Re: [PATCH 4/6] ARM: psci: cpuidle: Introduce PSCI CPUidle driver
From: Ulf Hansson <hidden>
Date: 2019-07-23 11:47:36
Also in:
linux-pm, lkml
[...]
quoted hunk ↗ jump to hunk
+++ b/drivers/cpuidle/cpuidle-psci.c@@ -0,0 +1,150 @@ +// 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/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/psci.h> +#include <linux/slab.h> + +#include <asm/cpuidle.h>
This should go away, right?
+
+#include "dt_idle_states.h"
+
+static int psci_enter_idle_state(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int idx)
+{
+ return CPU_PM_CPU_IDLE_ENTER(psci_cpu_suspend_enter, idx);
+}
+
+static struct cpuidle_driver psci_idle_driver __initdata = {
+ .name = "psci_idle",
+ .owner = THIS_MODULE,
+ /*
+ * PSCI idle states relies on architectural WFI to
+ * be represented as state index 0.
+ */
+ .states[0] = {
+ .enter = psci_enter_idle_state,
+ .exit_latency = 1,
+ .target_residency = 1,
+ .power_usage = UINT_MAX,
+ .name = "WFI",
+ .desc = "ARM WFI",
+ }
+};
+
+static const struct of_device_id psci_idle_state_match[] __initconst = {
+ { .compatible = "arm,idle-state",
+ .data = psci_enter_idle_state },
+ { },
+};
+
+static int __init psci_idle_init_cpu(int cpu)
+{
+ struct cpuidle_driver *drv;
+ struct device_node *cpu_node;
+ const char *enable_method;
+ int ret = 0;
+
+ drv = kmemdup(&psci_idle_driver, sizeof(*drv), GFP_KERNEL);
+ if (!drv)
+ return -ENOMEM;
+
+ drv->cpumask = (struct cpumask *)cpumask_of(cpu);
+
+ cpu_node = of_get_cpu_node(cpu, NULL);
+ if (!cpu_node)
+ return -ENODEV;You should free drv in case of error here (goto out_kfree_drv; etc).
+ + /* + * 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;
You should free drv in case of error here (goto out_kfree_drv;).
+
+ /*
+ * Initialize idle states data, starting at index 1, since
+ * by default idle state 0 is the quiescent state reached
+ * by the cpu by executing the wfi instruction.
+ *
+ * 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) {
+ ret = ret ? : -ENODEV;
+ goto out_kfree_drv;
+ }
+
+ /*
+ * Initialize PSCI idle states.
+ */
+ ret = psci_cpu_init_idle(cpu);
+ if (ret) {
+ pr_err("CPU %d failed to PSCI idle\n", cpu);
+ goto out_kfree_drv;
+ }
+
+ ret = cpuidle_register(drv, NULL);
+ if (ret)
+ goto out_kfree_drv;
+
+ return 0;
+
+out_kfree_drv:
+ kfree(drv);
+ return ret;
+}
+[...] Kind regards Uffe _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel