents a group of CPUs >> + * whose performance is scaled together. All CPUs of a performance domain >> + * must have the same micro-architecture. Performance domains often have >> + * a 1-to-1 mapping with CPUFreq policies. In case of other devices the @cpus >> + * field is unused. >> */ >> struct em_perf_domain { >> struct em_perf_state *table; >> @@ -71,10 +77,12 @@ struct em_data_callback { >> #define EM_DATA_CB(_active_power_cb) { .active_power = &_active_power_cb } >> >> struct em_perf_domain *em_cpu_get(int cpu); >> +struct em_perf_domain *em_pd_get(struct device *dev); >> int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, >> struct em_data_callback *cb); >> int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, >> struct em_data_callback *cb, cpumask_t *span); >> +void em_dev_unregister_perf_domain(struct device *dev); >> >> /** >> * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. domain >> @@ -184,10 +192,17 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, >> { >> return -EINVAL; >> } >> +static inline void em_dev_unregister_perf_domain(struct device *dev) >> +{ >> +} >> static inline struct em_perf_domain *em_cpu_get(int cpu) >> { >> return NULL; >> } >> +static inline struct em_perf_domain *em_pd_get(struct device *dev) >> +{ >> + return NULL; >> +} >> static inline unsigned long em_pd_energy(struct em_perf_domain *pd, >> unsigned long max_util, unsigned long sum_util) >> { >> diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c >> index 5b8a1566526a..32d76e78f992 100644 >> --- a/kernel/power/energy_model.c >> +++ b/kernel/power/energy_model.c >> @@ -1,9 +1,10 @@ >> // SPDX-License-Identifier: GPL-2.0 >> /* >> - * Energy Model of CPUs >> + * Energy Model of devices >> * >> - * Copyright (c) 2018, Arm ltd. >> + * Copyright (c) 2018-2020, Arm ltd. >> * Written by: Quentin Perret, Arm ltd. >> + * Improvements provided by: Lukasz Luba, Arm ltd. >> */ >> >> #define pr_fmt(fmt) "energy_model: " fmt >> @@ -15,15 +16,17 @@ >> #include <linux/sched/topology.h> >> #include <linux/slab.h> >> >> -/* Mapping of each CPU to the performance domain to which it belongs. */ >> -static DEFINE_PER_CPU(struct em_perf_domain *, em_data); >> - >> /* >> * Mutex serializing the registrations of performance domains and letting >> * callbacks defined by drivers sleep. >> */ >> static DEFINE_MUTEX(em_pd_mutex); >> >> +static bool _is_cpu_device(struct device *dev) >> +{ >> + return (dev->bus == &cpu_subsys); >> +} >> + >> #ifdef CONFIG_DEBUG_FS >> static struct dentry *rootdir; >> >> @@ -49,22 +52,30 @@ static int em_debug_cpus_show(struct seq_file *s, void *unused) >> } >> DEFINE_SHOW_ATTRIBUTE(em_debug_cpus); >> >> -static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) >> +static void em_debug_create_pd(struct device *dev) >> { >> 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); >> + d = debugfs_create_dir(dev_name(dev), rootdir); >> >> - debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops); >> + if (_is_cpu_device(dev)) >> + debugfs_create_file("cpus", 0444, d, dev->em_pd->cpus, >> + &em_debug_cpus_fops); >> >> /* Create a sub-directory for each performance state */ >> - for (i = 0; i < pd->nr_perf_states; i++) >> - em_debug_create_ps(&pd->table[i], d); >> + for (i = 0; i < dev->em_pd->nr_perf_states; i++) >> + em_debug_create_ps(&dev->em_pd->table[i], d); >> + >> +} >> + >> +static void em_debug_remove_pd(struct device *dev) >> +{ >> + struct dentry *debug_dir; >> + >> + debug_dir = debugfs_lookup(dev_name(dev), rootdir); >> + debugfs_remove_recursive(debug_dir); >> } >> >> static int __init em_debug_init(void) >> @@ -76,40 +87,34 @@ static int __init em_debug_init(void) >> } >> core_initcall(em_debug_init); >> #else /* CONFIG_DEBUG_FS */ >> -static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) {} >> +static void em_debug_create_pd(struct device *dev) {} >> +static void