--- /dev/null
+/* drivers/cpufreq/cpufreq_times.c
+ *
+ * Copyright (C) 2018 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/cpufreq.h>
+#include <linux/cpufreq_times.h>
+#include <linux/jiffies.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/threads.h>
+
+static DEFINE_SPINLOCK(task_time_in_state_lock); /* task->time_in_state */
+
+/**
+ * struct cpu_freqs - per-cpu frequency information
+ * @offset: start of these freqs' stats in task time_in_state array
+ * @max_state: number of entries in freq_table
+ * @last_index: index in freq_table of last frequency switched to
+ * @freq_table: list of available frequencies
+ */
+struct cpu_freqs {
+ unsigned int offset;
+ unsigned int max_state;
+ unsigned int last_index;
+ unsigned int freq_table[0];
+};
+
+static struct cpu_freqs *all_freqs[NR_CPUS];
+
+static unsigned int next_offset;
+
+void cpufreq_task_times_init(struct task_struct *p)
+{
+ void *temp;
+ unsigned long flags;
+ unsigned int max_state;
+
+ spin_lock_irqsave(&task_time_in_state_lock, flags);
+ p->time_in_state = NULL;
+ spin_unlock_irqrestore(&task_time_in_state_lock, flags);
+ p->max_state = 0;
+
+ max_state = READ_ONCE(next_offset);
+
+ /* We use one array to avoid multiple allocs per task */
+ temp = kcalloc(max_state, sizeof(p->time_in_state[0]), GFP_ATOMIC);
+ if (!temp)
+ return;
+
+ spin_lock_irqsave(&task_time_in_state_lock, flags);
+ p->time_in_state = temp;
+ spin_unlock_irqrestore(&task_time_in_state_lock, flags);
+ p->max_state = max_state;
+}
+
+/* Caller must hold task_time_in_state_lock */
+static int cpufreq_task_times_realloc_locked(struct task_struct *p)
+{
+ void *temp;
+ unsigned int max_state = READ_ONCE(next_offset);
+
+ temp = krealloc(p->time_in_state, max_state * sizeof(u64), GFP_ATOMIC);
+ if (!temp)
+ return -ENOMEM;
+ p->time_in_state = temp;
+ memset(p->time_in_state + p->max_state, 0,
+ (max_state - p->max_state) * sizeof(u64));
+ p->max_state = max_state;
+ return 0;
+}
+
+void cpufreq_task_times_exit(struct task_struct *p)
+{
+ unsigned long flags;
+ void *temp;
+
+ spin_lock_irqsave(&task_time_in_state_lock, flags);
+ temp = p->time_in_state;
+ p->time_in_state = NULL;
+ spin_unlock_irqrestore(&task_time_in_state_lock, flags);
+ kfree(temp);
+}
+
+int proc_time_in_state_show(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *p)
+{
+ unsigned int cpu, i;
+ u64 cputime;
+ unsigned long flags;
+ struct cpu_freqs *freqs;
+ struct cpu_freqs *last_freqs = NULL;
+
+ spin_lock_irqsave(&task_time_in_state_lock, flags);
+ for_each_possible_cpu(cpu) {
+ freqs = all_freqs[cpu];
+ if (!freqs || freqs == last_freqs)
+ continue;
+ last_freqs = freqs;
+
+ seq_printf(m, "cpu%u\n", cpu);
+ for (i = 0; i < freqs->max_state; i++) {
+ if (freqs->freq_table[i] == CPUFREQ_ENTRY_INVALID)
+ continue;
+ cputime = 0;
+ if (freqs->offset + i < p->max_state &&
+ p->time_in_state)
+ cputime = p->time_in_state[freqs->offset + i];
+ seq_printf(m, "%u %lu\n", freqs->freq_table[i],
+ (unsigned long)nsec_to_clock_t(cputime));
+ }
+ }
+ spin_unlock_irqrestore(&task_time_in_state_lock, flags);
+ return 0;
+}
+
+void cpufreq_acct_update_power(struct task_struct *p, u64 cputime)
+{
+ unsigned long flags;
+ unsigned int state;
+ struct cpu_freqs *freqs = all_freqs[task_cpu(p)];
+
+ if (!freqs || p->flags & PF_EXITING)
+ return;
+
+ state = freqs->offset + READ_ONCE(freqs->last_index);
+
+ spin_lock_irqsave(&task_time_in_state_lock, flags);
+ if ((state < p->max_state || !cpufreq_task_times_realloc_locked(p)) &&
+ p->time_in_state)
+ p->time_in_state[state] += cputime;
+ spin_unlock_irqrestore(&task_time_in_state_lock, flags);
+}
+
+void cpufreq_times_create_policy(struct cpufreq_policy *policy)
+{
+ int cpu, index;
+ unsigned int count = 0;
+ struct cpufreq_frequency_table *pos, *table;
+ struct cpu_freqs *freqs;
+ void *tmp;
+
+ if (all_freqs[policy->cpu])
+ return;
+
+ table = policy->freq_table;
+ if (!table)
+ return;
+
+ cpufreq_for_each_entry(pos, table)
+ count++;
+
+ tmp = kzalloc(sizeof(*freqs) + sizeof(freqs->freq_table[0]) * count,
+ GFP_KERNEL);
+ if (!tmp)
+ return;
+
+ freqs = tmp;
+ freqs->max_state = count;
+
+ index = cpufreq_frequency_table_get_index(policy, policy->cur);
+ if (index >= 0)
+ WRITE_ONCE(freqs->last_index, index);
+
+ cpufreq_for_each_entry(pos, table)
+ freqs->freq_table[pos - table] = pos->frequency;
+
+ freqs->offset = next_offset;
+ WRITE_ONCE(next_offset, freqs->offset + count);
+ for_each_cpu(cpu, policy->related_cpus)
+ all_freqs[cpu] = freqs;
+}
+
+void cpufreq_times_record_transition(struct cpufreq_freqs *freq)
+{
+ int index;
+ struct cpu_freqs *freqs = all_freqs[freq->cpu];
+ struct cpufreq_policy *policy;
+
+ if (!freqs)
+ return;
+
+ policy = cpufreq_cpu_get(freq->cpu);
+ if (!policy)
+ return;
+
+ index = cpufreq_frequency_table_get_index(policy, freq->new);
+ if (index >= 0)
+ WRITE_ONCE(freqs->last_index, index);
+
+ cpufreq_cpu_put(policy);
+}
--- /dev/null
+/* drivers/cpufreq/cpufreq_times.c
+ *
+ * Copyright (C) 2018 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_CPUFREQ_TIMES_H
+#define _LINUX_CPUFREQ_TIMES_H
+
+#include <linux/cpufreq.h>
+#include <linux/pid.h>
+
+#ifdef CONFIG_CPU_FREQ_TIMES
+void cpufreq_task_times_init(struct task_struct *p);
+void cpufreq_task_times_exit(struct task_struct *p);
+int proc_time_in_state_show(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *p);
+void cpufreq_acct_update_power(struct task_struct *p, u64 cputime);
+void cpufreq_times_create_policy(struct cpufreq_policy *policy);
+void cpufreq_times_record_transition(struct cpufreq_freqs *freq);
+#else
+static inline void cpufreq_times_create_policy(struct cpufreq_policy *policy) {}
+static inline void cpufreq_times_record_transition(
+ struct cpufreq_freqs *freq) {}
+#endif /* CONFIG_CPU_FREQ_TIMES */
+#endif /* _LINUX_CPUFREQ_TIMES_H */