mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 01:41:39 +00:00
![Stewart Smith](/assets/img/avatar_default.png)
Long ago, only in the lab, there was OPALv1 and OPALv2. Now there is just OPALv3, with nobody ever expecting anything on pre-OPALv3 to be cared about or supported by mainline kernels. So, let's remove FW_FEATURE_OPALv3 and instead use FW_FEATURE_OPAL exclusively. Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
302 lines
7.2 KiB
C
302 lines
7.2 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 MAX_POWERNV_IDLE_STATES 8
|
|
|
|
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 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
|
|
/*
|
|
* States for dedicated partition case.
|
|
*/
|
|
static struct cpuidle_state powernv_states[MAX_POWERNV_IDLE_STATES] = {
|
|
{ /* Snooze */
|
|
.name = "snooze",
|
|
.desc = "snooze",
|
|
.exit_latency = 0,
|
|
.target_residency = 0,
|
|
.enter = &snooze_loop },
|
|
};
|
|
|
|
static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
int hotcpu = (unsigned long)hcpu;
|
|
struct cpuidle_device *dev =
|
|
per_cpu(cpuidle_devices, hotcpu);
|
|
|
|
if (dev && cpuidle_get_driver()) {
|
|
switch (action) {
|
|
case CPU_ONLINE:
|
|
case CPU_ONLINE_FROZEN:
|
|
cpuidle_pause_and_lock();
|
|
cpuidle_enable_device(dev);
|
|
cpuidle_resume_and_unlock();
|
|
break;
|
|
|
|
case CPU_DEAD:
|
|
case CPU_DEAD_FROZEN:
|
|
cpuidle_pause_and_lock();
|
|
cpuidle_disable_device(dev);
|
|
cpuidle_resume_and_unlock();
|
|
break;
|
|
|
|
default:
|
|
return NOTIFY_DONE;
|
|
}
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block setup_hotplug_notifier = {
|
|
.notifier_call = powernv_cpuidle_add_cpu_notifier,
|
|
};
|
|
|
|
/*
|
|
* 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, *residency_ns, *flags;
|
|
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;
|
|
}
|
|
|
|
flags = kzalloc(sizeof(*flags) * dt_idle_states, GFP_KERNEL);
|
|
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_free_flags;
|
|
}
|
|
|
|
latency_ns = kzalloc(sizeof(*latency_ns) * dt_idle_states, GFP_KERNEL);
|
|
rc = of_property_read_u32_array(power_mgt,
|
|
"ibm,cpu-idle-state-latencies-ns", latency_ns, dt_idle_states);
|
|
if (rc) {
|
|
pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
|
|
goto out_free_latency;
|
|
}
|
|
|
|
residency_ns = kzalloc(sizeof(*residency_ns) * dt_idle_states, GFP_KERNEL);
|
|
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++) {
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
#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++;
|
|
}
|
|
|
|
kfree(residency_ns);
|
|
out_free_latency:
|
|
kfree(latency_ns);
|
|
out_free_flags:
|
|
kfree(flags);
|
|
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;
|
|
}
|
|
|
|
register_cpu_notifier(&setup_hotplug_notifier);
|
|
printk(KERN_DEBUG "powernv_idle_driver registered\n");
|
|
return 0;
|
|
}
|
|
|
|
device_initcall(powernv_processor_idle_init);
|