X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Frtc%2Frtc-dev.c;h=856cc1af40df85efe53805822c62886af0754143;hb=561b35b341b1aeeab486affe1ede0ee6640ce33b;hp=814583bd2fe709c1da0710808ed6f4cffbe8b50f;hpb=4c5cdb1e1f2a502069f57a60b5c6b97b8106c73c;p=linux-2.6 diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c index 814583bd2f..856cc1af40 100644 --- a/drivers/rtc/rtc-dev.c +++ b/drivers/rtc/rtc-dev.c @@ -13,6 +13,7 @@ #include #include +#include #include "rtc-core.h" static dev_t rtc_devt; @@ -26,11 +27,11 @@ static int rtc_dev_open(struct inode *inode, struct file *file) struct rtc_device, char_dev); const struct rtc_class_ops *ops = rtc->ops; - /* We keep the lock as long as the device is in use - * and return immediately if busy - */ - if (!(mutex_trylock(&rtc->char_lock))) - return -EBUSY; + lock_kernel(); + if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) { + err = -EBUSY; + goto out; + } file->private_data = rtc; @@ -40,11 +41,13 @@ static int rtc_dev_open(struct inode *inode, struct file *file) rtc->irq_data = 0; spin_unlock_irq(&rtc->irq_lock); - return 0; + goto out; } - /* something has gone wrong, release the lock */ - mutex_unlock(&rtc->char_lock); + /* something has gone wrong */ + clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); +out: + unlock_kernel(); return err; } @@ -206,7 +209,7 @@ static unsigned int rtc_dev_poll(struct file *file, poll_table *wait) return (data != 0) ? (POLLIN | POLLRDNORM) : 0; } -static int rtc_dev_ioctl(struct inode *inode, struct file *file, +static long rtc_dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int err = 0; @@ -216,6 +219,10 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file, struct rtc_wkalrm alarm; void __user *uarg = (void __user *) arg; + err = mutex_lock_interruptible(&rtc->ops_lock); + if (err) + return err; + /* check that the calling task has appropriate permissions * for certain ioctls. doing this check here is useful * to avoid duplicate code in each driver. @@ -224,44 +231,62 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file, case RTC_EPOCH_SET: case RTC_SET_TIME: if (!capable(CAP_SYS_TIME)) - return -EACCES; + err = -EACCES; break; case RTC_IRQP_SET: if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE)) - return -EACCES; + err = -EACCES; break; case RTC_PIE_ON: if (rtc->irq_freq > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE)) - return -EACCES; + err = -EACCES; break; } + if (err) + goto done; + /* try the driver's ioctl interface */ if (ops->ioctl) { err = ops->ioctl(rtc->dev.parent, cmd, arg); - if (err != -ENOIOCTLCMD) + if (err != -ENOIOCTLCMD) { + mutex_unlock(&rtc->ops_lock); return err; + } } /* if the driver does not provide the ioctl interface * or if that particular ioctl was not implemented * (-ENOIOCTLCMD), we will try to emulate here. + * + * Drivers *SHOULD NOT* provide ioctl implementations + * for these requests. Instead, provide methods to + * support the following code, so that the RTC's main + * features are accessible without using ioctls. + * + * RTC and alarm times will be in UTC, by preference, + * but dual-booting with MS-Windows implies RTCs must + * use the local wall clock time. */ switch (cmd) { case RTC_ALM_READ: + mutex_unlock(&rtc->ops_lock); + err = rtc_read_alarm(rtc, &alarm); if (err < 0) return err; if (copy_to_user(uarg, &alarm.time, sizeof(tm))) - return -EFAULT; - break; + err = -EFAULT; + return err; case RTC_ALM_SET: + mutex_unlock(&rtc->ops_lock); + if (copy_from_user(&alarm.time, uarg, sizeof(tm))) return -EFAULT; @@ -309,24 +334,26 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file, } } - err = rtc_set_alarm(rtc, &alarm); - break; + return rtc_set_alarm(rtc, &alarm); case RTC_RD_TIME: + mutex_unlock(&rtc->ops_lock); + err = rtc_read_time(rtc, &tm); if (err < 0) return err; if (copy_to_user(uarg, &tm, sizeof(tm))) - return -EFAULT; - break; + err = -EFAULT; + return err; case RTC_SET_TIME: + mutex_unlock(&rtc->ops_lock); + if (copy_from_user(&tm, uarg, sizeof(tm))) return -EFAULT; - err = rtc_set_time(rtc, &tm); - break; + return rtc_set_time(rtc, &tm); case RTC_PIE_ON: err = rtc_irq_set_state(rtc, NULL, 1); @@ -364,34 +391,37 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file, break; #endif case RTC_WKALM_SET: + mutex_unlock(&rtc->ops_lock); if (copy_from_user(&alarm, uarg, sizeof(alarm))) return -EFAULT; - err = rtc_set_alarm(rtc, &alarm); - break; + return rtc_set_alarm(rtc, &alarm); case RTC_WKALM_RD: + mutex_unlock(&rtc->ops_lock); err = rtc_read_alarm(rtc, &alarm); if (err < 0) return err; if (copy_to_user(uarg, &alarm, sizeof(alarm))) - return -EFAULT; - break; + err = -EFAULT; + return err; #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL case RTC_UIE_OFF: clear_uie(rtc); - return 0; + break; case RTC_UIE_ON: - return set_uie(rtc); + err = set_uie(rtc); #endif default: err = -ENOTTY; break; } +done: + mutex_unlock(&rtc->ops_lock); return err; } @@ -402,10 +432,12 @@ static int rtc_dev_release(struct inode *inode, struct file *file) #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL clear_uie(rtc); #endif + rtc_irq_set_state(rtc, NULL, 0); + if (rtc->ops->release) rtc->ops->release(rtc->dev.parent); - mutex_unlock(&rtc->char_lock); + clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); return 0; } @@ -420,7 +452,7 @@ static const struct file_operations rtc_dev_fops = { .llseek = no_llseek, .read = rtc_dev_read, .poll = rtc_dev_poll, - .ioctl = rtc_dev_ioctl, + .unlocked_ioctl = rtc_dev_ioctl, .open = rtc_dev_open, .release = rtc_dev_release, .fasync = rtc_dev_fasync, @@ -440,7 +472,6 @@ void rtc_dev_prepare(struct rtc_device *rtc) rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id); - mutex_init(&rtc->char_lock); #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL INIT_WORK(&rtc->uie_task, rtc_uie_task); setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);