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linux-sg2042/drivers/cpufreq/powernv-cpufreq.c

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/*
* POWERNV cpufreq driver for the IBM POWER processors
*
* (C) Copyright IBM 2014
*
* Author: Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#define pr_fmt(fmt) "powernv-cpufreq: " fmt
#include <linux/kernel.h>
#include <linux/sysfs.h>
#include <linux/cpumask.h>
#include <linux/module.h>
#include <linux/cpufreq.h>
#include <linux/smp.h>
#include <linux/of.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <linux/hashtable.h>
#include <trace/events/power.h>
#include <asm/cputhreads.h>
#include <asm/firmware.h>
#include <asm/reg.h>
#include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */
#include <asm/opal.h>
#include <linux/timer.h>
#define POWERNV_MAX_PSTATES_ORDER 8
#define POWERNV_MAX_PSTATES (1UL << (POWERNV_MAX_PSTATES_ORDER))
#define PMSR_PSAFE_ENABLE (1UL << 30)
#define PMSR_SPR_EM_DISABLE (1UL << 31)
#define MAX_PSTATE_SHIFT 32
#define LPSTATE_SHIFT 48
#define GPSTATE_SHIFT 56
#define MAX_RAMP_DOWN_TIME 5120
/*
* On an idle system we want the global pstate to ramp-down from max value to
* min over a span of ~5 secs. Also we want it to initially ramp-down slowly and
* then ramp-down rapidly later on.
*
* This gives a percentage rampdown for time elapsed in milliseconds.
* ramp_down_percentage = ((ms * ms) >> 18)
* ~= 3.8 * (sec * sec)
*
* At 0 ms ramp_down_percent = 0
* At 5120 ms ramp_down_percent = 100
*/
#define ramp_down_percent(time) ((time * time) >> 18)
/* Interval after which the timer is queued to bring down global pstate */
#define GPSTATE_TIMER_INTERVAL 2000
/**
* struct global_pstate_info - Per policy data structure to maintain history of
* global pstates
* @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_idx
* @last_sampled_time: Time from boot in ms when global pstates were
* last set
* @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
* routines called by the timer handler and
* governer's target_index calls
*/
struct global_pstate_info {
int highest_lpstate_idx;
unsigned int elapsed_time;
unsigned int last_sampled_time;
int last_lpstate_idx;
int last_gpstate_idx;
spinlock_t gpstate_lock;
struct timer_list timer;
struct cpufreq_policy *policy;
};
static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
DEFINE_HASHTABLE(pstate_revmap, POWERNV_MAX_PSTATES_ORDER);
/**
* struct pstate_idx_revmap_data: Entry in the hashmap pstate_revmap
* indexed by a function of pstate id.
*
* @pstate_id: pstate id for this entry.
*
* @cpufreq_table_idx: Index into the powernv_freqs
* cpufreq_frequency_table for frequency
* corresponding to pstate_id.
*
* @hentry: hlist_node that hooks this entry into the pstate_revmap
* hashtable
*/
struct pstate_idx_revmap_data {
u8 pstate_id;
unsigned int cpufreq_table_idx;
struct hlist_node hentry;
};
static bool rebooting, throttled, occ_reset;
static const char * const throttle_reason[] = {
"No throttling",
"Power Cap",
"Processor Over Temperature",
"Power Supply Failure",
"Over Current",
"OCC Reset"
};
enum throttle_reason_type {
NO_THROTTLE = 0,
POWERCAP,
CPU_OVERTEMP,
POWER_SUPPLY_FAILURE,
OVERCURRENT,
OCC_RESET_THROTTLE,
OCC_MAX_REASON
};
static struct chip {
unsigned int id;
bool throttled;
bool restore;
u8 throttle_reason;
cpumask_t mask;
struct work_struct throttle;
int throttle_turbo;
int throttle_sub_turbo;
int reason[OCC_MAX_REASON];
} *chips;
static int nr_chips;
static DEFINE_PER_CPU(struct chip *, chip_info);
/*
* 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.
*
* powernv_pstate_info.nominal indicates the index to the highest
* non-turbo frequency.
