1 files changed, 308 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
new file mode 100644
index 000000000000..423f03bbeb74
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-psci-domain.c
@@ -0,0 +1,308 @@
+// 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;
+}