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/rtc/rtc-mv.c | 346 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 346 insertions(+) create mode 100644 drivers/rtc/rtc-mv.c (limited to 'drivers/rtc/rtc-mv.c') diff --git a/drivers/rtc/rtc-mv.c b/drivers/rtc/rtc-mv.c new file mode 100644 index 000000000..f88976fd6 --- /dev/null +++ b/drivers/rtc/rtc-mv.c @@ -0,0 +1,346 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Driver for the RTC in Marvell SoCs. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +#define RTC_TIME_REG_OFFS 0 +#define RTC_SECONDS_OFFS 0 +#define RTC_MINUTES_OFFS 8 +#define RTC_HOURS_OFFS 16 +#define RTC_WDAY_OFFS 24 +#define RTC_HOURS_12H_MODE BIT(22) /* 12 hour mode */ + +#define RTC_DATE_REG_OFFS 4 +#define RTC_MDAY_OFFS 0 +#define RTC_MONTH_OFFS 8 +#define RTC_YEAR_OFFS 16 + +#define RTC_ALARM_TIME_REG_OFFS 8 +#define RTC_ALARM_DATE_REG_OFFS 0xc +#define RTC_ALARM_VALID BIT(7) + +#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS 0x10 +#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS 0x14 + +struct rtc_plat_data { + struct rtc_device *rtc; + void __iomem *ioaddr; + int irq; + struct clk *clk; +}; + +static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct rtc_plat_data *pdata = dev_get_drvdata(dev); + void __iomem *ioaddr = pdata->ioaddr; + u32 rtc_reg; + + rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) | + (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) | + (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) | + (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS); + writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS); + + rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) | + (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) | + (bin2bcd(tm->tm_year - 100) << RTC_YEAR_OFFS); + writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS); + + return 0; +} + +static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct rtc_plat_data *pdata = dev_get_drvdata(dev); + void __iomem *ioaddr = pdata->ioaddr; + u32 rtc_time, rtc_date; + unsigned int year, month, day, hour, minute, second, wday; + + rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS); + rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS); + + second = rtc_time & 0x7f; + minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f; + hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */ + wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7; + + day = rtc_date & 0x3f; + month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f; + year = (rtc_date >> RTC_YEAR_OFFS) & 0xff; + + tm->tm_sec = bcd2bin(second); + tm->tm_min = bcd2bin(minute); + tm->tm_hour = bcd2bin(hour); + tm->tm_mday = bcd2bin(day); + tm->tm_wday = bcd2bin(wday); + tm->tm_mon = bcd2bin(month) - 1; + /* hw counts from year 2000, but tm_year is relative to 1900 */ + tm->tm_year = bcd2bin(year) + 100; + + return 0; +} + +static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct rtc_plat_data *pdata = dev_get_drvdata(dev); + void __iomem *ioaddr = pdata->ioaddr; + u32 rtc_time, rtc_date; + unsigned int year, month, day, hour, minute, second, wday; + + rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS); + rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS); + + second = rtc_time & 0x7f; + minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f; + hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */ + wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7; + + day = rtc_date & 0x3f; + month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f; + year = (rtc_date >> RTC_YEAR_OFFS) & 0xff; + + alm->time.tm_sec = bcd2bin(second); + alm->time.tm_min = bcd2bin(minute); + alm->time.tm_hour = bcd2bin(hour); + alm->time.tm_mday = bcd2bin(day); + alm->time.tm_wday = bcd2bin(wday); + alm->time.tm_mon = bcd2bin(month) - 1; + /* hw counts from year 2000, but tm_year is relative to 1900 */ + alm->time.tm_year = bcd2bin(year) + 100; + + alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); + + return rtc_valid_tm(&alm->time); +} + +static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct rtc_plat_data *pdata = dev_get_drvdata(dev); + void __iomem *ioaddr = pdata->ioaddr; + u32 rtc_reg = 0; + + if (alm->time.tm_sec >= 0) + rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec)) + << RTC_SECONDS_OFFS; + if (alm->time.tm_min >= 0) + rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min)) + << RTC_MINUTES_OFFS; + if (alm->time.tm_hour >= 0) + rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour)) + << RTC_HOURS_OFFS; + + writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS); + + if (alm->time.tm_mday >= 0) + rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday)) + << RTC_MDAY_OFFS; + else + rtc_reg = 0; + + if (alm->time.tm_mon >= 0) + rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1)) + << RTC_MONTH_OFFS; + + if (alm->time.tm_year >= 0) + rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year - 100)) + << RTC_YEAR_OFFS; + + writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS); + writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS); + writel(alm->enabled ? 