Messages in this thread | | | Date | Mon, 13 May 2019 20:40:59 -0700 | From | Eduardo Valentin <> | Subject | Re: [PATCH v3 3/3] thermal: cpu_cooling: Migrate to using the EM framework |
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On Fri, May 03, 2019 at 10:44:09AM +0100, Quentin Perret wrote: > The newly introduced Energy Model framework manages power cost tables in > a generic way. Moreover, it supports a several types of models since the > tables can come from DT or firmware (through SCMI) for example. On the > other hand, the cpu_cooling subsystem manages its own power cost tables > using only DT data. > > In order to avoid the duplication of data in the kernel, and in order to > enable IPA with EMs coming from more than just DT, remove the private > tables from cpu_cooling.c and migrate it to using the centralized EM > framework. > > The case where the thermal subsystem is used without an Energy Model > (cpufreq_cooling_ops) is handled by looking directly at CPUFreq's > frequency table which is already a dependency for cpu_cooling.c anyway. > Since the thermal framework expects the cooling states in a particular > order, bail out whenever the CPUFreq table is unsorted, since that is > fairly uncommon in general, and there are currently no users of > cpu_cooling for this use-case.
Will this break DT in any way? After this change, are the existing DTs still compatible with this cpu cooling?
> > Signed-off-by: Quentin Perret <quentin.perret@arm.com> > --- > drivers/thermal/Kconfig | 1 + > drivers/thermal/cpu_cooling.c | 238 ++++++++++++---------------------- > 2 files changed, 82 insertions(+), 157 deletions(-) > > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig > index 653aa27a25a4..d695bd33c440 100644 > --- a/drivers/thermal/Kconfig > +++ b/drivers/thermal/Kconfig > @@ -144,6 +144,7 @@ config THERMAL_GOV_USER_SPACE > > config THERMAL_GOV_POWER_ALLOCATOR > bool "Power allocator thermal governor" > + depends on ENERGY_MODEL > help > Enable this to manage platform thermals by dynamically > allocating and limiting power to devices. > diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c > index f7c1f49ec87f..322ea89dd078 100644 > --- a/drivers/thermal/cpu_cooling.c > +++ b/drivers/thermal/cpu_cooling.c > @@ -31,6 +31,7 @@ > #include <linux/slab.h> > #include <linux/cpu.h> > #include <linux/cpu_cooling.h> > +#include <linux/energy_model.h> > > #include <trace/events/thermal.h> > > @@ -48,19 +49,6 @@ > * ... > */ > > -/** > - * struct freq_table - frequency table along with power entries > - * @frequency: frequency in KHz > - * @power: power in mW > - * > - * This structure is built when the cooling device registers and helps > - * in translating frequency to power and vice versa. > - */ > -struct freq_table { > - u32 frequency; > - u32 power; > -}; > - > /** > * struct time_in_idle - Idle time stats > * @time: previous reading of the absolute time that this cpu was idle > @@ -82,7 +70,7 @@ struct time_in_idle { > * frequency. > * @max_level: maximum cooling level. One less than total number of valid > * cpufreq frequencies. > - * @freq_table: Freq table in descending order of frequencies > + * @em: Reference on the Energy Model of the device > * @cdev: thermal_cooling_device pointer to keep track of the > * registered cooling device. > * @policy: cpufreq policy. > @@ -98,7 +86,7 @@ struct cpufreq_cooling_device { > unsigned int cpufreq_state; > unsigned int clipped_freq; > unsigned int max_level; > - struct freq_table *freq_table; /* In descending order */ > + struct em_perf_domain *em; > struct thermal_cooling_device *cdev; > struct cpufreq_policy *policy; > struct list_head node; > @@ -121,14 +109,14 @@ static LIST_HEAD(cpufreq_cdev_list); > static unsigned long get_level(struct cpufreq_cooling_device *cpufreq_cdev, > unsigned int freq) > { > - struct freq_table *freq_table = cpufreq_cdev->freq_table; > - unsigned long level; > + int i; > > - for (level = 1; level <= cpufreq_cdev->max_level; level++) > - if (freq > freq_table[level].frequency) > + for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) { > + if (freq > cpufreq_cdev->em->table[i].frequency) > break; > + } > > - return level - 1; > + return cpufreq_cdev->max_level - i - 1; > } > > /** > @@ -184,105 +172,30 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb, > return NOTIFY_OK; > } > > -/** > - * update_freq_table() - Update the freq table with power numbers > - * @cpufreq_cdev: the cpufreq cooling device in which to update the table > - * @capacitance: dynamic power coefficient for these cpus > - * > - * Update the freq table with power numbers. This table will be used in > - * cpu_power_to_freq() and cpu_freq_to_power() to convert between power and > - * frequency efficiently. Power is stored in mW, frequency in KHz. The > - * resulting table is in descending order. > - * > - * Return: 0 on success, -EINVAL if there are no OPPs for any CPUs, > - * or -ENOMEM if we run out of memory. > - */ > -static int update_freq_table(struct cpufreq_cooling_device *cpufreq_cdev, > - u32 capacitance) > -{ > - struct freq_table *freq_table = cpufreq_cdev->freq_table; > - struct dev_pm_opp *opp; > - struct device *dev = NULL; > - int num_opps = 0, cpu = cpufreq_cdev->policy->cpu, i; > - > - dev = get_cpu_device(cpu); > - if (unlikely(!dev)) { > - dev_warn(&cpufreq_cdev->cdev->device, > - "No cpu device for cpu %d\n", cpu); > - return -ENODEV; > - } > - > - num_opps = dev_pm_opp_get_opp_count(dev); > - if (num_opps < 0) > - return num_opps; > - > - /* > - * The cpufreq table is also built from the OPP table and so the count > - * should match. > - */ > - if (num_opps != cpufreq_cdev->max_level + 1) { > - dev_warn(dev, "Number of OPPs not matching with max_levels\n"); > - return -EINVAL; > - } > - > - for (i = 0; i <= cpufreq_cdev->max_level; i++) { > - unsigned long freq = freq_table[i].frequency * 1000; > - u32 freq_mhz = freq_table[i].frequency / 1000; > - u64 power; > - u32 voltage_mv; > - > - /* > - * Find ceil frequency as 'freq' may be slightly lower than OPP > - * freq due to truncation while converting to kHz. > - */ > - opp = dev_pm_opp_find_freq_ceil(dev, &freq); > - if (IS_ERR(opp)) { > - dev_err(dev, "failed to get opp for %lu frequency\n", > - freq); > - return -EINVAL; > - } > - > - voltage_mv = dev_pm_opp_get_voltage(opp) / 1000; > - dev_pm_opp_put(opp); > - > - /* > - * Do the multiplication with MHz and millivolt so as > - * to not overflow. > - */ > - power = (u64)capacitance * freq_mhz * voltage_mv * voltage_mv; > - do_div(power, 1000000000); > - > - /* power is stored in mW */ > - freq_table[i].power = power; > - } > - > - return 0; > -} > - > static u32 cpu_freq_to_power(struct cpufreq_cooling_device *cpufreq_cdev, > u32 freq) > { > int i; > - struct freq_table *freq_table = cpufreq_cdev->freq_table; > > - for (i = 1; i <= cpufreq_cdev->max_level; i++) > - if (freq > freq_table[i].frequency) > + for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) { > + if (freq > cpufreq_cdev->em->table[i].frequency) > break; > + } > > - return freq_table[i - 1].power; > + return cpufreq_cdev->em->table[i + 1].power; > } > > static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev, > u32 power) > { > int i; > - struct freq_table *freq_table = cpufreq_cdev->freq_table; > > - for (i = 1; i <= cpufreq_cdev->max_level; i++) > - if (power > freq_table[i].power) > + for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) { > + if (power > cpufreq_cdev->em->table[i].power) > break; > + } > > - return freq_table[i - 1].frequency; > + return cpufreq_cdev->em->table[i + 1].frequency; > } > > /** > @@ -374,6 +287,28 @@ static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, > return 0; > } > > +static unsigned int get_state_freq(struct cpufreq_cooling_device *cpufreq_cdev, > + unsigned long state) > +{ > + struct cpufreq_policy *policy; > + unsigned long idx; > + > + /* Use the Energy Model table if available */ > + if (cpufreq_cdev->em) { > + idx = cpufreq_cdev->max_level - state; > + return cpufreq_cdev->em->table[idx].frequency; > + } > + > + /* Otherwise, fallback on the CPUFreq table */ > + policy = cpufreq_cdev->policy; > + if (policy->freq_table_sorted == CPUFREQ_TABLE_SORTED_ASCENDING) > + idx = cpufreq_cdev->max_level - state; > + else > + idx = state; > + > + return policy->freq_table[idx].frequency; > +} > + > /** > * cpufreq_set_cur_state - callback function to set the current cooling state. > * @cdev: thermal cooling device pointer. > @@ -398,7 +333,7 @@ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, > if (cpufreq_cdev->cpufreq_state == state) > return 0; > > - clip_freq = cpufreq_cdev->freq_table[state].frequency; > + clip_freq = get_state_freq(cpufreq_cdev, state); > cpufreq_cdev->cpufreq_state = state; > cpufreq_cdev->clipped_freq = clip_freq; > > @@ -497,7 +432,7 @@ static int cpufreq_state2power(struct thermal_cooling_device *cdev, > struct thermal_zone_device *tz, > unsigned long state, u32 *power) > { > - unsigned int freq, num_cpus; > + unsigned int freq, num_cpus, idx; > struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; > > /* Request state should be less than max_level */ > @@ -506,7 +441,8 @@ static int cpufreq_state2power(struct thermal_cooling_device *cdev, > > num_cpus = cpumask_weight(cpufreq_cdev->policy->cpus); > > - freq = cpufreq_cdev->freq_table[state].frequency; > + idx = cpufreq_cdev->max_level - state; > + freq = cpufreq_cdev->em->table[idx].frequency; > *power = cpu_freq_to_power(cpufreq_cdev, freq) * num_cpus; > > return 0; > @@ -559,7 +495,6 @@ static struct thermal_cooling_device_ops cpufreq_cooling_ops = { > .get_cur_state = cpufreq_get_cur_state, > .set_cur_state = cpufreq_set_cur_state, > }; > - > static struct thermal_cooling_device_ops cpufreq_power_cooling_ops = { > .get_max_state = cpufreq_get_max_state, > .get_cur_state = cpufreq_get_cur_state, > @@ -574,18 +509,31 @@ static struct notifier_block thermal_cpufreq_notifier_block = { > .notifier_call = cpufreq_thermal_notifier, > }; > > -static unsigned int find_next_max(struct cpufreq_frequency_table *table, > - unsigned int prev_max) > -{ > - struct cpufreq_frequency_table *pos; > - unsigned int max = 0; > +static inline bool em_is_sane(struct cpufreq_cooling_device *cpufreq_cdev, > + struct em_perf_domain *em) { > + struct cpufreq_policy *policy; > + unsigned int nr_levels; > > - cpufreq_for_each_valid_entry(pos, table) { > - if (pos->frequency > max && pos->frequency < prev_max) > - max = pos->frequency; > + if (!em) > + return false; > + > + policy = cpufreq_cdev->policy; > + if (!cpumask_equal(policy->related_cpus, to_cpumask(em->cpus))) { > + pr_err("The span of pd %*pbl is misaligned with cpufreq policy %*pbl\n", > + cpumask_pr_args(to_cpumask(em->cpus)), > + cpumask_pr_args(policy->related_cpus)); > + return false; > } > > - return max; > + nr_levels = cpufreq_cdev->max_level + 1; > + if (em->nr_cap_states != nr_levels) { > + pr_err("The number of cap states in pd %*pbl (%u) doesn't match the number of cooling levels (%u)\n", > + cpumask_pr_args(to_cpumask(em->cpus)), > + em->nr_cap_states, nr_levels); > + return false; > + } > + > + return true; > } > > /** > @@ -593,7 +541,7 @@ static unsigned int find_next_max(struct cpufreq_frequency_table *table, > * @np: a valid struct device_node to the cooling device device tree node > * @policy: cpufreq policy > * Normally this should be same as cpufreq policy->related_cpus. > - * @capacitance: dynamic power coefficient for these cpus > + * @em: Energy Model of the cpufreq policy > * > * This interface function registers the cpufreq cooling device with the name > * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq > @@ -605,12 +553,13 @@ static unsigned int find_next_max(struct cpufreq_frequency_table *table, > */ > static struct thermal_cooling_device * > __cpufreq_cooling_register(struct device_node *np, > - struct cpufreq_policy *policy, u32 capacitance) > + struct cpufreq_policy *policy, > + struct em_perf_domain *em) > { > struct