mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 02:39:48 +00:00
![Ingo Molnar](/assets/img/avatar_default.png)
We are going to move scheduler ABI details to <uapi/linux/sched/types.h>, which will be used from a number of .c files. Create empty placeholder header that maps to <linux/types.h>. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
491 lines
13 KiB
C
491 lines
13 KiB
C
/*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* 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.
|
|
*
|
|
* Copyright (C) 2016 ARM Limited
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/atomic.h>
|
|
#include <linux/completion.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/cpuidle.h>
|
|
#include <linux/cpu_pm.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/kthread.h>
|
|
#include <uapi/linux/sched/types.h>
|
|
#include <linux/module.h>
|
|
#include <linux/preempt.h>
|
|
#include <linux/psci.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/tick.h>
|
|
#include <linux/topology.h>
|
|
|
|
#include <asm/cpuidle.h>
|
|
|
|
#include <uapi/linux/psci.h>
|
|
|
|
#define NUM_SUSPEND_CYCLE (10)
|
|
|
|
static unsigned int nb_available_cpus;
|
|
static int tos_resident_cpu = -1;
|
|
|
|
static atomic_t nb_active_threads;
|
|
static struct completion suspend_threads_started =
|
|
COMPLETION_INITIALIZER(suspend_threads_started);
|
|
static struct completion suspend_threads_done =
|
|
COMPLETION_INITIALIZER(suspend_threads_done);
|
|
|
|
/*
|
|
* We assume that PSCI operations are used if they are available. This is not
|
|
* necessarily true on arm64, since the decision is based on the
|
|
* "enable-method" property of each CPU in the DT, but given that there is no
|
|
* arch-specific way to check this, we assume that the DT is sensible.
|
|
*/
|
|
static int psci_ops_check(void)
|
|
{
|
|
int migrate_type = -1;
|
|
int cpu;
|
|
|
|
if (!(psci_ops.cpu_off && psci_ops.cpu_on && psci_ops.cpu_suspend)) {
|
|
pr_warn("Missing PSCI operations, aborting tests\n");
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
if (psci_ops.migrate_info_type)
|
|
migrate_type = psci_ops.migrate_info_type();
|
|
|
|
if (migrate_type == PSCI_0_2_TOS_UP_MIGRATE ||
|
|
migrate_type == PSCI_0_2_TOS_UP_NO_MIGRATE) {
|
|
/* There is a UP Trusted OS, find on which core it resides. */
|
|
for_each_online_cpu(cpu)
|
|
if (psci_tos_resident_on(cpu)) {
|
|
tos_resident_cpu = cpu;
|
|
break;
|
|
}
|
|
if (tos_resident_cpu == -1)
|
|
pr_warn("UP Trusted OS resides on no online CPU\n");
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int find_clusters(const struct cpumask *cpus,
|
|
const struct cpumask **clusters)
|
|
{
|
|
unsigned int nb = 0;
|
|
cpumask_var_t tmp;
|
|
|
|
if (!alloc_cpumask_var(&tmp, GFP_KERNEL))
|
|
return -ENOMEM;
|
|
cpumask_copy(tmp, cpus);
|
|
|
|
while (!cpumask_empty(tmp)) {
|
|
const struct cpumask *cluster =
|
|
topology_core_cpumask(cpumask_any(tmp));
|
|
|
|
clusters[nb++] = cluster;
|
|
cpumask_andnot(tmp, tmp, cluster);
|
|
}
|
|
|
|
free_cpumask_var(tmp);
|
|
return nb;
|
|
}
|
|
|
|
/*
|
|
* offlined_cpus is a temporary array but passing it as an argument avoids
|
|
* multiple allocations.
|
|
*/
|
|
static unsigned int down_and_up_cpus(const struct cpumask *cpus,
|
|
struct cpumask *offlined_cpus)
|
|
{
|
|
int cpu;
|
|
int err = 0;
|
|
|
|
cpumask_clear(offlined_cpus);
|
|
|
|
/* Try to power down all CPUs in the mask. */
|
|
for_each_cpu(cpu, cpus) {
|
|
int ret = cpu_down(cpu);
|
|
|
|
/*
|
|
* cpu_down() checks the number of online CPUs before the TOS
|
|
* resident CPU.
