From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/rtc/rtc-mv.c | 321 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 321 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..db64c459e --- /dev/null +++ b/drivers/rtc/rtc-mv.c @@ -0,0 +1,321 @@ +// 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_optional_prepared(&pdev->dev, NULL); + if (IS_ERR(pdata->clk)) + return PTR_ERR(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"); + return -EINVAL; + } + + /* 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"); + return -ENODEV; + } + } + + 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)) { + return PTR_ERR(pdata->rtc); + } + + 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) + devm_device_init_wakeup(&pdev->dev); + 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; + + return ret; +} + +#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); + +static struct platform_driver mv_rtc_driver = { + .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