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/soc/fujitsu/Kconfig | 16 +++++ drivers/soc/fujitsu/Makefile | 3 + drivers/soc/fujitsu/a64fx-diag.c | 151 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 170 insertions(+) create mode 100644 drivers/soc/fujitsu/Kconfig create mode 100644 drivers/soc/fujitsu/Makefile create mode 100644 drivers/soc/fujitsu/a64fx-diag.c (limited to 'drivers/soc/fujitsu') diff --git a/drivers/soc/fujitsu/Kconfig b/drivers/soc/fujitsu/Kconfig new file mode 100644 index 000000000..987731e80 --- /dev/null +++ b/drivers/soc/fujitsu/Kconfig @@ -0,0 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0-only +menu "fujitsu SoC drivers" + +config A64FX_DIAG + bool "A64FX diag driver" + depends on ARM64 + depends on ACPI + help + Say Y here if you want to enable diag interrupt on Fujitsu A64FX. + This driver enables BMC's diagnostic requests and enables + A64FX-specific interrupts. This allows administrators to obtain + kernel dumps via diagnostic requests using ipmitool, etc. + + If unsure, say N. + +endmenu diff --git a/drivers/soc/fujitsu/Makefile b/drivers/soc/fujitsu/Makefile new file mode 100644 index 000000000..945bc1c14 --- /dev/null +++ b/drivers/soc/fujitsu/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_A64FX_DIAG) += a64fx-diag.o diff --git a/drivers/soc/fujitsu/a64fx-diag.c b/drivers/soc/fujitsu/a64fx-diag.c new file mode 100644 index 000000000..76cb0b6a2 --- /dev/null +++ b/drivers/soc/fujitsu/a64fx-diag.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * A64FX diag driver. + * Copyright (c) 2022 Fujitsu Ltd. + */ + +#include +#include +#include +#include +#include + +#define A64FX_DIAG_IRQ 1 +#define BMC_DIAG_INTERRUPT_ENABLE 0x40 +#define BMC_DIAG_INTERRUPT_STATUS 0x44 +#define BMC_DIAG_INTERRUPT_MASK BIT(31) + +struct a64fx_diag_priv { + void __iomem *mmsc_reg_base; + int irq; + bool has_nmi; +}; + +static irqreturn_t a64fx_diag_handler_nmi(int irq, void *dev_id) +{ + nmi_panic(NULL, "a64fx_diag: interrupt received\n"); + + return IRQ_HANDLED; +} + +static irqreturn_t a64fx_diag_handler_irq(int irq, void *dev_id) +{ + panic("a64fx_diag: interrupt received\n"); + + return IRQ_HANDLED; +} + +static void a64fx_diag_interrupt_clear(struct a64fx_diag_priv *priv) +{ + void __iomem *diag_status_reg_addr; + u32 mmsc; + + diag_status_reg_addr = priv->mmsc_reg_base + BMC_DIAG_INTERRUPT_STATUS; + mmsc = readl(diag_status_reg_addr); + if (mmsc & BMC_DIAG_INTERRUPT_MASK) + writel(BMC_DIAG_INTERRUPT_MASK, diag_status_reg_addr); +} + +static void a64fx_diag_interrupt_enable(struct a64fx_diag_priv *priv) +{ + void __iomem *diag_enable_reg_addr; + u32 mmsc; + + diag_enable_reg_addr = priv->mmsc_reg_base + BMC_DIAG_INTERRUPT_ENABLE; + mmsc = readl(diag_enable_reg_addr); + if (!(mmsc & BMC_DIAG_INTERRUPT_MASK)) { + mmsc |= BMC_DIAG_INTERRUPT_MASK; + writel(mmsc, diag_enable_reg_addr); + } +} + +static void a64fx_diag_interrupt_disable(struct a64fx_diag_priv *priv) +{ + void __iomem *diag_enable_reg_addr; + u32 mmsc; + + diag_enable_reg_addr = priv->mmsc_reg_base + BMC_DIAG_INTERRUPT_ENABLE; + mmsc = readl(diag_enable_reg_addr); + if (mmsc & BMC_DIAG_INTERRUPT_MASK) { + mmsc &= ~BMC_DIAG_INTERRUPT_MASK; + writel(mmsc, diag_enable_reg_addr); + } +} + +static int a64fx_diag_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct a64fx_diag_priv *priv; + unsigned long irq_flags; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (priv == NULL) + return -ENOMEM; + + priv->mmsc_reg_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->mmsc_reg_base)) + return PTR_ERR(priv->mmsc_reg_base); + + priv->irq = platform_get_irq(pdev, A64FX_DIAG_IRQ); + if (priv->irq < 0) + return priv->irq; + + platform_set_drvdata(pdev, priv); + + irq_flags = IRQF_PERCPU | IRQF_NOBALANCING | IRQF_NO_AUTOEN | + IRQF_NO_THREAD; + ret = request_nmi(priv->irq, &a64fx_diag_handler_nmi, irq_flags, + "a64fx_diag_nmi", NULL); + if (ret) { + ret = request_irq(priv->irq, &a64fx_diag_handler_irq, + irq_flags, "a64fx_diag_irq", NULL); + if (ret) { + dev_err(dev, "cannot register IRQ %d\n", ret); + return ret; + } + enable_irq(priv->irq); + } else { + enable_nmi(priv->irq); + priv->has_nmi = true; + } + + a64fx_diag_interrupt_clear(priv); + a64fx_diag_interrupt_enable(priv); + + return 0; +} + +static void a64fx_diag_remove(struct platform_device *pdev) +{ + struct a64fx_diag_priv *priv = platform_get_drvdata(pdev); + + a64fx_diag_interrupt_disable(priv); + a64fx_diag_interrupt_clear(priv); + + if (priv->has_nmi) + free_nmi(priv->irq, NULL); + else + free_irq(priv->irq, NULL); +} + +static const struct acpi_device_id a64fx_diag_acpi_match[] = { + { "FUJI2007", 0 }, + { }, +}; +MODULE_DEVICE_TABLE(acpi, a64fx_diag_acpi_match); + + +static struct platform_driver a64fx_diag_driver = { + .driver = { + .name = "a64fx_diag_driver", + .acpi_match_table = ACPI_PTR(a64fx_diag_acpi_match), + }, + .probe = a64fx_diag_probe, + .remove = a64fx_diag_remove, +}; + +module_platform_driver(a64fx_diag_driver); + +MODULE_AUTHOR("Hitomi Hasegawa "); +MODULE_DESCRIPTION("A64FX diag driver"); -- cgit v1.3.1