2 * POWERNV cpufreq driver for the IBM POWER processors
4 * (C) Copyright IBM 2014
6 * Author: Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
20 #define pr_fmt(fmt) "powernv-cpufreq: " fmt
22 #include <linux/kernel.h>
23 #include <linux/sysfs.h>
24 #include <linux/cpumask.h>
25 #include <linux/module.h>
26 #include <linux/cpufreq.h>
27 #include <linux/smp.h>
29 #include <linux/reboot.h>
30 #include <linux/slab.h>
31 #include <linux/cpu.h>
32 #include <trace/events/power.h>
34 #include <asm/cputhreads.h>
35 #include <asm/firmware.h>
37 #include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */
39 #include <linux/timer.h>
41 #define POWERNV_MAX_PSTATES 256
42 #define PMSR_PSAFE_ENABLE (1UL << 30)
43 #define PMSR_SPR_EM_DISABLE (1UL << 31)
44 #define MAX_PSTATE_SHIFT 32
45 #define LPSTATE_SHIFT 48
46 #define GPSTATE_SHIFT 56
47 #define MAX_NR_CHIPS 32
49 #define MAX_RAMP_DOWN_TIME 5120
51 * On an idle system we want the global pstate to ramp-down from max value to
52 * min over a span of ~5 secs. Also we want it to initially ramp-down slowly and
53 * then ramp-down rapidly later on.
55 * This gives a percentage rampdown for time elapsed in milliseconds.
56 * ramp_down_percentage = ((ms * ms) >> 18)
57 * ~= 3.8 * (sec * sec)
59 * At 0 ms ramp_down_percent = 0
60 * At 5120 ms ramp_down_percent = 100
62 #define ramp_down_percent(time) ((time * time) >> 18)
64 /* Interval after which the timer is queued to bring down global pstate */
65 #define GPSTATE_TIMER_INTERVAL 2000
68 * struct global_pstate_info - Per policy data structure to maintain history of
70 * @highest_lpstate_idx: The local pstate index from which we are
72 * @elapsed_time: Time in ms spent in ramping down from
74 * @last_sampled_time: Time from boot in ms when global pstates were
76 * @last_lpstate_idx, Last set value of local pstate and global
77 * last_gpstate_idx pstate in terms of cpufreq table index
78 * @timer: Is used for ramping down if cpu goes idle for
79 * a long time with global pstate held high
80 * @gpstate_lock: A spinlock to maintain synchronization between
81 * routines called by the timer handler and
82 * governer's target_index calls
84 struct global_pstate_info {
85 int highest_lpstate_idx;
86 unsigned int elapsed_time;
87 unsigned int last_sampled_time;
90 spinlock_t gpstate_lock;
91 struct timer_list timer;
94 static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
95 u32 pstate_sign_prefix;
96 static bool rebooting, throttled, occ_reset;
98 static const char * const throttle_reason[] = {
101 "Processor Over Temperature",
102 "Power Supply Failure",
107 enum throttle_reason_type {
111 POWER_SUPPLY_FAILURE,
123 struct work_struct throttle;
125 int throttle_sub_turbo;
126 int reason[OCC_MAX_REASON];
130 static DEFINE_PER_CPU(struct chip *, chip_info);
134 * The set of pstates consists of contiguous integers.
135 * powernv_pstate_info stores the index of the frequency table for
136 * max, min and nominal frequencies. It also stores number of
137 * available frequencies.
139 * powernv_pstate_info.nominal indicates the index to the highest
140 * non-turbo frequency.