em_debug_remove_pd(struct device *dev) {} >> #endif >> -static struct em_perf_domain * >> -em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, >> - cpumask_t *span) >> + >> +static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd, >> + int nr_states, struct em_data_callback *cb) >> { >> unsigned long opp_eff, prev_opp_eff = ULONG_MAX; >> unsigned long power, freq, prev_freq = 0; >> - int i, ret, cpu = cpumask_first(span); >> struct em_perf_state *table; >> - struct em_perf_domain *pd; >> + int i, ret; >> u64 fmax; >> >> - if (!cb->active_power) >> - return NULL; >> - >> - pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL); >> - if (!pd) >> - return NULL; >> - >> table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL); >> if (!table) >> - goto free_pd; >> + return -ENOMEM; >> >> /* Build the list of performance states for this performance domain */ >> for (i = 0, freq = 0; i < nr_states; i++, freq++) { >> /* >> * active_power() is a driver callback which ceils 'freq' to >> - * lowest performance state of 'cpu' above 'freq' and updates >> + * lowest performance state of 'dev' above 'freq' and updates >> * 'power' and 'freq' accordingly. >> */ >> ret = cb->active_power(&power, &freq, dev); >> if (ret) { >> - pr_err("pd%d: invalid perf. state: %d\n", cpu, ret); >> + dev_err(dev, "EM: invalid perf. state: %d\n", >> + ret); >> goto free_ps_table; >> } >> >> @@ -118,7 +123,8 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, >> * higher performance states. >> */ >> if (freq <= prev_freq) { >> - pr_err("pd%d: non-increasing freq: %lu\n", cpu, freq); >> + dev_err(dev, "EM: non-increasing freq: %lu\n", >> + freq); >> goto free_ps_table; >> } >> >> @@ -127,7 +133,8 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, >> * positive, in milli-watts and to fit into 16 bits. >> */ >> if (!power || power > EM_MAX_POWER) { >> - pr_err("pd%d: invalid power: %lu\n", cpu, power); >> + dev_err(dev, "EM: invalid power: %lu\n", >> + power); >> goto free_ps_table; >> } >> >> @@ -142,8 +149,8 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, >> */ >> opp_eff = freq / power; >> if (opp_eff >= prev_opp_eff) >> - pr_warn("pd%d: hertz/watts ratio non-monotonically decreasing: em_perf_state %d >= em_perf_state%d\n", >> - cpu, i, i - 1); >> + dev_dbg(dev, "EM: hertz/watts ratio non-monotonically decreasing: em_perf_state %d >= em_perf_state%d\n", >> + i, i - 1); >> prev_opp_eff = opp_eff; >> } >> >> @@ -156,30 +163,82 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, >> >> pd->table = table; >> pd->nr_perf_states = nr_states; >> - cpumask_copy(to_cpumask(pd->cpus), span); >> >> - em_debug_create_pd(pd, cpu); >> - >> - return pd; >> + return 0; >> >> free_ps_table: >> kfree(table); >> -free_pd: >> - kfree(pd); >> + return -EINVAL; >> +} >> + >> +static int em_create_pd(struct device *dev, int nr_states, >> + struct em_data_callback *cb, cpumask_t *cpus) >> +{ >> + struct em_perf_domain *pd; >> + struct device *cpu_dev; >> + int cpu, ret; >> + >> + if (_is_cpu_device(dev)) { >> + pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL); >> + if (!pd) >> + return -ENOMEM; >> + >> + cpumask_copy(em_span_cpus(pd), cpus); >> + } else { >> + pd = kzalloc(sizeof(*pd), GFP_KERNEL); >> + if (!pd) >> + return -ENOMEM; >> + } >> + >> + ret = em_create_perf_table(dev, pd, nr_states, cb); >> + if (ret) { >> + kfree(pd); >> + return ret; >> + } >> + >> + if (_is_cpu_device(dev)) >> + for_each_cpu(cpu, cpus) { >> + cpu_dev = get_cpu_device(cpu); >> + cpu_dev->em_pd = pd; >> + } >> + >> + dev->em_pd = pd; >> + >> + return 0; >> +} >> + >> +/** >> + * em_pd_get() - Return the performance domain for a device >> + * @dev : Device to find the performance domain for >> + * >> + * Returns the performance domain to which @dev belongs, or NULL if it doesn't >> + * exist. >> + */ >> +struct em_perf_domain *em_pd_get(struct device *dev) >> +{ >> + if (IS_ERR_OR_NULL(dev)) >> + return NULL; >> >> - return NULL; >> + return dev->em_pd; >> } >> +EXPORT_SYMBOL_GPL(em_pd_get); >> >> /** >> * em_cpu_get() - Return the performance domain for a CPU >> * @cpu : CPU to find the performance domain for >> * >> - * Return: the performance domain to which 'cpu' belongs, or NULL if it doesn't >> + * Returns the performance domain to which @cpu belongs, or NULL if it doesn't >> * exist. >> */ >> struct em_perf_domain *em_cpu_get(int cpu) >> { >> - return READ_ONCE(per_cpu(em_data, cpu)); >> + struct device *cpu_dev; >> + >> + cpu_dev = get_cpu_device(cpu); >> + if (!cpu_dev) >> + return NULL; >> + >> + return em_pd_get(cpu_dev); >> } >> EXPORT_SYMBOL_GPL(em_cpu_get); >> >> @@ -188,7 +247,7 @@ EXPORT_SYMBOL_GPL(em_cpu_get); >> * @dev : Device for which the EM is to register >> * @nr_states : Number of performance states to register >> * @cb : Callback functions providing the data of the Energy Model >> - * @span : Pointer to cpumask_t, which in case of a CPU device is >> + * @cpus : Pointer to cpumask_t, which in case of a CPU device is >> * obligatory. It can be taken from i.e. 'policy->cpus'. For other >> * type of devices this should be set to NULL. >> * >> @@ -201,13 +260,12 @@ EXPORT_SYMBOL_GPL(em_cpu_get); >> * Return 0 on success >> */ >> int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, >> - struct em_data_callback *cb, cpumask_t *span) >> + struct em_data_callback *cb, cpumask_t *cpus) >> { >> unsigned long cap, prev_cap = 0; >> - struct em_perf_domain *pd; >> - int cpu, ret = 0; >> + int cpu, ret; >> >> - if (!dev || !span || !nr_states || !cb) >> + if (!dev || !nr_states || !cb) >> return -EINVAL; >> >> /* >> @@ -216,47 +274,50 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, >> */ >> mutex_lock(&em_pd_mutex); >> >> - for_each_cpu(cpu, span) { >> - /* Make sure we don't register again an existing domain. */ >> - if (READ_ONCE(per_cpu(em_data, cpu))) { >> - ret = -EEXIST; >> - goto unlock; >> - } >> + if (dev->em_pd) { >> + ret = -EEXIST; >> + goto unlock; >> + } >> >> - /* >> - * All CPUs of a domain must have the same micro-architecture >> - * since they all share the same table. >> - */ >> - cap = arch_scale_cpu_capacity(cpu); >> - if (prev_cap && prev_cap != cap) { >> - pr_err("CPUs of %*pbl must have the same capacity\n", >> - cpumask_pr_args(span)); >> + if (_is_cpu_device(dev)) { >> + if (!cpus) { >> + dev_err(dev, "EM: invalid CPU mask\n"); >> ret = -EINVAL; >> goto unlock; >> } >> - prev_cap = cap; >> + >> + for_each_cpu(cpu, cpus) { >> + if (em_cpu_get(cpu)) { >> + dev_err(dev, "EM: exists for CPU%d\n", cpu); >> + ret = -EEXIST; >> + goto unlock; >> + } >> + /* >> + * All CPUs of a domain must have the same >> + * micro-architecture since they all share the same >> + * table. >> + */ >> + cap = arch_scale_cpu_capacity(cpu); >> + if (prev_cap && prev_cap != cap) { >> + dev_err(dev, "EM: CPUs of %*pbl must have the same capacity\n", >> + cpumask_pr_args(cpus)); >> + >> + ret = -EINVAL; >> + goto unlock; >> + } >> + prev_cap = cap; >> + } >> } >> >> - /* Create the performance domain and add it to the Energy Model. */ >> - pd = em_create_pd(dev, nr_states, cb, span); >> - if (!pd) { >> - ret = -EINVAL; >> + ret = em_create_pd(dev, nr_states, cb, cpus); >> + if (ret) >> goto unlock; >> - } >> >> - for_each_cpu(cpu, span) { >> - /* >> - * The per-cpu array can be read concurrently from em_cpu_get(). >> - * The barrier enforces the ordering needed to make sure readers >> - * can only access well formed em_perf_domain structs. >> - */ >> - smp_store_release(per_cpu_ptr(&em_data, cpu), pd); >> - } >> + em_debug_create_pd(dev); >> + dev_info(dev, "EM: created perf domain\n"); >> >> - pr_debug("Created perf domain %*pbl\n", cpumask_pr_args(span)); >> unlock: >> mutex_unlock(&em_pd_mutex); >> - >> return