From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers 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 Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/net/phy/amd.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) create mode 100644 drivers/net/phy/amd.c (limited to 'drivers/net/phy/amd.c') diff --git a/drivers/net/phy/amd.c b/drivers/net/phy/amd.c new file mode 100644 index 000000000..75b5fe655 --- /dev/null +++ b/drivers/net/phy/amd.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Driver for AMD am79c PHYs + * + * Author: Heiko Schocher + * + * Copyright (c) 2011 DENX Software Engineering GmbH + */ +#include +#include +#include +#include +#include +#include + +#define PHY_ID_AC101L 0x00225520 +#define PHY_ID_AM79C874 0x0022561b + +#define MII_AM79C_IR 17 /* Interrupt Status/Control Register */ +#define MII_AM79C_IR_EN_LINK 0x0400 /* IR enable Linkstate */ +#define MII_AM79C_IR_EN_ANEG 0x0100 /* IR enable Aneg Complete */ +#define MII_AM79C_IR_IMASK_INIT (MII_AM79C_IR_EN_LINK | MII_AM79C_IR_EN_ANEG) + +#define MII_AM79C_IR_LINK_DOWN BIT(2) +#define MII_AM79C_IR_ANEG_DONE BIT(0) +#define MII_AM79C_IR_IMASK_STAT (MII_AM79C_IR_LINK_DOWN | MII_AM79C_IR_ANEG_DONE) + +MODULE_DESCRIPTION("AMD PHY driver"); +MODULE_AUTHOR("Heiko Schocher "); +MODULE_LICENSE("GPL"); + +static int am79c_ack_interrupt(struct phy_device *phydev) +{ + int err; + + err = phy_read(phydev, MII_BMSR); + if (err < 0) + return err; + + err = phy_read(phydev, MII_AM79C_IR); + if (err < 0) + return err; + + return 0; +} + +static int am79c_config_init(struct phy_device *phydev) +{ + return 0; +} + +static int am79c_config_intr(struct phy_device *phydev) +{ + int err; + + if (phydev->interrupts == PHY_INTERRUPT_ENABLED) { + err = am79c_ack_interrupt(phydev); + if (err) + return err; + + err = phy_write(phydev, MII_AM79C_IR, MII_AM79C_IR_IMASK_INIT); + } else { + err = phy_write(phydev, MII_AM79C_IR, 0); + if (err) + return err; + + err = am79c_ack_interrupt(phydev); + } + + return err; +} + +static irqreturn_t am79c_handle_interrupt(struct phy_device *phydev) +{ + int irq_status; + + irq_status = phy_read(phydev, MII_AM79C_IR); + if (irq_status < 0) { + phy_error(phydev); + return IRQ_NONE; + } + + if (!(irq_status & MII_AM79C_IR_IMASK_STAT)) + return IRQ_NONE; + + phy_trigger_machine(phydev); + + return IRQ_HANDLED; +} + +static struct phy_driver am79c_drivers[] = { + { + .phy_id = PHY_ID_AM79C874, + .name = "AM79C874", + .phy_id_mask = 0xfffffff0, + /* PHY_BASIC_FEATURES */ + .config_init = am79c_config_init, + .config_intr = am79c_config_intr, + .handle_interrupt = am79c_handle_interrupt, + }, + { + .phy_id = PHY_ID_AC101L, + .name = "AC101L", + .phy_id_mask = 0xfffffff0, + /* PHY_BASIC_FEATURES */ + .config_init = am79c_config_init, + .config_intr = am79c_config_intr, + .handle_interrupt = am79c_handle_interrupt, + }, +}; + +module_phy_driver(am79c_drivers); + +static const struct mdio_device_id __maybe_unused amd_tbl[] = { + { PHY_ID_AC101L, 0xfffffff0 }, + { PHY_ID_AM79C874, 0xfffffff0 }, + { } +}; + +MODULE_DEVICE_TABLE(mdio, amd_tbl); -- cgit v1.3.1