142 static struct powernv_pstate_info {
145 unsigned int nominal;
146 unsigned int nr_pstates;
148 } powernv_pstate_info;
150 static inline int extract_pstate(u64 pmsr_val, unsigned int shift)
152 int ret = ((pmsr_val >> shift) & 0xFF);
157 return (pstate_sign_prefix | ret);
160 #define extract_local_pstate(x) extract_pstate(x, LPSTATE_SHIFT)
161 #define extract_global_pstate(x) extract_pstate(x, GPSTATE_SHIFT)
162 #define extract_max_pstate(x) extract_pstate(x, MAX_PSTATE_SHIFT)
164 /* Use following macros for conversions between pstate_id and index */
165 static inline int idx_to_pstate(unsigned int i)
167 if (unlikely(i >= powernv_pstate_info.nr_pstates)) {
168 pr_warn_once("index %u is out of bound\n", i);
169 return powernv_freqs[powernv_pstate_info.nominal].driver_data;
172 return powernv_freqs[i].driver_data;
175 static inline unsigned int pstate_to_idx(int pstate)
177 int min = powernv_freqs[powernv_pstate_info.min].driver_data;
178 int max = powernv_freqs[powernv_pstate_info.max].driver_data;
181 if (unlikely((pstate < max) || (pstate > min))) {
182 pr_warn_once("pstate %d is out of bound\n", pstate);
183 return powernv_pstate_info.nominal;
186 if (unlikely((pstate > max) || (pstate < min))) {
187 pr_warn_once("pstate %d is out of bound\n", pstate);
188 return powernv_pstate_info.nominal;
192 * abs() is deliberately used so that is works with
193 * both monotonically increasing and decreasing
196 return abs(pstate - idx_to_pstate(powernv_pstate_info.max));
199 static inline void reset_gpstates(struct cpufreq_policy *policy)
201 struct global_pstate_info *gpstates = policy->driver_data;
203 gpstates->highest_lpstate_idx = 0;
204 gpstates->elapsed_time = 0;
205 gpstates->last_sampled_time = 0;
206 gpstates->last_lpstate_idx = 0;
207 gpstates->last_gpstate_idx = 0;
211 * Initialize the freq table based on data obtained
212 * from the firmware passed via device-tree
214 static int init_powernv_pstates(void)
216 struct device_node *power_mgt;
217 int i, nr_pstates = 0;
218 const __be32 *pstate_ids, *pstate_freqs;
219 u32 len_ids, len_freqs;
220 u32 pstate_min, pstate_max, pstate_nominal;
221 u32 pstate_turbo, pstate_ultra_turbo;
223 power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
225 pr_warn("power-mgt node not found\n");
229 if (of_property_read_u32(power_mgt, "ibm,pstate-min", &pstate_min)) {
230 pr_warn("ibm,pstate-min node not found\n");
234 if (of_property_read_u32(power_mgt, "ibm,pstate-max", &pstate_max)) {
235 pr_warn("ibm,pstate-max node not found\n");
239 if (of_property_read_u32(power_mgt, "ibm,pstate-nominal",
241 pr_warn("ibm,pstate-nominal not found\n");
245 if (of_property_read_u32(power_mgt, "ibm,pstate-ultra-turbo",
246 &pstate_ultra_turbo)) {
247 powernv_pstate_info.wof_enabled = false;
251 if (of_property_read_u32(power_mgt, "ibm,pstate-turbo",
253 powernv_pstate_info.wof_enabled = false;
257 if (pstate_turbo == pstate_ultra_turbo)
258 powernv_pstate_info.wof_enabled = false;
260 powernv_pstate_info.wof_enabled = true;
263 pr_info("cpufreq pstate min %d nominal %d max %d\n", pstate_min,
264 pstate_nominal, pstate_max);
265 pr_info("Workload Optimized Frequency is %s in the platform\n",
266 (powernv_pstate_info.wof_enabled) ? "enabled" : "disabled");
268 pstate_ids = of_get_property(power_mgt, "ibm,pstate-ids", &len_ids);
270 pr_warn("ibm,pstate-ids not found\n");
274 pstate_freqs = of_get_property(power_mgt, "ibm,pstate-frequencies-mhz",
277 pr_warn("ibm,pstate-frequencies-mhz not found\n");
281 if (len_ids != len_freqs) {
282 pr_warn("Entries in ibm,pstate-ids and "
283 "ibm,pstate-frequencies-mhz does not match\n");
286 nr_pstates = min(len_ids, len_freqs) / sizeof(u32);