ret; >> } >> EXPORT_SYMBOL_GPL(em_dev_register_perf_domain); >> @@ -285,3 +346,32 @@ int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, >> return em_dev_register_perf_domain(cpu_dev, nr_states, cb, span); >> } >> EXPORT_SYMBOL_GPL(em_register_perf_domain); >> + >> +/** >> + * em_dev_unregister_perf_domain() - Unregister Energy Model (EM) for a device >> + * @dev : Device for which the EM is registered >> + * >> + * Unregister the EM for the specified @dev (but not a CPU device). >> + */ >> +void em_dev_unregister_perf_domain(struct device *dev) >> +{ >> + if (IS_ERR_OR_NULL(dev) || !dev->em_pd) >> + return; >> + >> + if (_is_cpu_device(dev)) >> + return; >> + >> + /* >> + * The mutex separates all register/unregister requests and protects >> + * from potential clean-up/setup issues in the debugfs directories. >> + * The debugfs directory name is the same as device's name. >> + */ >> + mutex_lock(&em_pd_mutex); >> + em_debug_remove_pd(dev); >> + >> + kfree(dev->em_pd->table); >> + kfree(dev->em_pd); >> + dev->em_pd = NULL; >> + mutex_unlock(&em_pd_mutex); >> +} >> +EXPORT_SYMBOL_GPL(em_dev_unregister_perf_domain); >> -- >> 2.17.1 >>
diff --git a/include/linux/device.h b/include/linux/device.h index ac8e37cd716a..7023d3ea189b 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -13,6 +13,7 @@ #define _DEVICE_H_ #include <linux/dev_printk.h> +#include <linux/energy_model.h> #include <linux/ioport.h> #include <linux/kobject.h> #include <linux/klist.h> @@ -559,6 +560,10 @@ struct device { struct dev_pm_info power; struct dev_pm_domain *pm_domain; +#ifdef CONFIG_ENERGY_MODEL + struct em_perf_domain *em_pd; +#endif + #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN struct irq_domain *msi_domain; #endif diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index 7076cb22b247..2d4689964029 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -12,8 +12,10 @@ /** * em_perf_state - Performance state of a performance domain - * @frequency: The CPU frequency in KHz, for consistency with CPUFreq - * @power: The power consumed by 1 CPU at this level, in milli-watts + * @frequency: The frequency in KHz, for consistency with CPUFreq + * @power: The power consumed at this level, in milli-watts (by 1 CPU or + by a registered device). It can be a total power: static and + dynamic. * @cost: The cost coefficient associated with this level, used during * energy calculation. Equal to: power * max_frequency / frequency */ @@ -27,12 +29,16 @@ struct em_perf_state { * em_perf_domain - Performance domain * @table: List of performance states, in ascending order * @nr_perf_states: Number of performance states - * @cpus: Cpumask covering the CPUs of the domain + * @cpus: Cpumask covering the CPUs of the domain. It's here + * for performance reasons to avoid potential cache + * misses during energy calculations in the scheduler + * and simplifies allocating/freeing that memory region. * - * A "performance domain" represents a group of CPUs whose performance is - * scaled together. All CPUs of a performance domain must have the same - * micro-architecture. Performance domains often have a 1-to-1 mapping with - * CPUFreq policies. + * In case of CPU device, a "performance domain" represents a group of CPUs + * whose performance is scaled together. All CPUs of a performance domain + * must have the same micro-architecture. Performance domains often have + * a 1-to-1 mapping with CPUFreq policies. In case of other devices the @cpus + * field is unused. */ struct em_perf_domain { struct em_perf_state *table; @@ -71,10 +77,12 @@ struct em_data_callback { #define EM_DATA_CB(_active_power_cb) { .active_power = &_active_power_cb } struct em_perf_domain *em_cpu_get(int cpu); +struct em_perf_domain *em_pd_get(struct device *dev); int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, struct em_data_callback *cb); int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, struct