cpufreq: powernv: Replacing pstate_id with frequency table index
Refactoring code to use frequency table index instead of pstate_id. This abstraction will make the code independent of the pstate values. - No functional changes - The highest frequency is at frequency table index 0 and the frequency decreases as the index increases. - Macros pstates_to_idx() and idx_to_pstate() can be used for conversion between pstate_id and index. - powernv_pstate_info now contains frequency table index to min, max and nominal frequency (instead of pstate_ids) - global_pstate_info new stores index values instead pstate ids. - variables renamed as *_idx which now store index instead of pstate Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Akshay Adiga
Rafael J. Wysocki
parent
5fc8f707a2
commit
09ca4c9b59
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@ -64,12 +64,14 @@
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/**
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* struct global_pstate_info - Per policy data structure to maintain history of
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* global pstates
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* @highest_lpstate: The local pstate from which we are ramping down
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* @highest_lpstate_idx: The local pstate index from which we are
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* ramping down
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* @elapsed_time: Time in ms spent in ramping down from
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* highest_lpstate
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* highest_lpstate_idx
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* @last_sampled_time: Time from boot in ms when global pstates were
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* last set
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* @last_lpstate,last_gpstate: Last set values for local and global pstates
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* @last_lpstate_idx, Last set value of local pstate and global
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* last_gpstate_idx pstate in terms of cpufreq table index
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* @timer: Is used for ramping down if cpu goes idle for
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* a long time with global pstate held high
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* @gpstate_lock: A spinlock to maintain synchronization between
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@ -77,11 +79,11 @@
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* governer's target_index calls
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*/
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struct global_pstate_info {
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int highest_lpstate;
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int highest_lpstate_idx;
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unsigned int elapsed_time;
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unsigned int last_sampled_time;
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int last_lpstate;
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int last_gpstate;
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int last_lpstate_idx;
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int last_gpstate_idx;
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spinlock_t gpstate_lock;
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struct timer_list timer;
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};
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@ -124,29 +126,47 @@ static int nr_chips;
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static DEFINE_PER_CPU(struct chip *, chip_info);
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/*
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* Note: The set of pstates consists of contiguous integers, the
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* smallest of which is indicated by powernv_pstate_info.min, the
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* largest of which is indicated by powernv_pstate_info.max.
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* Note:
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* The set of pstates consists of contiguous integers.
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* powernv_pstate_info stores the index of the frequency table for
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* max, min and nominal frequencies. It also stores number of
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* available frequencies.
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*
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* The nominal pstate is the highest non-turbo pstate in this
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* platform. This is indicated by powernv_pstate_info.nominal.
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* powernv_pstate_info.nominal indicates the index to the highest
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* non-turbo frequency.
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*/
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static struct powernv_pstate_info {
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int min;
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int max;
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int nominal;
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int nr_pstates;
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unsigned int min;
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unsigned int max;
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unsigned int nominal;
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unsigned int nr_pstates;
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} powernv_pstate_info;
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/* Use following macros for conversions between pstate_id and index */
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static inline int idx_to_pstate(unsigned int i)
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{
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return powernv_freqs[i].driver_data;
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}
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static inline unsigned int pstate_to_idx(int pstate)
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{
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/*
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* abs() is deliberately used so that is works with
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* both monotonically increasing and decreasing
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* pstate values
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*/
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return abs(pstate - idx_to_pstate(powernv_pstate_info.max));
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}
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static inline void reset_gpstates(struct cpufreq_policy *policy)
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{
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struct global_pstate_info *gpstates = policy->driver_data;
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gpstates->highest_lpstate = 0;
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gpstates->highest_lpstate_idx = 0;
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gpstates->elapsed_time = 0;
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gpstates->last_sampled_time = 0;
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gpstates->last_lpstate = 0;
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gpstates->last_gpstate = 0;
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gpstates->last_lpstate_idx = 0;
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gpstates->last_gpstate_idx = 0;
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}
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/*
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@ -156,9 +176,10 @@ static inline void reset_gpstates(struct cpufreq_policy *policy)
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static int init_powernv_pstates(void)
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{
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struct device_node *power_mgt;
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int i, pstate_min, pstate_max, pstate_nominal, nr_pstates = 0;
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int i, nr_pstates = 0;
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const __be32 *pstate_ids, *pstate_freqs;