1 : 0, + ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); + + return 0; +} + +static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct rtc_plat_data *pdata = dev_get_drvdata(dev); + void __iomem *ioaddr = pdata->ioaddr; + + if (pdata->irq < 0) + return -EINVAL; /* fall back into rtc-dev's emulation */ + + if (enabled) + writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); + else + writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); + return 0; +} + +static irqreturn_t mv_rtc_interrupt(int irq, void *data) +{ + struct rtc_plat_data *pdata = data; + void __iomem *ioaddr = pdata->ioaddr; + + /* alarm irq? */ + if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS)) + return IRQ_NONE; + + /* clear interrupt */ + writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS); + rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF); + return IRQ_HANDLED; +} + +static const struct rtc_class_ops mv_rtc_ops = { + .read_time = mv_rtc_read_time, + .set_time = mv_rtc_set_time, + .read_alarm = mv_rtc_read_alarm, + .set_alarm = mv_rtc_set_alarm, + .alarm_irq_enable = mv_rtc_alarm_irq_enable, +}; + +static int __init mv_rtc_probe(struct platform_device *pdev) +{ + struct rtc_plat_data *pdata; + u32 rtc_time; + int ret = 0; + + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(pdata->ioaddr)) + return PTR_ERR(pdata->ioaddr); + + pdata->clk = devm_clk_get(&pdev->dev, NULL); + /* Not all SoCs require a clock.*/ + if (!IS_ERR(pdata->clk)) + clk_prepare_enable(pdata->clk); + + /* make sure the 24 hour mode is enabled */ + rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); + if (rtc_time & RTC_HOURS_12H_MODE) { + dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n"); + ret = -EINVAL; + goto out; + } + + /* make sure it is actually functional */ + if (rtc_time == 0x01000000) { + ssleep(1); + rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); + if (rtc_time == 0x01000000) { + dev_err(&pdev->dev, "internal RTC not ticking\n"); + ret = -ENODEV; + goto out; + } + } + + pdata->irq = platform_get_irq(pdev, 0); + + platform_set_drvdata(pdev, pdata); + + pdata->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(pdata->rtc)) { + ret = PTR_ERR(pdata->rtc); + goto out; + } + + if (pdata->irq >= 0) { + writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); + if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt, + IRQF_SHARED, + pdev->name, pdata) < 0) { + dev_warn(&pdev->dev, "interrupt not available.\n"); + pdata->irq = -1; + } + } + + if (pdata->irq >= 0) + device_init_wakeup(&pdev->dev, true); + else + clear_bit(RTC_FEATURE_ALARM, pdata->rtc->features); + + pdata->rtc->ops = &mv_rtc_ops; + pdata->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + pdata->rtc->range_max = RTC_TIMESTAMP_END_2099; + + ret = devm_rtc_register_device(pdata->rtc); + if (!ret) + return 0; +out: + if (!IS_ERR(pdata->clk)) + clk_disable_unprepare(pdata->clk); + + return ret; +} + +static void __exit mv_rtc_remove(struct platform_device *pdev) +{ + struct rtc_plat_data *pdata = platform_get_drvdata(pdev); + + if (pdata->irq >= 0) + device_init_wakeup(&pdev->dev, false); + + if (!IS_ERR(pdata->clk)) + clk_disable_unprepare(pdata->clk); +} + +#ifdef CONFIG_OF +static const struct of_device_id rtc_mv_of_match_table[] = { + { .compatible = "marvell,orion-rtc", }, + {} +}; +MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table); +#endif + +#ifdef CONFIG_PM_SLEEP +static int mv_rtc_suspend(struct device *dev) +{ + struct rtc_plat_data *pdata = dev_get_drvdata(dev); + + if (device_may_wakeup(dev) && pdata->irq >= 0) + enable_irq_wake(pdata->irq); + return 0; +} + +static int mv_rtc_resume(struct device *dev) +{ + struct rtc_plat_data *pdata = dev_get_drvdata(dev); + + if (device_may_wakeup(dev) && pdata->irq >= 0) + disable_irq_wake(pdata->irq); + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(mv_rtc_pm_ops, mv_rtc_suspend, mv_rtc_resume); + +/* + * mv_rtc_remove() lives in .exit.text. For drivers registered via + * module_platform_driver_probe() this is ok because they cannot get unbound at + * runtime. So mark the driver struct with __refdata to prevent modpost + * triggering a section mismatch warning. + */ +static struct platform_driver mv_rtc_driver __refdata = { + .remove = __exit_p(mv_rtc_remove), + .driver = { + .name = "rtc-mv", + .of_match_table = of_match_ptr(rtc_mv_of_match_table), + .pm = &mv_rtc_pm_ops, + }, +}; + +module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe); + +MODULE_AUTHOR("Saeed Bishara "); +MODULE_DESCRIPTION("Marvell RTC driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:rtc-mv"); -- cgit v1.3.1