|
|
*/
|
|
if (cpumask_weight(offlined_cpus) + 1 == nb_available_cpus) {
|
|
if (ret != -EBUSY) {
|
|
pr_err("Unexpected return code %d while trying "
|
|
"to power down last online CPU %d\n",
|
|
ret, cpu);
|
|
++err;
|
|
}
|
|
} else if (cpu == tos_resident_cpu) {
|
|
if (ret != -EPERM) {
|
|
pr_err("Unexpected return code %d while trying "
|
|
"to power down TOS resident CPU %d\n",
|
|
ret, cpu);
|
|
++err;
|
|
}
|
|
} else if (ret != 0) {
|
|
pr_err("Error occurred (%d) while trying "
|
|
"to power down CPU %d\n", ret, cpu);
|
|
++err;
|
|
}
|
|
|
|
if (ret == 0)
|
|
cpumask_set_cpu(cpu, offlined_cpus);
|
|
}
|
|
|
|
/* Try to power up all the CPUs that have been offlined. */
|
|
for_each_cpu(cpu, offlined_cpus) {
|
|
int ret = cpu_up(cpu);
|
|
|
|
if (ret != 0) {
|
|
pr_err("Error occurred (%d) while trying "
|
|
"to power up CPU %d\n", ret, cpu);
|
|
++err;
|
|
} else {
|
|
cpumask_clear_cpu(cpu, offlined_cpus);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Something went bad at some point and some CPUs could not be turned
|
|
* back on.
|
|
*/
|
|
WARN_ON(!cpumask_empty(offlined_cpus) ||
|
|
num_online_cpus() != nb_available_cpus);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int hotplug_tests(void)
|
|
{
|
|
int err;
|
|
cpumask_var_t offlined_cpus;
|
|
int i, nb_cluster;
|
|
const struct cpumask **clusters;
|
|
char *page_buf;
|
|
|
|
err = -ENOMEM;
|
|
if (!alloc_cpumask_var(&offlined_cpus, GFP_KERNEL))
|
|
return err;
|
|
/* We may have up to nb_available_cpus clusters. */
|
|
clusters = kmalloc_array(nb_available_cpus, sizeof(*clusters),
|
|
GFP_KERNEL);
|
|
if (!clusters)
|
|
goto out_free_cpus;
|
|
page_buf = (char *)__get_free_page(GFP_KERNEL);
|
|
if (!page_buf)
|
|
goto out_free_clusters;
|
|
|
|
err = 0;
|
|
nb_cluster = find_clusters(cpu_online_mask, clusters);
|
|
|
|
/*
|
|
* Of course the last CPU cannot be powered down and cpu_down() should
|
|
* refuse doing that.
|
|
*/
|
|
pr_info("Trying to turn off and on again all CPUs\n");
|
|
err += down_and_up_cpus(cpu_online_mask, offlined_cpus);
|
|
|
|
/*
|
|
* Take down CPUs by cluster this time. When the last CPU is turned
|
|
* off, the cluster itself should shut down.
|
|
*/
|
|
for (i = 0; i < nb_cluster; ++i) {
|
|
int cluster_id =
|
|
topology_physical_package_id(cpumask_any(clusters[i]));
|
|
ssize_t len = cpumap_print_to_pagebuf(true, page_buf,
|
|
clusters[i]);
|
|
/* Remove trailing newline. */
|
|
page_buf[len - 1] = '\0';
|
|
pr_info("Trying to turn off and on again cluster %d "
|
|
"(CPUs %s)\n", cluster_id, page_buf);
|
|
err += down_and_up_cpus(clusters[i], offlined_cpus);
|
|
}
|
|
|
|
free_page((unsigned long)page_buf);
|
|
out_free_clusters:
|
|
kfree(clusters);
|
|
out_free_cpus:
|
|
free_cpumask_var(offlined_cpus);
|
|
return err;
|
|
}
|
|
|
|
static void dummy_callback(unsigned long ignored) {}
|
|
|
|
static int suspend_cpu(int index, bool broadcast)
|
|
{
|
|
int ret;
|
|
|
|
arch_cpu_idle_enter();
|
|
|
|
if (broadcast) {
|
|
/*
|
|
* The local timer will be shut down, we need to enter tick
|
|
* broadcast.
|
|
*/
|
|
ret = tick_broadcast_enter();
|
|
if (ret) {
|
|
/*
|
|
* In the absence of hardware broadcast mechanism,
|
|
* this CPU might be used to broadcast wakeups, which
|
|
* may be why entering tick broadcast has failed.
|
|
* There is little the kernel can do to work around
|
|
* that, so enter WFI instead (idle state 0).
|
|
*/
|
|
cpu_do_idle();
|
|
ret = 0;
|
|
goto out_arch_exit;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Replicate the common ARM cpuidle enter function
|
|
* (arm_enter_idle_state).
