diff options
Diffstat (limited to 'include/linux/xarray.h')
| -rw-r--r-- | include/linux/xarray.h | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/include/linux/xarray.h b/include/linux/xarray.h index 883bb958e462..5ed6b462e754 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -242,6 +242,7 @@ enum xa_lock_type { #define XA_FLAGS_LOCK_BH ((__force gfp_t)XA_LOCK_BH) #define XA_FLAGS_TRACK_FREE ((__force gfp_t)4U) #define XA_FLAGS_ZERO_BUSY ((__force gfp_t)8U) +#define XA_FLAGS_ALLOC_WRAPPED ((__force gfp_t)16U) #define XA_FLAGS_MARK(mark) ((__force gfp_t)((1U << __GFP_BITS_SHIFT) << \ (__force unsigned)(mark))) @@ -499,6 +500,8 @@ void *__xa_cmpxchg(struct xarray *, unsigned long index, void *old, int __xa_insert(struct xarray *, unsigned long index, void *entry, gfp_t); int __must_check __xa_alloc(struct xarray *, u32 *id, void *entry, struct xa_limit, gfp_t); +int __must_check __xa_alloc_cyclic(struct xarray *, u32 *id, void *entry, + struct xa_limit, u32 *next, gfp_t); int __xa_reserve(struct xarray *, unsigned long index, gfp_t); void __xa_set_mark(struct xarray *, unsigned long index, xa_mark_t); void __xa_clear_mark(struct xarray *, unsigned long index, xa_mark_t); @@ -859,6 +862,105 @@ static inline int __must_check xa_alloc_irq(struct xarray *xa, u32 *id, } /** + * xa_alloc_cyclic() - Find somewhere to store this entry in the XArray. + * @xa: XArray. + * @id: Pointer to ID. + * @entry: New entry. + * @limit: Range of allocated ID. + * @next: Pointer to next ID to allocate. + * @gfp: Memory allocation flags. + * + * Finds an empty entry in @xa between @limit.min and @limit.max, + * stores the index into the @id pointer, then stores the entry at + * that index. A concurrent lookup will not see an uninitialised @id. + * The search for an empty entry will start at @next and will wrap + * around if necessary. + * + * Context: Any context. Takes and releases the xa_lock. May sleep if + * the @gfp flags permit. + * Return: 0 if the allocation succeeded without wrapping. 1 if the + * allocation succeeded after wrapping, -ENOMEM if memory could not be + * allocated or -EBUSY if there are no free entries in @limit. + */ +static inline int xa_alloc_cyclic(struct xarray *xa, u32 *id, void *entry, + struct xa_limit limit, u32 *next, gfp_t gfp) +{ + int err; + + xa_lock(xa); + err = __xa_alloc_cyclic(xa, id, entry, limit, next, gfp); + xa_unlock(xa); + + return err; +} + +/** + * xa_alloc_cyclic_bh() - Find somewhere to store this entry in the XArray. + * @xa: XArray. + * @id: Pointer to ID. + * @entry: New entry. + * @limit: Range of allocated ID. + * @next: Pointer to next ID to allocate. + * @gfp: Memory allocation flags. + * + * Finds an empty entry in @xa between @limit.min and @limit.max, + * stores the index into the @id pointer, then stores the entry at + * that index. A concurrent lookup will not see an uninitialised @id. + * The search for an empty entry will start at @next and will wrap + * around if necessary. + * + * Context: Any context. Takes and releases the xa_lock while + * disabling softirqs. May sleep if the @gfp flags permit. + * Return: 0 if the allocation succeeded without wrapping. 1 if the + * allocation succeeded after wrapping, -ENOMEM if memory could not be + * allocated or -EBUSY if there are no free entries in @limit. + */ +static inline int xa_alloc_cyclic_bh(struct xarray *xa, u32 *id, void *entry, + struct xa_limit limit, u32 *next, gfp_t gfp) +{ + int err; + + xa_lock_bh(xa); + err = __xa_alloc_cyclic(xa, id, entry, limit, next, gfp); + xa_unlock_bh(xa); + + return err; +} + +/** + * xa_alloc_cyclic_irq() - Find somewhere to store this entry in the XArray. + * @xa: XArray. + * @id: Pointer to ID. + * @entry: New entry. + * @limit: Range of allocated ID. + * @next: Pointer to next ID to allocate. + * @gfp: Memory allocation flags. + * + * Finds an empty entry in @xa between @limit.min and @limit.max, + * stores the index into the @id pointer, then stores the entry at + * that index. A concurrent lookup will not see an uninitialised @id. + * The search for an empty entry will start at @next and will wrap + * around if necessary. + * + * Context: Process context. Takes and releases the xa_lock while + * disabling interrupts. May sleep if the @gfp flags permit. + * Return: 0 if the allocation succeeded without wrapping. 1 if the + * allocation succeeded after wrapping, -ENOMEM if memory could not be + * allocated or -EBUSY if there are no free entries in @limit. + */ +static inline int xa_alloc_cyclic_irq(struct xarray *xa, u32 *id, void *entry, + struct xa_limit limit, u32 *next, gfp_t gfp) +{ + int err; + + xa_lock_irq(xa); + err = __xa_alloc_cyclic(xa, id, entry, limit, next, gfp); + xa_unlock_irq(xa); + + return err; +} + +/** * xa_reserve() - Reserve this index in the XArray. * @xa: XArray. * @index: Index into array. |