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![Ulf Hansson](/assets/img/avatar_default.png)
Depending on the SoC/platform, additional devices may be part of the PSCI PM domain topology. This is the case with 'qcom,rpmh-rsc' device, for example, even if this is not yet visible in the corresponding DTS-files. Without going into too much details, a device like the 'qcom,rpmh-rsc' may have HW constraints that needs to be obeyed to, before a domain idlestate can be picked. Therefore, let's implement the ->sync_state() callback to receive a notification when all consumers of the PSCI PM domain providers have been attached/probed to it. In this way, we can make sure all constraints from all relevant devices, are taken into account before allowing a domain idlestate to be picked. Acked-by: Saravana Kannan <saravanak@google.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
336 lines
7.1 KiB
C
336 lines
7.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* PM domains for CPUs via genpd - managed by cpuidle-psci.
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*
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* Copyright (C) 2019 Linaro Ltd.
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* Author: Ulf Hansson <ulf.hansson@linaro.org>
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*
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*/
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#define pr_fmt(fmt) "CPUidle PSCI: " fmt
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#include <linux/cpu.h>
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/platform_device.h>
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#include <linux/pm_domain.h>
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#include <linux/pm_runtime.h>
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#include <linux/psci.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include "cpuidle-psci.h"
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struct psci_pd_provider {
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struct list_head link;
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struct device_node *node;
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};
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static LIST_HEAD(psci_pd_providers);
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static bool psci_pd_allow_domain_state;
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static int psci_pd_power_off(struct generic_pm_domain *pd)
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{
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struct genpd_power_state *state = &pd->states[pd->state_idx];
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u32 *pd_state;
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if (!state->data)
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return 0;
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if (!psci_pd_allow_domain_state)
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return -EBUSY;
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/* OSI mode is enabled, set the corresponding domain state. */
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pd_state = state->data;
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psci_set_domain_state(*pd_state);
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return 0;
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}
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static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
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int state_count)
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{
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int i, ret;
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u32 psci_state, *psci_state_buf;
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for (i = 0; i < state_count; i++) {
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ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode),
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&psci_state);
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if (ret)
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goto free_state;
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psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
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if (!psci_state_buf) {
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ret = -ENOMEM;
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goto free_state;
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}
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*psci_state_buf = psci_state;
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states[i].data = psci_state_buf;
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}
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return 0;
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free_state:
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i--;
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for (; i >= 0; i--)
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kfree(states[i].data);
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return ret;
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}
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static int psci_pd_parse_states(struct device_node *np,
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struct genpd_power_state **states, int *state_count)
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{
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int ret;
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/* Parse the domain idle states. */
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ret = of_genpd_parse_idle_states(np, states, state_count);
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if (ret)
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return ret;
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/* Fill out the PSCI specifics for each found state. */
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ret = psci_pd_parse_state_nodes(*states, *state_count);
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if (ret)
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kfree(*states);
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return ret;
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}
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static void psci_pd_free_states(struct genpd_power_state *states,
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unsigned int state_count)
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{
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int i;
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for (i = 0; i < state_count; i++)
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kfree(states[i].data);
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kfree(states);
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}
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static int psci_pd_init(struct device_node *np)
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{
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struct generic_pm_domain *pd;
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struct psci_pd_provider *pd_provider;
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struct dev_power_governor *pd_gov;
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struct genpd_power_state *states = NULL;
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int ret = -ENOMEM, state_count = 0;
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pd = kzalloc(sizeof(*pd), GFP_KERNEL);
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if (!pd)
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goto out;
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pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL);
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if (!pd_provider)
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goto free_pd;
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pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
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if (!pd->name)
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goto free_pd_prov;
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/*
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* Parse the domain idle states and let genpd manage the state selection
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* for those being compatible with "domain-idle-state".