thermal_cooling_device *cdev; > struct cpufreq_cooling_device *cpufreq_cdev; > char dev_name[THERMAL_NAME_LENGTH]; > - unsigned int freq, i, num_cpus; > + unsigned int i, num_cpus; > int ret; > struct thermal_cooling_device_ops *cooling_ops; > bool first; > @@ -644,46 +593,26 @@ __cpufreq_cooling_register(struct device_node *np, > /* max_level is an index, not a counter */ > cpufreq_cdev->max_level = i - 1; > > - cpufreq_cdev->freq_table = kmalloc_array(i, > - sizeof(*cpufreq_cdev->freq_table), > - GFP_KERNEL); > - if (!cpufreq_cdev->freq_table) { > - cdev = ERR_PTR(-ENOMEM); > - goto free_idle_time; > - } > - > ret = ida_simple_get(&cpufreq_ida, 0, 0, GFP_KERNEL); > if (ret < 0) { > cdev = ERR_PTR(ret); > - goto free_table; > + goto free_idle_time; > } > cpufreq_cdev->id = ret; > > snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d", > cpufreq_cdev->id); > > - /* Fill freq-table in descending order of frequencies */ > - for (i = 0, freq = -1; i <= cpufreq_cdev->max_level; i++) { > - freq = find_next_max(policy->freq_table, freq); > - cpufreq_cdev->freq_table[i].frequency = freq; > - > - /* Warn for duplicate entries */ > - if (!freq) > - pr_warn("%s: table has duplicate entries\n", __func__); > - else > - pr_debug("%s: freq:%u KHz\n", __func__, freq); > - } > - > - if (capacitance) { > - ret = update_freq_table(cpufreq_cdev, capacitance); > - if (ret) { > - cdev = ERR_PTR(ret); > - goto remove_ida; > - } > - > + if (em_is_sane(cpufreq_cdev, em)) { > + cpufreq_cdev->em = em; > cooling_ops = &cpufreq_power_cooling_ops; > - } else { > + } else if (policy->freq_table_sorted != CPUFREQ_TABLE_UNSORTED) { > cooling_ops = &cpufreq_cooling_ops; > + } else { > + pr_err("%s: unsorted frequency tables are not supported\n", > + __func__); > + cdev = ERR_PTR(-EINVAL); > + goto remove_ida; > } > > cdev = thermal_of_cooling_device_register(np, dev_name, cpufreq_cdev, > @@ -691,7 +620,7 @@ __cpufreq_cooling_register(struct device_node *np, > if (IS_ERR(cdev)) > goto remove_ida; > > - cpufreq_cdev->clipped_freq = cpufreq_cdev->freq_table[0].frequency; > + cpufreq_cdev->clipped_freq = get_state_freq(cpufreq_cdev, 0); > cpufreq_cdev->cdev = cdev; > > mutex_lock(&cooling_list_lock); > @@ -708,8 +637,6 @@ __cpufreq_cooling_register(struct device_node *np, > > remove_ida: > ida_simple_remove(&cpufreq_ida, cpufreq_cdev->id); > -free_table: > - kfree(cpufreq_cdev->freq_table); > free_idle_time: > kfree(cpufreq_cdev->idle_time); > free_cdev: > @@ -731,7 +658,7 @@ __cpufreq_cooling_register(struct device_node *np, > struct thermal_cooling_device * > cpufreq_cooling_register(struct cpufreq_policy *policy) > { > - return __cpufreq_cooling_register(NULL, policy, 0); > + return __cpufreq_cooling_register(NULL, policy, NULL); > } > EXPORT_SYMBOL_GPL(cpufreq_cooling_register); > > @@ -759,7 +686,6 @@ of_cpufreq_cooling_register(struct cpufreq_policy *policy) > { > struct device_node *np = of_get_cpu_node(policy->cpu, NULL); > struct thermal_cooling_device *cdev = NULL; > - u32 capacitance = 0; > > if (!np) { > pr_err("cpu_cooling: OF node not available for cpu%d\n", > @@ -768,10 +694,9 @@ of_cpufreq_cooling_register(struct cpufreq_policy *policy) > } > > if (of_find_property(np, "#cooling-cells", NULL)) { > - of_property_read_u32(np, "dynamic-power-coefficient", > - &capacitance); > + struct em_perf_domain *em = em_cpu_get(policy->cpu); > > - cdev = __cpufreq_cooling_register(np, policy, capacitance); > + cdev = __cpufreq_cooling_register(np, policy, em); > if (IS_ERR(cdev)) { > pr_err("cpu_cooling: cpu%d failed to register as cooling device: %ld\n", > policy->cpu, PTR_ERR(cdev)); > @@ -813,7 +738,6 @@ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) > thermal_cooling_device_unregister(cpufreq_cdev->cdev); > ida_simple_remove(&cpufreq_ida, cpufreq_cdev->id); > kfree(cpufreq_cdev->idle_time); > - kfree(cpufreq_cdev->freq_table); > kfree(cpufreq_cdev); > } > EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);
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