ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/drivers/cpufreq/cpufreq_governor.c b/marvell/linux/drivers/cpufreq/cpufreq_governor.c
new file mode 100644
index 0000000..4bb054d
--- /dev/null
+++ b/marvell/linux/drivers/cpufreq/cpufreq_governor.c
@@ -0,0 +1,573 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * drivers/cpufreq/cpufreq_governor.c
+ *
+ * CPUFREQ governors common code
+ *
+ * Copyright (C) 2001 Russell King
+ * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
+ * (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
+ * (C) 2009 Alexander Clouter <alex@digriz.org.uk>
+ * (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/export.h>
+#include <linux/kernel_stat.h>
+#include <linux/slab.h>
+
+#include "cpufreq_governor.h"
+
+#define CPUFREQ_DBS_MIN_SAMPLING_INTERVAL (2 * TICK_NSEC / NSEC_PER_USEC)
+
+static DEFINE_PER_CPU(struct cpu_dbs_info, cpu_dbs);
+
+static DEFINE_MUTEX(gov_dbs_data_mutex);
+
+/* Common sysfs tunables */
+/**
+ * store_sampling_rate - update sampling rate effective immediately if needed.
+ *
+ * If new rate is smaller than the old, simply updating
+ * dbs.sampling_rate might not be appropriate. For example, if the
+ * original sampling_rate was 1 second and the requested new sampling rate is 10
+ * ms because the user needs immediate reaction from ondemand governor, but not
+ * sure if higher frequency will be required or not, then, the governor may
+ * change the sampling rate too late; up to 1 second later. Thus, if we are
+ * reducing the sampling rate, we need to make the new value effective
+ * immediately.
+ *
+ * This must be called with dbs_data->mutex held, otherwise traversing
+ * policy_dbs_list isn't safe.
+ */
+ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf,
+ size_t count)
+{
+ struct dbs_data *dbs_data = to_dbs_data(attr_set);
+ struct policy_dbs_info *policy_dbs;
+ unsigned int sampling_interval;
+ int ret;
+
+ ret = sscanf(buf, "%u", &sampling_interval);
+ if (ret != 1 || sampling_interval < CPUFREQ_DBS_MIN_SAMPLING_INTERVAL)
+ return -EINVAL;
+
+ dbs_data->sampling_rate = sampling_interval;
+
+ /*
+ * We are operating under dbs_data->mutex and so the list and its
+ * entries can't be freed concurrently.
+ */
+ list_for_each_entry(policy_dbs, &attr_set->policy_list, list) {
+ mutex_lock(&policy_dbs->update_mutex);
+ /*
+ * On 32-bit architectures this may race with the
+ * sample_delay_ns read in dbs_update_util_handler(), but that
+ * really doesn't matter. If the read returns a value that's
+ * too big, the sample will be skipped, but the next invocation
+ * of dbs_update_util_handler() (when the update has been
+ * completed) will take a sample.
+ *
+ * If this runs in parallel with dbs_work_handler(), we may end
+ * up overwriting the sample_delay_ns value that it has just
+ * written, but it will be corrected next time a sample is
+ * taken, so it shouldn't be significant.
+ */
+ gov_update_sample_delay(policy_dbs, 0);
+ mutex_unlock(&policy_dbs->update_mutex);
+ }
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(store_sampling_rate);
+
+/**
+ * gov_update_cpu_data - Update CPU load data.
+ * @dbs_data: Top-level governor data pointer.
+ *
+ * Update CPU load data for all CPUs in the domain governed by @dbs_data
+ * (that may be a single policy or a bunch of them if governor tunables are
+ * system-wide).
+ *
+ * Call under the @dbs_data mutex.
