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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/cpuidle/cpuidle-psci.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/cpuidle/cpuidle-psci.c')
-rw-r--r--drivers/cpuidle/cpuidle-psci.c455
1 files changed, 455 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
new file mode 100644
index 000000000..57bc3e3ae
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -0,0 +1,455 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PSCI CPU idle driver.
+ *
+ * Copyright (C) 2019 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ */
+
+#define pr_fmt(fmt) "CPUidle PSCI: " fmt
+
+#include <linux/cpuhotplug.h>
+#include <linux/cpu_cooling.h>
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/psci.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/syscore_ops.h>
+
+#include <asm/cpuidle.h>
+
+#include "cpuidle-psci.h"
+#include "dt_idle_states.h"
+
+struct psci_cpuidle_data {
+ u32 *psci_states;
+ struct device *dev;
+};
+
+static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data);
+static DEFINE_PER_CPU(u32, domain_state);
+static bool psci_cpuidle_use_cpuhp;
+
+void psci_set_domain_state(u32 state)
+{
+ __this_cpu_write(domain_state, state);
+}
+
+static inline u32 psci_get_domain_state(void)
+{
+ return __this_cpu_read(domain_state);
+}
+
+static inline int psci_enter_state(int idx, u32 state)
+{
+ return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state);
+}
+
+static int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int idx,
+ bool s2idle)
+{
+ struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data);
+ u32 *states = data->psci_states;
+ struct device *pd_dev = data->dev;
+ u32 state;
+ int ret;
+
+ ret = cpu_pm_enter();
+ if (ret)
+ return -1;
+
+ /* Do runtime PM to manage a hierarchical CPU toplogy. */
+ ct_irq_enter_irqson();
+ if (s2idle)
+ dev_pm_genpd_suspend(pd_dev);
+ else
+ pm_runtime_put_sync_suspend(pd_dev);
+ ct_irq_exit_irqson();
+
+ state = psci_get_domain_state();
+ if (!state)
+ state = states[idx];
+
+ ret = psci_cpu_suspend_enter(state) ? -1 : idx;
+
+ ct_irq_enter_irqson();
+ if (s2idle)
+ dev_pm_genpd_resume(pd_dev);
+ else
+ pm_runtime_get_sync(pd_dev);
+ ct_irq_exit_irqson();
+
+ cpu_pm_exit();
+
+ /* Clear the domain state to start fresh when back from idle. */
+ psci_set_domain_state(0);
+ return ret;
+}
+
+static int psci_enter_domain_idle_state(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int idx)
+{
+ return __psci_enter_domain_idle_state(dev, drv, idx, false);
+}
+
+static int psci_enter_s2idle_domain_idle_state(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int idx)
+{
+ return __psci_enter_domain_idle_state(dev, drv, idx, true);
+}
+
+static int psci_idle_cpuhp_up(unsigned int cpu)
+{
+ struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);
+
+ if (pd_dev)
+ pm_runtime_get_sync(pd_dev);
+
+ return 0;
+}
+
+static int psci_idle_cpuhp_down(unsigned int cpu)
+{
+ struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);
+
+ if (pd_dev) {
+ pm_runtime_put_sync(pd_dev);
+ /* Clear domain state to start fresh at next online. */
+ psci_set_domain_state(0);
+ }
+
+ return 0;
+}
+
+static void psci_idle_syscore_switch(bool suspend)
+{
+ bool cleared = false;
+ struct device *dev;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ dev = per_cpu_ptr(&psci_cpuidle_data, cpu)->dev;
+
+ if (dev && suspend) {
+ dev_pm_genpd_suspend(dev);
+ } else if (dev) {
+ dev_pm_genpd_resume(dev);
+
+ /* Account for userspace having offlined a CPU. */
+ if (pm_runtime_status_suspended(dev))
+ pm_runtime_set_active(dev);
+
+ /* Clear domain state to re-start fresh. */
+ if (!cleared) {
+ psci_set_domain_state(0);
+ cleared = true;
+ }
+ }
+ }
+}
+
+static int psci_idle_syscore_suspend(void)
+{
+ psci_idle_syscore_switch(true);
+ return 0;
+}
+
+static void psci_idle_syscore_resume(void)
+{
+ psci_idle_syscore_switch(false);
+}
+
+static struct syscore_ops psci_idle_syscore_ops = {