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u32 len_ids, len_freqs;
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u32 pstate_min, pstate_max, pstate_nominal;
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power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
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if (!power_mgt) {
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@ -208,6 +229,7 @@ static int init_powernv_pstates(void)
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return -ENODEV;
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}
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powernv_pstate_info.nr_pstates = nr_pstates;
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pr_debug("NR PStates %d\n", nr_pstates);
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for (i = 0; i < nr_pstates; i++) {
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u32 id = be32_to_cpu(pstate_ids[i]);
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@ -216,15 +238,17 @@ static int init_powernv_pstates(void)
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pr_debug("PState id %d freq %d MHz\n", id, freq);
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powernv_freqs[i].frequency = freq * 1000; /* kHz */
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powernv_freqs[i].driver_data = id;
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if (id == pstate_max)
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powernv_pstate_info.max = i;
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else if (id == pstate_nominal)
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powernv_pstate_info.nominal = i;
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else if (id == pstate_min)
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powernv_pstate_info.min = i;
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}
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/* End of list marker entry */
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powernv_freqs[i].frequency = CPUFREQ_TABLE_END;
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powernv_pstate_info.min = pstate_min;
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powernv_pstate_info.max = pstate_max;
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powernv_pstate_info.nominal = pstate_nominal;
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powernv_pstate_info.nr_pstates = nr_pstates;
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return 0;
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}
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@ -233,12 +257,12 @@ static unsigned int pstate_id_to_freq(int pstate_id)
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{
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int i;
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i = powernv_pstate_info.max - pstate_id;
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i = pstate_to_idx(pstate_id);
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if (i >= powernv_pstate_info.nr_pstates || i < 0) {
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pr_warn("PState id %d outside of PState table, "
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"reporting nominal id %d instead\n",
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pstate_id, powernv_pstate_info.nominal);
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i = powernv_pstate_info.max - powernv_pstate_info.nominal;
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pstate_id, idx_to_pstate(powernv_pstate_info.nominal));
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i = powernv_pstate_info.nominal;
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}
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return powernv_freqs[i].frequency;
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@ -252,7 +276,7 @@ static ssize_t cpuinfo_nominal_freq_show(struct cpufreq_policy *policy,
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char *buf)
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{
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return sprintf(buf, "%u\n",
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pstate_id_to_freq(powernv_pstate_info.nominal));
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powernv_freqs[powernv_pstate_info.nominal].frequency);
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}
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struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq =
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@ -426,7 +450,7 @@ static void set_pstate(void *data)
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*/
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static inline unsigned int get_nominal_index(void)
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{
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return powernv_pstate_info.max - powernv_pstate_info.nominal;
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return powernv_pstate_info.nominal;
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}
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static void powernv_cpufreq_throttle_check(void *data)
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@ -435,20 +459,22 @@ static void powernv_cpufreq_throttle_check(void *data)
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unsigned int cpu = smp_processor_id();
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unsigned long pmsr;
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int pmsr_pmax;
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unsigned int pmsr_pmax_idx;
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pmsr = get_pmspr(SPRN_PMSR);
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chip = this_cpu_read(chip_info);
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/* Check for Pmax Capping */
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pmsr_pmax = (s8)PMSR_MAX(pmsr);
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if (pmsr_pmax != powernv_pstate_info.max) {
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pmsr_pmax_idx = pstate_to_idx(pmsr_pmax);
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if (pmsr_pmax_idx != powernv_pstate_info.max) {
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if (chip->throttled)
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goto next;
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chip->throttled = true;
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if (pmsr_pmax < powernv_pstate_info.nominal) {
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pr_warn_once("CPU %d on Chip %u has Pmax reduced below nominal frequency (%d < %d)\n",
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if (pmsr_pmax_idx > powernv_pstate_info.nominal) {
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pr_warn_once("CPU %d on Chip %u has Pmax(%d) reduced below nominal frequency(%d)\n",
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cpu, chip->id, pmsr_pmax,
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powernv_pstate_info.nominal);
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idx_to_pstate(powernv_pstate_info.nominal));
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chip->throttle_sub_turbo++;
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} else {
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chip->throttle_turbo++;
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@ -484,34 +510,35 @@ next:
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/**
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* calc_global_pstate - Calculate global pstate
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* @elapsed_time: Elapsed time in milliseconds
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* @local_pstate: New local pstate
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* @highest_lpstate: pstate from which its ramping down
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* @elapsed_time: Elapsed time in milliseconds
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* @local_pstate_idx: New local pstate
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* @highest_lpstate_idx: pstate from which its ramping down
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*
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* Finds the appropriate global pstate based on the pstate from which its
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* ramping down and the time elapsed in ramping down. It follows a quadratic
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* equation which ensures that it reaches ramping down to pmin in 5sec.
