From ba4f3e47cb9ef72f864f1b5548688e0a195011e9 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Tue, 15 Dec 2009 16:45:58 -0800 Subject: [PATCH] rtc-ds1511: fix races around device registration - Call dev_set_drvdata before rtc device creation. - Use its own spinlock instead of rtc->irq_lock. Because pdata->rtc must be initialized to use the irq_lock (pdata->rtc->irq_lock). There is a small window which rtc methods can be called before pdata->rtc is initialized. And there is no need use the irq_lock to protect hardware registers. The driver's own spinlock shoule be enough. - Check pdata->rtc before calling rtc_update_irq. - Use {alarm,update}_irq_enable and remove ioctl routine. - Use devres APIs and simplify error/remove path. These fixes are ported from ds1553 driver and just compile-tested only. Signed-off-by: Atsushi Nemoto Cc: Andrew Sharp Cc: Thomas Hommel Cc: David Brownell Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-ds1511.c | 148 ++++++++++++++++----------------------- 1 file changed, 60 insertions(+), 88 deletions(-) diff --git a/drivers/rtc/rtc-ds1511.c b/drivers/rtc/rtc-ds1511.c index 539676e25fd8..4166b84cb514 100644 --- a/drivers/rtc/rtc-ds1511.c +++ b/drivers/rtc/rtc-ds1511.c @@ -87,7 +87,6 @@ enum ds1511reg { struct rtc_plat_data { struct rtc_device *rtc; void __iomem *ioaddr; /* virtual base address */ - unsigned long baseaddr; /* physical base address */ int size; /* amount of memory mapped */ int irq; unsigned int irqen; @@ -95,6 +94,7 @@ struct rtc_plat_data { int alrm_min; int alrm_hour; int alrm_mday; + spinlock_t lock; }; static DEFINE_SPINLOCK(ds1511_lock); @@ -302,7 +302,7 @@ ds1511_rtc_update_alarm(struct rtc_plat_data *pdata) { unsigned long flags; - spin_lock_irqsave(&pdata->rtc->irq_lock, flags); + spin_lock_irqsave(&pdata->lock, flags); rtc_write(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ? 0x80 : bin2bcd(pdata->alrm_mday) & 0x3f, RTC_ALARM_DATE); @@ -317,7 +317,7 @@ ds1511_rtc_update_alarm(struct rtc_plat_data *pdata) RTC_ALARM_SEC); rtc_write(rtc_read(RTC_CMD) | (pdata->irqen ? RTC_TIE : 0), RTC_CMD); rtc_read(RTC_CMD1); /* clear interrupts */ - spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags); + spin_unlock_irqrestore(&pdata->lock, flags); } static int @@ -362,61 +362,63 @@ ds1511_interrupt(int irq, void *dev_id) { struct platform_device *pdev = dev_id; struct rtc_plat_data *pdata = platform_get_drvdata(pdev); - unsigned long events = RTC_IRQF; + unsigned long events = 0; + spin_lock(&pdata->lock); /* * read and clear interrupt */ - if (!(rtc_read(RTC_CMD1) & DS1511_IRQF)) { - return IRQ_NONE; - } - if (rtc_read(RTC_ALARM_SEC) & 0x80) { - events |= RTC_UF; - } else { - events |= RTC_AF; - } - rtc_update_irq(pdata->rtc, 1, events); - return IRQ_HANDLED; + if (rtc_read(RTC_CMD1) & DS1511_IRQF) { + events = RTC_IRQF; + if (rtc_read(RTC_ALARM_SEC) & 0x80) + events |= RTC_UF; + else + events |= RTC_AF; + if (likely(pdata->rtc)) + rtc_update_irq(pdata->rtc, 1, events); + } + spin_unlock(&pdata->lock); + return events ? IRQ_HANDLED : IRQ_NONE; } - static int -ds1511_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) +static int ds1511_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); - if (pdata->irq <= 0) { - return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */ - } - switch (cmd) { - case RTC_AIE_OFF: - pdata->irqen &= ~RTC_AF; - ds1511_rtc_update_alarm(pdata); - break; - case RTC_AIE_ON: + if (pdata->irq <= 0) + return -EINVAL; + if (enabled) pdata->irqen |= RTC_AF; - ds1511_rtc_update_alarm(pdata); - break; - case RTC_UIE_OFF: - pdata->irqen &= ~RTC_UF; - ds1511_rtc_update_alarm(pdata); - break; - case RTC_UIE_ON: + else + pdata->irqen &= ~RTC_AF; + ds1511_rtc_update_alarm(pdata); + return 