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/clocksource/timer-sp.h | 63 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 drivers/clocksource/timer-sp.h (limited to 'drivers/clocksource/timer-sp.h') diff --git a/drivers/clocksource/timer-sp.h b/drivers/clocksource/timer-sp.h new file mode 100644 index 000000000..811f840be --- /dev/null +++ b/drivers/clocksource/timer-sp.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * ARM timer implementation, found in Integrator, Versatile and Realview + * platforms. Not all platforms support all registers and bits in these + * registers, so we mark them with A for Integrator AP, C for Integrator + * CP, V for Versatile and R for Realview. + * + * Integrator AP has 16-bit timers, Integrator CP, Versatile and Realview + * can have 16-bit or 32-bit selectable via a bit in the control register. + * + * Every SP804 contains two identical timers. + */ +#define NR_TIMERS 2 +#define TIMER_1_BASE 0x00 +#define TIMER_2_BASE 0x20 + +#define TIMER_LOAD 0x00 /* ACVR rw */ +#define TIMER_VALUE 0x04 /* ACVR ro */ +#define TIMER_CTRL 0x08 /* ACVR rw */ +#define TIMER_CTRL_ONESHOT (1 << 0) /* CVR */ +#define TIMER_CTRL_32BIT (1 << 1) /* CVR */ +#define TIMER_CTRL_DIV1 (0 << 2) /* ACVR */ +#define TIMER_CTRL_DIV16 (1 << 2) /* ACVR */ +#define TIMER_CTRL_DIV256 (2 << 2) /* ACVR */ +#define TIMER_CTRL_IE (1 << 5) /* VR */ +#define TIMER_CTRL_PERIODIC (1 << 6) /* ACVR */ +#define TIMER_CTRL_ENABLE (1 << 7) /* ACVR */ + +#define TIMER_INTCLR 0x0c /* ACVR wo */ +#define TIMER_RIS 0x10 /* CVR ro */ +#define TIMER_MIS 0x14 /* CVR ro */ +#define TIMER_BGLOAD 0x18 /* CVR rw */ + +struct sp804_timer { + int load; + int load_h; + int value; + int value_h; + int ctrl; + int intclr; + int ris; + int mis; + int bgload; + int bgload_h; + int timer_base[NR_TIMERS]; + int width; +}; + +struct sp804_clkevt { + void __iomem *base; + void __iomem *load; + void __iomem *load_h; + void __iomem *value; + void __iomem *value_h; + void __iomem *ctrl; + void __iomem *intclr; + void __iomem *ris; + void __iomem *mis; + void __iomem *bgload; + void __iomem *bgload_h; + unsigned long reload; + int width; +}; -- cgit v1.3.1