diff options
Diffstat (limited to 'include/linux/idr.h')
| -rw-r--r-- | include/linux/idr.h | 261 |
1 files changed, 198 insertions, 63 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h index bf70b3ef0a07..789e23e67444 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -1,9 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * include/linux/idr.h * * 2002-10-18 written by Jim Houston jim.houston@ccur.com * Copyright (C) 2002 by Concurrent Computer Corporation - * Distributed under the GNU GPL license version 2. * * Small id to pointer translation service avoiding fixed sized * tables. @@ -15,9 +15,11 @@ #include <linux/radix-tree.h> #include <linux/gfp.h> #include <linux/percpu.h> +#include <linux/cleanup.h> struct idr { struct radix_tree_root idr_rt; + unsigned int idr_base; unsigned int idr_next; }; @@ -28,13 +30,31 @@ struct idr { #define IDR_FREE 0 /* Set the IDR flag and the IDR_FREE tag */ -#define IDR_RT_MARKER ((__force gfp_t)(3 << __GFP_BITS_SHIFT)) +#define IDR_RT_MARKER (ROOT_IS_IDR | (__force gfp_t) \ + (1 << (ROOT_TAG_SHIFT + IDR_FREE))) -#define IDR_INIT \ -{ \ - .idr_rt = RADIX_TREE_INIT(IDR_RT_MARKER) \ +#define IDR_INIT_BASE(name, base) { \ + .idr_rt = RADIX_TREE_INIT(name, IDR_RT_MARKER), \ + .idr_base = (base), \ + .idr_next = 0, \ } -#define DEFINE_IDR(name) struct idr name = IDR_INIT + +/** + * IDR_INIT() - Initialise an IDR. + * @name: Name of IDR. + * + * A freshly-initialised IDR contains no IDs. + */ +#define IDR_INIT(name) IDR_INIT_BASE(name, 0) + +/** + * DEFINE_IDR() - Define a statically-allocated IDR. + * @name: Name of IDR. + * + * An IDR defined using this macro is ready for use with no additional + * initialisation required. It contains no IDs. + */ +#define DEFINE_IDR(name) struct idr name = IDR_INIT(name) /** * idr_get_cursor - Return the current position of the cyclic allocator @@ -79,26 +99,81 @@ static inline void idr_set_cursor(struct idr *idr, unsigned int val) * period). */ +#define idr_lock(idr) xa_lock(&(idr)->idr_rt) +#define idr_unlock(idr) xa_unlock(&(idr)->idr_rt) +#define idr_lock_bh(idr) xa_lock_bh(&(idr)->idr_rt) +#define idr_unlock_bh(idr) xa_unlock_bh(&(idr)->idr_rt) +#define idr_lock_irq(idr) xa_lock_irq(&(idr)->idr_rt) +#define idr_unlock_irq(idr) xa_unlock_irq(&(idr)->idr_rt) +#define idr_lock_irqsave(idr, flags) \ + xa_lock_irqsave(&(idr)->idr_rt, flags) +#define idr_unlock_irqrestore(idr, flags) \ + xa_unlock_irqrestore(&(idr)->idr_rt, flags) + void idr_preload(gfp_t gfp_mask); -int idr_alloc(struct idr *, void *entry, int start, int end, gfp_t); -int idr_alloc_cyclic(struct idr *, void *entry, int start, int end, gfp_t); + +int idr_alloc(struct idr *, void *ptr, int start, int end, gfp_t); +int __must_check idr_alloc_u32(struct idr *, void *ptr, u32 *id, + unsigned long max, gfp_t); +int idr_alloc_cyclic(struct idr *, void *ptr, int start, int end, gfp_t); +void *idr_remove(struct idr *, unsigned long id); +void *idr_find(const struct idr *, unsigned long id); int idr_for_each(const struct idr *, int (*fn)(int id, void *p, void *data), void *data); void *idr_get_next(struct idr *, int *nextid); -void *idr_replace(struct idr *, void *, int id); +void *idr_get_next_ul(struct idr *, unsigned long *nextid); +void *idr_replace(struct idr *, void *, unsigned long id); void idr_destroy(struct idr *); -static inline void *idr_remove(struct idr *idr, int id) +struct __class_idr { + struct idr *idr; + int id; +}; + +#define idr_null ((struct __class_idr){ NULL, -1 }) +#define