0; +} + +static int ds1511_rtc_update_irq_enable(struct device *dev, + unsigned int enabled) +{ + struct platform_device *pdev = to_platform_device(dev); + struct rtc_plat_data *pdata = platform_get_drvdata(pdev); + + if (pdata->irq <= 0) + return -EINVAL; + if (enabled) pdata->irqen |= RTC_UF; - ds1511_rtc_update_alarm(pdata); - break; - default: - return -ENOIOCTLCMD; - } + else + pdata->irqen &= ~RTC_UF; + ds1511_rtc_update_alarm(pdata); return 0; } static const struct rtc_class_ops ds1511_rtc_ops = { - .read_time = ds1511_rtc_read_time, - .set_time = ds1511_rtc_set_time, - .read_alarm = ds1511_rtc_read_alarm, - .set_alarm = ds1511_rtc_set_alarm, - .ioctl = ds1511_rtc_ioctl, + .read_time = ds1511_rtc_read_time, + .set_time = ds1511_rtc_set_time, + .read_alarm = ds1511_rtc_read_alarm, + .set_alarm = ds1511_rtc_set_alarm, + .alarm_irq_enable = ds1511_rtc_alarm_irq_enable, + .update_irq_enable = ds1511_rtc_update_irq_enable, }; static ssize_t @@ -492,29 +494,23 @@ ds1511_rtc_probe(struct platform_device *pdev) { struct rtc_device *rtc; struct resource *res; - struct rtc_plat_data *pdata = NULL; + struct rtc_plat_data *pdata; int ret = 0; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { return -ENODEV; } - pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); - if (!pdata) { + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) return -ENOMEM; - } pdata->size = res->end - res->start + 1; - if (!request_mem_region(res->start, pdata->size, pdev->name)) { - ret = -EBUSY; - goto out; - } - pdata->baseaddr = res->start; - pdata->size = pdata->size; - ds1511_base = ioremap(pdata->baseaddr, pdata->size); - if (!ds1511_base) { - ret = -ENOMEM; - goto out; - } + if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size, + pdev->name)) + return -EBUSY; + ds1511_base = devm_ioremap(&pdev->dev, res->start, pdata->size); + if (!ds1511_base) + return -ENOMEM; pdata->ioaddr = ds1511_base; pdata->irq = platform_get_irq(pdev, 0); @@ -540,13 +536,15 @@ ds1511_rtc_probe(struct platform_device *pdev) dev_warn(&pdev->dev, "voltage-low detected.\n"); } + spin_lock_init(&pdata->lock); + platform_set_drvdata(pdev, pdata); /* * if the platform has an interrupt in mind for this device, * then by all means, set it */ if (pdata->irq > 0) { rtc_read(RTC_CMD1); - if (request_irq(pdata->irq, ds1511_interrupt, + if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt, IRQF_DISABLED | IRQF_SHARED, pdev->name, pdev) < 0) { dev_warn(&pdev->dev, "interrupt not available.\n"); @@ -556,33 +554,13 @@ ds1511_rtc_probe(struct platform_device *pdev) rtc = rtc_device_register(pdev->name, &pdev->dev, &ds1511_rtc_ops, THIS_MODULE); - if (IS_ERR(rtc)) { - ret = PTR_ERR(rtc); - goto out; - } + if (IS_ERR(rtc)) + return PTR_ERR(rtc); pdata->rtc = rtc; - platform_set_drvdata(pdev, pdata); + ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr); - if (ret) { - goto out; - } - return 0; - out: - if (pdata->rtc) { + if (ret) rtc_device_unregister(pdata->rtc); - } - if (pdata->irq > 0) { - free_irq(pdata->irq, pdev); - } - if (ds1511_base) { - iounmap(ds1511_base); - ds1511_base = NULL; - } - if (pdata->baseaddr) { - release_mem_region(pdata->baseaddr, pdata->size); - } - - kfree(pdata); return ret; } @@ -593,19 +571,13 @@ ds1511_rtc_remove(struct platform_device *pdev) sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr); rtc_device_unregister(pdata->rtc); - pdata->rtc = NULL; if (pdata->irq > 0) { /* * disable the alarm interrupt */ rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD); rtc_read(RTC_CMD1); - free_irq(pdata->irq, pdev); } - iounmap(pdata->ioaddr); - ds1511_base = NULL; - release_mem_region(pdata->baseaddr, pdata->size); - kfree(pdata); return 0; } -- GitLab