*/
static struct powernv_pstate_info {
unsigned int min;
unsigned int max;
unsigned int nominal;
unsigned int nr_pstates;
bool wof_enabled;
} powernv_pstate_info;
static inline u8 extract_pstate(u64 pmsr_val, unsigned int shift)
{
return ((pmsr_val >> shift) & 0xFF);
}
#define extract_local_pstate(x) extract_pstate(x, LPSTATE_SHIFT)
#define extract_global_pstate(x) extract_pstate(x, GPSTATE_SHIFT)
#define extract_max_pstate(x) extract_pstate(x, MAX_PSTATE_SHIFT)
/* Use following functions for conversions between pstate_id and index */
/**
* idx_to_pstate : Returns the pstate id corresponding to the
* frequency in the cpufreq frequency table
* powernv_freqs indexed by @i.
*
* If @i is out of bound, this will return the pstate
* corresponding to the nominal frequency.
*/
static inline u8 idx_to_pstate(unsigned int i)
{
if (unlikely(i >= powernv_pstate_info.nr_pstates)) {
pr_warn_once("idx_to_pstate: index %u is out of bound\n", i);
return powernv_freqs[powernv_pstate_info.nominal].driver_data;
}
return powernv_freqs[i].driver_data;
}
/**
* pstate_to_idx : Returns the index in the cpufreq frequencytable
* powernv_freqs for the frequency whose corresponding
* pstate id is @pstate.
*
* If no frequency corresponding to @pstate is found,
* this will return the index of the nominal
* frequency.
*/
static unsigned int pstate_to_idx(u8 pstate)
{
unsigned int key = pstate % POWERNV_MAX_PSTATES;
struct pstate_idx_revmap_data *revmap_data;
hash_for_each_possible(pstate_revmap, revmap_data, hentry, key) {
if (revmap_data->pstate_id == pstate)
return revmap_data->cpufreq_table_idx;
}
pr_warn_once("pstate_to_idx: pstate 0x%x not found\n", pstate);
return powernv_pstate_info.nominal;
}
static inline void reset_gpstates(struct cpufreq_policy *policy)
{
struct global_pstate_info *gpstates = policy->driver_data;
gpstates->highest_lpstate_idx = 0;
gpstates->elapsed_time = 0;
gpstates->last_sampled_time = 0;
gpstates->last_lpstate_idx = 0;
gpstates->last_gpstate_idx = 0;
}
/*
* Initialize the freq table based on data obtained
* from the firmware passed via device-tree
*/
static int init_powernv_pstates(void)
{
struct device_node *power_mgt;
int i, nr_pstates = 0;
const __be32 *pstate_ids, *pstate_freqs;
u32 len_ids, len_freqs;
u32 pstate_min, pstate_max, pstate_nominal;
u32 pstate_turbo, pstate_ultra_turbo;
power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
if (!power_mgt) {
pr_warn("power-mgt node not found\n");
return -ENODEV;
}
if (of_property_read_u32(power_mgt, "ibm,pstate-min", &pstate_min)) {
pr_warn("ibm,pstate-min node not found\n");
return -ENODEV;
}
if (of_property_read_u32(power_mgt, "ibm,pstate-max", &pstate_max)) {
pr_warn("ibm,pstate-max node not found\n");
return -ENODEV;
}
if (of_property_read_u32(power_mgt, "ibm,pstate-nominal",
&pstate_nominal)) {
pr_warn("ibm,pstate-nominal not found\n");
return -ENODEV;
}
if (of_property_read_u32(power_mgt, "ibm,pstate-ultra-turbo",
&pstate_ultra_turbo)) {
powernv_pstate_info.wof_enabled = false;
goto next;
}
if (of_property_read_u32(power_mgt, "ibm,pstate-turbo",
&pstate_turbo)) {