+ .suspend = psci_idle_syscore_suspend,
+ .resume = psci_idle_syscore_resume,
+};
+
+static void psci_idle_init_cpuhp(void)
+{
+ int err;
+
+ if (!psci_cpuidle_use_cpuhp)
+ return;
+
+ register_syscore_ops(&psci_idle_syscore_ops);
+
+ err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING,
+ "cpuidle/psci:online",
+ psci_idle_cpuhp_up,
+ psci_idle_cpuhp_down);
+ if (err)
+ pr_warn("Failed %d while setup cpuhp state\n", err);
+}
+
+static int psci_enter_idle_state(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int idx)
+{
+ u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states);
+
+ return psci_enter_state(idx, state[idx]);
+}
+
+static const struct of_device_id psci_idle_state_match[] = {
+ { .compatible = "arm,idle-state",
+ .data = psci_enter_idle_state },
+ { },
+};
+
+int psci_dt_parse_state_node(struct device_node *np, u32 *state)
+{
+ int err = of_property_read_u32(np, "arm,psci-suspend-param", state);
+
+ if (err) {
+ pr_warn("%pOF missing arm,psci-suspend-param property\n", np);
+ return err;
+ }
+
+ if (!psci_power_state_is_valid(*state)) {
+ pr_warn("Invalid PSCI power state %#x\n", *state);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
+ struct psci_cpuidle_data *data,
+ unsigned int state_count, int cpu)
+{
+ /* Currently limit the hierarchical topology to be used in OSI mode. */
+ if (!psci_has_osi_support())
+ return 0;
+
+ data->dev = psci_dt_attach_cpu(cpu);
+ if (IS_ERR_OR_NULL(data->dev))
+ return PTR_ERR_OR_ZERO(data->dev);
+
+ /*
+ * Using the deepest state for the CPU to trigger a potential selection
+ * of a shared state for the domain, assumes the domain states are all
+ * deeper states.
+ */
+ drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
+ drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
+ psci_cpuidle_use_cpuhp = true;
+
+ return 0;
+}
+
+static int psci_dt_cpu_init_idle(struct device *dev, struct cpuidle_driver *drv,
+ struct device_node *cpu_node,
+ unsigned int state_count, int cpu)
+{
+ int i, ret = 0;
+ u32 *psci_states;
+ struct device_node *state_node;
+ struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
+
+ state_count++; /* Add WFI state too */
+ psci_states = devm_kcalloc(dev, state_count, sizeof(*psci_states),
+ GFP_KERNEL);
+ if (!psci_states)
+ return -ENOMEM;
+
+ for (i = 1; i < state_count; i++) {
+ state_node = of_get_cpu_state_node(cpu_node, i - 1);
+ if (!state_node)
+ break;
+
+ ret = psci_dt_parse_state_node(state_node, &psci_states[i]);
+ of_node_put(state_node);
+
+ if (ret)
+ return ret;
+
+ pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);
+ }
+
+ if (i != state_count)
+ return -ENODEV;
+
+ /* Initialize optional data, used for the hierarchical topology. */
+ ret = psci_dt_cpu_init_topology(drv, data, state_count, cpu);
+ if (ret < 0)
+ return ret;
+
+ /* Idle states parsed correctly, store them in the per-cpu struct. */
+ data->psci_states = psci_states;
+ return 0;
+}
+
+static int psci_cpu_init_idle(struct device *dev, struct cpuidle_driver *drv,
+ unsigned int cpu, unsigned int state_count)
+{
+ struct device_node *cpu_node;
+ int ret;
+
+ /*
+ * If the PSCI cpu_suspend function hook has not been initialized
+ * idle states must not be enabled, so bail out
+ */
+ if (!psci_ops.cpu_suspend)
+ return -EOPNOTSUPP;
+
+ cpu_node = of_cpu_device_node_get(cpu);
+ if (!cpu_node)
+ return -ENODEV;
+
+ ret = psci_dt_cpu_init_idle(dev, drv, cpu_node, state_count, cpu);
+
+ of_node_put(cpu_node);
+
+ return ret;
+}
+
+static void psci_cpu_deinit_idle(int cpu)
+{
+ struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
+
+ psci_dt_detach_cpu(data->dev);
+ psci_cpuidle_use_cpuhp = false;
+}
+
+static int psci_idle_init_cpu(struct device *dev, int cpu)
+{
+ struct cpuidle_driver *drv;
+ struct device_node *cpu_node;
+ const char *enable_method;
+ int ret = 0;
+
+ cpu_node = of_cpu_device_node_get(cpu);
+ if (!cpu_node)
+ return -ENODEV;
+
+ /*
+ * Check whether the enable-method for the cpu is PSCI, fail
+ * if it is not.
