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, 123 insertions, 0 deletions

diff --git a/drivers/phy/ti/Kconfig b/drivers/phy/ti/Kconfig
new file mode 100644
index 000000000..b52c7eabe
--- /dev/null
+++ b/drivers/phy/ti/Kconfig
@@ -0,0 +1,123 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for TI platforms
+#
+config OMAP_CONTROL_PHY
+	tristate "OMAP CONTROL PHY Driver"
+	depends on ARCH_OMAP2PLUS || COMPILE_TEST
+	help
+	  Enable this to add support for the PHY part present in the control
+	  module. This driver has API to power on the USB2 PHY and to write to
+	  the mailbox. The mailbox is present only in omap4 and the register to
+	  power on the USB2 PHY is present in OMAP4 and OMAP5. OMAP5 has an
+	  additional register to power on USB3 PHY/SATA PHY/PCIE PHY
+	  (PIPE3 PHY).
+
+config OMAP_USB2
+	tristate "OMAP USB2 PHY Driver"
+	depends on ARCH_OMAP2PLUS || ARCH_K3 || COMPILE_TEST
+	depends on USB_SUPPORT
+	select GENERIC_PHY
+	select USB_PHY
+	select OMAP_CONTROL_PHY if ARCH_OMAP2PLUS || COMPILE_TEST
+	help
+	  Enable this to support the transceiver that is part of SOC. This
+	  driver takes care of all the PHY functionality apart from comparator.
+	  The USB OTG controller communicates with the comparator using this
+	  driver.
+
+config PHY_AM654_SERDES
+	tristate "TI AM654 SERDES support"
+	depends on OF && (ARCH_K3 || COMPILE_TEST)
+	depends on COMMON_CLK
+	select GENERIC_PHY
+	select MULTIPLEXER
+	select REGMAP_MMIO
+	select MUX_MMIO
+	help
+	  This option enables support for TI AM654 SerDes PHY used for
+	  PCIe.
+
+config PHY_DA8XX_USB
+	tristate "TI DA8xx USB PHY Driver"
+	depends on ARCH_DAVINCI_DA8XX || COMPILE_TEST
+	select GENERIC_PHY
+	select MFD_SYSCON
+	help
+	  Enable this to support the USB PHY on DA8xx SoCs.
+
+	  This driver controls both the USB 1.1 PHY and the USB 2.0 PHY.
+
+config PHY_DM816X_USB
+	tristate "TI dm816x USB PHY driver"
+	depends on ARCH_OMAP2PLUS || COMPILE_TEST
+	depends on USB_SUPPORT
+	select GENERIC_PHY
+	select USB_PHY
+	help
+	  Enable this for dm816x USB to work.
+
+config PHY_J721E_WIZ
+	tristate "TI J721E WIZ (SERDES Wrapper) support"
+	depends on OF && (ARCH_K3 || COMPILE_TEST)
+	depends on HAS_IOMEM && OF_ADDRESS
+	depends on COMMON_CLK
+	select GENERIC_PHY
+	select MULTIPLEXER
+	select REGMAP_MMIO
+	select MUX_MMIO
+	help
+	  This option enables support for WIZ module present in TI's J721E
+	  SoC. WIZ is a serdes wrapper used to configure some of the input
+	  signals to the SERDES (Sierra/Torrent). This driver configures
+	  three clock selects (pll0, pll1, dig) and resets for each of the
+	  lanes.
+
+config PHY_TI_DS125DF111
+	tristate "TI DS125DF111 2-Channel Retimer Driver"
+	depends on OF && I2C
+	select GENERIC_PHY
+	help
+	  Enable this to add support for configuration and runtime management
+	  of the TI DS125DF111 Multi-Protocol 2-Channel Retimer.
+	  The retimer is modeled as a Generic PHY and supports both 10G and 1G
+	  link speeds.
+
+config PHY_TI_GMII_SEL
+	tristate
+	select GENERIC_PHY
+	select REGMAP
+	help
+	  This driver supports configuring of the TI CPSW Port mode depending on
+	  the Ethernet PHY connected to the CPSW Port.
+
+config PHY_TUSB1210
+	tristate "TI TUSB1210 ULPI PHY module"
+	depends on USB_ULPI_BUS
+	select GENERIC_PHY
+	help
+	  Support for TI TUSB1210 USB ULPI PHY.
+
+config TI_PIPE3
+	tristate "TI PIPE3 PHY Driver"
+	depends on ARCH_OMAP2PLUS || COMPILE_TEST
+	select GENERIC_PHY
+	select OMAP_CONTROL_PHY
+	help
+	  Enable this to support the PIPE3 PHY that is part of TI SOCs. This
+	  driver takes care of all the PHY functionality apart from comparator.
+	  This driver interacts with the "OMAP Control PHY Driver" to power
+	  on/off the PHY.
+
+config TWL4030_USB
+	tristate "TWL4030 USB Transceiver Driver"
+	depends on TWL4030_CORE && REGULATOR_TWL4030 && USB_MUSB_OMAP2PLUS
+	depends on USB_SUPPORT
+	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't 'y'
+	select GENERIC_PHY
+	select USB_PHY
+	help
+	  Enable this to support the USB OTG transceiver on TWL4030
+	  family chips (including the TWL5030 and TPS659x0 devices).
+	  This transceiver supports high and full speed devices plus,
+	  in host mode, low speed.