powernv_pstate_info.wof_enabled = false;
goto next;
}
if (pstate_turbo == pstate_ultra_turbo)
powernv_pstate_info.wof_enabled = false;
else
powernv_pstate_info.wof_enabled = true;
next:
pr_info("cpufreq pstate min 0x%x nominal 0x%x max 0x%x\n", pstate_min,
pstate_nominal, pstate_max);
pr_info("Workload Optimized Frequency is %s in the platform\n",
(powernv_pstate_info.wof_enabled) ? "enabled" : "disabled");
pstate_ids = of_get_property(power_mgt, "ibm,pstate-ids", &len_ids);
if (!pstate_ids) {
pr_warn("ibm,pstate-ids not found\n");
return -ENODEV;
}
pstate_freqs = of_get_property(power_mgt, "ibm,pstate-frequencies-mhz",
&len_freqs);
if (!pstate_freqs) {
pr_warn("ibm,pstate-frequencies-mhz not found\n");
return -ENODEV;
}
if (len_ids != len_freqs) {
pr_warn("Entries in ibm,pstate-ids and "
"ibm,pstate-frequencies-mhz does not match\n");
}
nr_pstates = min(len_ids, len_freqs) / sizeof(u32);
if (!nr_pstates) {
pr_warn("No PStates found\n");
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]);
u32 freq = be32_to_cpu(pstate_freqs[i]);
struct pstate_idx_revmap_data *revmap_data;
unsigned int key;
pr_debug("PState id %d freq %d MHz\n", id, freq);
powernv_freqs[i].frequency = freq * 1000; /* kHz */
powernv_freqs[i].driver_data = id & 0xFF;
revmap_data = (struct pstate_idx_revmap_data *)
kmalloc(sizeof(*revmap_data), GFP_KERNEL);
revmap_data->pstate_id = id & 0xFF;
revmap_data->cpufreq_table_idx = i;
key = (revmap_data->pstate_id) % POWERNV_MAX_PSTATES;
hash_add(pstate_revmap, &revmap_data->hentry, key);
if (id == pstate_max)
powernv_pstate_info.max = i;
if (id == pstate_nominal)
powernv_pstate_info.nominal = i;
if (id == pstate_min)
powernv_pstate_info.min = i;
if (powernv_pstate_info.wof_enabled && id == pstate_turbo) {
int j;
for (j = i - 1; j >= (int)powernv_pstate_info.max; j--)
powernv_freqs[j].flags = CPUFREQ_BOOST_FREQ;
}
}
/* End of list marker entry */
powernv_freqs[i].frequency = CPUFREQ_TABLE_END;
return 0;
}
/* Returns the CPU frequency corresponding to the pstate_id. */
static unsigned int pstate_id_to_freq(u8 pstate_id)
{
int i;
i = pstate_to_idx(pstate_id);
if (i >= powernv_pstate_info.nr_pstates || i < 0) {
pr_warn("PState id 0x%x outside of PState table, reporting nominal id 0x%x instead\n",
pstate_id, idx_to_pstate(powernv_pstate_info.nominal));
i = powernv_pstate_info.nominal;
}
return powernv_freqs[i].frequency;
}
/*
* cpuinfo_nominal_freq_show - Show the nominal CPU frequency as indicated by
* the firmware
*/
static ssize_t cpuinfo_nominal_freq_show(struct cpufreq_policy *policy,
char *buf)
{
return sprintf(buf, "%u\n",
powernv_freqs[powernv_pstate_info.nominal].frequency);
}
struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq =
__ATTR_RO(cpuinfo_nominal_freq);
#define SCALING_BOOST_FREQS_ATTR_INDEX 2
static struct freq_attr *powernv_cpu_freq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
&cpufreq_freq_attr_cpuinfo_nominal_freq,
&cpufreq_freq_attr_scaling_boost_freqs,
NULL,
};
#define throttle_attr(name, member) \
static ssize_t name##_show(struct cpufreq_policy *policy, char *buf) \