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*/
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static inline int calc_global_pstate(unsigned int elapsed_time,
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int highest_lpstate, int local_pstate)
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int highest_lpstate_idx,
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int local_pstate_idx)
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{
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int pstate_diff;
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int index_diff;
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/*
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* Using ramp_down_percent we get the percentage of rampdown
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* that we are expecting to be dropping. Difference between
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* highest_lpstate and powernv_pstate_info.min will give a absolute
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* highest_lpstate_idx and powernv_pstate_info.min will give a absolute
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* number of how many pstates we will drop eventually by the end of
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* 5 seconds, then just scale it get the number pstates to be dropped.
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*/
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pstate_diff = ((int)ramp_down_percent(elapsed_time) *
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(highest_lpstate - powernv_pstate_info.min)) / 100;
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index_diff = ((int)ramp_down_percent(elapsed_time) *
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(powernv_pstate_info.min - highest_lpstate_idx)) / 100;
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/* Ensure that global pstate is >= to local pstate */
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if (highest_lpstate - pstate_diff < local_pstate)
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return local_pstate;
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if (highest_lpstate_idx + index_diff >= local_pstate_idx)
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return local_pstate_idx;
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else
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return highest_lpstate - pstate_diff;
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return highest_lpstate_idx + index_diff;
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}
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static inline void queue_gpstate_timer(struct global_pstate_info *gpstates)
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@ -547,7 +574,7 @@ void gpstate_timer_handler(unsigned long data)
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{
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struct cpufreq_policy *policy = (struct cpufreq_policy *)data;
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struct global_pstate_info *gpstates = policy->driver_data;
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int gpstate_id;
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int gpstate_idx;
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unsigned int time_diff = jiffies_to_msecs(jiffies)
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- gpstates->last_sampled_time;
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struct powernv_smp_call_data freq_data;
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@ -557,29 +584,29 @@ void gpstate_timer_handler(unsigned long data)
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gpstates->last_sampled_time += time_diff;
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gpstates->elapsed_time += time_diff;
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freq_data.pstate_id = gpstates->last_lpstate;
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freq_data.pstate_id = idx_to_pstate(gpstates->last_lpstate_idx);
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if ((gpstates->last_gpstate == freq_data.pstate_id) ||
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if ((gpstates->last_gpstate_idx == gpstates->last_lpstate_idx) ||
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(gpstates->elapsed_time > MAX_RAMP_DOWN_TIME)) {
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gpstate_id = freq_data.pstate_id;
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gpstate_idx = pstate_to_idx(freq_data.pstate_id);
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reset_gpstates(policy);
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gpstates->highest_lpstate = freq_data.pstate_id;
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gpstates->highest_lpstate_idx = gpstate_idx;
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} else {
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gpstate_id = calc_global_pstate(gpstates->elapsed_time,
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gpstates->highest_lpstate,
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freq_data.pstate_id);
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gpstate_idx = calc_global_pstate(gpstates->elapsed_time,
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gpstates->highest_lpstate_idx,
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freq_data.pstate_id);
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}
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/*
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* If local pstate is equal to global pstate, rampdown is over
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* So timer is not required to be queued.
