diff options
author | Akshay Adiga <akshay.adiga@linux.vnet.ibm.com> | 2016-06-30 11:53:07 +0530 |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-07-12 02:47:10 +0200 |
commit | 09ca4c9b5958403bf05482b365a67d88f10463e4 (patch) | |
tree | 23ca25140a9f6ccac47ae85adbb30d9680fc0307 /drivers/cpufreq/powernv-cpufreq.c | |
parent | 5fc8f707a2aa40c767c3a338738b9b6fcd151ac1 (diff) | |
download | linux-09ca4c9b5958403bf05482b365a67d88f10463e4.tar.bz2 |
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>
Diffstat (limited to 'drivers/cpufreq/powernv-cpufreq.c')
-rw-r--r-- | drivers/cpufreq/powernv-cpufreq.c | 177 |
1 files changed, 102 insertions, 75 deletions
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index 2a2920c4fdf9..0f138b050e9a 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -64,12 +64,14 @@ /** * struct global_pstate_info - Per policy data structure to maintain history of * global pstates - * @highest_lpstate: The local pstate from which we are ramping down + * @highest_lpstate_idx: The local pstate index from which we are + * ramping down * @elapsed_time: Time in ms spent in ramping down from - * highest_lpstate + * highest_lpstate_idx * @last_sampled_time: Time from boot in ms when global pstates were * last set - * @last_lpstate,last_gpstate: Last set values for local and global pstates + * @last_lpstate_idx, Last set value of local pstate and global + * last_gpstate_idx pstate in terms of cpufreq table index * @timer: Is used for ramping down if cpu goes idle for * a long time with global pstate held high * @gpstate_lock: A spinlock to maintain synchronization between @@ -77,11 +79,11 @@ * governer's target_index calls */ struct global_pstate_info { - int highest_lpstate; + int highest_lpstate_idx; unsigned int elapsed_time; unsigned int last_sampled_time; - int last_lpstate; - int last_gpstate; + int last_lpstate_idx; + int last_gpstate_idx; spinlock_t gpstate_lock; struct timer_list timer; }; @@ -124,29 +126,47 @@ static int nr_chips; static DEFINE_PER_CPU(struct chip *, chip_info); /* - * Note: The set of pstates consists of contiguous integers, the - * smallest of which is indicated by powernv_pstate_info.min, the - * largest of which is indicated by powernv_pstate_info.max. + * Note: + * The set of pstates consists of contiguous integers. + * powernv_pstate_info stores the index of the frequency table for + * max, min and nominal frequencies. It also stores number of + * available frequencies. * - * The nominal pstate is the highest non-turbo pstate in this - * platform. This is indicated by powernv_pstate_info.nominal. + * powernv_pstate_info.nominal indicates the index to the highest + * non-turbo frequency. */ static struct powernv_pstate_info { - int min; - int max; - int nominal; - int nr_pstates; + unsigned int min; + unsigned int max; + unsigned int nominal; + unsigned int nr_pstates; } powernv_pstate_info; +/* Use following macros for conversions between pstate_id and index */ +static inline int idx_to_pstate(unsigned int i) +{ + return powernv_freqs[i].driver_data; +} + +static inline unsigned int pstate_to_idx(int pstate) +{ + /* + * abs() is deliberately used so that is works with + * both monotonically increasing and decreasing + * pstate values + */ + return abs(pstate - idx_to_pstate(powernv_pstate_info.max)); +} + static inline void reset_gpstates(struct cpufreq_policy *policy) { struct global_pstate_info *gpstates = policy->driver_data; - gpstates->highest_lpstate = 0; + gpstates->highest_lpstate_idx = 0; gpstates->elapsed_time = 0; gpstates->last_sampled_time = 0; - gpstates->last_lpstate = 0; - gpstates->last_gpstate = 0; + gpstates->last_lpstate_idx = 0; + gpstates->last_gpstate_idx = 0; } /* @@ -156,9 +176,10 @@ static inline void reset_gpstates(struct cpufreq_policy *policy) static int init_powernv_pstates(void) { struct device_node *power_mgt; - int i, pstate_min, pstate_max, pstate_nominal, nr_pstates = 0; + int i, nr_pstates = 0; const __be32 *pstate_ids, *pstate_freqs; u32 len_ids, len_freqs; + u32 pstate_min, pstate_max, pstate_nominal; power_mgt = of_find_node_by_path("/ibm,opal/power-mgt"); if (!power_mgt) { @@ -208,6 +229,7 @@ static int init_powernv_pstates(void) return -ENODEV; } + powernv_pstate_info.nr_pstates = nr_pstates; pr_debug("NR PStates %d\n", nr_pstates); for (i = 0; i < nr_pstates; i++) { u32 id = be32_to_cpu(pstate_ids[i]); @@ -216,15 +238,17 @@ static int init_powernv_pstates(void) pr_debug("PState id %d freq %d MHz\n", id, freq); powernv_freqs[i].frequency = freq * 1000; /* kHz */ powernv_freqs[i].driver_data = id; + + if (id == pstate_max) + powernv_pstate_info.max = i; + else if (id == pstate_nominal) + powernv_pstate_info.nominal = i; + else if (id == pstate_min) + powernv_pstate_info.min = i; } + /* End of list marker entry */ powernv_freqs[i].frequency = CPUFREQ_TABLE_END; - - powernv_pstate_info.min = pstate_min; - powernv_pstate_info.max = pstate_max; - powernv_pstate_info.nominal = pstate_nominal; - powernv_pstate_info.nr_pstates = nr_pstates; - return 0; } @@ -233,12 +257,12 @@ static unsigned int pstate_id_to_freq(int pstate_id) { int i; - i = powernv_pstate_info.max - pstate_id; + i = pstate_to_idx(pstate_id); if (i >= powernv_pstate_info.nr_pstates || i < 0) { pr_warn("PState id %d outside of PState table, " "reporting nominal id %d instead\n", - pstate_id, powernv_pstate_info.nominal); - i = powernv_pstate_info.max - powernv_pstate_info.nominal; + pstate_id, idx_to_pstate(powernv_pstate_info.nominal)); + i = powernv_pstate_info.nominal; } return powernv_freqs[i].frequency; @@ -252,7 +276,7 @@ static ssize_t cpuinfo_nominal_freq_show(struct cpufreq_policy *policy, char *buf) { return sprintf(buf, "%u\n", - pstate_id_to_freq(powernv_pstate_info.nominal)); + powernv_freqs[powernv_pstate_info.nominal].frequency); } struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq = @@ -426,7 +450,7 @@ static void set_pstate(void *data) */ static inline unsigned int get_nominal_index(void) { - return powernv_pstate_info.max - powernv_pstate_info.nominal; + return powernv_pstate_info.nominal; } static void powernv_cpufreq_throttle_check(void *data) @@ -435,20 +459,22 @@ static void powernv_cpufreq_throttle_check(void *data) unsigned int cpu = smp_processor_id(); unsigned long pmsr; int pmsr_pmax; + unsigned int pmsr_pmax_idx; pmsr = get_pmspr(SPRN_PMSR); chip = this_cpu_read(chip_info); /* Check for Pmax Capping */ pmsr_pmax = (s8)PMSR_MAX(pmsr); - if (pmsr_pmax != powernv_pstate_info.max) { + pmsr_pmax_idx = pstate_to_idx(pmsr_pmax); + if (pmsr_pmax_idx != powernv_pstate_info.max) { if (chip->throttled) goto next; chip->throttled = true; - if (pmsr_pmax < powernv_pstate_info.nominal) { - pr_warn_once("CPU %d on Chip %u has Pmax reduced below nominal frequency (%d < %d)\n", + if (pmsr_pmax_idx > powernv_pstate_info.nominal) { + pr_warn_once("CPU %d on Chip %u has Pmax(%d) reduced below nominal frequency(%d)\n", cpu, chip->id, pmsr_pmax, - powernv_pstate_info.nominal); + idx_to_pstate(powernv_pstate_info.nominal)); chip->throttle_sub_turbo++; } else { chip->throttle_turbo++; @@ -484,34 +510,35 @@ next: /** * calc_global_pstate - Calculate global pstate - * @elapsed_time: Elapsed time in milliseconds - * @local_pstate: New local pstate - * @highest_lpstate: pstate from which its ramping down + * @elapsed_time: Elapsed time in milliseconds + * @local_pstate_idx: New local pstate + * @highest_lpstate_idx: pstate from which its ramping down * * Finds the appropriate global pstate based on the pstate from which its * ramping down and the time elapsed in ramping down. It follows a quadratic * equation which ensures that it reaches ramping down to pmin in 5sec. */ static inline int calc_global_pstate(unsigned int elapsed_time, - int highest_lpstate, int local_pstate) + int highest_lpstate_idx, + int local_pstate_idx) { - int pstate_diff; + int index_diff; /* * Using ramp_down_percent we get the percentage of rampdown * that we are expecting to be dropping. Difference between - * highest_lpstate and powernv_pstate_info.min will give a absolute + * highest_lpstate_idx and powernv_pstate_info.min will give a absolute * number of how many pstates we will drop eventually by the end of * 5 seconds, then just scale it get the number pstates to be dropped. */ - pstate_diff = ((int)ramp_down_percent(elapsed_time) * - (highest_lpstate - powernv_pstate_info.min)) / 100; + index_diff = ((int)ramp_down_percent(elapsed_time) * + (powernv_pstate_info.min - highest_lpstate_idx)) / 100; /* Ensure that global pstate is >= to local pstate */ - if (highest_lpstate - pstate_diff < local_pstate) - return local_pstate; + if (highest_lpstate_idx + index_diff >= local_pstate_idx) + return local_pstate_idx; else - return highest_lpstate - pstate_diff; + return highest_lpstate_idx + index_diff; } static inline void queue_gpstate_timer(struct global_pstate_info *gpstates) @@ -547,7 +574,7 @@ void gpstate_timer_handler(unsigned long data) { struct cpufreq_policy *policy = (struct cpufreq_policy *)data; struct global_pstate_info *gpstates = policy->driver_data; - int gpstate_id; + int gpstate_idx; unsigned int time_diff = jiffies_to_msecs(jiffies) - gpstates->last_sampled_time; struct powernv_smp_call_data freq_data; @@ -557,29 +584,29 @@ void gpstate_timer_handler(unsigned long data) gpstates->last_sampled_time += time_diff; gpstates->elapsed_time += time_diff; - freq_data.pstate_id = gpstates->last_lpstate; + freq_data.pstate_id = idx_to_pstate(gpstates->last_lpstate_idx); - if ((gpstates->last_gpstate == freq_data.pstate_id) || + if ((gpstates->last_gpstate_idx == gpstates->last_lpstate_idx) || (gpstates->elapsed_time > MAX_RAMP_DOWN_TIME)) { - gpstate_id = freq_data.pstate_id; + gpstate_idx = pstate_to_idx(freq_data.pstate_id); reset_gpstates(policy); - gpstates->highest_lpstate = freq_data.pstate_id; + gpstates->highest_lpstate_idx = gpstate_idx; } else { - gpstate_id = calc_global_pstate(gpstates->elapsed_time, - gpstates->highest_lpstate, - freq_data.pstate_id); + gpstate_idx = calc_global_pstate(gpstates->elapsed_time, + gpstates->highest_lpstate_idx, + freq_data.pstate_id); } /* * If local pstate is equal to global pstate, rampdown is over * So timer is not required to be