{ \
struct chip *chip = per_cpu(chip_info, policy->cpu); \
\
return sprintf(buf, "%u\n", chip->member); \
} \
\
static struct freq_attr throttle_attr_##name = __ATTR_RO(name) \
throttle_attr(unthrottle, reason[NO_THROTTLE]);
throttle_attr(powercap, reason[POWERCAP]);
throttle_attr(overtemp, reason[CPU_OVERTEMP]);
throttle_attr(supply_fault, reason[POWER_SUPPLY_FAILURE]);
throttle_attr(overcurrent, reason[OVERCURRENT]);
throttle_attr(occ_reset, reason[OCC_RESET_THROTTLE]);
throttle_attr(turbo_stat, throttle_turbo);
throttle_attr(sub_turbo_stat, throttle_sub_turbo);
static struct attribute *throttle_attrs[] = {
&throttle_attr_unthrottle.attr,
&throttle_attr_powercap.attr,
&throttle_attr_overtemp.attr,
&throttle_attr_supply_fault.attr,
&throttle_attr_overcurrent.attr,
&throttle_attr_occ_reset.attr,
&throttle_attr_turbo_stat.attr,
&throttle_attr_sub_turbo_stat.attr,
NULL,
};
static const struct attribute_group throttle_attr_grp = {
.name = "throttle_stats",
.attrs = throttle_attrs,
};
/* Helper routines */
/* Access helpers to power mgt SPR */
static inline unsigned long get_pmspr(unsigned long sprn)
{
switch (sprn) {
case SPRN_PMCR:
return mfspr(SPRN_PMCR);
case SPRN_PMICR:
return mfspr(SPRN_PMICR);
case SPRN_PMSR:
return mfspr(SPRN_PMSR);
}
BUG();
}
static inline void set_pmspr(unsigned long sprn, unsigned long val)
{
switch (sprn) {
case SPRN_PMCR:
mtspr(SPRN_PMCR, val);
return;
case SPRN_PMICR:
mtspr(SPRN_PMICR, val);
return;
}
BUG();
}
/*
* Use objects of this type to query/update
* pstates on a remote CPU via smp_call_function.
*/
struct powernv_smp_call_data {
unsigned int freq;
u8 pstate_id;
u8 gpstate_id;
};
/*
* powernv_read_cpu_freq: Reads the current frequency on this CPU.
*
* Called via smp_call_function.
*
* Note: The caller of the smp_call_function should pass an argument of
* the type 'struct powernv_smp_call_data *' along with this function.
*
* The current frequency on this CPU will be returned via
* ((struct powernv_smp_call_data *)arg)->freq;
*/
static void powernv_read_cpu_freq(void *arg)
{
unsigned long pmspr_val;
struct powernv_smp_call_data *freq_data = arg;
pmspr_val = get_pmspr(SPRN_PMSR);
freq_data->pstate_id = extract_local_pstate(pmspr_val);
freq_data->freq = pstate_id_to_freq(freq_data->pstate_id);
pr_debug("cpu %d pmsr %016lX pstate_id 0x%x frequency %d kHz\n",
raw_smp_processor_id(), pmspr_val, freq_data->pstate_id,
freq_data->freq);
}
/*
* powernv_cpufreq_get: Returns the CPU frequency as reported by the
* firmware for CPU 'cpu'. This value is reported through the sysfs
* file cpuinfo_cur_freq.
*/
static unsigned int powernv_cpufreq_get(unsigned int cpu)
{
struct powernv_smp_call_data freq_data;
smp_call_function_any(cpu_sibling_mask(cpu), powernv_read_cpu_freq,
&freq_data, 1);
return freq_data.freq;
}
/*
* set_pstate: Sets the pstate on this CPU.
*
* This is called via an smp_call_function.
*
* The caller must ensure that freq_data is of the type
* (struct powernv_smp_call_data *) and the pstate_id which needs to be set
* on this CPU should be present in freq_data->pstate_id.
