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 --- include/media/cec-pin.h | 79 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 include/media/cec-pin.h (limited to 'include/media/cec-pin.h') diff --git a/include/media/cec-pin.h b/include/media/cec-pin.h new file mode 100644 index 000000000..483bc4769 --- /dev/null +++ b/include/media/cec-pin.h @@ -0,0 +1,79 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * cec-pin.h - low-level CEC pin control + * + * Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved. + */ + +#ifndef LINUX_CEC_PIN_H +#define LINUX_CEC_PIN_H + +#include +#include + +/** + * struct cec_pin_ops - low-level CEC pin operations + * @read: read the CEC pin. Returns > 0 if high, 0 if low, or an error + * if negative. + * @low: drive the CEC pin low. + * @high: stop driving the CEC pin. The pull-up will drive the pin + * high, unless someone else is driving the pin low. + * @enable_irq: optional, enable the interrupt to detect pin voltage changes. + * @disable_irq: optional, disable the interrupt. + * @free: optional. Free any allocated resources. Called when the + * adapter is deleted. + * @status: optional, log status information. + * @read_hpd: optional. Read the HPD pin. Returns > 0 if high, 0 if low or + * an error if negative. + * @read_5v: optional. Read the 5V pin. Returns > 0 if high, 0 if low or + * an error if negative. + * @received: optional. High-level CEC message callback. Allows the driver + * to process CEC messages. + * + * These operations (except for the @received op) are used by the + * cec pin framework to manipulate the CEC pin. + */ +struct cec_pin_ops { + int (*read)(struct cec_adapter *adap); + void (*low)(struct cec_adapter *adap); + void (*high)(struct cec_adapter *adap); + bool (*enable_irq)(struct cec_adapter *adap); + void (*disable_irq)(struct cec_adapter *adap); + void (*free)(struct cec_adapter *adap); + void (*status)(struct cec_adapter *adap, struct seq_file *file); + int (*read_hpd)(struct cec_adapter *adap); + int (*read_5v)(struct cec_adapter *adap); + + /* High-level CEC message callback */ + int (*received)(struct cec_adapter *adap, struct cec_msg *msg); +}; + +/** + * cec_pin_changed() - update pin state from interrupt + * + * @adap: pointer to the cec adapter + * @value: when true the pin is high, otherwise it is low + * + * If changes of the CEC voltage are detected via an interrupt, then + * cec_pin_changed is called from the interrupt with the new value. + */ +void cec_pin_changed(struct cec_adapter *adap, bool value); + +/** + * cec_pin_allocate_adapter() - allocate a pin-based cec adapter + * + * @pin_ops: low-level pin operations + * @priv: will be stored in adap->priv and can be used by the adapter ops. + * Use cec_get_drvdata(adap) to get the priv pointer. + * @name: the name of the CEC adapter. Note: this name will be copied. + * @caps: capabilities of the CEC adapter. This will be ORed with + * CEC_CAP_MONITOR_ALL and CEC_CAP_MONITOR_PIN. + * + * Allocate a cec adapter using the cec pin framework. + * + * Return: a pointer to the cec adapter or an error pointer + */ +struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops, + void *priv, const char *name, u32 caps); + +#endif -- cgit v1.3.1