+ cputime64_t idle_time;
+ cputime64_t cur_wall_time;
+ cputime64_t busy_time;
+
+ cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
+ busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user,
+ kstat_cpu(cpu).cpustat.system);
+
+ busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq);
+ busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq);
+ busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal);
+ busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.nice);
+
+ idle_time = cputime64_sub(cur_wall_time, busy_time);
+ if (wall)
+ *wall = (cputime64_t)jiffies_to_usecs(cur_wall_time);
+
+ return (cputime64_t)jiffies_to_usecs(idle_time);;
+}
+
+static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
+{
+ u64 idle_time = get_cpu_idle_time_us(cpu, wall);
+
+ if (idle_time == -1ULL)
+ return get_cpu_idle_time_jiffy(cpu, wall);
+
+ return idle_time;
+}
+
+/* keep track of frequency transitions */
+static int
+dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
+ void *data)
+{
+ struct cpufreq_freqs *freq = data;
+ struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cs_cpu_dbs_info,
+ freq->cpu);
+
+ struct cpufreq_policy *policy;
+
+ if (!this_dbs_info->enable)
+ return 0;
+
+ policy = this_dbs_info->cur_policy;
+
+ /*
+ * we only care if our internally tracked freq moves outside
+ * the 'valid' ranges of freqency available to us otherwise
+ * we do not change it
+ */
+ if (this_dbs_info->requested_freq > policy->max
+ || this_dbs_info->requested_freq < policy->min)
+ this_dbs_info->requested_freq = freq->new;
+
+ return 0;