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*/
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ret = psci_pd_parse_states(np, &states, &state_count);
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if (ret)
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goto free_name;
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pd->free_states = psci_pd_free_states;
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pd->name = kbasename(pd->name);
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pd->power_off = psci_pd_power_off;
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pd->states = states;
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pd->state_count = state_count;
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pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
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/* Use governor for CPU PM domains if it has some states to manage. */
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pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL;
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ret = pm_genpd_init(pd, pd_gov, false);
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if (ret) {
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psci_pd_free_states(states, state_count);
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goto free_name;
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}
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ret = of_genpd_add_provider_simple(np, pd);
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if (ret)
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goto remove_pd;
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pd_provider->node = of_node_get(np);
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list_add(&pd_provider->link, &psci_pd_providers);
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pr_debug("init PM domain %s\n", pd->name);
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return 0;
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remove_pd:
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pm_genpd_remove(pd);
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free_name:
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kfree(pd->name);
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free_pd_prov:
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kfree(pd_provider);
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free_pd:
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kfree(pd);
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out:
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pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
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return ret;
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}
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static void psci_pd_remove(void)
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{
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struct psci_pd_provider *pd_provider, *it;
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struct generic_pm_domain *genpd;
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list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
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of_genpd_del_provider(pd_provider->node);
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genpd = of_genpd_remove_last(pd_provider->node);
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if (!IS_ERR(genpd))
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kfree(genpd);
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of_node_put(pd_provider->node);
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list_del(&pd_provider->link);
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kfree(pd_provider);
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}
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}
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static int psci_pd_init_topology(struct device_node *np, bool add)
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{
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struct device_node *node;
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struct of_phandle_args child, parent;
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int ret;
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for_each_child_of_node(np, node) {
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if (of_parse_phandle_with_args(node, "power-domains",
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"#power-domain-cells", 0, &parent))
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continue;
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child.np = node;
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child.args_count = 0;
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ret = add ? of_genpd_add_subdomain(&parent, &child) :
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of_genpd_remove_subdomain(&parent, &child);
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of_node_put(parent.np);
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if (ret) {
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of_node_put(node);
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return ret;
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}
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}
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return 0;
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}
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static int psci_pd_add_topology(struct device_node *np)
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{
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return psci_pd_init_topology(np, true);
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}
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static void psci_pd_remove_topology(struct device_node *np)
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{
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psci_pd_init_topology(np, false);
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}
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static void psci_cpuidle_domain_sync_state(struct device *dev)
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{
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/*
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* All devices have now been attached/probed to the PM domain topology,
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* hence it's fine to allow domain states to be picked.
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*/
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psci_pd_allow_domain_state = true;
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}
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static const struct of_device_id psci_of_match[] = {
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{ .compatible = "arm,psci-1.0" },
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{}
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};
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static int psci_cpuidle_domain_probe(struct platform_device *pdev)
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{
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struct device_node *np = pdev->dev.of_node;
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struct device_node *node;
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int ret = 0, pd_count = 0;
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if (!np)
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return -ENODEV;
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/* Currently limit the hierarchical topology to be used in OSI mode. */
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if (!psci_has_osi_support())
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return 0;
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/*
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* Parse child nodes for the "#power-domain-cells" property and
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* initialize a genpd/genpd-of-provider pair when it's found.
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*/
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for_each_child_of_node(np, node) {
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if (!of_find_property(node, "#power-domain-cells", NULL))
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continue;
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ret = psci_pd_init(node);
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if (ret)
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goto put_node;
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pd_count++;
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}
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/* Bail out if not using the hierarchical CPU topology. */
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if (!pd_count)
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return 0;
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/* Link genpd masters/subdomains to model the CPU topology. */
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ret = psci_pd_add_topology(np);
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if (ret)
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goto remove_pd;
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/* Try to enable OSI mode. */
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ret = psci_set_osi_mode();
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if (ret) {
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pr_warn("failed to enable OSI mode: %d\n", ret);
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psci_pd_remove_topology(np);
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goto remove_pd;
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}
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pr_info("Initialized CPU PM domain topology\n");
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return 0;
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put_node:
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of_node_put(node);
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remove_pd:
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if (pd_count)
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psci_pd_remove();
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pr_err("failed to create CPU PM domains ret=%d\n", ret);
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return ret;
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}
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static struct platform_driver psci_cpuidle_domain_driver = {
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.probe = psci_cpuidle_domain_probe,
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.driver = {
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.name = "psci-cpuidle-domain",
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.of_match_table = psci_of_match,
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.sync_state = psci_cpuidle_domain_sync_state,
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},
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};
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static int __init psci_idle_init_domains(void)
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{
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return platform_driver_register(&psci_cpuidle_domain_driver);
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}
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subsys_initcall(psci_idle_init_domains);
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struct device *psci_dt_attach_cpu(int cpu)
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{
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struct device *dev;
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dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
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if (IS_ERR_OR_NULL(dev))
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return dev;
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pm_runtime_irq_safe(dev);
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if (cpu_online(cpu))
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pm_runtime_get_sync(dev);
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return dev;
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}
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void psci_dt_detach_cpu(struct device *dev)
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{
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if (IS_ERR_OR_NULL(dev))
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return;
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dev_pm_domain_detach(dev, false);
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}
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