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, 161 insertions, 0 deletions

diff --git a/include/sound/wm8904.h b/include/sound/wm8904.h
new file mode 100644
index 000000000..8b2c16b52
--- /dev/null
+++ b/include/sound/wm8904.h
@@ -0,0 +1,161 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Platform data for WM8904
+ *
+ * Copyright 2009 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ */
+
+#ifndef __MFD_WM8994_PDATA_H__
+#define __MFD_WM8994_PDATA_H__
+
+/* Used to enable configuration of a GPIO to all zeros */
+#define WM8904_GPIO_NO_CONFIG 0x8000
+
+/*
+ * R6 (0x06) - Mic Bias Control 0
+ */
+#define WM8904_MICDET_THR_MASK                  0x0070  /* MICDET_THR - [6:4] */
+#define WM8904_MICDET_THR_SHIFT                      4  /* MICDET_THR - [6:4] */
+#define WM8904_MICDET_THR_WIDTH                      3  /* MICDET_THR - [6:4] */
+#define WM8904_MICSHORT_THR_MASK                0x000C  /* MICSHORT_THR - [3:2] */
+#define WM8904_MICSHORT_THR_SHIFT                    2  /* MICSHORT_THR - [3:2] */
+#define WM8904_MICSHORT_THR_WIDTH                    2  /* MICSHORT_THR - [3:2] */
+#define WM8904_MICDET_ENA                       0x0002  /* MICDET_ENA */
+#define WM8904_MICDET_ENA_MASK                  0x0002  /* MICDET_ENA */
+#define WM8904_MICDET_ENA_SHIFT                      1  /* MICDET_ENA */
+#define WM8904_MICDET_ENA_WIDTH                      1  /* MICDET_ENA */
+#define WM8904_MICBIAS_ENA                      0x0001  /* MICBIAS_ENA */
+#define WM8904_MICBIAS_ENA_MASK                 0x0001  /* MICBIAS_ENA */
+#define WM8904_MICBIAS_ENA_SHIFT                     0  /* MICBIAS_ENA */
+#define WM8904_MICBIAS_ENA_WIDTH                     1  /* MICBIAS_ENA */
+
+/*
+ * R7 (0x07) - Mic Bias Control 1
+ */
+#define WM8904_MIC_DET_FILTER_ENA               0x8000  /* MIC_DET_FILTER_ENA */
+#define WM8904_MIC_DET_FILTER_ENA_MASK          0x8000  /* MIC_DET_FILTER_ENA */
+#define WM8904_MIC_DET_FILTER_ENA_SHIFT             15  /* MIC_DET_FILTER_ENA */
+#define WM8904_MIC_DET_FILTER_ENA_WIDTH              1  /* MIC_DET_FILTER_ENA */
+#define WM8904_MIC_SHORT_FILTER_ENA             0x4000  /* MIC_SHORT_FILTER_ENA */
+#define WM8904_MIC_SHORT_FILTER_ENA_MASK        0x4000  /* MIC_SHORT_FILTER_ENA */
+#define WM8904_MIC_SHORT_FILTER_ENA_SHIFT           14  /* MIC_SHORT_FILTER_ENA */
+#define WM8904_MIC_SHORT_FILTER_ENA_WIDTH            1  /* MIC_SHORT_FILTER_ENA */
+#define WM8904_MICBIAS_SEL_MASK                 0x0007  /* MICBIAS_SEL - [2:0] */
+#define WM8904_MICBIAS_SEL_SHIFT                     0  /* MICBIAS_SEL - [2:0] */
+#define WM8904_MICBIAS_SEL_WIDTH                     3  /* MICBIAS_SEL - [2:0] */
+
+
+/*
+ * R121 (0x79) - GPIO Control 1
+ */
+#define WM8904_GPIO1_PU                         0x0020  /* GPIO1_PU */
+#define WM8904_GPIO1_PU_MASK                    0x0020  /* GPIO1_PU */
+#define WM8904_GPIO1_PU_SHIFT                        5  /* GPIO1_PU */
+#define WM8904_GPIO1_PU_WIDTH                        1  /* GPIO1_PU */
+#define WM8904_GPIO1_PD                         0x0010  /* GPIO1_PD */
+#define WM8904_GPIO1_PD_MASK                    0x0010  /* GPIO1_PD */
+#define WM8904_GPIO1_PD_SHIFT                        4  /* GPIO1_PD */
+#define WM8904_GPIO1_PD_WIDTH                        1  /* GPIO1_PD */
+#define WM8904_GPIO1_SEL_MASK                   0x000F  /* GPIO1_SEL - [3:0] */
+#define WM8904_GPIO1_SEL_SHIFT                       0  /* GPIO1_SEL - [3:0] */
+#define WM8904_GPIO1_SEL_WIDTH                       4  /* GPIO1_SEL - [3:0] */
+
+/*
+ * R122 (0x7A) - GPIO Control 2
+ */
+#define WM8904_GPIO2_PU                         0x0020  /* GPIO2_PU */
+#define WM8904_GPIO2_PU_MASK                    0x0020  /* GPIO2_PU */
+#define WM8904_GPIO2_PU_SHIFT                        5  /* GPIO2_PU */
+#define WM8904_GPIO2_PU_WIDTH                        1  /* GPIO2_PU */