288 pr_warn("No PStates found\n");
292 powernv_pstate_info.nr_pstates = nr_pstates;
293 pr_debug("NR PStates %d\n", nr_pstates);
295 pstate_sign_prefix = pstate_min & ~0xFF;
297 for (i = 0; i < nr_pstates; i++) {
298 u32 id = be32_to_cpu(pstate_ids[i]);
299 u32 freq = be32_to_cpu(pstate_freqs[i]);
301 pr_debug("PState id %d freq %d MHz\n", id, freq);
302 powernv_freqs[i].frequency = freq * 1000; /* kHz */
303 powernv_freqs[i].driver_data = id;
305 if (id == pstate_max)
306 powernv_pstate_info.max = i;
307 if (id == pstate_nominal)
308 powernv_pstate_info.nominal = i;
309 if (id == pstate_min)
310 powernv_pstate_info.min = i;
312 if (powernv_pstate_info.wof_enabled && id == pstate_turbo) {
315 for (j = i - 1; j >= (int)powernv_pstate_info.max; j--)
316 powernv_freqs[j].flags = CPUFREQ_BOOST_FREQ;
320 /* End of list marker entry */
321 powernv_freqs[i].frequency = CPUFREQ_TABLE_END;
325 /* Returns the CPU frequency corresponding to the pstate_id. */
326 static unsigned int pstate_id_to_freq(int pstate_id)
330 i = pstate_to_idx(pstate_id);
331 if (i >= powernv_pstate_info.nr_pstates || i < 0) {
332 pr_warn("PState id %d outside of PState table, "
333 "reporting nominal id %d instead\n",
334 pstate_id, idx_to_pstate(powernv_pstate_info.nominal));
335 i = powernv_pstate_info.nominal;
338 return powernv_freqs[i].frequency;
342 * cpuinfo_nominal_freq_show - Show the nominal CPU frequency as indicated by
345 static ssize_t cpuinfo_nominal_freq_show(struct cpufreq_policy *policy,
348 return sprintf(buf, "%u\n",
349 powernv_freqs[powernv_pstate_info.nominal].frequency);
352 struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq =
353 __ATTR_RO(cpuinfo_nominal_freq);
355 #define SCALING_BOOST_FREQS_ATTR_INDEX 2
357 static struct freq_attr *powernv_cpu_freq_attr[] = {
358 &cpufreq_freq_attr_scaling_available_freqs,
359 &cpufreq_freq_attr_cpuinfo_nominal_freq,
360 &cpufreq_freq_attr_scaling_boost_freqs,
364 #define throttle_attr(name, member) \
365 static ssize_t name##_show(struct cpufreq_policy *policy, char *buf) \
367 struct chip *chip = per_cpu(chip_info, policy->cpu); \
369 return sprintf(buf, "%u\n", chip->member); \
372 static struct freq_attr throttle_attr_##name = __ATTR_RO(name) \
374 throttle_attr(unthrottle, reason[NO_THROTTLE]);
375 throttle_attr(powercap, reason[POWERCAP]);
376 throttle_attr(overtemp, reason[CPU_OVERTEMP]);
377 throttle_attr(supply_fault, reason[POWER_SUPPLY_FAILURE]);
378 throttle_attr(overcurrent, reason[OVERCURRENT]);
379 throttle_attr(occ_reset, reason[OCC_RESET_THROTTLE]);
380 throttle_attr(turbo_stat, throttle_turbo);
381 throttle_attr(sub_turbo_stat, throttle_sub_turbo);
383 static struct attribute *throttle_attrs[] = {
384 &throttle_attr_unthrottle.attr,
385 &throttle_attr_powercap.attr,
386 &throttle_attr_overtemp.attr,
387 &throttle_attr_supply_fault.attr,
388 &throttle_attr_overcurrent.attr,
389 &throttle_attr_occ_reset.attr,
390 &throttle_attr_turbo_stat.attr,
391 &throttle_attr_sub_turbo_stat.attr,
395 static const struct attribute_group throttle_attr_grp = {
396 .name = "throttle_stats",
397 .attrs = throttle_attrs,
400 /* Helper routines */
402 /* Access helpers to power mgt SPR */
404 static inline unsigned long get_pmspr(unsigned long sprn)
408 return mfspr(SPRN_PMCR);
411 return mfspr(SPRN_PMICR);
414 return mfspr(SPRN_PMSR);
419 static inline void set_pmspr(unsigned long sprn, unsigned long val)
423 mtspr(SPRN_PMCR, val);
427 mtspr(SPRN_PMICR, val);
434 * Use objects of this type to query/update
435 * pstates on a remote CPU via smp_call_function.
437 struct powernv_smp_call_data {
444 * powernv_read_cpu_freq: Reads the current frequency on this CPU.
446 * Called via smp_call_function.
