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/sh/intc/access.c | 246 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 246 insertions(+) create mode 100644 drivers/sh/intc/access.c (limited to 'drivers/sh/intc/access.c') diff --git a/drivers/sh/intc/access.c b/drivers/sh/intc/access.c new file mode 100644 index 000000000..114390f96 --- /dev/null +++ b/drivers/sh/intc/access.c @@ -0,0 +1,246 @@ +/* + * Common INTC2 register accessors + * + * Copyright (C) 2007, 2008 Magnus Damm + * Copyright (C) 2009, 2010 Paul Mundt + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#include +#include "internals.h" + +unsigned long intc_phys_to_virt(struct intc_desc_int *d, unsigned long address) +{ + struct intc_window *window; + int k; + + /* scan through physical windows and convert address */ + for (k = 0; k < d->nr_windows; k++) { + window = d->window + k; + + if (address < window->phys) + continue; + + if (address >= (window->phys + window->size)) + continue; + + address -= window->phys; + address += (unsigned long)window->virt; + + return address; + } + + /* no windows defined, register must be 1:1 mapped virt:phys */ + return address; +} + +unsigned int intc_get_reg(struct intc_desc_int *d, unsigned long address) +{ + unsigned int k; + + address = intc_phys_to_virt(d, address); + + for (k = 0; k < d->nr_reg; k++) { + if (d->reg[k] == address) + return k; + } + + BUG(); + return 0; +} + +unsigned int intc_set_field_from_handle(unsigned int value, + unsigned int field_value, + unsigned int handle) +{ + unsigned int width = _INTC_WIDTH(handle); + unsigned int shift = _INTC_SHIFT(handle); + + value &= ~(((1 << width) - 1) << shift); + value |= field_value << shift; + return value; +} + +unsigned long intc_get_field_from_handle(unsigned int value, unsigned int handle) +{ + unsigned int width = _INTC_WIDTH(handle); + unsigned int shift = _INTC_SHIFT(handle); + unsigned int mask = ((1 << width) - 1) << shift; + + return (value & mask) >> shift; +} + +static unsigned long test_8(unsigned long addr, unsigned long h, + unsigned long ignore) +{ + void __iomem *ptr = (void __iomem *)addr; + return intc_get_field_from_handle(__raw_readb(ptr), h); +} + +static unsigned long test_16(unsigned long addr, unsigned long h, + unsigned long ignore) +{ + void __iomem *ptr = (void __iomem *)addr; + return intc_get_field_from_handle(__raw_readw(ptr), h); +} + +static unsigned long test_32(unsigned long addr, unsigned long h, + unsigned long ignore) +{ + void __iomem *ptr = (void __iomem *)addr; + return intc_get_field_from_handle(__raw_readl(ptr), h); +} + +static unsigned long write_8(unsigned long addr, unsigned long h, + unsigned long data) +{ + void __iomem *ptr = (void __iomem *)addr; + __raw_writeb(intc_set_field_from_handle(0, data, h), ptr); + (void)__raw_readb(ptr); /* Defeat write posting */ + return 0; +} + +static unsigned long write_16(unsigned long addr, unsigned long h, + unsigned long data) +{ + void __iomem *ptr = (void __iomem *)addr; + __raw_writew(intc_set_field_from_handle(0, data, h), ptr); + (void)__raw_readw(ptr); /* Defeat write posting */ + return 0; +} + +static unsigned long write_32(unsigned long addr, unsigned long h, + unsigned long data) +{ + void __iomem *ptr = (void __iomem *)addr; + __raw_writel(intc_set_field_from_handle(0, data, h), ptr); + (void)__raw_readl(ptr); /* Defeat write posting */ + return 0; +} + +static unsigned long