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/input/misc/ariel-pwrbutton.c | 169 +++++++++++++++++++++++++++++++++++ 1 file changed, 169 insertions(+) create mode 100644 drivers/input/misc/ariel-pwrbutton.c (limited to 'drivers/input/misc/ariel-pwrbutton.c') diff --git a/drivers/input/misc/ariel-pwrbutton.c b/drivers/input/misc/ariel-pwrbutton.c new file mode 100644 index 000000000..f0e06ee60 --- /dev/null +++ b/drivers/input/misc/ariel-pwrbutton.c @@ -0,0 +1,169 @@ +// SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0-or-later +/* + * Dell Wyse 3020 a.k.a. "Ariel" Power Button Driver + * + * Copyright (C) 2020 Lubomir Rintel + */ + +#include +#include +#include +#include +#include +#include + +#define RESP_COUNTER(response) (response.header & 0x3) +#define RESP_SIZE(response) ((response.header >> 2) & 0x3) +#define RESP_TYPE(response) ((response.header >> 4) & 0xf) + +struct ec_input_response { + u8 reserved; + u8 header; + u8 data[3]; +} __packed; + +struct ariel_pwrbutton { + struct spi_device *client; + struct input_dev *input; + u8 msg_counter; +}; + +static int ec_input_read(struct ariel_pwrbutton *priv, + struct ec_input_response *response) +{ + u8 read_request[] = { 0x00, 0x5a, 0xa5, 0x00, 0x00 }; + struct spi_device *spi = priv->client; + struct spi_transfer t = { + .tx_buf = read_request, + .rx_buf = response, + .len = sizeof(read_request), + }; + + compiletime_assert(sizeof(read_request) == sizeof(*response), + "SPI xfer request/response size mismatch"); + + return spi_sync_transfer(spi, &t, 1); +} + +static irqreturn_t ec_input_interrupt(int irq, void *dev_id) +{ + struct ariel_pwrbutton *priv = dev_id; + struct spi_device *spi = priv->client; + struct ec_input_response response; + int error; + int i; + + error = ec_input_read(priv, &response); + if (error < 0) { + dev_err(&spi->dev, "EC read failed: %d\n", error); + goto out; + } + + if (priv->msg_counter == RESP_COUNTER(response)) { + dev_warn(&spi->dev, "No new data to read?\n"); + goto out; + } + + priv->msg_counter = RESP_COUNTER(response); + + if (RESP_TYPE(response) != 0x3 && RESP_TYPE(response) != 0xc) { + dev_dbg(&spi->dev, "Ignoring message that's not kbd data\n"); + goto out; + } + + for (i = 0; i < RESP_SIZE(response); i++) { + switch (response.data[i]) { + case 0x74: + input_report_key(priv->input, KEY_POWER, 1); + input_sync(priv->input); + break; + case 0xf4: + input_report_key(priv->input, KEY_POWER, 0); + input_sync(priv->input); + break; + default: + dev_dbg(&spi->dev, "Unknown scan code: %02x\n", + response.data[i]); + } + } + +out: + return IRQ_HANDLED; +} + +static int ariel_pwrbutton_probe(struct spi_device *spi) +{ + struct ec_input_response response; + struct ariel_pwrbutton *priv; + int error; + + if (!spi->irq) { + dev_err(&spi->dev, "Missing IRQ.\n"); + return -EINVAL; + } + + priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->client = spi; + spi_set_drvdata(spi, priv); + + priv->input = devm_input_allocate_device(&spi->dev); + if (!priv->input) + return -ENOMEM; + priv->input->name = "Power Button"; + priv->input->dev.parent = &spi->dev; + input_set_capability(priv->input, EV_KEY, KEY_POWER); + error = input_register_device(priv->input); + if (error) { + dev_err(&spi->dev, "error registering input device: %d\n", error); + return error; + } + + error = ec_input_read(priv, &response); + if (error < 0) { + dev_err(&spi->dev, "EC read failed: %d\n", error); + return error; + } + priv->msg_counter = RESP_COUNTER(response); + + error = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, + ec_input_interrupt, + IRQF_ONESHOT, + "Ariel EC Input", priv); + + if (error) { + dev_err(&spi->dev, "Failed to request IRQ %d: %d\n", + spi->irq, error); + return error; + } + + return 0; +} + +static const struct of_device_id ariel_pwrbutton_of_match[] = { + { .compatible = "dell,wyse-ariel-ec-input" }, + { } +}; +MODULE_DEVICE_TABLE(of, ariel_pwrbutton_of_match); + +static const struct spi_device_id ariel_pwrbutton_spi_ids[] = { + { .name = "wyse-ariel-ec-input" }, + { } +}; +MODULE_DEVICE_TABLE(spi, ariel_pwrbutton_spi_ids); + +static struct spi_driver ariel_pwrbutton_driver = { + .driver = { + .name = "dell-wyse-ariel-ec-input", + .of_match_table = ariel_pwrbutton_of_match, + }, + .probe = ariel_pwrbutton_probe, + .id_table = ariel_pwrbutton_spi_ids, +}; +module_spi_driver(ariel_pwrbutton_driver); + +MODULE_AUTHOR("Lubomir Rintel "); +MODULE_DESCRIPTION("Dell Wyse 3020 Power Button Input Driver"); +MODULE_LICENSE("Dual BSD/GPL"); -- cgit v1.3.1