448 * Note: The caller of the smp_call_function should pass an argument of
449 * the type 'struct powernv_smp_call_data *' along with this function.
451 * The current frequency on this CPU will be returned via
452 * ((struct powernv_smp_call_data *)arg)->freq;
454 static void powernv_read_cpu_freq(void *arg)
456 unsigned long pmspr_val;
457 struct powernv_smp_call_data *freq_data = arg;
459 pmspr_val = get_pmspr(SPRN_PMSR);
460 freq_data->pstate_id = extract_local_pstate(pmspr_val);
461 freq_data->freq = pstate_id_to_freq(freq_data->pstate_id);
463 pr_debug("cpu %d pmsr %016lX pstate_id %d frequency %d kHz\n",
464 raw_smp_processor_id(), pmspr_val, freq_data->pstate_id,
469 * powernv_cpufreq_get: Returns the CPU frequency as reported by the
470 * firmware for CPU 'cpu'. This value is reported through the sysfs
471 * file cpuinfo_cur_freq.
473 static unsigned int powernv_cpufreq_get(unsigned int cpu)
475 struct powernv_smp_call_data freq_data;
477 smp_call_function_any(cpu_sibling_mask(cpu), powernv_read_cpu_freq,
480 return freq_data.freq;
484 * set_pstate: Sets the pstate on this CPU.
486 * This is called via an smp_call_function.
488 * The caller must ensure that freq_data is of the type
489 * (struct powernv_smp_call_data *) and the pstate_id which needs to be set
490 * on this CPU should be present in freq_data->pstate_id.
492 static void set_pstate(void *data)
495 struct powernv_smp_call_data *freq_data = data;
496 unsigned long pstate_ul = freq_data->pstate_id;
497 unsigned long gpstate_ul = freq_data->gpstate_id;
499 val = get_pmspr(SPRN_PMCR);
500 val = val & 0x0000FFFFFFFFFFFFULL;
502 pstate_ul = pstate_ul & 0xFF;
503 gpstate_ul = gpstate_ul & 0xFF;
505 /* Set both global(bits 56..63) and local(bits 48..55) PStates */
506 val = val | (gpstate_ul << 56) | (pstate_ul << 48);
508 pr_debug("Setting cpu %d pmcr to %016lX\n",
509 raw_smp_processor_id(), val);
510 set_pmspr(SPRN_PMCR, val);
514 * get_nominal_index: Returns the index corresponding to the nominal
515 * pstate in the cpufreq table
517 static inline unsigned int get_nominal_index(void)
519 return powernv_pstate_info.nominal;
522 static void powernv_cpufreq_throttle_check(void *data)
525 unsigned int cpu = smp_processor_id();
528 unsigned int pmsr_pmax_idx;
530 pmsr = get_pmspr(SPRN_PMSR);
531 chip = this_cpu_read(chip_info);
533 /* Check for Pmax Capping */
534 pmsr_pmax = extract_max_pstate(pmsr);
535 pmsr_pmax_idx = pstate_to_idx(pmsr_pmax);
536 if (pmsr_pmax_idx != powernv_pstate_info.max) {
539 chip->throttled = true;
540 if (pmsr_pmax_idx > powernv_pstate_info.nominal) {
541 pr_warn_once("CPU %d on Chip %u has Pmax(%d) reduced below nominal frequency(%d)\n",
542 cpu, chip->id, pmsr_pmax,
543 idx_to_pstate(powernv_pstate_info.nominal));
544 chip->throttle_sub_turbo++;
546 chip->throttle_turbo++;
548 trace_powernv_throttle(chip->id,
549 throttle_reason[chip->throttle_reason],
551 } else if (chip->throttled) {
552 chip->throttled = false;
553 trace_powernv_throttle(chip->id,
554 throttle_reason[chip->throttle_reason],
558 /* Check if Psafe_mode_active is set in PMSR. */
560 if (pmsr & PMSR_PSAFE_ENABLE) {
562 pr_info("Pstate set to safe frequency\n");
565 /* Check if SPR_EM_DISABLE is set in PMSR */
566 if (pmsr & PMSR_SPR_EM_DISABLE) {
568 pr_info("Frequency Control disabled from OS\n");
572 pr_info("PMSR = %16lx\n", pmsr);
573 pr_warn("CPU Frequency could be throttled\n");
578 * calc_global_pstate - Calculate global pstate
579 * @elapsed_time: Elapsed time in milliseconds
580 * @local_pstate_idx: New local pstate
581 * @highest_lpstate_idx: pstate from which its ramping down
583 * Finds the appropriate global pstate based on the pstate from which its
584 * ramping down and the time elapsed in ramping down. It follows a quadratic
585 * equation which ensures that it reaches ramping down to pmin in 5sec.
