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| author | Miguel Ojeda <ojeda@kernel.org> | 2026-08-16 15:32:33 +0200 |
|---|---|---|
| committer | Miguel Ojeda <ojeda@kernel.org> | 2026-08-23 21:27:17 +0200 |
| commit | 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 (patch) | |
| tree | 93a1ed1d337bc53adf1e572c2586d347703b286e /drivers/tty/serial/timbuart.h | |
| download | linux-stable-5febf432df1cfa5b25d99b54c32103fafbdd0eb9.tar.gz linux-stable-5febf432df1cfa5b25d99b54c32103fafbdd0eb9.zip | |
kbuild: rust: keep Rust objects out of Clang LTO with inline helpersgrafted
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 <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'drivers/tty/serial/timbuart.h')
| -rw-r--r-- | drivers/tty/serial/timbuart.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/drivers/tty/serial/timbuart.h b/drivers/tty/serial/timbuart.h new file mode 100644 index 000000000..007e59af6 --- /dev/null +++ b/drivers/tty/serial/timbuart.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * timbuart.c timberdale FPGA GPIO driver + * Copyright (c) 2009 Intel Corporation + */ + +/* Supports: + * Timberdale FPGA UART + */ + +#ifndef _TIMBUART_H +#define _TIMBUART_H + +#define TIMBUART_FIFO_SIZE 2048 + +#define TIMBUART_RXFIFO 0x08 +#define TIMBUART_TXFIFO 0x0c +#define TIMBUART_IER 0x10 +#define TIMBUART_IPR 0x14 +#define TIMBUART_ISR 0x18 +#define TIMBUART_CTRL 0x1c +#define TIMBUART_BAUDRATE 0x20 + +#define TIMBUART_CTRL_RTS 0x01 +#define TIMBUART_CTRL_CTS 0x02 +#define TIMBUART_CTRL_FLSHTX 0x40 +#define TIMBUART_CTRL_FLSHRX 0x80 + +#define TXBF 0x01 +#define TXBAE 0x02 +#define CTS_DELTA 0x04 +#define RXDP 0x08 +#define RXBAF 0x10 +#define RXBF 0x20 +#define RXTT 0x40 +#define RXBNAE 0x80 +#define TXBE 0x100 + +#define RXFLAGS (RXDP | RXBAF | RXBF | RXTT | RXBNAE) +#define TXFLAGS (TXBF | TXBAE) + +#define TIMBUART_MAJOR 204 +#define TIMBUART_MINOR 192 + +#endif /* _TIMBUART_H */ + |