ed61390bff
powernv_idle_driver isn't exported, it can be made static. Found by sparse. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
361 lines
9.1 KiB
C
361 lines
9.1 KiB
C
/*
|
|
* cpuidle-powernv - idle state cpuidle driver.
|
|
* Adapted from drivers/cpuidle/cpuidle-pseries
|
|
*
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/cpuidle.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/clockchips.h>
|
|
#include <linux/of.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include <asm/machdep.h>
|
|
#include <asm/firmware.h>
|
|
#include <asm/opal.h>
|
|
#include <asm/runlatch.h>
|
|
|
|
#define POWERNV_THRESHOLD_LATENCY_NS 200000
|
|
|
|
static struct cpuidle_driver powernv_idle_driver = {
|
|
.name = "powernv_idle",
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int max_idle_state;
|
|
static struct cpuidle_state *cpuidle_state_table;
|
|
|
|
static u64 stop_psscr_table[CPUIDLE_STATE_MAX];
|
|
|
|
static u64 snooze_timeout;
|
|
static bool snooze_timeout_en;
|
|
|
|
static int snooze_loop(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv,
|
|
int index)
|
|
{
|
|
u64 snooze_exit_time;
|
|
|
|
local_irq_enable();
|
|
set_thread_flag(TIF_POLLING_NRFLAG);
|
|
|
|
snooze_exit_time = get_tb() + snooze_timeout;
|
|
ppc64_runlatch_off();
|
|
while (!need_resched()) {
|
|
HMT_low();
|
|
HMT_very_low();
|
|
if (snooze_timeout_en && get_tb() > snooze_exit_time)
|
|
break;
|
|
}
|
|
|
|
HMT_medium();
|
|
ppc64_runlatch_on();
|
|
clear_thread_flag(TIF_POLLING_NRFLAG);
|
|
smp_mb();
|
|
return index;
|
|
}
|
|
|
|
static int nap_loop(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv,
|
|
int index)
|
|
{
|
|
ppc64_runlatch_off();
|
|
power7_idle();
|
|
ppc64_runlatch_on();
|
|
return index;
|
|
}
|
|
|
|
/* Register for fastsleep only in oneshot mode of broadcast */
|
|
#ifdef CONFIG_TICK_ONESHOT
|
|
static int fastsleep_loop(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv,
|
|
int index)
|
|
{
|
|
unsigned long old_lpcr = mfspr(SPRN_LPCR);
|
|
unsigned long new_lpcr;
|
|
|
|
if (unlikely(system_state < SYSTEM_RUNNING))
|
|
return index;
|
|
|
|
new_lpcr = old_lpcr;
|
|
/* Do not exit powersave upon decrementer as we've setup the timer
|
|
* offload.
|
|
*/
|
|
new_lpcr &= ~LPCR_PECE1;
|
|
|
|
mtspr(SPRN_LPCR, new_lpcr);
|
|
power7_sleep();
|
|
|
|
mtspr(SPRN_LPCR, old_lpcr);
|
|
|
|
return index;
|
|
}
|
|
#endif
|
|
|
|
static int stop_loop(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv,
|
|
int index)
|
|
{
|
|
ppc64_runlatch_off();
|
|
power9_idle_stop(stop_psscr_table[index]);
|
|
ppc64_runlatch_on();
|
|
return index;
|
|
}
|
|
|
|
/*
|
|
* States for dedicated partition case.