587 static inline int calc_global_pstate(unsigned int elapsed_time,
588 int highest_lpstate_idx,
589 int local_pstate_idx)
594 * Using ramp_down_percent we get the percentage of rampdown
595 * that we are expecting to be dropping. Difference between
596 * highest_lpstate_idx and powernv_pstate_info.min will give a absolute
597 * number of how many pstates we will drop eventually by the end of
598 * 5 seconds, then just scale it get the number pstates to be dropped.
600 index_diff = ((int)ramp_down_percent(elapsed_time) *
601 (powernv_pstate_info.min - highest_lpstate_idx)) / 100;
603 /* Ensure that global pstate is >= to local pstate */
604 if (highest_lpstate_idx + index_diff >= local_pstate_idx)
605 return local_pstate_idx;
607 return highest_lpstate_idx + index_diff;
610 static inline void queue_gpstate_timer(struct global_pstate_info *gpstates)
612 unsigned int timer_interval;
615 * Setting up timer to fire after GPSTATE_TIMER_INTERVAL ms, But
616 * if it exceeds MAX_RAMP_DOWN_TIME ms for ramp down time.
617 * Set timer such that it fires exactly at MAX_RAMP_DOWN_TIME
618 * seconds of ramp down time.
620 if ((gpstates->elapsed_time + GPSTATE_TIMER_INTERVAL)
621 > MAX_RAMP_DOWN_TIME)
622 timer_interval = MAX_RAMP_DOWN_TIME - gpstates->elapsed_time;
624 timer_interval = GPSTATE_TIMER_INTERVAL;
626 mod_timer(&gpstates->timer, jiffies + msecs_to_jiffies(timer_interval));
630 * gpstate_timer_handler
632 * @data: pointer to cpufreq_policy on which timer was queued
634 * This handler brings down the global pstate closer to the local pstate
635 * according quadratic equation. Queues a new timer if it is still not equal
638 void gpstate_timer_handler(unsigned long data)
640 struct cpufreq_policy *policy = (struct cpufreq_policy *)data;
641 struct global_pstate_info *gpstates = policy->driver_data;
642 int gpstate_idx, lpstate_idx;
644 unsigned int time_diff = jiffies_to_msecs(jiffies)
645 - gpstates->last_sampled_time;
646 struct powernv_smp_call_data freq_data;
648 if (!spin_trylock(&gpstates->gpstate_lock))
651 * If the timer has migrated to the different cpu then bring
652 * it back to one of the policy->cpus
654 if (!cpumask_test_cpu(raw_smp_processor_id(), policy->cpus)) {
655 gpstates->timer.expires = jiffies + msecs_to_jiffies(1);
656 add_timer_on(&gpstates->timer, cpumask_first(policy->cpus));
657 spin_unlock(&gpstates->gpstate_lock);
662 * If PMCR was last updated was using fast_swtich then
663 * We may have wrong in gpstate->last_lpstate_idx
664 * value. Hence, read from PMCR to get correct data.
666 val = get_pmspr(SPRN_PMCR);
667 freq_data.gpstate_id = extract_global_pstate(val);
668 freq_data.pstate_id = extract_local_pstate(val);
669 if (freq_data.gpstate_id == freq_data.pstate_id) {
670 reset_gpstates(policy);
671 spin_unlock(&gpstates->gpstate_lock);
675 gpstates->last_sampled_time += time_diff;
676 gpstates->elapsed_time += time_diff;
678 if (gpstates->elapsed_time > MAX_RAMP_DOWN_TIME) {
679 gpstate_idx = pstate_to_idx(freq_data.pstate_id);
680 lpstate_idx = gpstate_idx;
681 reset_gpstates(policy);
682 gpstates->highest_lpstate_idx = gpstate_idx;
684 lpstate_idx = pstate_to_idx(freq_data.pstate_id);
685 gpstate_idx = calc_global_pstate(gpstates->elapsed_time,
686 gpstates->highest_lpstate_idx,
689 freq_data.gpstate_id = idx_to_pstate(gpstate_idx);
690 gpstates->last_gpstate_idx = gpstate_idx;
691 gpstates->last_lpstate_idx = lpstate_idx;
693 * If local pstate is equal to global pstate, rampdown is over
694 * So timer is not required to be queued.
