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/input/input-leds.c | 226 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 226 insertions(+) create mode 100644 drivers/input/input-leds.c (limited to 'drivers/input/input-leds.c') diff --git a/drivers/input/input-leds.c b/drivers/input/input-leds.c new file mode 100644 index 000000000..b08d1d08d --- /dev/null +++ b/drivers/input/input-leds.c @@ -0,0 +1,226 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * LED support for the input layer + * + * Copyright 2010-2015 Samuel Thibault + */ + +#include +#include +#include +#include +#include +#include + +#if IS_ENABLED(CONFIG_VT) +#define VT_TRIGGER(_name) .trigger = _name +#else +#define VT_TRIGGER(_name) .trigger = NULL +#endif + +#if IS_ENABLED(CONFIG_SND_CTL_LED) +#define AUDIO_TRIGGER(_name) .trigger = _name +#else +#define AUDIO_TRIGGER(_name) .trigger = NULL +#endif + +static const struct { + const char *name; + const char *trigger; +} input_led_info[LED_CNT] = { + [LED_NUML] = { "numlock", VT_TRIGGER("kbd-numlock") }, + [LED_CAPSL] = { "capslock", VT_TRIGGER("kbd-capslock") }, + [LED_SCROLLL] = { "scrolllock", VT_TRIGGER("kbd-scrolllock") }, + [LED_COMPOSE] = { "compose" }, + [LED_KANA] = { "kana", VT_TRIGGER("kbd-kanalock") }, + [LED_SLEEP] = { "sleep" } , + [LED_SUSPEND] = { "suspend" }, + [LED_MUTE] = { "mute", AUDIO_TRIGGER("audio-mute") }, + [LED_MISC] = { "misc" }, + [LED_MAIL] = { "mail" }, + [LED_CHARGING] = { "charging" }, +}; + +struct input_led { + struct led_classdev cdev; + struct input_handle *handle; + unsigned int code; /* One of LED_* constants */ +}; + +struct input_leds { + struct input_handle handle; + unsigned int num_leds; + struct input_led leds[] __counted_by(num_leds); +}; + +static enum led_brightness input_leds_brightness_get(struct led_classdev *cdev) +{ + struct input_led *led = container_of(cdev, struct input_led, cdev); + struct input_dev *input = led->handle->dev; + + return test_bit(led->code, input->led) ? cdev->max_brightness : 0; +} + +static void input_leds_brightness_set(struct led_classdev *cdev, + enum led_brightness brightness) +{ + struct input_led *led = container_of(cdev, struct input_led, cdev); + + input_inject_event(led->handle, EV_LED, led->code, !!brightness); +} + +static void input_leds_event(struct input_handle *handle, unsigned int type, + unsigned int code, int value) +{ +} + +static int input_leds_get_count(struct input_dev *dev) +{ + unsigned int led_code; + int count = 0; + + for_each_set_bit(led_code, dev->ledbit, LED_CNT) + if (input_led_info[led_code].name) + count++; + + return count; +} + +static int input_leds_connect(struct input_handler *handler, + struct input_dev *dev, + const struct input_device_id *id) +{ + struct input_leds *leds; + struct input_led *led; + unsigned int num_leds; + unsigned int led_code; + int led_no; + int error; + + num_leds = input_leds_get_count(dev); + if (!num_leds) + return -ENXIO; + + leds = kzalloc_flex(*leds, leds, num_leds); + if (!leds) + return -ENOMEM; + + leds->num_leds = num_leds; + + leds->handle.dev = dev; + leds->handle.handler = handler; + leds->handle.name = "leds"; + leds->handle.private = leds; + + error = input_register_handle(&leds->handle); + if (error) + goto err_free_mem; + + error = input_open_device(&leds->handle); + if (error) + goto err_unregister_handle; + + led_no = 0; + for_each_set_bit(led_code, dev->ledbit, LED_CNT) { + if (!input_led_info[led_code].name) + continue; + + led = &leds->leds[led_no]; + led->handle = &leds->handle; + led->code = led_code; + + led->cdev.name = kasprintf(GFP_KERNEL, "%s::%s", + dev_name(&dev->dev), + input_led_info[led_code].name); + if (!led->cdev.name) { + error = -ENOMEM; + goto err_unregister_leds; + } + + led->cdev.max_brightness = 1; + led->cdev.brightness_get = input_leds_brightness_get; + led->cdev.brightness_set = input_leds_brightness_set; + led->cdev.default_trigger = input_led_info[led_code].trigger; + + error = led_classdev_register(&dev->dev, &led->cdev); + if (error) { + dev_err(&dev->dev, "failed to register LED %s: %d\n", + led->cdev.name, error); + kfree(led->cdev.name); + goto err_unregister_leds; + } + + led_no++; + } + + return 0; + +err_unregister_leds: + while (--led_no >= 0) { + struct input_led *led = &leds->leds[led_no]; + + led_classdev_unregister(&led->cdev); + kfree(led->cdev.name); + } + + input_close_device(&leds->handle); + +err_unregister_handle: + input_unregister_handle(&leds->handle); + +err_free_mem: + kfree(leds); + return error; +} + +static void input_leds_disconnect(struct input_handle *handle) +{ + struct input_leds *leds = handle->private; + int i; + + for (i = 0; i < leds->num_leds; i++) { + struct input_led *led = &leds->leds[i]; + + led_classdev_unregister(&led->cdev); + kfree(led->cdev.name); + } + + input_close_device(handle); + input_unregister_handle(handle); + + kfree(leds); +} + +static const struct input_device_id input_leds_ids[] = { + { + .flags = INPUT_DEVICE_ID_MATCH_EVBIT, + .evbit = { BIT_MASK(EV_LED) }, + }, + { }, +}; +MODULE_DEVICE_TABLE(input, input_leds_ids); + +static struct input_handler input_leds_handler = { + .event = input_leds_event, + .connect = input_leds_connect, + .disconnect = input_leds_disconnect, + .name = "leds", + .id_table = input_leds_ids, +}; + +static int __init input_leds_init(void) +{ + return input_register_handler(&input_leds_handler); +} +module_init(input_leds_init); + +static void __exit input_leds_exit(void) +{ + input_unregister_handler(&input_leds_handler); +} +module_exit(input_leds_exit); + +MODULE_AUTHOR("Samuel Thibault "); +MODULE_AUTHOR("Dmitry Torokhov "); +MODULE_DESCRIPTION("Input -> LEDs Bridge"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1