|
|
*/
|
|
static struct cpuidle_state powernv_states[CPUIDLE_STATE_MAX] = {
|
|
{ /* Snooze */
|
|
.name = "snooze",
|
|
.desc = "snooze",
|
|
.exit_latency = 0,
|
|
.target_residency = 0,
|
|
.enter = snooze_loop },
|
|
};
|
|
|
|
static int powernv_cpuidle_cpu_online(unsigned int cpu)
|
|
{
|
|
struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu);
|
|
|
|
if (dev && cpuidle_get_driver()) {
|
|
cpuidle_pause_and_lock();
|
|
cpuidle_enable_device(dev);
|
|
cpuidle_resume_and_unlock();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int powernv_cpuidle_cpu_dead(unsigned int cpu)
|
|
{
|
|
struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu);
|
|
|
|
if (dev && cpuidle_get_driver()) {
|
|
cpuidle_pause_and_lock();
|
|
cpuidle_disable_device(dev);
|
|
cpuidle_resume_and_unlock();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* powernv_cpuidle_driver_init()
|
|
*/
|
|
static int powernv_cpuidle_driver_init(void)
|
|
{
|
|
int idle_state;
|
|
struct cpuidle_driver *drv = &powernv_idle_driver;
|
|
|
|
drv->state_count = 0;
|
|
|
|
for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
|
|
/* Is the state not enabled? */
|
|
if (cpuidle_state_table[idle_state].enter == NULL)
|
|
continue;
|
|
|
|
drv->states[drv->state_count] = /* structure copy */
|
|
cpuidle_state_table[idle_state];
|
|
|
|
drv->state_count += 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int powernv_add_idle_states(void)
|
|
{
|
|
struct device_node *power_mgt;
|
|
int nr_idle_states = 1; /* Snooze */
|
|
int dt_idle_states;
|
|
u32 latency_ns[CPUIDLE_STATE_MAX];
|
|
u32 residency_ns[CPUIDLE_STATE_MAX];
|
|
u32 flags[CPUIDLE_STATE_MAX];
|
|
u64 psscr_val[CPUIDLE_STATE_MAX];
|
|
const char *names[CPUIDLE_STATE_MAX];
|
|
int i, rc;
|
|
|
|
/* Currently we have snooze statically defined */
|
|
|
|
power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
|
|
if (!power_mgt) {
|
|
pr_warn("opal: PowerMgmt Node not found\n");
|
|
goto out;
|
|
}
|
|
|
|
/* Read values of any property to determine the num of idle states */
|
|
dt_idle_states = of_property_count_u32_elems(power_mgt, "ibm,cpu-idle-state-flags");
|
|
if (dt_idle_states < 0) {
|
|
pr_warn("cpuidle-powernv: no idle states found in the DT\n");
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Since snooze is used as first idle state, max idle states allowed is
|
|
* CPUIDLE_STATE_MAX -1
|
|
*/
|
|
if (dt_idle_states > CPUIDLE_STATE_MAX - 1) {
|
|
pr_warn("cpuidle-powernv: discovered idle states more than allowed");
|
|
dt_idle_states = CPUIDLE_STATE_MAX - 1;
|
|
}
|
|
|
|
if (of_property_read_u32_array(power_mgt,
|
|
"ibm,cpu-idle-state-flags", flags, dt_idle_states)) {
|
|
pr_warn("cpuidle-powernv : missing ibm,cpu-idle-state-flags in DT\n");
|
|
goto out;
|
|
}
|
|
|
|
if (of_property_read_u32_array(power_mgt,
|
|
"ibm,cpu-idle-state-latencies-ns", latency_ns,
|
|
dt_idle_states)) {
|
|
pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
|
|
goto out;
|
|
}
|
|
if (of_property_read_string_array(power_mgt,
|
|
"ibm,cpu-idle-state-names", names, dt_idle_states) < 0) {
|
|
pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-names in DT\n");
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* If the idle states use stop instruction, probe for psscr values
|
|
* which are necessary to specify required stop level.
|
|
*/
|
|
if (flags[0] & (OPAL_PM_STOP_INST_FAST | OPAL_PM_STOP_INST_DEEP))
|
|
if (of_property_read_u64_array(power_mgt,
|
|
"ibm,cpu-idle-state-psscr", psscr_val, dt_idle_states)) {
|
|
pr_warn("cpuidle-powernv: missing ibm,cpu-idle-states-psscr in DT\n");
|
|
goto out;
|
|
}
|
|
|
|
rc = of_property_read_u32_array(power_mgt,
|
|
"ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);
|
|
|
|
for (i = 0; i < dt_idle_states; i++) {
|
|
/*
|
|
* If an idle state has exit latency beyond
|
|
* POWERNV_THRESHOLD_LATENCY_NS then don't use it
|
|
* in cpu-idle.
|
|
*/
|
|
if (latency_ns[i] > POWERNV_THRESHOLD_LATENCY_NS)
|
|
continue;
|
|
|
|
/*
|
|
* Cpuidle accepts exit_latency and target_residency in us.
|
|
* Use default target_residency values if f/w does not expose it.