696 if (gpstate_idx != gpstates->last_lpstate_idx)
697 queue_gpstate_timer(gpstates);
699 set_pstate(&freq_data);
700 spin_unlock(&gpstates->gpstate_lock);
704 * powernv_cpufreq_target_index: Sets the frequency corresponding to
705 * the cpufreq table entry indexed by new_index on the cpus in the
708 static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
709 unsigned int new_index)
711 struct powernv_smp_call_data freq_data;
712 unsigned int cur_msec, gpstate_idx;
713 struct global_pstate_info *gpstates = policy->driver_data;
715 if (unlikely(rebooting) && new_index != get_nominal_index())
719 /* we don't want to be preempted while
720 * checking if the CPU frequency has been throttled
723 powernv_cpufreq_throttle_check(NULL);
727 cur_msec = jiffies_to_msecs(get_jiffies_64());
729 spin_lock(&gpstates->gpstate_lock);
730 freq_data.pstate_id = idx_to_pstate(new_index);
732 if (!gpstates->last_sampled_time) {
733 gpstate_idx = new_index;
734 gpstates->highest_lpstate_idx = new_index;
738 if (gpstates->last_gpstate_idx < new_index) {
739 gpstates->elapsed_time += cur_msec -
740 gpstates->last_sampled_time;
743 * If its has been ramping down for more than MAX_RAMP_DOWN_TIME
744 * we should be resetting all global pstate related data. Set it
745 * equal to local pstate to start fresh.
747 if (gpstates->elapsed_time > MAX_RAMP_DOWN_TIME) {
748 reset_gpstates(policy);
749 gpstates->highest_lpstate_idx = new_index;
750 gpstate_idx = new_index;
752 /* Elaspsed_time is less than 5 seconds, continue to rampdown */
753 gpstate_idx = calc_global_pstate(gpstates->elapsed_time,
754 gpstates->highest_lpstate_idx,
758 reset_gpstates(policy);
759 gpstates->highest_lpstate_idx = new_index;
760 gpstate_idx = new_index;
764 * If local pstate is equal to global pstate, rampdown is over
765 * So timer is not required to be queued.
767 if (gpstate_idx != new_index)
768 queue_gpstate_timer(gpstates);
770 del_timer_sync(&gpstates->timer);
773 freq_data.gpstate_id = idx_to_pstate(gpstate_idx);
774 gpstates->last_sampled_time = cur_msec;
775 gpstates->last_gpstate_idx = gpstate_idx;
776 gpstates->last_lpstate_idx = new_index;
778 spin_unlock(&gpstates->gpstate_lock);
781 * Use smp_call_function to send IPI and execute the
782 * mtspr on target CPU. We could do that without IPI
783 * if current CPU is within policy->cpus (core)
785 smp_call_function_any(policy->cpus, set_pstate, &freq_data, 1);
789 static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
792 struct kernfs_node *kn;
793 struct global_pstate_info *gpstates;
795 base = cpu_first_thread_sibling(policy->cpu);
797 for (i = 0; i < threads_per_core; i++)
798 cpumask_set_cpu(base + i, policy->cpus);
800 kn = kernfs_find_and_get(policy->kobj.sd, throttle_attr_grp.name);
804 ret = sysfs_create_group(&policy->kobj, &throttle_attr_grp);
806 pr_info("Failed to create throttle stats directory for cpu %d\n",
814 gpstates = kzalloc(sizeof(*gpstates), GFP_KERNEL);
818 policy->driver_data = gpstates;
820 /* initialize timer */
821 init_timer_pinned_deferrable(&gpstates->timer);
822 gpstates->timer.data = (unsigned long)policy;
823 gpstates->timer.function = gpstate_timer_handler;
824 gpstates->timer.expires = jiffies +
825 msecs_to_jiffies(GPSTATE_TIMER_INTERVAL);
826 spin_lock_init(&gpstates->gpstate_lock);
827 ret = cpufreq_table_validate_and_show(policy, powernv_freqs);
