diff options
| -rw-r--r-- | include/linux/idr.h | 2 | ||||
| -rw-r--r-- | lib/idr.c | 31 |
2 files changed, 33 insertions, 0 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h index 7867d6117535..561a4cbabca6 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -131,6 +131,8 @@ static inline int idr_alloc_ext(struct idr *idr, void *ptr, return idr_alloc_cmn(idr, ptr, index, start, end, gfp, true); } +int __must_check idr_alloc_u32(struct idr *, void *ptr, u32 *nextid, + unsigned long max, gfp_t); int idr_alloc_cyclic(struct idr *, void *entry, int start, int end, gfp_t); int idr_for_each(const struct idr *, int (*fn)(int id, void *p, void *data), void *data); diff --git a/lib/idr.c b/lib/idr.c index 577bfd4fe5c2..6d4ec2c2982b 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -7,6 +7,37 @@ DEFINE_PER_CPU(struct ida_bitmap *, ida_bitmap); static DEFINE_SPINLOCK(simple_ida_lock); +/** + * idr_alloc_u32() - Allocate an ID. + * @idr: IDR handle. + * @ptr: Pointer to be associated with the new ID. + * @nextid: Pointer to an ID. + * @max: The maximum ID to allocate (inclusive). + * @gfp: Memory allocation flags. + * + * Allocates an unused ID in the range specified by @nextid and @max. + * Note that @max is inclusive whereas the @end parameter to idr_alloc() + * is exclusive. + * + * The caller should provide their own locking to ensure that two + * concurrent modifications to the IDR are not possible. Read-only + * accesses to the IDR may be done under the RCU read lock or may + * exclude simultaneous writers. + * + * Return: 0 if an ID was allocated, -ENOMEM if memory allocation failed, + * or -ENOSPC if no free IDs could be found. If an error occurred, + * @nextid is unchanged. + */ +int idr_alloc_u32(struct idr *idr, void *ptr, u32 *nextid, + unsigned long max, gfp_t gfp) +{ + unsigned long tmp = *nextid; + int ret = idr_alloc_ext(idr, ptr, &tmp, tmp, max + 1, gfp); + *nextid = tmp; + return ret; +} +EXPORT_SYMBOL_GPL(idr_alloc_u32); + int idr_alloc_cmn(struct idr *idr, void *ptr, unsigned long *index, unsigned long start, unsigned long end, gfp_t gfp, bool ext) |