*/
static void set_pstate(void *data)
{
unsigned long val;
struct powernv_smp_call_data *freq_data = data;
unsigned long pstate_ul = freq_data->pstate_id;
unsigned long gpstate_ul = freq_data->gpstate_id;
val = get_pmspr(SPRN_PMCR);
val = val & 0x0000FFFFFFFFFFFFULL;
pstate_ul = pstate_ul & 0xFF;
gpstate_ul = gpstate_ul & 0xFF;
/* Set both global(bits 56..63) and local(bits 48..55) PStates */
val = val | (gpstate_ul << 56) | (pstate_ul << 48);
pr_debug("Setting cpu %d pmcr to %016lX\n",
raw_smp_processor_id(), val);
set_pmspr(SPRN_PMCR, val);
}
/*
* get_nominal_index: Returns the index corresponding to the nominal
* pstate in the cpufreq table
*/
static inline unsigned int get_nominal_index(void)
{
return powernv_pstate_info.nominal;
}
static void powernv_cpufreq_throttle_check(void *data)
{
struct chip *chip;
unsigned int cpu = smp_processor_id();
unsigned long pmsr;
u8 pmsr_pmax;
unsigned int pmsr_pmax_idx;
pmsr = get_pmspr(SPRN_PMSR);
chip = this_cpu_read(chip_info);
/* Check for Pmax Capping */
pmsr_pmax = extract_max_pstate(pmsr);
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_idx > powernv_pstate_info.nominal) {
pr_warn_once("CPU %d on Chip %u has Pmax(0x%x) reduced below that of nominal frequency(0x%x)\n",
cpu, chip->id, pmsr_pmax,
idx_to_pstate(powernv_pstate_info.nominal));
chip->throttle_sub_turbo++;
} else {
chip->throttle_turbo++;
}
trace_powernv_throttle(chip->id,
throttle_reason[chip->throttle_reason],
pmsr_pmax);
} else if (chip->throttled) {
chip->throttled = false;
trace_powernv_throttle(chip->id,
throttle_reason[chip->throttle_reason],
pmsr_pmax);
}
/* Check if Psafe_mode_active is set in PMSR. */
next:
if (pmsr & PMSR_PSAFE_ENABLE) {
throttled = true;
pr_info("Pstate set to safe frequency\n");
}
/* Check if SPR_EM_DISABLE is set in PMSR */
if (pmsr & PMSR_SPR_EM_DISABLE) {
throttled = true;
pr_info("Frequency Control disabled from OS\n");
}
if (throttled) {
pr_info("PMSR = %16lx\n", pmsr);
pr_warn("CPU Frequency could be throttled\n");
}
}
/**
* calc_global_pstate - Calculate global pstate
* @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_idx,
int local_pstate_idx)
{
int index_diff;
/*
* Using ramp_down_percent we get the percentage of rampdown
* that we are expecting to be dropping. Difference between
* 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.
*/
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_idx + index_diff >= local_pstate_idx)
return local_pstate_idx;
else
return highest_lpstate_idx + index_diff;
}
static inline void queue_gpstate_timer(struct global_pstate_info *gpstates)
{
unsigned int timer_interval;
/*
* Setting up timer to fire after GPSTATE_TIMER_INTERVAL ms, But
* if it exceeds MAX_RAMP_DOWN_TIME ms for ramp down time.
* Set timer such that it fires exactly at MAX_RAMP_DOWN_TIME
* seconds of ramp down time.
*/
if ((gpstates->elapsed_time + GPSTATE_TIMER_INTERVAL)
> MAX_RAMP_DOWN_TIME)
timer_interval = MAX_RAMP_DOWN_TIME - gpstates->elapsed_time;
else
timer_interval = GPSTATE_TIMER_INTERVAL;
mod_timer(&gpstates->timer, jiffies + msecs_to_jiffies(timer_interval));
}
/**
* gpstate_timer_handler
*
* @data: pointer to cpufreq_policy on which timer was queued
*
* This handler brings down the global pstate closer to the local pstate
* according quadratic equation. Queues a new timer if it is still not equal
* to local pstate
*/
void gpstate_timer_handler(struct timer_list *t)
{
struct global_pstate_info *gpstates = from_timer(gpstates, t, timer);
struct cpufreq_policy *policy = gpstates->policy;
int gpstate_idx, lpstate_idx;
unsigned long val;
unsigned int time_diff = jiffies_to_msecs(jiffies)
- gpstates->last_sampled_time;
struct powernv_smp_call_data freq_data;
if (!spin_trylock(&gpstates->gpstate_lock))
return;
/*
* If PMCR was last updated was using fast_swtich then
* We may have wrong in gpstate->last_lpstate_idx
* value. Hence, read from PMCR to get correct data.
