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 --- arch/mips/bcm63xx/timer.c | 206 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 206 insertions(+) create mode 100644 arch/mips/bcm63xx/timer.c (limited to 'arch/mips/bcm63xx/timer.c') diff --git a/arch/mips/bcm63xx/timer.c b/arch/mips/bcm63xx/timer.c new file mode 100644 index 000000000..74b83807d --- /dev/null +++ b/arch/mips/bcm63xx/timer.c @@ -0,0 +1,206 @@ +/* + * 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. + * + * Copyright (C) 2008 Maxime Bizon + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static DEFINE_RAW_SPINLOCK(timer_reg_lock); +static DEFINE_RAW_SPINLOCK(timer_data_lock); +static struct clk *periph_clk; + +static struct timer_data { + void (*cb)(void *); + void *data; +} timer_data[BCM63XX_TIMER_COUNT]; + +static irqreturn_t timer_interrupt(int irq, void *dev_id) +{ + u32 stat; + int i; + + raw_spin_lock(&timer_reg_lock); + stat = bcm_timer_readl(TIMER_IRQSTAT_REG); + bcm_timer_writel(stat, TIMER_IRQSTAT_REG); + raw_spin_unlock(&timer_reg_lock); + + for (i = 0; i < BCM63XX_TIMER_COUNT; i++) { + if (!(stat & TIMER_IRQSTAT_TIMER_CAUSE(i))) + continue; + + raw_spin_lock(&timer_data_lock); + if (!timer_data[i].cb) { + raw_spin_unlock(&timer_data_lock); + continue; + } + + timer_data[i].cb(timer_data[i].data); + raw_spin_unlock(&timer_data_lock); + } + + return IRQ_HANDLED; +} + +int bcm63xx_timer_enable(int id) +{ + u32 reg; + unsigned long flags; + + if (id >= BCM63XX_TIMER_COUNT) + return -EINVAL; + + raw_spin_lock_irqsave(&timer_reg_lock, flags); + + reg = bcm_timer_readl(TIMER_CTLx_REG(id)); + reg |= TIMER_CTL_ENABLE_MASK; + bcm_timer_writel(reg, TIMER_CTLx_REG(id)); + + reg = bcm_timer_readl(TIMER_IRQSTAT_REG); + reg |= TIMER_IRQSTAT_TIMER_IR_EN(id); + bcm_timer_writel(reg, TIMER_IRQSTAT_REG); + + raw_spin_unlock_irqrestore(&timer_reg_lock, flags); + return 0; +} + +EXPORT_SYMBOL(bcm63xx_timer_enable); + +int bcm63xx_timer_disable(int id) +{ + u32 reg; + unsigned long flags; + + if (id >= BCM63XX_TIMER_COUNT) + return -EINVAL; + + raw_spin_lock_irqsave(&timer_reg_lock, flags); + + reg = bcm_timer_readl(TIMER_CTLx_REG(id)); + reg &= ~TIMER_CTL_ENABLE_MASK; + bcm_timer_writel(reg, TIMER_CTLx_REG(id)); + + reg = bcm_timer_readl(TIMER_IRQSTAT_REG); + reg &= ~TIMER_IRQSTAT_TIMER_IR_EN(id); + bcm_timer_writel(reg, TIMER_IRQSTAT_REG); + + raw_spin_unlock_irqrestore(&timer_reg_lock, flags); + return 0; +} + +EXPORT_SYMBOL(bcm63xx_timer_disable); + +int bcm63xx_timer_register(int id, void (*callback)(void *data), void *data) +{ + unsigned long flags; + int ret; + + if (id >= BCM63XX_TIMER_COUNT || !callback) + return -EINVAL; + + ret = 0; + raw_spin_lock_irqsave(&timer_data_lock, flags); + if (timer_data[id].cb) { + ret = -EBUSY; + goto out; + } + + timer_data[id].cb = callback; + timer_data[id].data = data; + +out: + raw_spin_unlock_irqrestore(&timer_data_lock, flags); + return ret; +} + +EXPORT_SYMBOL(bcm63xx_timer_register); + +void bcm63xx_timer_unregister(int id) +{ + unsigned long flags; + + if (id >= BCM63XX_TIMER_COUNT) + return; + + raw_spin_lock_irqsave(&timer_data_lock, flags); + timer_data[id].cb = NULL; + raw_spin_unlock_irqrestore(&timer_data_lock, flags); +} + +EXPORT_SYMBOL(bcm63xx_timer_unregister); + +unsigned int bcm63xx_timer_countdown(unsigned int countdown_us) +{ + return (clk_get_rate(periph_clk) / (1000 * 1000)) * countdown_us; +} + +EXPORT_SYMBOL(bcm63xx_timer_countdown); + +int bcm63xx_timer_set(int id, int monotonic, unsigned int countdown_us) +{ + u32 reg, countdown; + unsigned long flags; + + if (id >= BCM63XX_TIMER_COUNT) + return -EINVAL; + + countdown = bcm63xx_timer_countdown(countdown_us); + if (countdown & ~TIMER_CTL_COUNTDOWN_MASK) + return -EINVAL; + + raw_spin_lock_irqsave(&timer_reg_lock, flags); + reg = bcm_timer_readl(TIMER_CTLx_REG(id)); + + if (monotonic) + reg &= ~TIMER_CTL_MONOTONIC_MASK; + else + reg |= TIMER_CTL_MONOTONIC_MASK; + + reg &= ~TIMER_CTL_COUNTDOWN_MASK; + reg |= countdown; + bcm_timer_writel(reg, TIMER_CTLx_REG(id)); + + raw_spin_unlock_irqrestore(&timer_reg_lock, flags); + return 0; +} + +EXPORT_SYMBOL(bcm63xx_timer_set); + +static int bcm63xx_timer_init(void) +{ + int ret, irq; + u32 reg; + + reg = bcm_timer_readl(TIMER_IRQSTAT_REG); + reg &= ~TIMER_IRQSTAT_TIMER0_IR_EN; + reg &= ~TIMER_IRQSTAT_TIMER1_IR_EN; + reg &= ~TIMER_IRQSTAT_TIMER2_IR_EN; + bcm_timer_writel(reg, TIMER_IRQSTAT_REG); + + periph_clk = clk_get(NULL, "periph"); + if (IS_ERR(periph_clk)) + return -ENODEV; + + irq = bcm63xx_get_irq_number(IRQ_TIMER); + ret = request_irq(irq, timer_interrupt, 0, "bcm63xx_timer", NULL); + if (ret) { + pr_err("%s: failed to register irq\n", __func__); + return ret; + } + + return 0; +} + +arch_initcall(bcm63xx_timer_init); -- cgit v1.3.1