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*/
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if (gpstate_id != freq_data.pstate_id)
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if (gpstate_idx != gpstates->last_lpstate_idx)
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queue_gpstate_timer(gpstates);
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freq_data.gpstate_id = gpstate_id;
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gpstates->last_gpstate = freq_data.gpstate_id;
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gpstates->last_lpstate = freq_data.pstate_id;
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freq_data.gpstate_id = idx_to_pstate(gpstate_idx);
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gpstates->last_gpstate_idx = pstate_to_idx(freq_data.gpstate_id);
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gpstates->last_lpstate_idx = pstate_to_idx(freq_data.pstate_id);
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spin_unlock(&gpstates->gpstate_lock);
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@ -596,7 +623,7 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
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unsigned int new_index)
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{
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struct powernv_smp_call_data freq_data;
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unsigned int cur_msec, gpstate_id;
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unsigned int cur_msec, gpstate_idx;
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struct global_pstate_info *gpstates = policy->driver_data;
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if (unlikely(rebooting) && new_index != get_nominal_index())
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@ -608,15 +635,15 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
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cur_msec = jiffies_to_msecs(get_jiffies_64());
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spin_lock(&gpstates->gpstate_lock);
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freq_data.pstate_id = powernv_freqs[new_index].driver_data;
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freq_data.pstate_id = idx_to_pstate(new_index);
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if (!gpstates->last_sampled_time) {
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gpstate_id = freq_data.pstate_id;
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gpstates->highest_lpstate = freq_data.pstate_id;
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gpstate_idx = new_index;
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gpstates->highest_lpstate_idx = new_index;
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goto gpstates_done;
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}
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if (gpstates->last_gpstate > freq_data.pstate_id) {
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if (gpstates->last_gpstate_idx < new_index) {
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gpstates->elapsed_time += cur_msec -
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gpstates->last_sampled_time;
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@ -627,34 +654,34 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
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*/
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if (gpstates->elapsed_time > MAX_RAMP_DOWN_TIME) {
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reset_gpstates(policy);
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gpstates->highest_lpstate = freq_data.pstate_id;
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gpstate_id = freq_data.pstate_id;
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gpstates->highest_lpstate_idx = new_index;
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gpstate_idx = new_index;
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} else {
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/* Elaspsed_time is less than 5 seconds, continue to rampdown */
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gpstate_id = calc_global_pstate(gpstates->elapsed_time,
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gpstates->highest_lpstate,
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freq_data.pstate_id);
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gpstate_idx = calc_global_pstate(gpstates->elapsed_time,
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gpstates->highest_lpstate_idx,
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new_index);
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}
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} else {
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reset_gpstates(policy);
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gpstates->highest_lpstate = freq_data.pstate_id;
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gpstate_id = freq_data.pstate_id;
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gpstates->highest_lpstate_idx = new_index;
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gpstate_idx = new_index;
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}
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/*
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* If local pstate is equal to global pstate, rampdown is over
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* So timer is not required to be queued.
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*/
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if (gpstate_id != freq_data.pstate_id)
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if (gpstate_idx != new_index)
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queue_gpstate_timer(gpstates);
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else
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del_timer_sync(&gpstates->timer);
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gpstates_done:
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freq_data.gpstate_id = gpstate_id;
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freq_data.gpstate_id = idx_to_pstate(gpstate_idx);
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gpstates->last_sampled_time = cur_msec;
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gpstates->last_gpstate = freq_data.gpstate_id;
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gpstates->last_lpstate = freq_data.pstate_id;
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gpstates->last_gpstate_idx = gpstate_idx;
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gpstates->last_lpstate_idx = new_index;
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spin_unlock(&gpstates->gpstate_lock);
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@ -846,8 +873,8 @@ static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy)
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struct powernv_smp_call_data freq_data;
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struct global_pstate_info *gpstates = policy->driver_data;
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freq_data.pstate_id = powernv_pstate_info.min;
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freq_data.gpstate_id = powernv_pstate_info.min;
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freq_data.pstate_id = idx_to_pstate(powernv_pstate_info.min);
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freq_data.gpstate_id = idx_to_pstate(powernv_pstate_info.min);
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smp_call_function_single(policy->cpu, set_pstate, &freq_data, 1);
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del_timer_sync(&gpstates->timer);
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}
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