830 kfree(policy->driver_data);
834 policy->fast_switch_possible = true;
838 static int powernv_cpufreq_cpu_exit(struct cpufreq_policy *policy)
840 /* timer is deleted in cpufreq_cpu_stop() */
841 kfree(policy->driver_data);
846 static int powernv_cpufreq_reboot_notifier(struct notifier_block *nb,
847 unsigned long action, void *unused)
850 struct cpufreq_policy *cpu_policy;
853 for_each_online_cpu(cpu) {
854 cpu_policy = cpufreq_cpu_get(cpu);
857 powernv_cpufreq_target_index(cpu_policy, get_nominal_index());
858 cpufreq_cpu_put(cpu_policy);
864 static struct notifier_block powernv_cpufreq_reboot_nb = {
865 .notifier_call = powernv_cpufreq_reboot_notifier,
868 void powernv_cpufreq_work_fn(struct work_struct *work)
870 struct chip *chip = container_of(work, struct chip, throttle);
871 struct cpufreq_policy *policy;
876 cpumask_and(&mask, &chip->mask, cpu_online_mask);
877 smp_call_function_any(&mask,
878 powernv_cpufreq_throttle_check, NULL, 0);
883 chip->restore = false;
884 for_each_cpu(cpu, &mask) {
887 policy = cpufreq_cpu_get(cpu);
890 index = cpufreq_table_find_index_c(policy, policy->cur);
891 powernv_cpufreq_target_index(policy, index);
892 cpumask_andnot(&mask, &mask, policy->cpus);
893 cpufreq_cpu_put(policy);
899 static int powernv_cpufreq_occ_msg(struct notifier_block *nb,
900 unsigned long msg_type, void *_msg)
902 struct opal_msg *msg = _msg;
903 struct opal_occ_msg omsg;
906 if (msg_type != OPAL_MSG_OCC)
909 omsg.type = be64_to_cpu(msg->params[0]);
914 pr_info("OCC (On Chip Controller - enforces hard thermal/power limits) Resetting\n");
916 * powernv_cpufreq_throttle_check() is called in
917 * target() callback which can detect the throttle state
918 * for governors like ondemand.
919 * But static governors will not call target() often thus
920 * report throttling here.
924 pr_warn("CPU frequency is throttled for duration\n");
929 pr_info("OCC Loading, CPU frequency is throttled until OCC is started\n");
932 omsg.chip = be64_to_cpu(msg->params[1]);
933 omsg.throttle_status = be64_to_cpu(msg->params[2]);
938 pr_info("OCC Active, CPU frequency is no longer throttled\n");
940 for (i = 0; i < nr_chips; i++) {
941 chips[i].restore = true;
942 schedule_work(&chips[i].throttle);
948 for (i = 0; i < nr_chips; i++)
949 if (chips[i].id == omsg.chip)
952 if (omsg.throttle_status >= 0 &&
953 omsg.throttle_status <= OCC_MAX_THROTTLE_STATUS) {
954 chips[i].throttle_reason = omsg.throttle_status;
955 chips[i].reason[omsg.throttle_status]++;
958 if (!omsg.throttle_status)
959 chips[i].restore = true;
961 schedule_work(&chips[i].throttle);
966 static struct notifier_block powernv_cpufreq_opal_nb = {
967 .notifier_call = powernv_cpufreq_occ_msg,
972 static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy)
974 struct powernv_smp_call_data freq_data;
975 struct global_pstate_info *gpstates = policy->driver_data;
977 freq_data.pstate_id = idx_to_pstate(powernv_pstate_info.min);
978 freq_data.gpstate_id = idx_to_pstate(powernv_pstate_info.min);
979 smp_call_function_single(policy->cpu, set_pstate, &freq_data, 1);
980 del_timer_sync(&gpstates->timer);
983 static unsigned int powernv_fast_switch(struct cpufreq_policy *policy,
984 unsigned int target_freq)
987 struct powernv_smp_call_data freq_data;
989 index = cpufreq_table_find_index_dl(policy, target_freq);