take_idr_id(id) __get_and_null(id, idr_null) + +DEFINE_CLASS(idr_alloc, struct __class_idr, + if (_T.id >= 0) idr_remove(_T.idr, _T.id), + ((struct __class_idr){ + .idr = idr, + .id = idr_alloc(idr, ptr, start, end, gfp), + }), + struct idr *idr, void *ptr, int start, int end, gfp_t gfp); + +/** + * idr_init_base() - Initialise an IDR. + * @idr: IDR handle. + * @base: The base value for the IDR. + * + * This variation of idr_init() creates an IDR which will allocate IDs + * starting at %base. + */ +static inline void idr_init_base(struct idr *idr, int base) { - return radix_tree_delete_item(&idr->idr_rt, id, NULL); + INIT_RADIX_TREE(&idr->idr_rt, IDR_RT_MARKER); + idr->idr_base = base; + idr->idr_next = 0; } +/** + * idr_init() - Initialise an IDR. + * @idr: IDR handle. + * + * Initialise a dynamically allocated IDR. To initialise a + * statically allocated IDR, use DEFINE_IDR(). + */ static inline void idr_init(struct idr *idr) { - INIT_RADIX_TREE(&idr->idr_rt, IDR_RT_MARKER); - idr->idr_next = 0; + idr_init_base(idr, 0); } +/** + * idr_is_empty() - Are there any IDs allocated? + * @idr: IDR handle. + * + * Return: %true if any IDs have been allocated from this IDR. + */ static inline bool idr_is_empty(const struct idr *idr) { return radix_tree_empty(&idr->idr_rt) && @@ -113,56 +188,69 @@ static inline bool idr_is_empty(const struct idr *idr) */ static inline void idr_preload_end(void) { - preempt_enable(); + local_unlock(&radix_tree_preloads.lock); } /** - * idr_find - return pointer for given id - * @idr: idr handle - * @id: lookup key + * idr_for_each_entry() - Iterate over an IDR's elements of a given type. + * @idr: IDR handle. + * @entry: The type * to use as cursor + * @id: Entry ID. * - * Return the pointer given the id it has been registered with. A %NULL - * return indicates that @id is not valid or you passed %NULL in - * idr_get_new(). - * - * This function can be called under rcu_read_lock(), given that the leaf - * pointers lifetimes are correctly managed. + * @entry and @id do not need to be initialized before the loop, and + * after normal termination @entry is left with the value NULL. This + * is convenient for a "not found" value. */ -static inline void *idr_find(const struct idr *idr, int id) -{ - return radix_tree_lookup(&idr->idr_rt, id); -} +#define idr_for_each_entry(idr, entry, id) \ + for (id = 0; ((entry) = idr_get_next(idr, &(id))) != NULL; id += 1U) /** - * idr_for_each_entry - iterate over an idr's elements of a given type - * @idr: idr handle - * @entry: the type * to use as cursor - * @id: id entry's key + * idr_for_each_entry_ul() - Iterate over an IDR's elements of a given type. + * @idr: IDR handle. + * @entry: The type * to use as cursor. + * @tmp: A temporary placeholder for ID. + * @id: Entry ID. * * @entry and @id do not need to be initialized before the loop, and - * after normal terminatinon @entry is left with the value NULL. This + * after normal termination @entry is left with the value NULL. This * is convenient for a "not found" value. */ -#define idr_for_each_entry(idr, entry, id) \ - for (id = 0; ((entry) = idr_get_next(idr, &(id))) != NULL; ++id) +#define idr_for_each_entry_ul(idr, entry, tmp, id) \ + for (tmp = 0, id = 0; \ + ((entry) = tmp <= id ? idr_get_next_ul(idr, &(id)) : NULL) != NULL; \ + tmp = id, ++id) /** - * idr_for_each_entry_continue - continue iteration over an idr's elements of a given type - * @idr: idr handle - * @entry: the type * to use as cursor - * @id: id entry's key + * idr_for_each_entry_continue() - Continue iteration