em_data_callback *cb, cpumask_t *span); +void em_dev_unregister_perf_domain(struct device *dev); /** * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. domain @@ -184,10 +192,17 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, { return -EINVAL; } +static inline void em_dev_unregister_perf_domain(struct device *dev) +{ +} static inline struct em_perf_domain *em_cpu_get(int cpu) { return NULL; } +static inline struct em_perf_domain *em_pd_get(struct device *dev) +{ + return NULL; +} static inline unsigned long em_pd_energy(struct em_perf_domain *pd, unsigned long max_util, unsigned long sum_util) { diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 5b8a1566526a..32d76e78f992 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -1,9 +1,10 @@ // SPDX-License-Identifier: GPL-2.0 /* - * Energy Model of CPUs + * Energy Model of devices * - * Copyright (c) 2018, Arm ltd. + * Copyright (c) 2018-2020, Arm ltd. * Written by: Quentin Perret, Arm ltd. + * Improvements provided by: Lukasz Luba, Arm ltd. */ #define pr_fmt(fmt) "energy_model: " fmt @@ -15,15 +16,17 @@ #include <linux/sched/topology.h> #include <linux/slab.h> -/* Mapping of each CPU to the performance domain to which it belongs. */ -static DEFINE_PER_CPU(struct em_perf_domain *, em_data); - /* * Mutex serializing the registrations of performance domains and letting * callbacks defined by drivers sleep. */ static DEFINE_MUTEX(em_pd_mutex); +static bool _is_cpu_device(struct device *dev) +{ + return (dev->bus == &cpu_subsys); +} + #ifdef CONFIG_DEBUG_FS static struct dentry *rootdir; @@ -49,22 +52,30 @@ static int em_debug_cpus_show(struct seq_file *s, void *unused) } DEFINE_SHOW_ATTRIBUTE(em_debug_cpus); -static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) +static void em_debug_create_pd(struct device *dev) { 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); + d = debugfs_create_dir(dev_name(dev), rootdir); - debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops); + if (_is_cpu_device(dev)) + debugfs_create_file("cpus", 0444, d, dev->em_pd->cpus, + &em_debug_cpus_fops); /* Create a sub-directory for each performance state */ - for (i = 0; i < pd->nr_perf_states; i++) - em_debug_create_ps(&pd->table[i], d); + for (i = 0; i < dev->em_pd->nr_perf_states; i++) + em_debug_create_ps(&dev->em_pd->table[i], d); + +} + +static void em_debug_remove_pd(struct device *dev) +{ + struct dentry *debug_dir; + + debug_dir = debugfs_lookup(dev_name(dev), rootdir); + debugfs_remove_recursive(debug_dir); } static int __init em_debug_init(void) @@ -76,40 +87,34 @@ static int __init em_debug_init(void) } core_initcall(em_debug_init); #else /* CONFIG_DEBUG_FS */ -static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) {} +static void em_debug_create_pd(struct device *dev) {} +static void em_debug_remove_pd(struct device *dev) {} #endif -static struct em_perf_domain * -em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, - cpumask_t *span) + +static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd, + int nr_states, struct em_data_callback *cb) { unsigned long opp_eff, prev_opp_eff = ULONG_MAX; unsigned long power, freq, prev_freq = 0; - int i, ret, cpu = cpumask_first(span); struct em_perf_state *table; - struct em_perf_domain *pd; + int i, ret; u64 fmax; - if (!cb->active_power) - return NULL; - - pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL); - if (!pd) - return NULL; - table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL); if (!table) - goto free_pd; + return -ENOMEM; /* Build the list of performance states for this performance domain */ for (i = 0, freq = 0; i < nr_states; i++, freq++) { /* * active_power() is a driver callback which ceils 'freq' to - * lowest performance state of 'cpu' above 'freq' and updates + * lowest performance state of 'dev' above 'freq' and updates * 'power' and 