*/
val = get_pmspr(SPRN_PMCR);
freq_data.gpstate_id = extract_global_pstate(val);
freq_data.pstate_id = extract_local_pstate(val);
if (freq_data.gpstate_id == freq_data.pstate_id) {
reset_gpstates(policy);
spin_unlock(&gpstates->gpstate_lock);
return;
}
gpstates->last_sampled_time += time_diff;
gpstates->elapsed_time += time_diff;
if (gpstates->elapsed_time > MAX_RAMP_DOWN_TIME) {
gpstate_idx = pstate_to_idx(freq_data.pstate_id);
lpstate_idx = gpstate_idx;
reset_gpstates(policy);
gpstates->highest_lpstate_idx = gpstate_idx;
} else {
lpstate_idx = pstate_to_idx(freq_data.pstate_id);
gpstate_idx = calc_global_pstate(gpstates->elapsed_time,
gpstates->highest_lpstate_idx,
lpstate_idx);
}
freq_data.gpstate_id = idx_to_pstate(gpstate_idx);
gpstates->last_gpstate_idx = gpstate_idx;
gpstates->last_lpstate_idx = lpstate_idx;
/*
* If local pstate is equal to global pstate, rampdown is over
* So timer is not required to be queued.
*/
if (gpstate_idx != gpstates->last_lpstate_idx)
queue_gpstate_timer(gpstates);
spin_unlock(&gpstates->gpstate_lock);
/* Timer may get migrated to a different cpu on cpu hot unplug */
smp_call_function_any(policy->cpus, set_pstate, &freq_data, 1);
}
/*
* powernv_cpufreq_target_index: Sets the frequency corresponding to
* the cpufreq table entry indexed by new_index on the cpus in the
* mask policy->cpus
*/
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_idx;
struct global_pstate_info *gpstates = policy->driver_data;
if (unlikely(rebooting) && new_index != get_nominal_index())
return 0;
if (!throttled) {
/* we don't want to be preempted while
* checking if the CPU frequency has been throttled
*/
preempt_disable();
powernv_cpufreq_throttle_check(NULL);
preempt_enable();
}
cur_msec = jiffies_to_msecs(get_jiffies_64());
spin_lock(&gpstates->gpstate_lock);
freq_data.pstate_id = idx_to_pstate(new_index);
if (!gpstates->last_sampled_time) {
gpstate_idx = new_index;
gpstates->highest_lpstate_idx = new_index;
goto gpstates_done;
}
if (gpstates->last_gpstate_idx < new_index) {
gpstates->elapsed_time += cur_msec -
gpstates->last_sampled_time;
/*
* If its has been ramping down for more than MAX_RAMP_DOWN_TIME
* we should be resetting all global pstate related data. Set it
* equal to local pstate to start fresh.
*/
if (gpstates->elapsed_time > MAX_RAMP_DOWN_TIME) {
reset_gpstates(policy);
gpstates->highest_lpstate_idx = new_index;
gpstate_idx = new_index;
} else {
/* Elaspsed_time is less than 5 seconds, continue to rampdown */
gpstate_idx = calc_global_pstate(gpstates->elapsed_time,
gpstates->highest_lpstate_idx,
new_index);
}
} else {
reset_gpstates(policy);
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_idx != new_index)
queue_gpstate_timer(gpstates);
else
del_timer_sync(&gpstates->timer);
gpstates_done:
freq_data.gpstate_id = idx_to_pstate(gpstate_idx);
gpstates->last_sampled_time = cur_msec;
gpstates->last_gpstate_idx = gpstate_idx;
gpstates->last_lpstate_idx = new_index;
spin_unlock(&gpstates->gpstate_lock);
/*
* Use smp_call_function to send IPI and execute the
