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>

1 files changed, 51 insertions, 0 deletions

diff --git a/include/sound/da7219.h b/include/sound/da7219.h
new file mode 100644
index 000000000..dde4542b0
--- /dev/null
+++ b/include/sound/da7219.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * da7219.h - DA7219 ASoC Codec Driver Platform Data
+ *
+ * Copyright (c) 2015 Dialog Semiconductor
+ *
+ * Author: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
+ */
+
+#ifndef __DA7219_PDATA_H
+#define __DA7219_PDATA_H
+
+/* Mic Bias */
+enum da7219_micbias_voltage {
+	DA7219_MICBIAS_1_6V = 0,
+	DA7219_MICBIAS_1_8V,
+	DA7219_MICBIAS_2_0V,
+	DA7219_MICBIAS_2_2V,
+	DA7219_MICBIAS_2_4V,
+	DA7219_MICBIAS_2_6V,
+};
+
+/* Mic input type */
+enum da7219_mic_amp_in_sel {
+	DA7219_MIC_AMP_IN_SEL_DIFF = 0,
+	DA7219_MIC_AMP_IN_SEL_SE_P,
+	DA7219_MIC_AMP_IN_SEL_SE_N,
+};
+
+struct da7219_aad_pdata;
+
+enum da7219_dai_clks {
+	DA7219_DAI_WCLK_IDX = 0,
+	DA7219_DAI_BCLK_IDX,
+	DA7219_DAI_NUM_CLKS,
+};
+
+struct da7219_pdata {
+	bool wakeup_source;
+
+	const char *dai_clk_names[DA7219_DAI_NUM_CLKS];
+
+	/* Mic */
+	enum da7219_micbias_voltage micbias_lvl;
+	enum da7219_mic_amp_in_sel mic_amp_in_sel;
+
+	/* AAD */
+	struct da7219_aad_pdata *aad_pdata;
+};
+
+#endif /* __DA7219_PDATA_H */