From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/extcon/extcon-gpio.c | 165 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 165 insertions(+) create mode 100644 drivers/extcon/extcon-gpio.c (limited to 'drivers/extcon/extcon-gpio.c') diff --git a/drivers/extcon/extcon-gpio.c b/drivers/extcon/extcon-gpio.c new file mode 100644 index 000000000..4105df74f --- /dev/null +++ b/drivers/extcon/extcon-gpio.c @@ -0,0 +1,165 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * extcon_gpio.c - Single-state GPIO extcon driver based on extcon class + * + * Copyright (C) 2008 Google, Inc. + * Author: Mike Lockwood + * + * Modified by MyungJoo Ham to support extcon + * (originally switch class is supported) + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/** + * struct gpio_extcon_data - A simple GPIO-controlled extcon device state container. + * @edev: Extcon device. + * @work: Work fired by the interrupt. + * @debounce_jiffies: Number of jiffies to wait for the GPIO to stabilize, from the debounce + * value. + * @gpiod: GPIO descriptor for this external connector. + * @extcon_id: The unique id of specific external connector. + * @debounce: Debounce time for GPIO IRQ in ms. + * @check_on_resume: Boolean describing whether to check the state of gpio + * while resuming from sleep. + */ +struct gpio_extcon_data { + struct extcon_dev *edev; + struct delayed_work work; + unsigned long debounce_jiffies; + struct gpio_desc *gpiod; + unsigned int extcon_id; + unsigned long debounce; + bool check_on_resume; +}; + +static void gpio_extcon_work(struct work_struct *work) +{ + int state; + struct gpio_extcon_data *data = + container_of(to_delayed_work(work), struct gpio_extcon_data, + work); + + state = gpiod_get_value_cansleep(data->gpiod); + extcon_set_state_sync(data->edev, data->extcon_id, state); +} + +static irqreturn_t gpio_irq_handler(int irq, void *dev_id) +{ + struct gpio_extcon_data *data = dev_id; + + queue_delayed_work(system_power_efficient_wq, &data->work, + data->debounce_jiffies); + return IRQ_HANDLED; +} + +static int gpio_extcon_probe(struct platform_device *pdev) +{ + struct gpio_extcon_data *data; + struct device *dev = &pdev->dev; + unsigned long irq_flags; + int irq; + int ret; + + data = devm_kzalloc(dev, sizeof(struct gpio_extcon_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + /* + * FIXME: extcon_id represents the unique identifier of external + * connectors such as EXTCON_USB, EXTCON_DISP_HDMI and so on. extcon_id + * is necessary to register the extcon device. But, it's not yet + * developed to get the extcon id from device-tree or others. + * On later, it have to be solved. + */ + if (data->extcon_id > EXTCON_NONE) + return -EINVAL; + + data->gpiod = devm_gpiod_get(dev, "extcon", GPIOD_IN); + if (IS_ERR(data->gpiod)) + return PTR_ERR(data->gpiod); + irq = gpiod_to_irq(data->gpiod); + if (irq <= 0) + return irq; + + /* + * It is unlikely that this is an acknowledged interrupt that goes + * away after handling, what we are looking for are falling edges + * if the signal is active low, and rising edges if the signal is + * active high. + */ + if (gpiod_is_active_low(data->gpiod)) + irq_flags = IRQF_TRIGGER_FALLING; + else + irq_flags = IRQF_TRIGGER_RISING; + + /* Allocate the memory of extcon devie and register extcon device */ + data->edev = devm_extcon_dev_allocate(dev, &data->extcon_id); + if (IS_ERR(data->edev)) { + dev_err(dev, "failed to allocate extcon device\n"); + return -ENOMEM; + } + + ret = devm_extcon_dev_register(dev, data->edev); + if (ret < 0) + return ret; + + ret = devm_delayed_work_autocancel(dev, &data->work, gpio_extcon_work); + if (ret) + return ret; + + /* + * Request the interrupt of gpio to detect whether external connector + * is attached or detached. + */ + ret = devm_request_any_context_irq(dev, irq, + gpio_irq_handler, irq_flags, + pdev->name, data); + if (ret < 0) + return ret; + + platform_set_drvdata(pdev, data); + /* Perform initial detection */ + gpio_extcon_work(&data->work.work); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int gpio_extcon_resume(struct device *dev) +{ + struct gpio_extcon_data *data; + + data = dev_get_drvdata(dev); + if (data->check_on_resume) + queue_delayed_work(system_power_efficient_wq, + &data->work, data->debounce_jiffies); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume); + +static struct platform_driver gpio_extcon_driver = { + .probe = gpio_extcon_probe, + .driver = { + .name = "extcon-gpio", + .pm = &gpio_extcon_pm_ops, + }, +}; + +module_platform_driver(gpio_extcon_driver); + +MODULE_AUTHOR("Mike Lockwood "); +MODULE_DESCRIPTION("GPIO extcon driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1