|
|
*/
|
|
ret = CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, index);
|
|
|
|
if (broadcast)
|
|
tick_broadcast_exit();
|
|
|
|
out_arch_exit:
|
|
arch_cpu_idle_exit();
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int suspend_test_thread(void *arg)
|
|
{
|
|
int cpu = (long)arg;
|
|
int i, nb_suspend = 0, nb_shallow_sleep = 0, nb_err = 0;
|
|
struct sched_param sched_priority = { .sched_priority = MAX_RT_PRIO-1 };
|
|
struct cpuidle_device *dev;
|
|
struct cpuidle_driver *drv;
|
|
/* No need for an actual callback, we just want to wake up the CPU. */
|
|
struct timer_list wakeup_timer;
|
|
|
|
/* Wait for the main thread to give the start signal. */
|
|
wait_for_completion(&suspend_threads_started);
|
|
|
|
/* Set maximum priority to preempt all other threads on this CPU. */
|
|
if (sched_setscheduler_nocheck(current, SCHED_FIFO, &sched_priority))
|
|
pr_warn("Failed to set suspend thread scheduler on CPU %d\n",
|
|
cpu);
|
|
|
|
dev = this_cpu_read(cpuidle_devices);
|
|
drv = cpuidle_get_cpu_driver(dev);
|
|
|
|
pr_info("CPU %d entering suspend cycles, states 1 through %d\n",
|
|
cpu, drv->state_count - 1);
|
|
|
|
setup_timer_on_stack(&wakeup_timer, dummy_callback, 0);
|
|
for (i = 0; i < NUM_SUSPEND_CYCLE; ++i) {
|
|
int index;
|
|
/*
|
|
* Test all possible states, except 0 (which is usually WFI and
|
|
* doesn't use PSCI).
|
|
*/
|
|
for (index = 1; index < drv->state_count; ++index) {
|
|
struct cpuidle_state *state = &drv->states[index];
|
|
bool broadcast = state->flags & CPUIDLE_FLAG_TIMER_STOP;
|
|
int ret;
|
|
|
|
/*
|
|
* Set the timer to wake this CPU up in some time (which
|
|
* should be largely sufficient for entering suspend).
|
|
* If the local tick is disabled when entering suspend,
|
|
* suspend_cpu() takes care of switching to a broadcast
|
|
* tick, so the timer will still wake us up.
|
|
*/
|
|
mod_timer(&wakeup_timer, jiffies +
|
|
usecs_to_jiffies(state->target_residency));
|
|
|
|
/* IRQs must be disabled during suspend operations. */
|
|
local_irq_disable();
|
|
|
|
ret = suspend_cpu(index, broadcast);
|
|
|
|
/*
|
|
* We have woken up. Re-enable IRQs to handle any
|
|
* pending interrupt, do not wait until the end of the
|
|
* loop.
|
|
*/
|
|
local_irq_enable();
|
|
|
|
if (ret == index) {
|
|
++nb_suspend;
|
|
} else if (ret >= 0) {
|
|
/* We did not enter the expected state. */
|
|
++nb_shallow_sleep;
|
|
} else {
|
|
pr_err("Failed to suspend CPU %d: error %d "
|
|
"(requested state %d, cycle %d)\n",
|
|
cpu, ret, index, i);
|
|
++nb_err;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Disable the timer to make sure that the timer will not trigger
|
|
* later.
|
|
*/
|
|
del_timer(&wakeup_timer);
|
|
|
|
if (atomic_dec_return_relaxed(&nb_active_threads) == 0)
|
|
complete(&suspend_threads_done);
|
|
|
|
/* Give up on RT scheduling and wait for termination. */
|
|
sched_priority.sched_priority = 0;
|
|
if (sched_setscheduler_nocheck(current, SCHED_NORMAL, &sched_priority))
|
|
pr_warn("Failed to set suspend thread scheduler on CPU %d\n",
|
|
cpu);
|
|
for (;;) {
|
|
/* Needs to be set first to avoid missing a wakeup. */
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
if (kthread_should_stop()) {
|
|
__set_current_state(TASK_RUNNING);
|
|
break;
|
|
}
|
|
schedule();
|
|
}
|
|
|
|
pr_info("CPU %d suspend test results: success %d, shallow states %d, errors %d\n",
|
|
cpu, nb_suspend, nb_shallow_sleep, nb_err);
|
|
|
|
return nb_err;
|
|
}
|
|
|
|
static int suspend_tests(void)
|
|
{
|
|
int i, cpu, err = 0;
|
|
struct task_struct **threads;
|
|
int nb_threads = 0;
|
|
|
|
threads = kmalloc_array(nb_available_cpus, sizeof(*threads),
|
|
GFP_KERNEL);
|
|
if (!threads)
|
|
return -ENOMEM;
|
|
|
|
/*
|
|
* Stop cpuidle to prevent the idle tasks from entering a deep sleep
|
|
* mode, as it might interfere with the suspend threads on other CPUs.
