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, 138 insertions, 0 deletions

diff --git a/drivers/phy/marvell/Kconfig b/drivers/phy/marvell/Kconfig
new file mode 100644
index 000000000..bccd72dcc
--- /dev/null
+++ b/drivers/phy/marvell/Kconfig
@@ -0,0 +1,138 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Marvell platforms
+#
+config ARMADA375_USBCLUSTER_PHY
+	bool "Armada 375 USB cluster PHY support" if COMPILE_TEST
+	default y if MACH_ARMADA_375
+	depends on OF && HAS_IOMEM
+	select GENERIC_PHY
+
+config PHY_BERLIN_SATA
+	tristate "Marvell Berlin SATA PHY driver"
+	depends on ARCH_BERLIN || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support the SATA PHY on Marvell Berlin SoCs.
+
+config PHY_BERLIN_USB
+	tristate "Marvell Berlin USB PHY Driver"
+	depends on ARCH_BERLIN || COMPILE_TEST
+	depends on OF && HAS_IOMEM && RESET_CONTROLLER
+	select GENERIC_PHY
+	help
+	  Enable this to support the USB PHY on Marvell Berlin SoCs.
+
+config PHY_MVEBU_A3700_COMPHY
+	tristate "Marvell A3700 comphy driver"
+	depends on ARCH_MVEBU || COMPILE_TEST
+	depends on OF
+	depends on HAVE_ARM_SMCCC
+	default ARCH_MVEBU
+	select GENERIC_PHY
+	help
+	  This driver allows to control the comphy, a hardware block providing
+	  shared serdes PHYs on Marvell Armada 3700. Its serdes lanes can be
+	  used by various controllers: Ethernet, SATA, USB3, PCIe.
+
+config PHY_MVEBU_A3700_UTMI
+	tristate "Marvell A3700 UTMI driver"
+	depends on ARCH_MVEBU || COMPILE_TEST
+	depends on OF
+	default ARCH_MVEBU
+	select GENERIC_PHY
+	help
+	  Enable this to support Marvell A3700 UTMI PHY driver.
+
+config PHY_MVEBU_A38X_COMPHY
+	tristate "Marvell Armada 38x comphy driver"
+	depends on ARCH_MVEBU || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  This driver allows to control the comphy, an hardware block providing
+	  shared serdes PHYs on Marvell Armada 38x. Its serdes lanes can be
+	  used by various controllers (Ethernet, sata, usb, PCIe...).
+
+config PHY_MVEBU_CP110_COMPHY
+	tristate "Marvell CP110 comphy driver"
+	depends on ARCH_MVEBU || COMPILE_TEST
+	depends on OF
+	depends on HAVE_ARM_SMCCC
+	select GENERIC_PHY
+	help
+	  This driver allows to control the comphy, an hardware block providing
+	  shared serdes PHYs on Marvell Armada 7k/8k (in the CP110). Its serdes
+	  lanes can be used by various controllers (Ethernet, sata, usb,
+	  PCIe...).
+
+config PHY_MVEBU_CP110_UTMI
+	tristate "Marvell CP110 UTMI driver"
+	depends on ARCH_MVEBU || COMPILE_TEST
+	depends on OF && USB_COMMON
+	select GENERIC_PHY
+	help
+	  Enable this to support Marvell CP110 UTMI PHY driver.
+
+config PHY_MVEBU_SATA
+	def_bool y
+	depends on ARCH_DOVE || MACH_DOVE || MACH_KIRKWOOD
+	depends on OF
+	select GENERIC_PHY
+
+config PHY_PXA_28NM_HSIC
+	tristate "Marvell USB HSIC 28nm PHY Driver"
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support Marvell USB HSIC PHY driver for Marvell
+	  SoC. This driver will do the PHY initialization and shutdown.
+	  The PHY driver will be used by Marvell ehci driver.
+
+	  To compile this driver as a module, choose M here.
+
+config PHY_PXA_28NM_USB2
+	tristate "Marvell USB 2.0 28nm PHY Driver"
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support Marvell USB 2.0 PHY driver for Marvell
+	  SoC. This driver will do the PHY initialization and shutdown.
+	  The PHY driver will be used by Marvell udc/ehci/otg driver.
+
+	  To compile this driver as a module, choose M here.
+
+config PHY_PXA_USB
+	tristate "Marvell PXA USB PHY Driver"
+	depends on ARCH_PXA || ARCH_MMP || COMPILE_TEST
+	select GENERIC_PHY
+	help
+	  Enable this to support Marvell PXA USB PHY driver for Marvell
+	  SoC. This driver will do the PHY initialization and shutdown.
+	  The PHY driver will be used by Marvell udc/ehci/otg driver.
+
+	  To compile this driver as a module, choose M here.
+
+config PHY_MMP3_USB
+	tristate "Marvell MMP3 USB PHY Driver"
+	depends on MACH_MMP3_DT || COMPILE_TEST
+	select GENERIC_PHY
+	help
+	  Enable this to support Marvell MMP3 USB PHY driver for Marvell
+	  SoC. This driver will do the PHY initialization and shutdown.
+	  The PHY driver will be used by Marvell udc/ehci/otg driver.
+
+	  To compile this driver as a module, choose M here.
+
+config PHY_MMP3_HSIC
+	tristate "Marvell MMP3 USB HSIC PHY Driver"
+	depends on MACH_MMP3_DT || COMPILE_TEST
+	select GENERIC_PHY
+	help
+	  Enable this to support Marvell MMP3 USB HSIC PHY driver for
+	  Marvell MMP3 SoC. This driver will be used my the Marvell EHCI
+	  driver to initialize the interface to internal USB HSIC
+	  components on MMP3-based boards.
+
+	  To compile this driver as a module, choose M here.