'freq' accordingly. */ ret = cb->active_power(&power, &freq, dev); if (ret) { - pr_err("pd%d: invalid perf. state: %d\n", cpu, ret); + dev_err(dev, "EM: invalid perf. state: %d\n", + ret); goto free_ps_table; } @@ -118,7 +123,8 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, * higher performance states. */ if (freq <= prev_freq) { - pr_err("pd%d: non-increasing freq: %lu\n", cpu, freq); + dev_err(dev, "EM: non-increasing freq: %lu\n", + freq); goto free_ps_table; } @@ -127,7 +133,8 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, * positive, in milli-watts and to fit into 16 bits. */ if (!power || power > EM_MAX_POWER) { - pr_err("pd%d: invalid power: %lu\n", cpu, power); + dev_err(dev, "EM: invalid power: %lu\n", + power); goto free_ps_table; } @@ -142,8 +149,8 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, */ opp_eff = freq / power; if (opp_eff >= prev_opp_eff) - pr_warn("pd%d: hertz/watts ratio non-monotonically decreasing: em_perf_state %d >= em_perf_state%d\n", - cpu, i, i - 1); + dev_dbg(dev, "EM: hertz/watts ratio non-monotonically decreasing: em_perf_state %d >= em_perf_state%d\n", + i, i - 1); prev_opp_eff = opp_eff; } @@ -156,30 +163,82 @@ em_create_pd(struct device *dev, int nr_states, struct em_data_callback *cb, pd->table = table; pd->nr_perf_states = nr_states; - cpumask_copy(to_cpumask(pd->cpus), span); - em_debug_create_pd(pd, cpu); - - return pd; + return 0; free_ps_table: kfree(table); -free_pd: - kfree(pd); + return -EINVAL; +} + +static int em_create_pd(struct device *dev, int nr_states, + struct em_data_callback *cb, cpumask_t *cpus) +{ + struct em_perf_domain *pd; + struct device *cpu_dev; + int cpu, ret; + + if (_is_cpu_device(dev)) { + pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL); + if (!pd) + return -ENOMEM; + + cpumask_copy(em_span_cpus(pd), cpus); + } else { + pd = kzalloc(sizeof(*pd), GFP_KERNEL); + if (!pd) + return -ENOMEM; + } + + ret = em_create_perf_table(dev, pd, nr_states, cb); + if (ret) { + kfree(pd); + return ret; + } + + if (_is_cpu_device(dev)) + for_each_cpu(cpu, cpus) { + cpu_dev = get_cpu_device(cpu); + cpu_dev->em_pd = pd; + } + + dev->em_pd = pd; + + return 0; +} + +/** + * em_pd_get() - Return the performance domain for a device + * @dev : Device to find the performance domain for + * + * Returns the performance domain to which @dev belongs, or NULL if it doesn't + * exist. + */ +struct em_perf_domain *em_pd_get(struct device *dev) +{ + if (IS_ERR_OR_NULL(dev)) + return NULL; - return NULL; + return dev->em_pd; } +EXPORT_SYMBOL_GPL(em_pd_get); /** * em_cpu_get() - Return the performance domain for a CPU * @cpu : CPU to find the performance domain for * - * Return: the performance domain to which 'cpu' belongs, or NULL if it doesn't + * Returns the performance domain to which @cpu belongs, or NULL if it doesn't * exist. */ struct em_perf_domain *em_cpu_get(int cpu) { - return READ_ONCE(per_cpu(em_data, cpu)); + struct device *cpu_dev; + + cpu_dev = get_cpu_device(cpu); + if (!cpu_dev) + return NULL; + + return em_pd_get(cpu_dev); } EXPORT_SYMBOL_GPL(em_cpu_get); @@ -188,7 +247,7 @@ EXPORT_SYMBOL_GPL(em_cpu_get); * @dev : Device for which the EM is to register * @nr_states : Number of performance states to register * @cb : Callback functions providing the data of the Energy Model - * @span : Pointer to cpumask_t, which in case of a CPU device is + * @cpus : Pointer to cpumask_t, which in case of a CPU device is * obligatory. It can be taken from i.e. 