+ */
+ enable_method = of_get_property(cpu_node, "enable-method", NULL);
+ if (!enable_method || (strcmp(enable_method, "psci")))
+ ret = -ENODEV;
+
+ of_node_put(cpu_node);
+ if (ret)
+ return ret;
+
+ drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
+ if (!drv)
+ return -ENOMEM;
+
+ drv->name = "psci_idle";
+ drv->owner = THIS_MODULE;
+ drv->cpumask = (struct cpumask *)cpumask_of(cpu);
+
+ /*
+ * PSCI idle states relies on architectural WFI to be represented as
+ * state index 0.
+ */
+ drv->states[0].enter = psci_enter_idle_state;
+ drv->states[0].exit_latency = 1;
+ drv->states[0].target_residency = 1;
+ drv->states[0].power_usage = UINT_MAX;
+ strcpy(drv->states[0].name, "WFI");
+ strcpy(drv->states[0].desc, "ARM WFI");
+
+ /*
+ * If no DT idle states are detected (ret == 0) let the driver
+ * initialization fail accordingly since there is no reason to
+ * initialize the idle driver if only wfi is supported, the
+ * default archictectural back-end already executes wfi
+ * on idle entry.
+ */
+ ret = dt_init_idle_driver(drv, psci_idle_state_match, 1);
+ if (ret <= 0)
+ return ret ? : -ENODEV;
+
+ /*
+ * Initialize PSCI idle states.
+ */
+ ret = psci_cpu_init_idle(dev, drv, cpu, ret);
+ if (ret) {
+ pr_err("CPU %d failed to PSCI idle\n", cpu);
+ return ret;
+ }
+
+ ret = cpuidle_register(drv, NULL);
+ if (ret)
+ goto deinit;
+
+ cpuidle_cooling_register(drv);
+
+ return 0;
+deinit:
+ psci_cpu_deinit_idle(cpu);
+ return ret;
+}
+
+/*
+ * psci_idle_probe - Initializes PSCI cpuidle driver
+ *
+ * Initializes PSCI cpuidle driver for all CPUs, if any CPU fails
+ * to register cpuidle driver then rollback to cancel all CPUs
+ * registration.
+ */
+static int psci_cpuidle_probe(struct platform_device *pdev)
+{
+ int cpu, ret;
+ struct cpuidle_driver *drv;
+ struct cpuidle_device *dev;
+
+ for_each_possible_cpu(cpu) {
+ ret = psci_idle_init_cpu(&pdev->dev, cpu);
+ if (ret)
+ goto out_fail;
+ }
+
+ psci_idle_init_cpuhp();
+ return 0;
+
+out_fail:
+ while (--cpu >= 0) {
+ dev = per_cpu(cpuidle_devices, cpu);
+ drv = cpuidle_get_cpu_driver(dev);
+ cpuidle_unregister(drv);
+ psci_cpu_deinit_idle(cpu);
+ }
+
+ return ret;
+}
+
+static struct platform_driver psci_cpuidle_driver = {
+ .probe = psci_cpuidle_probe,
+ .driver = {
+ .name = "psci-cpuidle",
+ },
+};
+
+static int __init psci_idle_init(void)
+{
+ struct platform_device *pdev;
+ int ret;
+
+ ret = platform_driver_register(&psci_cpuidle_driver);
+ if (ret)
+ return ret;
+
+ pdev = platform_device_register_simple("psci-cpuidle", -1, NULL, 0);
+ if (IS_ERR(pdev)) {
+ platform_driver_unregister(&psci_cpuidle_driver);
+ return PTR_ERR(pdev);
+ }
+
+ return 0;
+}
+device_initcall(psci_idle_init);