|
|
*/
|
|
if (flags[i] & OPAL_PM_NAP_ENABLED) {
|
|
/* Add NAP state */
|
|
strcpy(powernv_states[nr_idle_states].name, "Nap");
|
|
strcpy(powernv_states[nr_idle_states].desc, "Nap");
|
|
powernv_states[nr_idle_states].flags = 0;
|
|
powernv_states[nr_idle_states].target_residency = 100;
|
|
powernv_states[nr_idle_states].enter = nap_loop;
|
|
} else if ((flags[i] & OPAL_PM_STOP_INST_FAST) &&
|
|
!(flags[i] & OPAL_PM_TIMEBASE_STOP)) {
|
|
strncpy(powernv_states[nr_idle_states].name,
|
|
names[i], CPUIDLE_NAME_LEN);
|
|
strncpy(powernv_states[nr_idle_states].desc,
|
|
names[i], CPUIDLE_NAME_LEN);
|
|
powernv_states[nr_idle_states].flags = 0;
|
|
|
|
powernv_states[nr_idle_states].enter = stop_loop;
|
|
stop_psscr_table[nr_idle_states] = psscr_val[i];
|
|
}
|
|
|
|
/*
|
|
* All cpuidle states with CPUIDLE_FLAG_TIMER_STOP set must come
|
|
* within this config dependency check.
|
|
*/
|
|
#ifdef CONFIG_TICK_ONESHOT
|
|
if (flags[i] & OPAL_PM_SLEEP_ENABLED ||
|
|
flags[i] & OPAL_PM_SLEEP_ENABLED_ER1) {
|
|
/* Add FASTSLEEP state */
|
|
strcpy(powernv_states[nr_idle_states].name, "FastSleep");
|
|
strcpy(powernv_states[nr_idle_states].desc, "FastSleep");
|
|
powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
|
|
powernv_states[nr_idle_states].target_residency = 300000;
|
|
powernv_states[nr_idle_states].enter = fastsleep_loop;
|
|
} else if ((flags[i] & OPAL_PM_STOP_INST_DEEP) &&
|
|
(flags[i] & OPAL_PM_TIMEBASE_STOP)) {
|
|
strncpy(powernv_states[nr_idle_states].name,
|
|
names[i], CPUIDLE_NAME_LEN);
|
|
strncpy(powernv_states[nr_idle_states].desc,
|
|
names[i], CPUIDLE_NAME_LEN);
|
|
|
|
powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
|
|
powernv_states[nr_idle_states].enter = stop_loop;
|
|
stop_psscr_table[nr_idle_states] = psscr_val[i];
|
|
}
|
|
#endif
|
|
powernv_states[nr_idle_states].exit_latency =
|
|
((unsigned int)latency_ns[i]) / 1000;
|
|
|
|
if (!rc) {
|
|
powernv_states[nr_idle_states].target_residency =
|
|
((unsigned int)residency_ns[i]) / 1000;
|
|
}
|
|
|
|
nr_idle_states++;
|
|
}
|
|
out:
|
|
return nr_idle_states;
|
|
}
|
|
|
|
/*
|
|
* powernv_idle_probe()
|
|
* Choose state table for shared versus dedicated partition
|
|
*/
|
|
static int powernv_idle_probe(void)
|
|
{
|
|
if (cpuidle_disable != IDLE_NO_OVERRIDE)
|
|
return -ENODEV;
|
|
|
|
if (firmware_has_feature(FW_FEATURE_OPAL)) {
|
|
cpuidle_state_table = powernv_states;
|
|
/* Device tree can indicate more idle states */
|
|
max_idle_state = powernv_add_idle_states();
|
|
if (max_idle_state > 1) {
|
|
snooze_timeout_en = true;
|
|
snooze_timeout = powernv_states[1].target_residency *
|
|
tb_ticks_per_usec;
|
|
}
|
|
} else
|
|
return -ENODEV;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init powernv_processor_idle_init(void)
|
|
{
|
|
int retval;
|
|
|
|
retval = powernv_idle_probe();
|
|
if (retval)
|
|
return retval;
|
|
|
|
powernv_cpuidle_driver_init();
|
|
retval = cpuidle_register(&powernv_idle_driver, NULL);
|
|
if (retval) {
|
|
printk(KERN_DEBUG "Registration of powernv driver failed.\n");
|
|
return retval;
|
|
}
|
|
|
|
retval = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
|
|
"cpuidle/powernv:online",
|
|
powernv_cpuidle_cpu_online, NULL);
|
|
WARN_ON(retval < 0);
|
|
retval = cpuhp_setup_state_nocalls(CPUHP_CPUIDLE_DEAD,
|
|
"cpuidle/powernv:dead", NULL,
|
|
powernv_cpuidle_cpu_dead);
|
|
WARN_ON(retval < 0);
|
|
printk(KERN_DEBUG "powernv_idle_driver registered\n");
|
|
return 0;
|
|
}
|
|
|
|
device_initcall(powernv_processor_idle_init);
|