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
48 #define MAX_RAMP_DOWN_TIME 5120
50 * On an idle system we want the global pstate to ramp-down from max value to
51 * min over a span of ~5 secs. Also we want it to initially ramp-down slowly and
52 * then ramp-down rapidly later on.
54 * This gives a percentage rampdown for time elapsed in milliseconds.
55 * ramp_down_percentage = ((ms * ms) >> 18)
56 * ~= 3.8 * (sec * sec)
58 * At 0 ms ramp_down_percent = 0
59 * At 5120 ms ramp_down_percent = 100
61 #define ramp_down_percent(time) ((time * time) >> 18)
63 /* Interval after which the timer is queued to bring down global pstate */
64 #define GPSTATE_TIMER_INTERVAL 2000
67 * struct global_pstate_info - Per policy data structure to maintain history of
69 * @highest_lpstate_idx: The local pstate index from which we are
71 * @elapsed_time: Time in ms spent in ramping down from
73 * @last_sampled_time: Time from boot in ms when global pstates were
75 * @last_lpstate_idx, Last set value of local pstate and global
76 * last_gpstate_idx pstate in terms of cpufreq table index
77 * @timer: Is used for ramping down if cpu goes idle for
78 * a long time with global pstate held high
79 * @gpstate_lock: A spinlock to maintain synchronization between
80 * routines called by the timer handler and
81 * governer's target_index calls
83 struct global_pstate_info
{
84 int highest_lpstate_idx
;
85 unsigned int elapsed_time
;
86 unsigned int last_sampled_time
;
89 spinlock_t gpstate_lock
;
90 struct timer_list timer
;
91 struct cpufreq_policy
*policy
;
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(struct timer_list
*t
)
640 struct global_pstate_info
*gpstates
= from_timer(gpstates
, t
, timer
);
641 struct cpufreq_policy
*policy
= gpstates
->policy
;
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 gpstates
->policy
= policy
;
822 timer_setup(&gpstates
->timer
, gpstate_timer_handler
,
823 TIMER_PINNED
| TIMER_DEFERRABLE
);
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 cpufreq_get_policy(&cpu_policy
, cpu
);
855 powernv_cpufreq_target_index(&cpu_policy
, get_nominal_index());
861 static struct notifier_block powernv_cpufreq_reboot_nb
= {
862 .notifier_call
= powernv_cpufreq_reboot_notifier
,
865 void powernv_cpufreq_work_fn(struct work_struct
*work
)
867 struct chip
*chip
= container_of(work
, struct chip
, throttle
);
872 cpumask_and(&mask
, &chip
->mask
, cpu_online_mask
);
873 smp_call_function_any(&mask
,
874 powernv_cpufreq_throttle_check
, NULL
, 0);
879 chip
->restore
= false;
880 for_each_cpu(cpu
, &mask
) {
882 struct cpufreq_policy policy
;
884 cpufreq_get_policy(&policy
, cpu
);
885 index
= cpufreq_table_find_index_c(&policy
, policy
.cur
);
886 powernv_cpufreq_target_index(&policy
, index
);
887 cpumask_andnot(&mask
, &mask
, policy
.cpus
);
893 static int powernv_cpufreq_occ_msg(struct notifier_block
*nb
,
894 unsigned long msg_type
, void *_msg
)
896 struct opal_msg
*msg
= _msg
;
897 struct opal_occ_msg omsg
;
900 if (msg_type
!= OPAL_MSG_OCC
)
903 omsg
.type
= be64_to_cpu(msg
->params
[0]);
908 pr_info("OCC (On Chip Controller - enforces hard thermal/power limits) Resetting\n");
910 * powernv_cpufreq_throttle_check() is called in
911 * target() callback which can detect the throttle state
912 * for governors like ondemand.
913 * But static governors will not call target() often thus
914 * report throttling here.