+ */
+void gov_update_cpu_data(struct dbs_data *dbs_data)
+{
+ struct policy_dbs_info *policy_dbs;
+
+ list_for_each_entry(policy_dbs, &dbs_data->attr_set.policy_list, list) {
+ unsigned int j;
+
+ for_each_cpu(j, policy_dbs->policy->cpus) {
+ struct cpu_dbs_info *j_cdbs = &per_cpu(cpu_dbs, j);
+
+ j_cdbs->prev_cpu_idle = get_cpu_idle_time(j, &j_cdbs->prev_update_time,
+ dbs_data->io_is_busy);
+ if (dbs_data->ignore_nice_load)
+ j_cdbs->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
+ }
+ }
+}
+EXPORT_SYMBOL_GPL(gov_update_cpu_data);
+
+unsigned int dbs_update(struct cpufreq_policy *policy)
+{
+ struct policy_dbs_info *policy_dbs = policy->governor_data;
+ struct dbs_data *dbs_data = policy_dbs->dbs_data;
+ unsigned int ignore_nice = dbs_data->ignore_nice_load;
+ unsigned int max_load = 0, idle_periods = UINT_MAX;
+ unsigned int sampling_rate, io_busy, j;
+
+ /*
+ * Sometimes governors may use an additional multiplier to increase
+ * sample delays temporarily. Apply that multiplier to sampling_rate
+ * so as to keep the wake-up-from-idle detection logic a bit
+ * conservative.
+ */
+ sampling_rate = dbs_data->sampling_rate * policy_dbs->rate_mult;
+ /*
+ * For the purpose of ondemand, waiting for disk IO is an indication
+ * that you're performance critical, and not that the system is actually
+ * idle, so do not add the iowait time to the CPU idle time then.
+ */
+ io_busy = dbs_data->io_is_busy;
+
+ /* Get Absolute Load */
+ for_each_cpu(j, policy->cpus) {
+ struct cpu_dbs_info *j_cdbs = &per_cpu(cpu_dbs, j);
+ u64 update_time, cur_idle_time;
+ unsigned int idle_time, time_elapsed;
+ unsigned int load;
+
+ cur_idle_time = get_cpu_idle_time(j, &update_time, io_busy);
+
+ time_elapsed = update_time - j_cdbs->prev_update_time;
+ j_cdbs->prev_update_time = update_time;
+
+ idle_time = cur_idle_time - j_cdbs->prev_cpu_idle;
+ j_cdbs->prev_cpu_idle = cur_idle_time;
+
+ if (ignore_nice) {
+ u64 cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
+
+ idle_time += div_u64(cur_nice - j_cdbs->prev_cpu_nice, NSEC_PER_USEC);
+ j_cdbs->prev_cpu_nice = cur_nice;
+ }
+
+ if (unlikely(!time_elapsed)) {
+ /*
+ * That can only happen when this function is called
+ * twice in a row with a very short interval between the
+ * calls, so the previous load value can be used then.
+ */
+ load = j_cdbs->prev_load;
+ } else if (unlikely((int)idle_time > 2 * sampling_rate &&
+ j_cdbs->prev_load)) {
+ /*
+ * If the CPU had gone completely idle and a task has
+ * just woken up on this CPU now, it would be unfair to
+ * calculate 'load' the usual way for this elapsed
+ * time-window, because it would show near-zero load,
+ * irrespective of how CPU intensive that task actually
+ * was. This is undesirable for latency-sensitive bursty
+ * workloads.
+ *
+ * To avoid this, reuse the 'load' from the previous
+ * time-window and give this task a chance to start with
+ * a reasonably high CPU frequency. However, that
+ * shouldn't be over-done, lest we get stuck at a high
+ * load (high frequency) for too long, even when the
+ * current system load has actually dropped down, so
+ * clear prev_load to guarantee that the load will be
+ * computed again next time.
+ *
+ * Detecting this situation is easy: an unusually large
+ * 'idle_time' (as compared to the sampling rate)
+ * indicates this scenario.
+ */
+ load = j_cdbs->prev_load;
+ j_cdbs->prev_load = 0;
+ } else {
+ if (time_elapsed >= idle_time) {
+ load = 100 * (time_elapsed - idle_time) / time_elapsed;
+ } else {
+ /*
+ * That can happen if idle_time is returned by
+ * get_cpu_idle_time_jiffy(). In that case
+ * idle_time is roughly equal to the difference
+ * between time_elapsed and "busy time" obtained
+ * from CPU statistics. Then, the "busy time"
+ * can end up being greater than time_elapsed
+ * (for example, if jiffies_64 and the CPU
+ * statistics are updated by different CPUs),
+ * so idle_time may in fact be negative. That
+ * means, though, that the CPU was busy all
+ * the time (on the rough average) during the
+ * last sampling interval and 100 can be
+ * returned as the load.
