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, 58 insertions, 0 deletions

diff --git a/include/sound/wm8962.h b/include/sound/wm8962.h
new file mode 100644
index 000000000..f77722573
--- /dev/null
+++ b/include/sound/wm8962.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * wm8962.h  --  WM8962 Soc Audio driver platform data
+ */
+
+#ifndef _WM8962_PDATA_H
+#define _WM8962_PDATA_H
+
+#define WM8962_MAX_GPIO 6
+
+/* Use to set GPIO default values to zero */
+#define WM8962_GPIO_SET 0x10000
+
+#define WM8962_GPIO_FN_CLKOUT           0
+#define WM8962_GPIO_FN_LOGIC            1
+#define WM8962_GPIO_FN_SDOUT            2
+#define WM8962_GPIO_FN_IRQ              3
+#define WM8962_GPIO_FN_THERMAL          4
+#define WM8962_GPIO_FN_PLL2_LOCK        6
+#define WM8962_GPIO_FN_PLL3_LOCK        7
+#define WM8962_GPIO_FN_FLL_LOCK         9
+#define WM8962_GPIO_FN_DRC_ACT         10
+#define WM8962_GPIO_FN_WSEQ_DONE       11
+#define WM8962_GPIO_FN_ALC_NG_ACT      12
+#define WM8962_GPIO_FN_ALC_PEAK_LIMIT  13
+#define WM8962_GPIO_FN_ALC_SATURATION  14
+#define WM8962_GPIO_FN_ALC_LEVEL_THR   15
+#define WM8962_GPIO_FN_ALC_LEVEL_LOCK  16
+#define WM8962_GPIO_FN_FIFO_ERR        17
+#define WM8962_GPIO_FN_OPCLK           18
+#define WM8962_GPIO_FN_DMICCLK         19
+#define WM8962_GPIO_FN_DMICDAT         20
+#define WM8962_GPIO_FN_MICD            21
+#define WM8962_GPIO_FN_MICSCD          22
+
+struct wm8962_pdata {
+	struct clk *mclk;
+	int gpio_base;
+	u32 gpio_init[WM8962_MAX_GPIO];
+
+	/* Setup for microphone detection, raw value to be written to
+	 * R48(0x30) - only microphone related bits will be updated.
+	 * Detection may be enabled here for use with signals brought
+	 * out on the GPIOs. */
+	u32 mic_cfg;
+
+	bool irq_active_low;
+
+	bool spk_mono;   /* Speaker outputs tied together as mono */
+
+	/**
+	 * This flag should be set if one or both IN4 inputs is wired
+	 * in a DC measurement configuration.
+	 */
+	bool in4_dc_measure;
+};
+
+#endif