diff options
| -rw-r--r-- | include/linux/idr.h | 59 | ||||
| -rw-r--r-- | lib/idr.c | 70 |
2 files changed, 87 insertions, 42 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h index e856f4e0ab35..cd339da0b1aa 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -230,15 +230,68 @@ int ida_get_new_above(struct ida *ida, int starting_id, int *p_id); void ida_remove(struct ida *ida, int id); void ida_destroy(struct ida *ida); -int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end, - gfp_t gfp_mask); -void ida_simple_remove(struct ida *ida, unsigned int id); +int ida_alloc_range(struct ida *, unsigned int min, unsigned int max, gfp_t); +void ida_free(struct ida *, unsigned int id); + +/** + * ida_alloc() - Allocate an unused ID. + * @ida: IDA handle. + * @gfp: Memory allocation flags. + * + * Allocate an ID between 0 and %INT_MAX, inclusive. + * + * Context: Any context. + * Return: The allocated ID, or %-ENOMEM if memory could not be allocated, + * or %-ENOSPC if there are no free IDs. + */ +static inline int ida_alloc(struct ida *ida, gfp_t gfp) +{ + return ida_alloc_range(ida, 0, ~0, gfp); +} + +/** + * ida_alloc_min() - Allocate an unused ID. + * @ida: IDA handle. + * @min: Lowest ID to allocate. + * @gfp: Memory allocation flags. + * + * Allocate an ID between @min and %INT_MAX, inclusive. + * + * Context: Any context. + * Return: The allocated ID, or %-ENOMEM if memory could not be allocated, + * or %-ENOSPC if there are no free IDs. + */ +static inline int ida_alloc_min(struct ida *ida, unsigned int min, gfp_t gfp) +{ + return ida_alloc_range(ida, min, ~0, gfp); +} + +/** + * ida_alloc_max() - Allocate an unused ID. + * @ida: IDA handle. + * @max: Highest ID to allocate. + * @gfp: Memory allocation flags. + * + * Allocate an ID between 0 and @max, inclusive. + * + * Context: Any context. + * Return: The allocated ID, or %-ENOMEM if memory could not be allocated, + * or %-ENOSPC if there are no free IDs. + */ +static inline int ida_alloc_max(struct ida *ida, unsigned int max, gfp_t gfp) +{ + return ida_alloc_range(ida, 0, max, gfp); +} static inline void ida_init(struct ida *ida) { INIT_RADIX_TREE(&ida->ida_rt, IDR_RT_MARKER | GFP_NOWAIT); } +#define ida_simple_get(ida, start, end, gfp) \ + ida_alloc_range(ida, start, (end) - 1, gfp) +#define ida_simple_remove(ida, id) ida_free(ida, id) + /** * ida_get_new - allocate new ID * @ida: idr handle diff --git a/lib/idr.c b/lib/idr.c index 352c6160e2e0..760fce92f1fb 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -317,7 +317,8 @@ EXPORT_SYMBOL(idr_replace); * bit per ID, and so is more space efficient than an IDR. To use an IDA, * define it using DEFINE_IDA() (or embed a &struct ida in a data structure, * then initialise it using ida_init()). To allocate a new ID, call - * ida_simple_get(). To free an ID, call ida_simple_remove(). + * ida_alloc(), ida_alloc_min(), ida_alloc_max() or ida_alloc_range(). + * To free an ID, call ida_free(). * * If you have more complex locking requirements, use a loop around * ida_pre_get() and ida_get_new() to allocate a new ID. Then use @@ -378,7 +379,7 @@ EXPORT_SYMBOL(idr_replace); * Allocate new ID above or equal to @start. It should be called * with any required locks to ensure that concurrent calls to * ida_get_new_above() / ida_get_new() / ida_remove() are not allowed. - * Consider using ida_simple_get() if you do not have complex locking + * Consider using ida_alloc_range() if you do not have complex locking * requirements. * * If memory is required, it will return %-EAGAIN, you should unlock @@ -551,43 +552,34 @@ void ida_destroy(struct ida *ida) EXPORT_SYMBOL(ida_destroy); /** - * ida_simple_get - get a new id. - * @ida: the (initialized) ida. - * @start: the minimum id (inclusive, < 0x8000000) - * @end: the maximum id (exclusive, < 0x8000000 or 0) - * @gfp_mask: memory allocation flags - * - * Allocates an id in the range start <= id < end, or returns -ENOSPC. - * On memory allocation failure, returns -ENOMEM. + * ida_alloc_range() - Allocate an unused ID. + * @ida: IDA handle. + * @min: Lowest ID to allocate. + * @max: Highest ID to allocate. + * @gfp: Memory allocation flags. * - * Compared to ida_get_new_above() this function does its own locking, and - * should be used unless there are special requirements. + * Allocate an ID between @min and @max, inclusive. The allocated ID will + * not exceed %INT_MAX, even if @max is larger. * - * Use ida_simple_remove() to get rid of an id. + * Context: Any context. + * Return: The allocated ID, or %-ENOMEM if memory could not be allocated, + * or %-ENOSPC if there are no free IDs. */ -int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end, - gfp_t gfp_mask) +int ida_alloc_range(struct ida *ida, unsigned int min, unsigned int max, + gfp_t gfp) { int ret, id; - unsigned int max; unsigned long flags; - BUG_ON((int)start < 0); - BUG_ON((int)end < 0); + if ((int)min < 0) + return -ENOSPC; - if (end == 0) - max = 0x80000000; - else { - BUG_ON(end < start); - max = end - 1; - } + if ((int)max < 0) + max = INT_MAX; again: - if (!ida_pre_get(ida, gfp_mask)) - return -ENOMEM; - xa_lock_irqsave(&ida->ida_rt, flags); - ret = ida_get_new_above(ida, start, &id); + ret = ida_get_new_above(ida, min, &id); if (!ret) { if (id > max) { ida_remove(ida, id); @@ -598,24 +590,24 @@ again: } xa_unlock_irqrestore(&ida->ida_rt, flags); - if (unlikely(ret == -EAGAIN)) + if (unlikely(ret == -EAGAIN)) { + if (!ida_pre_get(ida, gfp)) + return -ENOMEM; goto again; + } return ret; } -EXPORT_SYMBOL(ida_simple_get); +EXPORT_SYMBOL(ida_alloc_range); /** - * ida_simple_remove - remove an allocated id. - * @ida: the (initialized) ida. - * @id: the id returned by ida_simple_get. - * - * Use to release an id allocated with ida_simple_get(). + * ida_free() - Release an allocated ID. + * @ida: IDA handle. + * @id: Previously allocated ID. * - * Compared to ida_remove() this function does its own locking, and should be - * used unless there are special requirements. + * Context: Any context. */ -void ida_simple_remove(struct ida *ida, unsigned int id) +void ida_free(struct ida *ida, unsigned int id) { unsigned long flags; @@ -624,4 +616,4 @@ void ida_simple_remove(struct ida *ida, unsigned int id) ida_remove(ida, id); xa_unlock_irqrestore(&ida->ida_rt, flags); } -EXPORT_SYMBOL(ida_simple_remove); +EXPORT_SYMBOL(ida_free); |