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/clocksource/timer-orion.c | 189 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 189 insertions(+) create mode 100644 drivers/clocksource/timer-orion.c (limited to 'drivers/clocksource/timer-orion.c') diff --git a/drivers/clocksource/timer-orion.c b/drivers/clocksource/timer-orion.c new file mode 100644 index 000000000..61f1e27fc --- /dev/null +++ b/drivers/clocksource/timer-orion.c @@ -0,0 +1,189 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Marvell Orion SoC timer handling. + * + * Sebastian Hesselbarth + * + * Timer 0 is used as free-running clocksource, while timer 1 is + * used as clock_event_device. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define TIMER_CTRL 0x00 +#define TIMER0_EN BIT(0) +#define TIMER0_RELOAD_EN BIT(1) +#define TIMER1_EN BIT(2) +#define TIMER1_RELOAD_EN BIT(3) +#define TIMER0_RELOAD 0x10 +#define TIMER0_VAL 0x14 +#define TIMER1_RELOAD 0x18 +#define TIMER1_VAL 0x1c + +#define ORION_ONESHOT_MIN 1 +#define ORION_ONESHOT_MAX 0xfffffffe + +static void __iomem *timer_base; + +static unsigned long notrace orion_read_timer(void) +{ + return ~readl(timer_base + TIMER0_VAL); +} + +static struct delay_timer orion_delay_timer = { + .read_current_timer = orion_read_timer, +}; + +static void __init orion_delay_timer_init(unsigned long rate) +{ + orion_delay_timer.freq = rate; + register_current_timer_delay(&orion_delay_timer); +} + +/* + * Free-running clocksource handling. + */ +static u64 notrace orion_read_sched_clock(void) +{ + return ~readl(timer_base + TIMER0_VAL); +} + +/* + * Clockevent handling. + */ +static u32 ticks_per_jiffy; + +static int orion_clkevt_next_event(unsigned long delta, + struct clock_event_device *dev) +{ + /* setup and enable one-shot timer */ + writel(delta, timer_base + TIMER1_VAL); + atomic_io_modify(timer_base + TIMER_CTRL, + TIMER1_RELOAD_EN | TIMER1_EN, TIMER1_EN); + + return 0; +} + +static int orion_clkevt_shutdown(struct clock_event_device *dev) +{ + /* disable timer */ + atomic_io_modify(timer_base + TIMER_CTRL, + TIMER1_RELOAD_EN | TIMER1_EN, 0); + return 0; +} + +static int orion_clkevt_set_periodic(struct clock_event_device *dev) +{ + /* setup and enable periodic timer at 1/HZ intervals */ + writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD); + writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL); + atomic_io_modify(timer_base + TIMER_CTRL, + TIMER1_RELOAD_EN | TIMER1_EN, + TIMER1_RELOAD_EN | TIMER1_EN); + return 0; +} + +static struct clock_event_device orion_clkevt = { + .name = "orion_event", + .features = CLOCK_EVT_FEAT_ONESHOT | + CLOCK_EVT_FEAT_PERIODIC, + .shift = 32, + .rating = 300, + .set_next_event = orion_clkevt_next_event, + .set_state_shutdown = orion_clkevt_shutdown, + .set_state_periodic = orion_clkevt_set_periodic, + .set_state_oneshot = orion_clkevt_shutdown, + .tick_resume = orion_clkevt_shutdown, +}; + +static irqreturn_t orion_clkevt_irq_handler(int irq, void *dev_id) +{ + orion_clkevt.event_handler(&orion_clkevt); + return IRQ_HANDLED; +} + +static int __init orion_timer_init(struct device_node *np) +{ + unsigned long rate; + struct clk *clk; + int irq, ret; + + /* timer registers are shared with watchdog timer */ + timer_base = of_iomap(np, 0); + if (!timer_base) { + pr_err("%pOFn: unable to map resource\n", np); + return -ENXIO; + } + + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) { + pr_err("%pOFn: unable to get clk\n", np); + return PTR_ERR(clk); + } + + ret = clk_prepare_enable(clk); + if (ret) { + pr_err("Failed to prepare clock\n"); + return ret; + } + + /* we are only interested in timer1 irq */ + irq = irq_of_parse_and_map(np, 1); + if (irq <= 0) { + pr_err("%pOFn: unable to parse timer1 irq\n", np); + ret = -EINVAL; + goto out_unprep_clk; + } + + rate = clk_get_rate(clk); + + /* setup timer0 as free-running clocksource */ + writel(~0, timer_base + TIMER0_VAL); + writel(~0, timer_base + TIMER0_RELOAD); + atomic_io_modify(timer_base + TIMER_CTRL, + TIMER0_RELOAD_EN | TIMER0_EN, + TIMER0_RELOAD_EN | TIMER0_EN); + + ret = clocksource_mmio_init(timer_base + TIMER0_VAL, + "orion_clocksource", rate, 300, 32, + clocksource_mmio_readl_down); + if (ret) { + pr_err("Failed to initialize mmio timer\n"); + goto out_unprep_clk; + } + + sched_clock_register(orion_read_sched_clock, 32, rate); + + /* setup timer1 as clockevent timer */ + ret = request_irq(irq, orion_clkevt_irq_handler, IRQF_TIMER, + "orion_event", NULL); + if (ret) { + pr_err("%pOFn: unable to setup irq\n", np); + goto out_unprep_clk; + } + + ticks_per_jiffy = (clk_get_rate(clk) + HZ/2) / HZ; + orion_clkevt.cpumask = cpumask_of(0); + orion_clkevt.irq = irq; + clockevents_config_and_register(&orion_clkevt, rate, + ORION_ONESHOT_MIN, ORION_ONESHOT_MAX); + + + orion_delay_timer_init(rate); + + return 0; + +out_unprep_clk: + clk_disable_unprepare(clk); + return ret; +} +TIMER_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init); -- cgit v1.3.1