|
|
* This does not prevent the suspend threads from using cpuidle (only
|
|
* the idle tasks check this status). Take the idle lock so that
|
|
* the cpuidle driver and device look-up can be carried out safely.
|
|
*/
|
|
cpuidle_pause_and_lock();
|
|
|
|
for_each_online_cpu(cpu) {
|
|
struct task_struct *thread;
|
|
/* Check that cpuidle is available on that CPU. */
|
|
struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu);
|
|
struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
|
|
|
|
if (!dev || !drv) {
|
|
pr_warn("cpuidle not available on CPU %d, ignoring\n",
|
|
cpu);
|
|
continue;
|
|
}
|
|
|
|
thread = kthread_create_on_cpu(suspend_test_thread,
|
|
(void *)(long)cpu, cpu,
|
|
"psci_suspend_test");
|
|
if (IS_ERR(thread))
|
|
pr_err("Failed to create kthread on CPU %d\n", cpu);
|
|
else
|
|
threads[nb_threads++] = thread;
|
|
}
|
|
|
|
if (nb_threads < 1) {
|
|
err = -ENODEV;
|
|
goto out;
|
|
}
|
|
|
|
atomic_set(&nb_active_threads, nb_threads);
|
|
|
|
/*
|
|
* Wake up the suspend threads. To avoid the main thread being preempted
|
|
* before all the threads have been unparked, the suspend threads will
|
|
* wait for the completion of suspend_threads_started.
|
|
*/
|
|
for (i = 0; i < nb_threads; ++i)
|
|
wake_up_process(threads[i]);
|
|
complete_all(&suspend_threads_started);
|
|
|
|
wait_for_completion(&suspend_threads_done);
|
|
|
|
|
|
/* Stop and destroy all threads, get return status. */
|
|
for (i = 0; i < nb_threads; ++i)
|
|
err += kthread_stop(threads[i]);
|
|
out:
|
|
cpuidle_resume_and_unlock();
|
|
kfree(threads);
|
|
return err;
|
|
}
|
|
|
|
static int __init psci_checker(void)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* Since we're in an initcall, we assume that all the CPUs that all
|
|
* CPUs that can be onlined have been onlined.
|
|
*
|
|
* The tests assume that hotplug is enabled but nobody else is using it,
|
|
* otherwise the results will be unpredictable. However, since there
|
|
* is no userspace yet in initcalls, that should be fine, as long as
|
|
* no torture test is running at the same time (see Kconfig).
|
|
*/
|
|
nb_available_cpus = num_online_cpus();
|
|
|
|
/* Check PSCI operations are set up and working. */
|
|
ret = psci_ops_check();
|
|
if (ret)
|
|
return ret;
|
|
|
|
pr_info("PSCI checker started using %u CPUs\n", nb_available_cpus);
|
|
|
|
pr_info("Starting hotplug tests\n");
|
|
ret = hotplug_tests();
|
|
if (ret == 0)
|
|
pr_info("Hotplug tests passed OK\n");
|
|
else if (ret > 0)
|
|
pr_err("%d error(s) encountered in hotplug tests\n", ret);
|
|
else {
|
|
pr_err("Out of memory\n");
|
|
return ret;
|
|
}
|
|
|
|
pr_info("Starting suspend tests (%d cycles per state)\n",
|
|
NUM_SUSPEND_CYCLE);
|
|
ret = suspend_tests();
|
|
if (ret == 0)
|
|
pr_info("Suspend tests passed OK\n");
|
|
else if (ret > 0)
|
|
pr_err("%d error(s) encountered in suspend tests\n", ret);
|
|
else {
|
|
switch (ret) {
|
|
case -ENOMEM:
|
|
pr_err("Out of memory\n");
|
|
break;
|
|
case -ENODEV:
|
|
pr_warn("Could not start suspend tests on any CPU\n");
|
|
break;
|
|
}
|
|
}
|
|
|
|
pr_info("PSCI checker completed\n");
|
|
return ret < 0 ? ret : 0;
|
|
}
|
|
late_initcall(psci_checker);
|