990 freq_data.pstate_id = powernv_freqs[index].driver_data;
991 freq_data.gpstate_id = powernv_freqs[index].driver_data;
992 set_pstate(&freq_data);
994 return powernv_freqs[index].frequency;
997 static struct cpufreq_driver powernv_cpufreq_driver = {
998 .name = "powernv-cpufreq",
999 .flags = CPUFREQ_CONST_LOOPS,
1000 .init = powernv_cpufreq_cpu_init,
1001 .exit = powernv_cpufreq_cpu_exit,
1002 .verify = cpufreq_generic_frequency_table_verify,
1003 .target_index = powernv_cpufreq_target_index,
1004 .fast_switch = powernv_fast_switch,
1005 .get = powernv_cpufreq_get,
1006 .stop_cpu = powernv_cpufreq_stop_cpu,
1007 .attr = powernv_cpu_freq_attr,
1010 static int init_chip_info(void)
1013 unsigned int cpu, i;
1014 unsigned int prev_chip_id = UINT_MAX;
1015 cpumask_t *chip_cpu_mask;
1018 chip = kcalloc(num_possible_cpus(), sizeof(*chip), GFP_KERNEL);
1022 /* Allocate a chip cpu mask large enough to fit mask for all chips */
1023 chip_cpu_mask = kcalloc(MAX_NR_CHIPS, sizeof(cpumask_t), GFP_KERNEL);
1024 if (!chip_cpu_mask) {
1026 goto free_and_return;
1029 for_each_possible_cpu(cpu) {
1030 unsigned int id = cpu_to_chip_id(cpu);
1032 if (prev_chip_id != id) {
1034 chip[nr_chips++] = id;
1036 cpumask_set_cpu(cpu, &chip_cpu_mask[nr_chips-1]);
1039 chips = kcalloc(nr_chips, sizeof(struct chip), GFP_KERNEL);
1042 goto out_free_chip_cpu_mask;
1045 for (i = 0; i < nr_chips; i++) {
1046 chips[i].id = chip[i];
1047 cpumask_copy(&chips[i].mask, &chip_cpu_mask[i]);
1048 INIT_WORK(&chips[i].throttle, powernv_cpufreq_work_fn);
1049 for_each_cpu(cpu, &chips[i].mask)
1050 per_cpu(chip_info, cpu) = &chips[i];
1053 out_free_chip_cpu_mask:
1054 kfree(chip_cpu_mask);
1060 static inline void clean_chip_info(void)
1064 /* flush any pending work items */
1066 for (i = 0; i < nr_chips; i++)
1067 cancel_work_sync(&chips[i].throttle);
1071 static inline void unregister_all_notifiers(void)
1073 opal_message_notifier_unregister(OPAL_MSG_OCC,
1074 &powernv_cpufreq_opal_nb);
1075 unregister_reboot_notifier(&powernv_cpufreq_reboot_nb);
1078 static int __init powernv_cpufreq_init(void)
1082 /* Don't probe on pseries (guest) platforms */
1083 if (!firmware_has_feature(FW_FEATURE_OPAL))
1086 /* Discover pstates from device tree and init */
1087 rc = init_powernv_pstates();
1091 /* Populate chip info */
1092 rc = init_chip_info();
1096 register_reboot_notifier(&powernv_cpufreq_reboot_nb);
1097 opal_message_notifier_register(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb);
1099 if (powernv_pstate_info.wof_enabled)
1100 powernv_cpufreq_driver.boost_enabled = true;
1102 powernv_cpu_freq_attr[SCALING_BOOST_FREQS_ATTR_INDEX] = NULL;
1104 rc = cpufreq_register_driver(&powernv_cpufreq_driver);
1106 pr_info("Failed to register the cpufreq driver (%d)\n", rc);
1107 goto cleanup_notifiers;
1110 if (powernv_pstate_info.wof_enabled)
1111 cpufreq_enable_boost_support();
1115 unregister_all_notifiers();
1118 pr_info("Platform driver disabled. System does not support PState control\n");
1121 module_init(powernv_cpufreq_init);
1123 static void __exit powernv_cpufreq_exit(void)
1125 cpufreq_unregister_driver(&powernv_cpufreq_driver);
1126 unregister_all_notifiers();
1129 module_exit(powernv_cpufreq_exit);
1131 MODULE_LICENSE("GPL");
1132 MODULE_AUTHOR("Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>");