+ */
+ load = (int)idle_time < 0 ? 100 : 0;
+ }
+ j_cdbs->prev_load = load;
+ }
+
+ if (unlikely((int)idle_time > 2 * sampling_rate)) {
+ unsigned int periods = idle_time / sampling_rate;
+
+ if (periods < idle_periods)
+ idle_periods = periods;
+ }
+
+ if (load > max_load)
+ max_load = load;
+ }
+
+ policy_dbs->idle_periods = idle_periods;
+
+ return max_load;
+}
+EXPORT_SYMBOL_GPL(dbs_update);
+
+static void dbs_work_handler(struct work_struct *work)
+{
+ struct policy_dbs_info *policy_dbs;
+ struct cpufreq_policy *policy;
+ struct dbs_governor *gov;
+
+ policy_dbs = container_of(work, struct policy_dbs_info, work);
+ policy = policy_dbs->policy;
+ gov = dbs_governor_of(policy);
+
+ /*
+ * Make sure cpufreq_governor_limits() isn't evaluating load or the
+ * ondemand governor isn't updating the sampling rate in parallel.
+ */
+ mutex_lock(&policy_dbs->update_mutex);
+ gov_update_sample_delay(policy_dbs, gov->gov_dbs_update(policy));
+ mutex_unlock(&policy_dbs->update_mutex);
+
+ /* Allow the utilization update handler to queue up more work. */
+ atomic_set(&policy_dbs->work_count, 0);
+ /*
+ * If the update below is reordered with respect to the sample delay
+ * modification, the utilization update handler may end up using a stale
+ * sample delay value.
+ */
+ smp_wmb();
+ policy_dbs->work_in_progress = false;
+}
+
+static void dbs_irq_work(struct irq_work *irq_work)
+{
+ struct policy_dbs_info *policy_dbs;
+
+ policy_dbs = container_of(irq_work, struct policy_dbs_info, irq_work);
+ schedule_work_on(smp_processor_id(), &policy_dbs->work);
+}
+
+static void dbs_update_util_handler(struct update_util_data *data, u64 time,
+ unsigned int flags)
+{
+ struct cpu_dbs_info *cdbs = container_of(data, struct cpu_dbs_info, update_util);
+ struct policy_dbs_info *policy_dbs = cdbs->policy_dbs;
+ u64 delta_ns, lst;
+
+ if (!cpufreq_this_cpu_can_update(policy_dbs->policy))
+ return;
+
+ /*
+ * The work may not be allowed to be queued up right now.
+ * Possible reasons:
+ * - Work has already been queued up or is in progress.
+ * - It is too early (too little time from the previous sample).
+ */
+ if (policy_dbs->work_in_progress)
+ return;
+
+ /*
+ * If the reads below are reordered before the check above, the value
+ * of sample_delay_ns used in the computation may be stale.
+ */
+ smp_rmb();
+ lst = READ_ONCE(policy_dbs->last_sample_time);
+ delta_ns = time - lst;
+ if ((s64)delta_ns < policy_dbs->sample_delay_ns)
+ return;
+
+ /*
+ * If the policy is not shared, the irq_work may be queued up right away
+ * at this point. Otherwise, we need to ensure that only one of the
+ * CPUs sharing the policy will do that.
+ */
+ if (policy_dbs->is_shared) {
+ if (!atomic_add_unless(&policy_dbs->work_count, 1, 1))
+ return;
+
+ /*
+ * If another CPU updated last_sample_time in the meantime, we
+ * shouldn't be here, so clear the work counter and bail out.