'policy->cpus'. For other * type of devices this should be set to NULL. * @@ -201,13 +260,12 @@ EXPORT_SYMBOL_GPL(em_cpu_get); * Return 0 on success */ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, - struct em_data_callback *cb, cpumask_t *span) + struct em_data_callback *cb, cpumask_t *cpus) { unsigned long cap, prev_cap = 0; - struct em_perf_domain *pd; - int cpu, ret = 0; + int cpu, ret; - if (!dev || !span || !nr_states || !cb) + if (!dev || !nr_states || !cb) return -EINVAL; /* @@ -216,47 +274,50 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, */ mutex_lock(&em_pd_mutex); - for_each_cpu(cpu, span) { - /* Make sure we don't register again an existing domain. */ - if (READ_ONCE(per_cpu(em_data, cpu))) { - ret = -EEXIST; - goto unlock; - } + if (dev->em_pd) { + ret = -EEXIST; + goto unlock; + } - /* - * All CPUs of a domain must have the same micro-architecture - * since they all share the same table. - */ - cap = arch_scale_cpu_capacity(cpu); - if (prev_cap && prev_cap != cap) { - pr_err("CPUs of %*pbl must have the same capacity\n", - cpumask_pr_args(span)); + if (_is_cpu_device(dev)) { + if (!cpus) { + dev_err(dev, "EM: invalid CPU mask\n"); ret = -EINVAL; goto unlock; } - prev_cap = cap; + + for_each_cpu(cpu, cpus) { + if (em_cpu_get(cpu)) { + dev_err(dev, "EM: exists for CPU%d\n", cpu); + ret = -EEXIST; + goto unlock; + } + /* + * All CPUs of a domain must have the same + * micro-architecture since they all share the same + * table. + */ + cap = arch_scale_cpu_capacity(cpu); + if (prev_cap && prev_cap != cap) { + dev_err(dev, "EM: CPUs of %*pbl must have the same capacity\n", + cpumask_pr_args(cpus)); + + ret = -EINVAL; + goto unlock; + } + prev_cap = cap; + } } - /* Create the performance domain and add it to the Energy Model. */ - pd = em_create_pd(dev, nr_states, cb, span); - if (!pd) { - ret = -EINVAL; + ret = em_create_pd(dev, nr_states, cb, cpus); + if (ret) goto unlock; - } - for_each_cpu(cpu, span) { - /* - * The per-cpu array can be read concurrently from em_cpu_get(). - * The barrier enforces the ordering needed to make sure readers - * can only access well formed em_perf_domain structs. - */ - smp_store_release(per_cpu_ptr(&em_data, cpu), pd); - } + em_debug_create_pd(dev); + dev_info(dev, "EM: created perf domain\n"); - pr_debug("Created perf domain %*pbl\n", cpumask_pr_args(span)); unlock: mutex_unlock(&em_pd_mutex); - return ret; } EXPORT_SYMBOL_GPL(em_dev_register_perf_domain); @@ -285,3 +346,32 @@ int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, return em_dev_register_perf_domain(cpu_dev, nr_states, cb, span); } EXPORT_SYMBOL_GPL(em_register_perf_domain); + +/** + * em_dev_unregister_perf_domain() - Unregister Energy Model (EM) for a device + * @dev : Device for which the EM is registered + * + * Unregister the EM for the specified @dev (but not a CPU device). + */ +void em_dev_unregister_perf_domain(struct device *dev) +{ + if (IS_ERR_OR_NULL(dev) || !dev->em_pd) + return; + + if (_is_cpu_device(dev)) + return; + + /* + * The mutex separates all register/unregister requests and protects + * from potential clean-up/setup issues in the debugfs directories. + * The debugfs directory name is the same as device's name. + */ + mutex_lock(&em_pd_mutex); + em_debug_remove_pd(dev); + + kfree(dev->em_pd->table); + kfree(dev->em_pd); + dev->em_pd = NULL; + mutex_unlock(&em_pd_mutex); +} +EXPORT_SYMBOL_GPL(em_dev_unregister_perf_domain);
Add support for other devices than CPUs. The registration function does not require a valid cpumask pointer and is ready to handle new devices. Some of the internal structures has been reorganized in order to keep consistent view (like removing per_cpu pd pointers). Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> --- Hi all, This is just a small change compared to v8 addressing Rafael's comments an Dan's static analyzes. Here are the changes: - added comment about mutex usage in the unregister function - changed 'dev' into @dev in the kerneldoc comments - removed 'else' statement from em_create_pd() to calm down static analizers Regards, Lukasz include/linux/device.h | 5 + include/linux/energy_model.h | 29 ++++- kernel/power/energy_model.c | 244 ++++++++++++++++++++++++----------- 3 files changed, 194 insertions(+), 84 deletions(-)