kernel_optimize_test/drivers/cpufreq/powernv-cpufreq.c
Shilpasri G Bhat c89f2682a3 cpufreq: powernv: Replace pr_info with trace print for throttle event
Currently we use printk message to notify the throttle event. But this
can flood the console if the cpu is throttled frequently. So replace the
printk with the tracepoint to notify the throttle event. And also events
like throttle below nominal frequency and OCC_RESET are reduced to
pr_warn/pr_warn_once as pointed by MFG to not mark them as critical
messages. This patch adds 'throttle_reason' to struct chip to store the
throttle reason.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@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>
2016-02-05 02:38:03 +01:00

637 lines
16 KiB
C

/*
* 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 <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>
#define POWERNV_MAX_PSTATES 256
#define PMSR_PSAFE_ENABLE (1UL << 30)
#define PMSR_SPR_EM_DISABLE (1UL << 31)
#define PMSR_MAX(x) ((x >> 32) & 0xFF)
static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
static bool rebooting, throttled, occ_reset;
static unsigned int *core_to_chip_map;
static const char * const throttle_reason[] = {
"No throttling",
"Power Cap",
"Processor Over Temperature",
"Power Supply Failure",
"Over Current",
"OCC Reset"
};
static struct chip {
unsigned int id;
bool throttled;
bool restore;
u8 throttle_reason;
cpumask_t mask;
struct work_struct throttle;
} *chips;
static int nr_chips;
/*
* 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.
*
* The nominal pstate is the highest non-turbo pstate in this
* platform. This is indicated by powernv_pstate_info.nominal.
*/
static struct powernv_pstate_info {
int min;
int max;
int nominal;
int nr_pstates;
} powernv_pstate_info;
/*
* 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, pstate_min, pstate_max, pstate_nominal, nr_pstates = 0;
const __be32 *pstate_ids, *pstate_freqs;
u32 len_ids, len_freqs;
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;
}
pr_info("cpufreq pstate min %d nominal %d max %d\n", pstate_min,
pstate_nominal, pstate_max);
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;
}
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]);
pr_debug("PState id %d freq %d MHz\n", id, freq);
powernv_freqs[i].frequency = freq * 1000; /* kHz */
powernv_freqs[i].driver_data = id;
}
/* 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;
}
/* Returns the CPU frequency corresponding to the pstate_id. */
static unsigned int pstate_id_to_freq(int pstate_id)
{
int i;
i = powernv_pstate_info.max - 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;
}
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",
pstate_id_to_freq(powernv_pstate_info.nominal));
}
struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq =
__ATTR_RO(cpuinfo_nominal_freq);
static struct freq_attr *powernv_cpu_freq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
&cpufreq_freq_attr_cpuinfo_nominal_freq,
NULL,
};
/* 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;
int pstate_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;
s8 local_pstate_id;
struct powernv_smp_call_data *freq_data = arg;
pmspr_val = get_pmspr(SPRN_PMSR);
/*
* The local pstate id corresponds bits 48..55 in the PMSR.
* Note: Watch out for the sign!
*/
local_pstate_id = (pmspr_val >> 48) & 0xFF;
freq_data->pstate_id = local_pstate_id;
freq_data->freq = pstate_id_to_freq(freq_data->pstate_id);
pr_debug("cpu %d pmsr %016lX pstate_id %d 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 *freq_data)
{
unsigned long val;
unsigned long pstate_ul =
((struct powernv_smp_call_data *) freq_data)->pstate_id;
val = get_pmspr(SPRN_PMCR);
val = val & 0x0000FFFFFFFFFFFFULL;
pstate_ul = pstate_ul & 0xFF;
/* Set both global(bits 56..63) and local(bits 48..55) PStates */
val = val | (pstate_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.max - powernv_pstate_info.nominal;
}
static void powernv_cpufreq_throttle_check(void *data)
{
unsigned int cpu = smp_processor_id();
unsigned int chip_id = core_to_chip_map[cpu_core_index_of_thread(cpu)];
unsigned long pmsr;
int pmsr_pmax, i;
pmsr = get_pmspr(SPRN_PMSR);
for (i = 0; i < nr_chips; i++)
if (chips[i].id == chip_id)
break;
/* Check for Pmax Capping */
pmsr_pmax = (s8)PMSR_MAX(pmsr);
if (pmsr_pmax != powernv_pstate_info.max) {
if (chips[i].throttled)
goto next;
chips[i].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",
cpu, chips[i].id, pmsr_pmax,
powernv_pstate_info.nominal);
trace_powernv_throttle(chips[i].id,
throttle_reason[chips[i].throttle_reason],
pmsr_pmax);
} else if (chips[i].throttled) {
chips[i].throttled = false;
trace_powernv_throttle(chips[i].id,
throttle_reason[chips[i].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");
}
}
/*
* 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;
if (unlikely(rebooting) && new_index != get_nominal_index())
return 0;
if (!throttled)
powernv_cpufreq_throttle_check(NULL);
freq_data.pstate_id = powernv_freqs[new_index].driver_data;
/*
* 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;
base = cpu_first_thread_sibling(policy->cpu);
for (i = 0; i < threads_per_core; i++)
cpumask_set_cpu(base + i, policy->cpus);
return cpufreq_table_validate_and_show(policy, powernv_freqs);
}
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);
cpufreq_frequency_table_target(&policy, policy.freq_table,
policy.cur,
CPUFREQ_RELATION_C, &index);
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;
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;
freq_data.pstate_id = powernv_pstate_info.min;
smp_call_function_single(policy->cpu, set_pstate, &freq_data, 1);
}
static struct cpufreq_driver powernv_cpufreq_driver = {
.name = "powernv-cpufreq",
.flags = CPUFREQ_CONST_LOOPS,
.init = powernv_cpufreq_cpu_init,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = powernv_cpufreq_target_index,
.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;
cpumask_t cpu_mask;
int ret = -ENOMEM;
core_to_chip_map = kcalloc(cpu_nr_cores(), sizeof(unsigned int),
GFP_KERNEL);
if (!core_to_chip_map)
goto out;
cpumask_copy(&cpu_mask, cpu_possible_mask);
for_each_cpu(cpu, &cpu_mask) {
unsigned int id = cpu_to_chip_id(cpu);
if (prev_chip_id != id) {
prev_chip_id = id;
chip[nr_chips++] = id;
}
core_to_chip_map[cpu_core_index_of_thread(cpu)] = id;
cpumask_andnot(&cpu_mask, &cpu_mask, cpu_sibling_mask(cpu));
}
chips = kcalloc(nr_chips, sizeof(struct chip), GFP_KERNEL);
if (!chips)
goto free_chip_map;
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);
}
return 0;
free_chip_map:
kfree(core_to_chip_map);
out:
return ret;
}
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) {
pr_info("powernv-cpufreq disabled. System does not support PState control\n");
return rc;
}
/* Populate chip info */
rc = init_chip_info();
if (rc)
return rc;
register_reboot_notifier(&powernv_cpufreq_reboot_nb);
opal_message_notifier_register(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb);
return cpufreq_register_driver(&powernv_cpufreq_driver);
}
module_init(powernv_cpufreq_init);
static void __exit powernv_cpufreq_exit(void)
{
unregister_reboot_notifier(&powernv_cpufreq_reboot_nb);
opal_message_notifier_unregister(OPAL_MSG_OCC,
&powernv_cpufreq_opal_nb);
kfree(chips);
kfree(core_to_chip_map);
cpufreq_unregister_driver(&powernv_cpufreq_driver);
}
module_exit(powernv_cpufreq_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>");