+ */
+ if (unlikely(lst != READ_ONCE(policy_dbs->last_sample_time))) {
+ atomic_set(&policy_dbs->work_count, 0);
+ return;
+ }
+ }
+
+ policy_dbs->last_sample_time = time;
+ policy_dbs->work_in_progress = true;
+ irq_work_queue(&policy_dbs->irq_work);
+}
+
+static void gov_set_update_util(struct policy_dbs_info *policy_dbs,
+ unsigned int delay_us)
+{
+ struct cpufreq_policy *policy = policy_dbs->policy;
+ int cpu;
+
+ gov_update_sample_delay(policy_dbs, delay_us);
+ policy_dbs->last_sample_time = 0;
+
+ for_each_cpu(cpu, policy->cpus) {
+ struct cpu_dbs_info *cdbs = &per_cpu(cpu_dbs, cpu);
+
+ cpufreq_add_update_util_hook(cpu, &cdbs->update_util,
+ dbs_update_util_handler);
+ }
+}
+
+static inline void gov_clear_update_util(struct cpufreq_policy *policy)
+{
+ int i;
+
+ for_each_cpu(i, policy->cpus)
+ cpufreq_remove_update_util_hook(i);
+
+ synchronize_rcu();
+}
+
+static struct policy_dbs_info *alloc_policy_dbs_info(struct cpufreq_policy *policy,
+ struct dbs_governor *gov)
+{
+ struct policy_dbs_info *policy_dbs;
+ int j;
+
+ /* Allocate memory for per-policy governor data. */
+ policy_dbs = gov->alloc();
+ if (!policy_dbs)
+ return NULL;
+
+ policy_dbs->policy = policy;
+ mutex_init(&policy_dbs->update_mutex);
+ atomic_set(&policy_dbs->work_count, 0);
+ init_irq_work(&policy_dbs->irq_work, dbs_irq_work);
+ INIT_WORK(&policy_dbs->work, dbs_work_handler);
+
+ /* Set policy_dbs for all CPUs, online+offline */
+ for_each_cpu(j, policy->related_cpus) {
+ struct cpu_dbs_info *j_cdbs = &per_cpu(cpu_dbs, j);
+
+ j_cdbs->policy_dbs = policy_dbs;
+ }
+ return policy_dbs;
+}
+
+static void free_policy_dbs_info(struct policy_dbs_info *policy_dbs,
+ struct dbs_governor *gov)
+{
+ int j;
+
+ mutex_destroy(&policy_dbs->update_mutex);
+
+ for_each_cpu(j, policy_dbs->policy->related_cpus) {
+ struct cpu_dbs_info *j_cdbs = &per_cpu(cpu_dbs, j);
+
+ j_cdbs->policy_dbs = NULL;
+ j_cdbs->update_util.func = NULL;
+ }
+ gov->free(policy_dbs);
+}
+
+int cpufreq_dbs_governor_init(struct cpufreq_policy *policy)
+{
+ struct dbs_governor *gov = dbs_governor_of(policy);
+ struct dbs_data *dbs_data;
+ struct policy_dbs_info *policy_dbs;
+ int ret = 0;
+
+ /* State should be equivalent to EXIT */
+ if (policy->governor_data)
+ return -EBUSY;
+
+ policy_dbs = alloc_policy_dbs_info(policy, gov);
+ if (!policy_dbs)
+ return -ENOMEM;
+
+ /* Protect gov->gdbs_data against concurrent updates. */
+ mutex_lock(&gov_dbs_data_mutex);
+
+ dbs_data = gov->gdbs_data;
+ if (dbs_data) {
+ if (WARN_ON(have_governor_per_policy())) {
+ ret = -EINVAL;
+ goto free_policy_dbs_info;
+ }
+ policy_dbs->dbs_data = dbs_data;
+ policy->governor_data = policy_dbs;
+
+ gov_attr_set_get(&dbs_data->attr_set, &policy_dbs->list);
+ goto out;
+ }
+
+ dbs_data = kzalloc(sizeof(*dbs_data), GFP_KERNEL);
+ if (!dbs_data) {
+ ret = -ENOMEM;
+ goto free_policy_dbs_info;
+ }
+
+ gov_attr_set_init(&dbs_data->attr_set, &policy_dbs->list);
+
+ ret = gov->init(dbs_data);
+ if (ret)
+ goto free_policy_dbs_info;
+
+ /*
+ * The sampling interval should not be less than the transition latency
+ * of the CPU and it also cannot be too small for dbs_update() to work
+ * correctly.