* mtspr on target CPU. We could do that without IPI
* if current CPU is within policy->cpus (core)
*/
smp_call_function_any(policy->cpus, set_pstate, &freq_data, 1);
return 0;
}
static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
int base, i;
struct kernfs_node *kn;
struct global_pstate_info *gpstates;
base = cpu_first_thread_sibling(policy->cpu);
for (i = 0; i < threads_per_core; i++)
cpumask_set_cpu(base + i, policy->cpus);
kn = kernfs_find_and_get(policy->kobj.sd, throttle_attr_grp.name);
if (!kn) {
int ret;
ret = sysfs_create_group(&policy->kobj, &throttle_attr_grp);
if (ret) {
pr_info("Failed to create throttle stats directory for cpu %d\n",
policy->cpu);
return ret;
}
} else {
kernfs_put(kn);
}
gpstates = kzalloc(sizeof(*gpstates), GFP_KERNEL);
if (!gpstates)
return -ENOMEM;
policy->driver_data = gpstates;
/* initialize timer */
gpstates->policy = policy;
timer_setup(&gpstates->timer, gpstate_timer_handler,
TIMER_PINNED | TIMER_DEFERRABLE);
gpstates->timer.expires = jiffies +
msecs_to_jiffies(GPSTATE_TIMER_INTERVAL);
spin_lock_init(&gpstates->gpstate_lock);
policy->freq_table = powernv_freqs;
policy->fast_switch_possible = true;
return 0;
}
static int powernv_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
/* timer is deleted in cpufreq_cpu_stop() */
kfree(policy->driver_data);
return 0;
}
static int powernv_cpufreq_reboot_notifier(struct notifier_block *nb,
unsigned long action, void *unused)
{
int cpu;
struct cpufreq_policy cpu_policy;
rebooting = true;
for_each_online_cpu(cpu) {
cpufreq_get_policy(&cpu_policy, cpu);
powernv_cpufreq_target_index(&cpu_policy, get_nominal_index());
}
return NOTIFY_DONE;
}
static struct notifier_block powernv_cpufreq_reboot_nb = {
.notifier_call = powernv_cpufreq_reboot_notifier,
};
void powernv_cpufreq_work_fn(struct work_struct *work)
{
struct chip *chip = container_of(work, struct chip, throttle);
unsigned int cpu;
cpumask_t mask;
get_online_cpus();
cpumask_and(&mask, &chip->mask, cpu_online_mask);
smp_call_function_any(&mask,
powernv_cpufreq_throttle_check, NULL, 0);
if (!chip->restore)
goto out;
chip->restore = false;
for_each_cpu(cpu, &mask) {
int index;
struct cpufreq_policy policy;
cpufreq_get_policy(&policy, cpu);
index = cpufreq_table_find_index_c(&policy, policy.cur);
powernv_cpufreq_target_index(&policy, index);
cpumask_andnot(&mask, &mask, policy.cpus);
}
out:
put_online_cpus();
}
static int powernv_cpufreq_occ_msg(struct notifier_block *nb,
unsigned long msg_type, void *_msg)
{
struct opal_msg *msg = _msg;
struct opal_occ_msg omsg;
int i;
if (msg_type != OPAL_MSG_OCC)
return 0;
omsg.type = be64_to_cpu(msg->params[0]);
switch (omsg.type) {
case OCC_RESET:
occ_reset = true;
pr_info("OCC (On Chip Controller - enforces hard thermal/power limits) Resetting\n");
/*
* powernv_cpufreq_throttle_check() is called in
* target() callback which can detect the throttle state
* for governors like ondemand.
* But static governors will not call target() often thus
* report throttling here.
