diff options
| -rw-r--r-- | drivers/hwmon/hwmon.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c index dddd3eb9b38..106fa01cdb6 100644 --- a/drivers/hwmon/hwmon.c +++ b/drivers/hwmon/hwmon.c @@ -17,6 +17,7 @@ #include <linux/idr.h> #include <linux/hwmon.h> #include <linux/gfp.h> +#include <linux/spinlock.h> #define HWMON_ID_PREFIX "hwmon" #define HWMON_ID_FORMAT HWMON_ID_PREFIX "%d" @@ -24,6 +25,7 @@ static struct class *hwmon_class; static DEFINE_IDR(hwmon_idr); +static DEFINE_SPINLOCK(idr_lock); /** * hwmon_device_register - register w/ hwmon sysfs class @@ -37,20 +39,30 @@ static DEFINE_IDR(hwmon_idr); struct class_device *hwmon_device_register(struct device *dev) { struct class_device *cdev; - int id; + int id, err; - if (idr_pre_get(&hwmon_idr, GFP_KERNEL) == 0) +again: + if (unlikely(idr_pre_get(&hwmon_idr, GFP_KERNEL) == 0)) return ERR_PTR(-ENOMEM); - if (idr_get_new(&hwmon_idr, NULL, &id) < 0) - return ERR_PTR(-ENOMEM); + spin_lock(&idr_lock); + err = idr_get_new(&hwmon_idr, NULL, &id); + spin_unlock(&idr_lock); + + if (unlikely(err == -EAGAIN)) + goto again; + else if (unlikely(err)) + return ERR_PTR(err); id = id & MAX_ID_MASK; cdev = class_device_create(hwmon_class, NULL, MKDEV(0,0), dev, HWMON_ID_FORMAT, id); - if (IS_ERR(cdev)) + if (IS_ERR(cdev)) { + spin_lock(&idr_lock); idr_remove(&hwmon_idr, id); + spin_unlock(&idr_lock); + } return cdev; } @@ -64,9 +76,11 @@ void hwmon_device_unregister(struct class_device *cdev) { int id; - if (sscanf(cdev->class_id, HWMON_ID_FORMAT, &id) == 1) { + if (likely(sscanf(cdev->class_id, HWMON_ID_FORMAT, &id) == 1)) { class_device_unregister(cdev); + spin_lock(&idr_lock); idr_remove(&hwmon_idr, id); + spin_unlock(&idr_lock); } else dev_dbg(cdev->dev, "hwmon_device_unregister() failed: bad class ID!\n"); |