modify_8(unsigned long addr, unsigned long h, + unsigned long data) +{ + void __iomem *ptr = (void __iomem *)addr; + unsigned long flags; + unsigned int value; + local_irq_save(flags); + value = intc_set_field_from_handle(__raw_readb(ptr), data, h); + __raw_writeb(value, ptr); + (void)__raw_readb(ptr); /* Defeat write posting */ + local_irq_restore(flags); + return 0; +} + +static unsigned long modify_16(unsigned long addr, unsigned long h, + unsigned long data) +{ + void __iomem *ptr = (void __iomem *)addr; + unsigned long flags; + unsigned int value; + local_irq_save(flags); + value = intc_set_field_from_handle(__raw_readw(ptr), data, h); + __raw_writew(value, ptr); + (void)__raw_readw(ptr); /* Defeat write posting */ + local_irq_restore(flags); + return 0; +} + +static unsigned long modify_32(unsigned long addr, unsigned long h, + unsigned long data) +{ + void __iomem *ptr = (void __iomem *)addr; + unsigned long flags; + unsigned int value; + local_irq_save(flags); + value = intc_set_field_from_handle(__raw_readl(ptr), data, h); + __raw_writel(value, ptr); + (void)__raw_readl(ptr); /* Defeat write posting */ + local_irq_restore(flags); + return 0; +} + +static unsigned long intc_mode_field(unsigned long addr, + unsigned long handle, + unsigned long (*fn)(unsigned long, + unsigned long, + unsigned long), + unsigned int irq) +{ + return fn(addr, handle, ((1 << _INTC_WIDTH(handle)) - 1)); +} + +static unsigned long intc_mode_zero(unsigned long addr, + unsigned long handle, + unsigned long (*fn)(unsigned long, + unsigned long, + unsigned long), + unsigned int irq) +{ + return fn(addr, handle, 0); +} + +static unsigned long intc_mode_prio(unsigned long addr, + unsigned long handle, + unsigned long (*fn)(unsigned long, + unsigned long, + unsigned long), + unsigned int irq) +{ + return fn(addr, handle, intc_get_prio_level(irq)); +} + +unsigned long (*intc_reg_fns[])(unsigned long addr, + unsigned long h, + unsigned long data) = { + [REG_FN_TEST_BASE + 0] = test_8, + [REG_FN_TEST_BASE + 1] = test_16, + [REG_FN_TEST_BASE + 3] = test_32, + [REG_FN_WRITE_BASE + 0] = write_8, + [REG_FN_WRITE_BASE + 1] = write_16, + [REG_FN_WRITE_BASE + 3] = write_32, + [REG_FN_MODIFY_BASE + 0] = modify_8, + [REG_FN_MODIFY_BASE + 1] = modify_16, + [REG_FN_MODIFY_BASE + 3] = modify_32, +}; + +unsigned long (*intc_enable_fns[])(unsigned long addr, + unsigned long handle, + unsigned long (*fn)(unsigned long, + unsigned long, + unsigned long), + unsigned int irq) = { + [MODE_ENABLE_REG] = intc_mode_field, + [MODE_MASK_REG] = intc_mode_zero, + [MODE_DUAL_REG] = intc_mode_field, + [MODE_PRIO_REG] = intc_mode_prio, + [MODE_PCLR_REG] = intc_mode_prio, +}; + +unsigned long (*intc_disable_fns[])(unsigned long addr, + unsigned long handle, + unsigned long (*fn)(unsigned long, + unsigned long, + unsigned long), + unsigned int irq) = { + [MODE_ENABLE_REG] = intc_mode_zero, + [MODE_MASK_REG] = intc_mode_field, + [MODE_DUAL_REG] = intc_mode_field, + [MODE_PRIO_REG] = intc_mode_zero, + [MODE_PCLR_REG] = intc_mode_field, +}; + +unsigned long (*intc_enable_noprio_fns[])(unsigned long addr, + unsigned long handle, + unsigned long (*fn)(unsigned long, + unsigned long, + unsigned long), + unsigned int irq) = { + [MODE_ENABLE_REG] = intc_mode_field, + [MODE_MASK_REG] = intc_mode_zero, + [MODE_DUAL_REG] = intc_mode_field, + [MODE_PRIO_REG] = intc_mode_field, + [MODE_PCLR_REG] = intc_mode_field, +}; -- cgit v1.3.1