*/
if (!throttled) {
throttled = true;
pr_warn("CPU frequency is throttled for duration\n");
}
break;
case OCC_LOAD:
pr_info("OCC Loading, CPU frequency is throttled until OCC is started\n");
break;
case OCC_THROTTLE:
omsg.chip = be64_to_cpu(msg->params[1]);
omsg.throttle_status = be64_to_cpu(msg->params[2]);
if (occ_reset) {
occ_reset = false;
throttled = false;
pr_info("OCC Active, CPU frequency is no longer throttled\n");
for (i = 0; i < nr_chips; i++) {
chips[i].restore = true;
schedule_work(&chips[i].throttle);
}
return 0;
}
for (i = 0; i < nr_chips; i++)
if (chips[i].id == omsg.chip)
break;
if (omsg.throttle_status >= 0 &&
omsg.throttle_status <= OCC_MAX_THROTTLE_STATUS) {
chips[i].throttle_reason = omsg.throttle_status;
chips[i].reason[omsg.throttle_status]++;
}
if (!omsg.throttle_status)
chips[i].restore = true;
schedule_work(&chips[i].throttle);
}
return 0;
}
static struct notifier_block powernv_cpufreq_opal_nb = {
.notifier_call = powernv_cpufreq_occ_msg,
.next = NULL,
.priority = 0,
};
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 = 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);
}
static unsigned int powernv_fast_switch(struct cpufreq_policy *policy,
unsigned int target_freq)
{
int index;
struct powernv_smp_call_data freq_data;
index = cpufreq_table_find_index_dl(policy, target_freq);
freq_data.pstate_id = powernv_freqs[index].driver_data;
freq_data.gpstate_id = powernv_freqs[index].driver_data;
set_pstate(&freq_data);
return powernv_freqs[index].frequency;
}
static struct cpufreq_driver powernv_cpufreq_driver = {
.name = "powernv-cpufreq",
.flags = CPUFREQ_CONST_LOOPS,
.init = powernv_cpufreq_cpu_init,
.exit = powernv_cpufreq_cpu_exit,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = powernv_cpufreq_target_index,
.fast_switch = powernv_fast_switch,
.get = powernv_cpufreq_get,
.stop_cpu = powernv_cpufreq_stop_cpu,
.attr = powernv_cpu_freq_attr,
};
static int init_chip_info(void)
{
unsigned int chip[256];
unsigned int cpu, i;
unsigned int prev_chip_id = UINT_MAX;
for_each_possible_cpu(cpu) {
unsigned int id = cpu_to_chip_id(cpu);
if (prev_chip_id != id) {
prev_chip_id = id;
chip[nr_chips++] = id;
}
}
chips = kcalloc(nr_chips, sizeof(struct chip), GFP_KERNEL);
if (!chips)
return -ENOMEM;
for (i = 0; i < nr_chips; i++) {
chips[i].id = chip[i];
cpumask_copy(&chips[i].mask, cpumask_of_node(chip[i]));
INIT_WORK(&chips[i].throttle, powernv_cpufreq_work_fn);
for_each_cpu(cpu, &chips[i].mask)
per_cpu(chip_info, cpu) = &chips[i];
}
return 0;
}
static inline void clean_chip_info(void)
{
kfree(chips);
}
static inline void unregister_all_notifiers(void)
{
opal_message_notifier_unregister(OPAL_MSG_OCC,
&powernv_cpufreq_opal_nb);
unregister_reboot_notifier(&powernv_cpufreq_reboot_nb);
}
static int __init powernv_cpufreq_init(void)
{
int rc = 0;
/* Don't probe on pseries (guest) platforms */
if (!firmware_has_feature(FW_FEATURE_OPAL))
return -ENODEV;
/* Discover pstates from device tree and init */
rc = init_powernv_pstates();
if (rc)
goto out;
/* Populate chip info */
rc = init_chip_info();
if (rc)
goto out;
register_reboot_notifier(&powernv_cpufreq_reboot_nb);
opal_message_notifier_register(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb);
if (powernv_pstate_info.wof_enabled)
powernv_cpufreq_driver.boost_enabled = true;
else
powernv_cpu_freq_attr[SCALING_BOOST_FREQS_ATTR_INDEX] = NULL;
rc = cpufreq_register_driver(&powernv_cpufreq_driver);
if (rc) {
pr_info("Failed to register the cpufreq driver (%d)\n", rc);
goto cleanup_notifiers;
}
if (powernv_pstate_info.wof_enabled)
cpufreq_enable_boost_support();
return 0;
cleanup_notifiers:
unregister_all_notifiers();
clean_chip_info();
out:
pr_info("Platform driver disabled. System does not support PState control\n");
return rc;
}
module_init(powernv_cpufreq_init);
static void __exit powernv_cpufreq_exit(void)
{
cpufreq_unregister_driver(&powernv_cpufreq_driver);
unregister_all_notifiers();
clean_chip_info();
}
module_exit(powernv_cpufreq_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>");
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