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Diffstat (limited to 'drivers/firmware/psci_checker.c')
-rw-r--r--drivers/firmware/psci_checker.c505
1 files changed, 0 insertions, 505 deletions
diff --git a/drivers/firmware/psci_checker.c b/drivers/firmware/psci_checker.c
deleted file mode 100644
index 346943657962..000000000000
--- a/drivers/firmware/psci_checker.c
+++ /dev/null
@@ -1,505 +0,0 @@
-/*
- * 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;
-}
-
-/*
- * 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 void free_cpu_groups(int num, cpumask_var_t **pcpu_groups)
-{
- int i;
- cpumask_var_t *cpu_groups = *pcpu_groups;
-
- for (i = 0; i < num; ++i)
- free_cpumask_var(cpu_groups[i]);
- kfree(cpu_groups);
-}
-
-static int alloc_init_cpu_groups(cpumask_var_t **pcpu_groups)
-{
- int num_groups = 0;
- cpumask_var_t tmp, *cpu_groups;
-
- if (!alloc_cpumask_var(&tmp, GFP_KERNEL))
- return -ENOMEM;
-
- cpu_groups = kcalloc(nb_available_cpus, sizeof(cpu_groups),
- GFP_KERNEL);
- if (!cpu_groups)
- return -ENOMEM;
-
- cpumask_copy(tmp, cpu_online_mask);
-
- while (!cpumask_empty(tmp)) {
- const struct cpumask *cpu_group =
- topology_core_cpumask(cpumask_any(tmp));
-
- if (!alloc_cpumask_var(&cpu_groups[num_groups], GFP_KERNEL)) {
- free_cpu_groups(num_groups, &cpu_groups);
- return -ENOMEM;
- }
- cpumask_copy(cpu_groups[num_groups++], cpu_group);
- cpumask_andnot(tmp, tmp, cpu_group);
- }
-
- free_cpumask_var(tmp);
- *pcpu_groups = cpu_groups;
-
- return num_groups;
-}
-
-static int hotplug_tests(void)
-{
- int i, nb_cpu_group, err = -ENOMEM;
- cpumask_var_t offlined_cpus, *cpu_groups;
- char *page_buf;
-
- if (!alloc_cpumask_var(&offlined_cpus, GFP_KERNEL))
- return err;
-
- nb_cpu_group = alloc_init_cpu_groups(&cpu_groups);
- if (nb_cpu_group < 0)
- goto out_free_cpus;
- page_buf = (char *)__get_free_page(GFP_KERNEL);
- if (!page_buf)
- goto out_free_cpu_groups;
-
- err = 0;
- /*
- * 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 cpu group this time. When the last CPU is turned
- * off, the cpu group itself should shut down.
- */
- for (i = 0; i < nb_cpu_group; ++i) {
- ssize_t len = cpumap_print_to_pagebuf(true, page_buf,
- cpu_groups[i]);
- /* Remove trailing newline. */
- page_buf[len - 1] = '\0';
- pr_info("Trying to turn off and on again group %d (CPUs %s)\n",
- i, page_buf);
- err += down_and_up_cpus(cpu_groups[i], offlined_cpus);
- }
-
- free_page((unsigned long)page_buf);
-out_free_cpu_groups:
- free_cpu_groups(nb_cpu_group, &cpu_groups);
-out_free_cpus:
- free_cpumask_var(offlined_cpus);
- return err;
-}
-
-static void dummy_callback(struct timer_list *unused) {}
-
-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);
-
- timer_setup_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);
- destroy_timer_on_stack(&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);
generated by cgit (git 2.34.1) at 2025-08-09 11:35:57 +0000