From a9e3760b0838299649c0d57cca44daaf40ba3c33 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 14 Sep 2026 22:12:34 -1000 Subject: sched_ext: Maintain an online cid mask in the scheduler arena Schedulers on the default cid mapping treat [0, nr_online_cids) as the online set and restart on hotplug. Schedulers that install their own mapping with scx_bpf_cid_override() have no way to learn which cids are online: the count no longer identifies members and the CPU-form cpumask is unusable from cid programs. This is an obvious hole in the cid API. Add scx_bpf_online_cmask(), a kernel-maintained cmask in the scheduler's arena, allocated alongside the per-CPU scratch masks and populated after the cid mapping is finalized and before ops.init(), for child schedulers too. The pointer stays valid through ops.exit() with no reference to take. It is the arena offset as a void pointer, the same form struct_ops arena arguments arrive in. The verifier types the void return as a scalar for the program's arena cast. The mask follows the SCX hotplug notifications: seeded from cpu_active_mask and updated before ops.cid_online/offline() runs, so it lags cpu_online_mask only inside a hotplug transition. Updates walk the scheduler list under the lock that also serializes unlinking. Reads are live, not atomic snapshots. Root initialization excludes hotplug. v2: Reworded the getter kerneldoc (Andrea Righi). Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi --- drivers/regulator/virtual.c | 373 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 373 insertions(+) create mode 100644 drivers/regulator/virtual.c (limited to 'drivers/regulator/virtual.c') diff --git a/drivers/regulator/virtual.c b/drivers/regulator/virtual.c new file mode 100644 index 000000000..218a0d66a --- /dev/null +++ b/drivers/regulator/virtual.c @@ -0,0 +1,373 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * reg-virtual-consumer.c + * + * Copyright 2008 Wolfson Microelectronics PLC. + * + * Author: Mark Brown + */ + +#include +#include +#include +#include +#include +#include +#include + +struct virtual_consumer_data { + struct mutex lock; + struct regulator *regulator; + bool enabled; + int min_uV; + int max_uV; + int min_uA; + int max_uA; + unsigned int mode; +}; + +static void update_voltage_constraints(struct device *dev, + struct virtual_consumer_data *data) +{ + int ret; + + if (data->min_uV && data->max_uV + && data->min_uV <= data->max_uV) { + dev_dbg(dev, "Requesting %d-%duV\n", + data->min_uV, data->max_uV); + ret = regulator_set_voltage(data->regulator, + data->min_uV, data->max_uV); + if (ret != 0) { + dev_err(dev, + "regulator_set_voltage() failed: %d\n", ret); + return; + } + } + + if (data->min_uV && data->max_uV && !data->enabled) { + dev_dbg(dev, "Enabling regulator\n"); + ret = regulator_enable(data->regulator); + if (ret == 0) + data->enabled = true; + else + dev_err(dev, "regulator_enable() failed: %d\n", + ret); + } + + if (!(data->min_uV && data->max_uV) && data->enabled) { + dev_dbg(dev, "Disabling regulator\n"); + ret = regulator_disable(data->regulator); + if (ret == 0) + data->enabled = false; + else + dev_err(dev, "regulator_disable() failed: %d\n", + ret); + } +} + +static void update_current_limit_constraints(struct device *dev, + struct virtual_consumer_data *data) +{ + int ret; + + if (data->max_uA + && data->min_uA <= data->max_uA) { + dev_dbg(dev, "Requesting %d-%duA\n", + data->min_uA, data->max_uA); + ret = regulator_set_current_limit(data->regulator, + data->min_uA, data->max_uA); + if (ret != 0) { + dev_err(dev, + "regulator_set_current_limit() failed: %d\n", + ret); + return; + } + } + + if (data->max_uA && !data->enabled) { + dev_dbg(dev, "Enabling regulator\n"); + ret = regulator_enable(data->regulator); + if (ret == 0) + data->enabled = true; + else + dev_err(dev, "regulator_enable() failed: %d\n", + ret); + } + + if (!(data->min_uA && data->max_uA) && data->enabled) { + dev_dbg(dev, "Disabling regulator\n"); + ret = regulator_disable(data->regulator); + if (ret == 0) + data->enabled = false; + else + dev_err(dev, "regulator_disable() failed: %d\n", + ret); + } +} + +static ssize_t show_min_uV(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct virtual_consumer_data *data = dev_get_drvdata(dev); + return sprintf(buf, "%d\n", data->min_uV); +} + +static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct virtual_consumer_data *data = dev_get_drvdata(dev); + long val; + + if (kstrtol(buf, 10, &val) != 0) + return count; + + mutex_lock(&data->lock); + + data->min_uV = val; + update_voltage_constraints(dev, data); + + mutex_unlock(&data->lock); + + return count; +} + +static ssize_t show_max_uV(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct virtual_consumer_data *data = dev_get_drvdata(dev); + return sprintf(buf, "%d\n", data->max_uV); +} + +static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct virtual_consumer_data *data = dev_get_drvdata(dev); + long val; + + if (kstrtol(buf, 10, &val) != 0) + return count; + + mutex_lock(&data->lock); + + data->max_uV = val; + update_voltage_constraints(dev, data); + + mutex_unlock(&data->lock); + + return count; +} + +static ssize_t show_min_uA(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct virtual_consumer_data *data = dev_get_drvdata(dev); + return sprintf(buf, "%d\n", data->min_uA); +} + +static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct virtual_consumer_data *data = dev_get_drvdata(dev); + long val; + + if (kstrtol(buf, 10, &val) != 0) + return count; + + mutex_lock(&data->lock); + + data->min_uA = val; + update_current_limit_constraints(dev, data); + + mutex_unlock(&data->lock); + + return count; +} + +static ssize_t show_max_uA(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct virtual_consumer_data *data = dev_get_drvdata(dev); + return sprintf(buf, "%d\n", data->max_uA); +} + +static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct virtual_consumer_data *data = dev_get_drvdata(dev); + long val; + + if (kstrtol(buf, 10, &val) != 0) + return count; + + mutex_lock(&data->lock); + + data->max_uA = val; + update_current_limit_constraints(dev, data); + + mutex_unlock(&data->lock); + + return count; +} + +static ssize_t show_mode(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct virtual_consumer_data *data = dev_get_drvdata(dev); + + switch (data->mode) { + case REGULATOR_MODE_FAST: + return sprintf(buf, "fast\n"); + case REGULATOR_MODE_NORMAL: + return sprintf(buf, "normal\n"); + case REGULATOR_MODE_IDLE: + return sprintf(buf, "idle\n"); + case REGULATOR_MODE_STANDBY: + return sprintf(buf, "standby\n"); + default: + return sprintf(buf, "unknown\n"); + } +} + +static ssize_t set_mode(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct virtual_consumer_data *data = dev_get_drvdata(dev); + unsigned int mode; + int ret; + + /* + * sysfs_streq() doesn't need the \n's, but we add them so the strings + * will be shared with show_mode(), above. + */ + if (sysfs_streq(buf, "fast\n")) + mode = REGULATOR_MODE_FAST; + else if (sysfs_streq(buf, "normal\n")) + mode = REGULATOR_MODE_NORMAL; + else if (sysfs_streq(buf, "idle\n")) + mode = REGULATOR_MODE_IDLE; + else if (sysfs_streq(buf, "standby\n")) + mode = REGULATOR_MODE_STANDBY; + else { + dev_err(dev, "Configuring invalid mode\n"); + return count; + } + + mutex_lock(&data->lock); + ret = regulator_set_mode(data->regulator, mode); + if (ret == 0) + data->mode = mode; + else + dev_err(dev, "Failed to configure mode: %d\n", ret); + mutex_unlock(&data->lock); + + return count; +} + +static DEVICE_ATTR(min_microvolts, 0664, show_min_uV, set_min_uV); +static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV); +static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA); +static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA); +static DEVICE_ATTR(mode, 0664, show_mode, set_mode); + +static struct attribute *regulator_virtual_attributes[] = { + &dev_attr_min_microvolts.attr, + &dev_attr_max_microvolts.attr, + &dev_attr_min_microamps.attr, + &dev_attr_max_microamps.attr, + &dev_attr_mode.attr, + NULL +}; + +static const struct attribute_group regulator_virtual_attr_group = { + .attrs = regulator_virtual_attributes, +}; + +#ifdef CONFIG_OF +static const struct of_device_id regulator_virtual_consumer_of_match[] = { + { .compatible = "regulator-virtual-consumer" }, + {}, +}; +MODULE_DEVICE_TABLE(of, regulator_virtual_consumer_of_match); +#endif + +static int regulator_virtual_probe(struct platform_device *pdev) +{ + char *reg_id = dev_get_platdata(&pdev->dev); + struct virtual_consumer_data *drvdata; + static bool warned; + int ret; + + if (!warned) { + warned = true; + pr_warn("**********************************************************\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("** **\n"); + pr_warn("** regulator-virtual-consumer is only for testing and **\n"); + pr_warn("** debugging. Do not use it in a production kernel. **\n"); + pr_warn("** **\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("**********************************************************\n"); + } + + drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data), + GFP_KERNEL); + if (drvdata == NULL) + return -ENOMEM; + + /* + * This virtual consumer does not have any hardware-defined supply + * name, so just allow the regulator to be specified in a property + * named "default-supply" when we're being probed from devicetree. + */ + if (!reg_id && pdev->dev.of_node) + reg_id = "default"; + + mutex_init(&drvdata->lock); + + drvdata->regulator = devm_regulator_get(&pdev->dev, reg_id); + if (IS_ERR(drvdata->regulator)) + return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->regulator), + "Failed to obtain supply '%s'\n", + reg_id); + + ret = sysfs_create_group(&pdev->dev.kobj, + ®ulator_virtual_attr_group); + if (ret != 0) { + dev_err(&pdev->dev, + "Failed to create attribute group: %d\n", ret); + return ret; + } + + drvdata->mode = regulator_get_mode(drvdata->regulator); + + platform_set_drvdata(pdev, drvdata); + + return 0; +} + +static void regulator_virtual_remove(struct platform_device *pdev) +{ + struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev); + + sysfs_remove_group(&pdev->dev.kobj, ®ulator_virtual_attr_group); + + if (drvdata->enabled) + regulator_disable(drvdata->regulator); +} + +static struct platform_driver regulator_virtual_consumer_driver = { + .probe = regulator_virtual_probe, + .remove = regulator_virtual_remove, + .driver = { + .name = "reg-virt-consumer", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + .of_match_table = of_match_ptr(regulator_virtual_consumer_of_match), + }, +}; + +module_platform_driver(regulator_virtual_consumer_driver); + +MODULE_AUTHOR("Mark Brown "); +MODULE_DESCRIPTION("Virtual regulator consumer"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:reg-virt-consumer"); -- cgit v1.3.1