+#define WM8904_GPIO2_PD                         0x0010  /* GPIO2_PD */
+#define WM8904_GPIO2_PD_MASK                    0x0010  /* GPIO2_PD */
+#define WM8904_GPIO2_PD_SHIFT                        4  /* GPIO2_PD */
+#define WM8904_GPIO2_PD_WIDTH                        1  /* GPIO2_PD */
+#define WM8904_GPIO2_SEL_MASK                   0x000F  /* GPIO2_SEL - [3:0] */
+#define WM8904_GPIO2_SEL_SHIFT                       0  /* GPIO2_SEL - [3:0] */
+#define WM8904_GPIO2_SEL_WIDTH                       4  /* GPIO2_SEL - [3:0] */
+
+/*
+ * R123 (0x7B) - GPIO Control 3
+ */
+#define WM8904_GPIO3_PU                         0x0020  /* GPIO3_PU */
+#define WM8904_GPIO3_PU_MASK                    0x0020  /* GPIO3_PU */
+#define WM8904_GPIO3_PU_SHIFT                        5  /* GPIO3_PU */
+#define WM8904_GPIO3_PU_WIDTH                        1  /* GPIO3_PU */
+#define WM8904_GPIO3_PD                         0x0010  /* GPIO3_PD */
+#define WM8904_GPIO3_PD_MASK                    0x0010  /* GPIO3_PD */
+#define WM8904_GPIO3_PD_SHIFT                        4  /* GPIO3_PD */
+#define WM8904_GPIO3_PD_WIDTH                        1  /* GPIO3_PD */
+#define WM8904_GPIO3_SEL_MASK                   0x000F  /* GPIO3_SEL - [3:0] */
+#define WM8904_GPIO3_SEL_SHIFT                       0  /* GPIO3_SEL - [3:0] */
+#define WM8904_GPIO3_SEL_WIDTH                       4  /* GPIO3_SEL - [3:0] */
+
+/*
+ * R124 (0x7C) - GPIO Control 4
+ */
+#define WM8904_GPI7_ENA                         0x0200  /* GPI7_ENA */
+#define WM8904_GPI7_ENA_MASK                    0x0200  /* GPI7_ENA */
+#define WM8904_GPI7_ENA_SHIFT                        9  /* GPI7_ENA */
+#define WM8904_GPI7_ENA_WIDTH                        1  /* GPI7_ENA */
+#define WM8904_GPI8_ENA                         0x0100  /* GPI8_ENA */
+#define WM8904_GPI8_ENA_MASK                    0x0100  /* GPI8_ENA */
+#define WM8904_GPI8_ENA_SHIFT                        8  /* GPI8_ENA */
+#define WM8904_GPI8_ENA_WIDTH                        1  /* GPI8_ENA */
+#define WM8904_GPIO_BCLK_MODE_ENA               0x0080  /* GPIO_BCLK_MODE_ENA */
+#define WM8904_GPIO_BCLK_MODE_ENA_MASK          0x0080  /* GPIO_BCLK_MODE_ENA */
+#define WM8904_GPIO_BCLK_MODE_ENA_SHIFT              7  /* GPIO_BCLK_MODE_ENA */
+#define WM8904_GPIO_BCLK_MODE_ENA_WIDTH              1  /* GPIO_BCLK_MODE_ENA */
+#define WM8904_GPIO_BCLK_SEL_MASK               0x000F  /* GPIO_BCLK_SEL - [3:0] */
+#define WM8904_GPIO_BCLK_SEL_SHIFT                   0  /* GPIO_BCLK_SEL - [3:0] */
+#define WM8904_GPIO_BCLK_SEL_WIDTH                   4  /* GPIO_BCLK_SEL - [3:0] */
+
+#define WM8904_MIC_REGS  2
+#define WM8904_GPIO_REGS 4
+#define WM8904_DRC_REGS  4
+#define WM8904_EQ_REGS   24
+
+/**
+ * DRC configurations are specified with a label and a set of register
+ * values to write (the enable bits will be ignored).  At runtime an
+ * enumerated control will be presented for each DRC block allowing
+ * the user to choose the configuration to use.
+ *
+ * Configurations may be generated by hand or by using the DRC control
+ * panel provided by the WISCE - see  http://www.wolfsonmicro.com/wisce/
+ * for details.
+ */
+struct wm8904_drc_cfg {
+	const char *name;
+	u16 regs[WM8904_DRC_REGS];
+};
+
+/**
+ * ReTune Mobile configurations are specified with a label, sample
+ * rate and set of values to write (the enable bits will be ignored).
+ *
+ * Configurations are expected to be generated using the ReTune Mobile
+ * control panel in WISCE - see http://www.wolfsonmicro.com/wisce/
+ */
+struct wm8904_retune_mobile_cfg {
+	const char *name;
+	unsigned int rate;
+	u16 regs[WM8904_EQ_REGS];
+};
+
+struct wm8904_pdata {
+	int num_drc_cfgs;
+	struct wm8904_drc_cfg *drc_cfgs;
+
+	int num_retune_mobile_cfgs;
+	struct wm8904_retune_mobile_cfg *retune_mobile_cfgs;
+
+	bool in1l_as_dmicdat1;
+	bool in1r_as_dmicdat2;
+
+	u32 gpio_cfg[WM8904_GPIO_REGS];
+	u32 mic_cfg[WM8904_MIC_REGS];
+};
+
+#endif