918 pr_warn("CPU frequency is throttled for duration\n");
923 pr_info("OCC Loading, CPU frequency is throttled until OCC is started\n");
926 omsg
.chip
= be64_to_cpu(msg
->params
[1]);
927 omsg
.throttle_status
= be64_to_cpu(msg
->params
[2]);
932 pr_info("OCC Active, CPU frequency is no longer throttled\n");
934 for (i
= 0; i
< nr_chips
; i
++) {
935 chips
[i
].restore
= true;
936 schedule_work(&chips
[i
].throttle
);
942 for (i
= 0; i
< nr_chips
; i
++)
943 if (chips
[i
].id
== omsg
.chip
)
946 if (omsg
.throttle_status
>= 0 &&
947 omsg
.throttle_status
<= OCC_MAX_THROTTLE_STATUS
) {
948 chips
[i
].throttle_reason
= omsg
.throttle_status
;
949 chips
[i
].reason
[omsg
.throttle_status
]++;
952 if (!omsg
.throttle_status
)
953 chips
[i
].restore
= true;
955 schedule_work(&chips
[i
].throttle
);
960 static struct notifier_block powernv_cpufreq_opal_nb
= {
961 .notifier_call
= powernv_cpufreq_occ_msg
,
966 static void powernv_cpufreq_stop_cpu(struct cpufreq_policy
*policy
)
968 struct powernv_smp_call_data freq_data
;
969 struct global_pstate_info
*gpstates
= policy
->driver_data
;
971 freq_data
.pstate_id
= idx_to_pstate(powernv_pstate_info
.min
);
972 freq_data
.gpstate_id
= idx_to_pstate(powernv_pstate_info
.min
);
973 smp_call_function_single(policy
->cpu
, set_pstate
, &freq_data
, 1);
974 del_timer_sync(&gpstates
->timer
);
977 static unsigned int powernv_fast_switch(struct cpufreq_policy
*policy
,
978 unsigned int target_freq
)
981 struct powernv_smp_call_data freq_data
;
983 index
= cpufreq_table_find_index_dl(policy
, target_freq
);
984 freq_data
.pstate_id
= powernv_freqs
[index
].driver_data
;
985 freq_data
.gpstate_id
= powernv_freqs
[index
].driver_data
;
986 set_pstate(&freq_data
);
988 return powernv_freqs
[index
].frequency
;
991 static struct cpufreq_driver powernv_cpufreq_driver
= {
992 .name
= "powernv-cpufreq",
993 .flags
= CPUFREQ_CONST_LOOPS
,
994 .init
= powernv_cpufreq_cpu_init
,
995 .exit
= powernv_cpufreq_cpu_exit
,
996 .verify
= cpufreq_generic_frequency_table_verify
,
997 .target_index
= powernv_cpufreq_target_index
,
998 .fast_switch
= powernv_fast_switch
,
999 .get
= powernv_cpufreq_get
,
1000 .stop_cpu
= powernv_cpufreq_stop_cpu
,
1001 .attr
= powernv_cpu_freq_attr
,
1004 static int init_chip_info(void)
1006 unsigned int chip
[256];
1007 unsigned int cpu
, i
;
1008 unsigned int prev_chip_id
= UINT_MAX
;
1010 for_each_possible_cpu(cpu
) {
1011 unsigned int id
= cpu_to_chip_id(cpu
);
1013 if (prev_chip_id
!= id
) {
1015 chip
[nr_chips
++] = id
;
1019 chips
= kcalloc(nr_chips
, sizeof(struct chip
), GFP_KERNEL
);
1023 for (i
= 0; i
< nr_chips
; i
++) {
1024 chips
[i
].id
= chip
[i
];
1025 cpumask_copy(&chips
[i
].mask
, cpumask_of_node(chip
[i
]));
1026 INIT_WORK(&chips
[i
].throttle
, powernv_cpufreq_work_fn
);
1027 for_each_cpu(cpu
, &chips
[i
].mask
)
1028 per_cpu(chip_info
, cpu
) = &chips
[i
];
1034 static inline void clean_chip_info(void)
1039 static inline void unregister_all_notifiers(void)
1041 opal_message_notifier_unregister(OPAL_MSG_OCC
,
1042 &powernv_cpufreq_opal_nb
);
1043 unregister_reboot_notifier(&powernv_cpufreq_reboot_nb
);
1046 static int __init
powernv_cpufreq_init(void)
1050 /* Don't probe on pseries (guest) platforms */
1051 if (!firmware_has_feature(FW_FEATURE_OPAL
))
1054 /* Discover pstates from device tree and init */
1055 rc
= init_powernv_pstates();
1059 /* Populate chip info */
1060 rc
= init_chip_info();
1064 register_reboot_notifier(&powernv_cpufreq_reboot_nb
);
1065 opal_message_notifier_register(OPAL_MSG_OCC
, &powernv_cpufreq_opal_nb
);
1067 if (powernv_pstate_info
.wof_enabled
)
1068 powernv_cpufreq_driver
.boost_enabled
= true;
1070 powernv_cpu_freq_attr
[SCALING_BOOST_FREQS_ATTR_INDEX
] = NULL
;
1072 rc
= cpufreq_register_driver(&powernv_cpufreq_driver
);
1074 pr_info("Failed to register the cpufreq driver (%d)\n", rc
);
1075 goto cleanup_notifiers
;
1078 if (powernv_pstate_info
.wof_enabled
)
1079 cpufreq_enable_boost_support();
1083 unregister_all_notifiers();
1086 pr_info("Platform driver disabled. System does not support PState control\n");
1089 module_init(powernv_cpufreq_init
);
1091 static void __exit
powernv_cpufreq_exit(void)
1093 cpufreq_unregister_driver(&powernv_cpufreq_driver
);
1094 unregister_all_notifiers();
1097 module_exit(powernv_cpufreq_exit
);
1099 MODULE_LICENSE("GPL");
1100 MODULE_AUTHOR("Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>");