// SPDX-License-Identifier: GPL-2.0 /* * PM domains for CPUs via genpd - managed by cpuidle-psci. * * Copyright (C) 2019 Linaro Ltd. * Author: Ulf Hansson <ulf.hansson@linaro.org> * */ #define pr_fmt(fmt) "CPUidle PSCI: " fmt #include <linux/cpu.h> #include <linux/device.h> #include <linux/kernel.h> #include <linux/pm_domain.h> #include <linux/pm_runtime.h> #include <linux/psci.h> #include <linux/slab.h> #include <linux/string.h> #include "cpuidle-psci.h" struct psci_pd_provider { struct list_head link; struct device_node *node; }; static LIST_HEAD(psci_pd_providers); static bool osi_mode_enabled __initdata; static int psci_pd_power_off(struct generic_pm_domain *pd) { struct genpd_power_state *state = &pd->states[pd->state_idx]; u32 *pd_state; if (!state->data) return 0; /* OSI mode is enabled, set the corresponding domain state. */ pd_state = state->data; psci_set_domain_state(*pd_state); return 0; } static int __init psci_pd_parse_state_nodes(struct genpd_power_state *states, int state_count) { int i, ret; u32 psci_state, *psci_state_buf; for (i = 0; i < state_count; i++) { ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode), &psci_state); if (ret) goto free_state; psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL); if (!psci_state_buf) { ret = -ENOMEM; goto free_state; } *psci_state_buf = psci_state; states[i].data = psci_state_buf; } return 0; free_state: i--; for (; i >= 0; i--) kfree(states[i].data); return ret; } static int __init psci_pd_parse_states(struct device_node *np, struct genpd_power_state **states, int *state_count) { int ret; /* Parse the domain idle states. */ ret = of_genpd_parse_idle_states(np, states, state_count); if (ret) return ret; /* Fill out the PSCI specifics for each found state. */ ret = psci_pd_parse_state_nodes(*states, *state_count); if (ret) kfree(*states); return ret; } static void psci_pd_free_states(struct genpd_power_state *states, unsigned int state_count) { int i; for (i = 0; i < state_count; i++) kfree(states[i].data); kfree(states); } static int __init psci_pd_init(struct device_node *np) { struct generic_pm_domain *pd; struct psci_pd_provider *pd_provider; struct dev_power_governor *pd_gov; struct genpd_power_state *states = NULL; int ret = -ENOMEM, state_count = 0; pd = kzalloc(sizeof(*pd), GFP_KERNEL); if (!pd) goto out; pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL); if (!pd_provider) goto free_pd; pd->name = kasprintf(GFP_KERNEL, "%pOF", np); if (!pd->name) goto free_pd_prov; /* * Parse the domain idle states and let genpd manage the state selection * for those being compatible with "domain-idle-state". */ ret = psci_pd_parse_states(np, &states, &state_count); if (ret) goto free_name; pd->free_states = psci_pd_free_states; pd->name = kbasename(pd->name); pd->power_off = psci_pd_power_off; pd->states = states; pd->state_count = state_count; pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN; /* Use governor for CPU PM domains if it has some states to manage. */ pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL; ret = pm_genpd_init(pd, pd_gov, false); if (ret) { psci_pd_free_states(states, state_count); goto free_name; } ret = of_genpd_add_provider_simple(np, pd); if (ret) goto remove_pd; pd_provider->node = of_node_get(np); list_add(&pd_provider->link, &psci_pd_providers); pr_debug("init PM domain %s\n", pd->name); return 0; remove_pd: pm_genpd_remove(pd); free_name: kfree(pd->name); free_pd_prov: kfree(pd_provider); free_pd: kfree(pd); out: pr_err("failed to init PM domain ret=%d %pOF\n", ret, np); return ret; } static void __init psci_pd_remove(void) { struct psci_pd_provider *pd_provider, *it; struct generic_pm_domain *genpd; list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) { of_genpd_del_provider(pd_provider->node); genpd = of_genpd_remove_last(pd_provider->node); if (!IS_ERR(genpd)) kfree(genpd); of_node_put(pd_provider->node); list_del(&pd_provider->link); kfree(pd_provider); } } static int __init psci_pd_init_topology(struct device_node *np, bool add) { struct device_node *node; struct of_phandle_args child, parent; int ret; for_each_child_of_node(np, node) { if (of_parse_phandle_with_args(node, "power-domains", "#power-domain-cells", 0, &parent)) continue; child.np = node; child.args_count = 0; ret = add ? of_genpd_add_subdomain(&parent, &child) : of_genpd_remove_subdomain(&parent, &child); of_node_put(parent.np); if (ret) { of_node_put(node); return ret; } } return 0; } static int __init psci_pd_add_topology(struct device_node *np) { return psci_pd_init_topology(np, true); } static void __init psci_pd_remove_topology(struct device_node *np) { psci_pd_init_topology(np, false); } static const struct of_device_id psci_of_match[] __initconst = { { .compatible = "arm,psci-1.0" }, {} }; static int __init psci_idle_init_domains(void) { struct device_node *np = of_find_matching_node(NULL, psci_of_match); struct device_node *node; int ret = 0, pd_count = 0; if (!np) return -ENODEV; /* Currently limit the hierarchical topology to be used in OSI mode. */ if (!psci_has_osi_support()) goto out; /* * Parse child nodes for the "#power-domain-cells" property and * initialize a genpd/genpd-of-provider pair when it's found. */ for_each_child_of_node(np, node) { if (!of_find_property(node, "#power-domain-cells", NULL)) continue; ret = psci_pd_init(node); if (ret) goto put_node; pd_count++; } /* Bail out if not using the hierarchical CPU topology. */ if (!pd_count) goto out; /* Link genpd masters/subdomains to model the CPU topology. */ ret = psci_pd_add_topology(np); if (ret) goto remove_pd; /* Try to enable OSI mode. */ ret = psci_set_osi_mode(); if (ret) { pr_warn("failed to enable OSI mode: %d\n", ret); psci_pd_remove_topology(np); goto remove_pd; } osi_mode_enabled = true; of_node_put(np); pr_info("Initialized CPU PM domain topology\n"); return pd_count; put_node: of_node_put(node); remove_pd: if (pd_count) psci_pd_remove(); pr_err("failed to create CPU PM domains ret=%d\n", ret); out: of_node_put(np); return ret; } subsys_initcall(psci_idle_init_domains); struct device __init *psci_dt_attach_cpu(int cpu) { struct device *dev; if (!osi_mode_enabled) return NULL; dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci"); if (IS_ERR_OR_NULL(dev)) return dev; pm_runtime_irq_safe(dev); if (cpu_online(cpu)) pm_runtime_get_sync(dev); return dev; }