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, 46 insertions, 0 deletions

diff --git a/include/sound/da7213.h b/include/sound/da7213.h
new file mode 100644
index 000000000..6216a0a7b
--- /dev/null
+++ b/include/sound/da7213.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * da7213.h - DA7213 ASoC Codec Driver Platform Data
+ *
+ * Copyright (c) 2013 Dialog Semiconductor
+ *
+ * Author: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
+ */
+
+#ifndef _DA7213_PDATA_H
+#define _DA7213_PDATA_H
+
+enum da7213_micbias_voltage {
+	DA7213_MICBIAS_1_6V = 0,
+	DA7213_MICBIAS_2_2V = 1,
+	DA7213_MICBIAS_2_5V = 2,
+	DA7213_MICBIAS_3_0V = 3,
+};
+
+enum da7213_dmic_data_sel {
+	DA7213_DMIC_DATA_LRISE_RFALL = 0,
+	DA7213_DMIC_DATA_LFALL_RRISE = 1,
+};
+
+enum da7213_dmic_samplephase {
+	DA7213_DMIC_SAMPLE_ON_CLKEDGE = 0,
+	DA7213_DMIC_SAMPLE_BETWEEN_CLKEDGE = 1,
+};
+
+enum da7213_dmic_clk_rate {
+	DA7213_DMIC_CLK_3_0MHZ = 0,
+	DA7213_DMIC_CLK_1_5MHZ = 1,
+};
+
+struct da7213_platform_data {
+	/* Mic Bias voltage */
+	enum da7213_micbias_voltage micbias1_lvl;
+	enum da7213_micbias_voltage micbias2_lvl;
+
+	/* DMIC config */
+	enum da7213_dmic_data_sel dmic_data_sel;
+	enum da7213_dmic_samplephase dmic_samplephase;
+	enum da7213_dmic_clk_rate dmic_clk_rate;
+};
+
+#endif /* _DA7213_PDATA_H */