queued. */ - if (gpstate_id != freq_data.pstate_id) + if (gpstate_idx != gpstates->last_lpstate_idx) queue_gpstate_timer(gpstates); - freq_data.gpstate_id = gpstate_id; - gpstates->last_gpstate = freq_data.gpstate_id; - gpstates->last_lpstate = freq_data.pstate_id; + freq_data.gpstate_id = idx_to_pstate(gpstate_idx); + gpstates->last_gpstate_idx = pstate_to_idx(freq_data.gpstate_id); + gpstates->last_lpstate_idx = pstate_to_idx(freq_data.pstate_id); spin_unlock(&gpstates->gpstate_lock); @@ -596,7 +623,7 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy, unsigned int new_index) { struct powernv_smp_call_data freq_data; - unsigned int cur_msec, gpstate_id; + unsigned int cur_msec, gpstate_idx; struct global_pstate_info *gpstates = policy->driver_data; if (unlikely(rebooting) && new_index != get_nominal_index()) @@ -608,15 +635,15 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy, cur_msec = jiffies_to_msecs(get_jiffies_64()); spin_lock(&gpstates->gpstate_lock); - freq_data.pstate_id = powernv_freqs[new_index].driver_data; + freq_data.pstate_id = idx_to_pstate(new_index); if (!gpstates->last_sampled_time) { - gpstate_id = freq_data.pstate_id; - gpstates->highest_lpstate = freq_data.pstate_id; + gpstate_idx = new_index; + gpstates->highest_lpstate_idx = new_index; goto gpstates_done; } - if (gpstates->last_gpstate > freq_data.pstate_id) { + if (gpstates->last_gpstate_idx < new_index) { gpstates->elapsed_time += cur_msec - gpstates->last_sampled_time; @@ -627,34 +654,34 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy, */ if (gpstates->elapsed_time > MAX_RAMP_DOWN_TIME) { reset_gpstates(policy); - gpstates->highest_lpstate = freq_data.pstate_id; - gpstate_id = freq_data.pstate_id; + gpstates->highest_lpstate_idx = new_index; + gpstate_idx = new_index; } else { /* Elaspsed_time is less than 5 seconds, continue to rampdown */ - gpstate_id = calc_global_pstate(gpstates->elapsed_time, - gpstates->highest_lpstate, - freq_data.pstate_id); + gpstate_idx = calc_global_pstate(gpstates->elapsed_time, + gpstates->highest_lpstate_idx, + new_index); } } else { reset_gpstates(policy); - gpstates->highest_lpstate = freq_data.pstate_id; - gpstate_id = freq_data.pstate_id; + gpstates->highest_lpstate_idx = new_index; + gpstate_idx = new_index; } /* * If local pstate is equal to global pstate, rampdown is over * So timer is not required to be queued. */ - if (gpstate_id != freq_data.pstate_id) + if (gpstate_idx != new_index) queue_gpstate_timer(gpstates); else del_timer_sync(&gpstates->timer); gpstates_done: - freq_data.gpstate_id = gpstate_id; + freq_data.gpstate_id = idx_to_pstate(gpstate_idx); gpstates->last_sampled_time = cur_msec; - gpstates->last_gpstate = freq_data.gpstate_id; - gpstates->last_lpstate = freq_data.pstate_id; + gpstates->last_gpstate_idx = gpstate_idx; + gpstates->last_lpstate_idx = new_index; spin_unlock(&gpstates->gpstate_lock); @@ -846,8 +873,8 @@ static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy) struct powernv_smp_call_data freq_data; struct global_pstate_info *gpstates = policy->driver_data; - freq_data.pstate_id = powernv_pstate_info.min; - freq_data.gpstate_id = powernv_pstate_info.min; + freq_data.pstate_id = idx_to_pstate(powernv_pstate_info.min); + freq_data.gpstate_id = idx_to_pstate(powernv_pstate_info.min); smp_call_function_single(policy->cpu, set_pstate, &freq_data, 1); del_timer_sync(&gpstates->timer); } |