+ */
+ dbs_data->sampling_rate = max_t(unsigned int,
+ CPUFREQ_DBS_MIN_SAMPLING_INTERVAL,
+ cpufreq_policy_transition_delay_us(policy));
+
+ if (!have_governor_per_policy())
+ gov->gdbs_data = dbs_data;
+
+ policy_dbs->dbs_data = dbs_data;
+ policy->governor_data = policy_dbs;
+
+ gov->kobj_type.sysfs_ops = &governor_sysfs_ops;
+ ret = kobject_init_and_add(&dbs_data->attr_set.kobj, &gov->kobj_type,
+ get_governor_parent_kobj(policy),
+ "%s", gov->gov.name);
+ if (!ret)
+ goto out;
+
+ /* Failure, so roll back. */
+ pr_err("initialization failed (dbs_data kobject init error %d)\n", ret);
+
+ kobject_put(&dbs_data->attr_set.kobj);
+
+ policy->governor_data = NULL;
+
+ if (!have_governor_per_policy())
+ gov->gdbs_data = NULL;
+ gov->exit(dbs_data);
+ kfree(dbs_data);
+
+free_policy_dbs_info:
+ free_policy_dbs_info(policy_dbs, gov);
+
+out:
+ mutex_unlock(&gov_dbs_data_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpufreq_dbs_governor_init);
+
+void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy)
+{
+ struct dbs_governor *gov = dbs_governor_of(policy);
+ struct policy_dbs_info *policy_dbs = policy->governor_data;
+ struct dbs_data *dbs_data = policy_dbs->dbs_data;
+ unsigned int count;
+
+ /* Protect gov->gdbs_data against concurrent updates. */
+ mutex_lock(&gov_dbs_data_mutex);
+
+ count = gov_attr_set_put(&dbs_data->attr_set, &policy_dbs->list);
+
+ policy->governor_data = NULL;
+
+ if (!count) {
+ if (!have_governor_per_policy())
+ gov->gdbs_data = NULL;
+
+ gov->exit(dbs_data);
+ kfree(dbs_data);
+ }
+
+ free_policy_dbs_info(policy_dbs, gov);
+
+ mutex_unlock(&gov_dbs_data_mutex);
+}
+EXPORT_SYMBOL_GPL(cpufreq_dbs_governor_exit);
+
+int cpufreq_dbs_governor_start(struct cpufreq_policy *policy)
+{
+ struct dbs_governor *gov = dbs_governor_of(policy);
+ struct policy_dbs_info *policy_dbs = policy->governor_data;
+ struct dbs_data *dbs_data = policy_dbs->dbs_data;
+ unsigned int sampling_rate, ignore_nice, j;
+ unsigned int io_busy;
+
+ if (!policy->cur)
+ return -EINVAL;
+
+ policy_dbs->is_shared = policy_is_shared(policy);
+ policy_dbs->rate_mult = 1;
+
+ sampling_rate = dbs_data->sampling_rate;
+ ignore_nice = dbs_data->ignore_nice_load;
+ io_busy = dbs_data->io_is_busy;
+
+ for_each_cpu(j, policy->cpus) {
+ struct cpu_dbs_info *j_cdbs = &per_cpu(cpu_dbs, j);
+
+ j_cdbs->prev_cpu_idle = get_cpu_idle_time(j, &j_cdbs->prev_update_time, io_busy);
+ /*
+ * Make the first invocation of dbs_update() compute the load.
+ */
+ j_cdbs->prev_load = 0;
+
+ if (ignore_nice)
+ j_cdbs->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
+ }
+
+ gov->start(policy);
+
+ gov_set_update_util(policy_dbs, sampling_rate);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_dbs_governor_start);
+
+void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy)
+{
+ struct policy_dbs_info *policy_dbs = policy->governor_data;
+
+ gov_clear_update_util(policy_dbs->policy);
+ irq_work_sync(&policy_dbs->irq_work);
+ cancel_work_sync(&policy_dbs->work);
+ atomic_set(&policy_dbs->work_count, 0);
+ policy_dbs->work_in_progress = false;
+}
+EXPORT_SYMBOL_GPL(cpufreq_dbs_governor_stop);
+
+void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy)
+{
+ struct policy_dbs_info *policy_dbs;
+
+ /* Protect gov->gdbs_data against cpufreq_dbs_governor_exit() */
+ mutex_lock(&gov_dbs_data_mutex);
+ policy_dbs = policy->governor_data;
+ if (!policy_dbs)
+ goto out;
+
+ mutex_lock(&policy_dbs->update_mutex);
+ cpufreq_policy_apply_limits(policy);
+ gov_update_sample_delay(policy_dbs, 0);
+ mutex_unlock(&policy_dbs->update_mutex);
+
+out:
+ mutex_unlock(&gov_dbs_data_mutex);
+}
+EXPORT_SYMBOL_GPL(cpufreq_dbs_governor_limits);