over an IDR's elements of a given type + * @idr: IDR handle. + * @entry: The type * to use as a cursor. + * @id: Entry ID. * - * Continue to iterate over list of given type, continuing after - * the current position. + * Continue to iterate over entries, continuing after the current position. */ #define idr_for_each_entry_continue(idr, entry, id) \ for ((entry) = idr_get_next((idr), &(id)); \ entry; \ ++id, (entry) = idr_get_next((idr), &(id))) +/** + * idr_for_each_entry_continue_ul() - Continue iteration over an IDR's elements of a given type + * @idr: IDR handle. + * @entry: The type * to use as a cursor. + * @tmp: A temporary placeholder for ID. + * @id: Entry ID. + * + * Continue to iterate over entries, continuing after the current position. + * After normal termination @entry is left with the value NULL. This + * is convenient for a "not found" value. + */ +#define idr_for_each_entry_continue_ul(idr, entry, tmp, id) \ + for (tmp = id; \ + ((entry) = tmp <= id ? idr_get_next_ul(idr, &(id)) : NULL) != NULL; \ + tmp = id, ++id) + /* - * IDA - IDR based id allocator, use when translation from id to - * pointer isn't necessary. + * IDA - ID Allocator, use when translation from id to pointer isn't necessary. */ #define IDA_CHUNK_SIZE 128 /* 128 bytes per chunk */ #define IDA_BITMAP_LONGS (IDA_CHUNK_SIZE / sizeof(long)) @@ -172,45 +260,92 @@ struct ida_bitmap { unsigned long bitmap[IDA_BITMAP_LONGS]; }; -DECLARE_PER_CPU(struct ida_bitmap *, ida_bitmap); - struct ida { - struct radix_tree_root ida_rt; + struct xarray xa; }; -#define IDA_INIT { \ - .ida_rt = RADIX_TREE_INIT(IDR_RT_MARKER | GFP_NOWAIT), \ +#define IDA_INIT_FLAGS (XA_FLAGS_LOCK_IRQ | XA_FLAGS_ALLOC) + +#define IDA_INIT(name) { \ + .xa = XARRAY_INIT(name, IDA_INIT_FLAGS) \ } -#define DEFINE_IDA(name) struct ida name = IDA_INIT +#define DEFINE_IDA(name) struct ida name = IDA_INIT(name) -int ida_pre_get(struct ida *ida, gfp_t gfp_mask); -int ida_get_new_above(struct ida *ida, int starting_id, int *p_id); -void ida_remove(struct ida *ida, int id); +int ida_alloc_range(struct ida *, unsigned int min, unsigned int max, gfp_t); +void ida_free(struct ida *, unsigned int id); void ida_destroy(struct ida *ida); +int ida_find_first_range(struct ida *ida, unsigned int min, unsigned int max); -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); +/** + * 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. It is safe to call this function without + * locking in your code. + * 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); +} -static inline void ida_init(struct ida *ida) +/** + * 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. It is safe to call this function without + * locking in your code. + * 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) { - INIT_RADIX_TREE(&ida->ida_rt, IDR_RT_MARKER | GFP_NOWAIT); + return ida_alloc_range(ida, min, ~0, gfp); } /** - * ida_get_new - allocate new ID - * @ida: idr handle - * @p_id: pointer to the allocated handle + * 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. * - * Simple wrapper around ida_get_new_above() w/ @starting_id of zero. + * Context: Any context. It is safe to call this function without + * locking in your code. + * Return: The allocated ID, or %-ENOMEM if memory could not be allocated, + * or %-ENOSPC if there are no free IDs. */ -static inline int ida_get_new(struct ida *ida, int *p_id) +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) { - return ida_get_new_above(ida, 0, p_id); + xa_init_flags(&ida->xa, IDA_INIT_FLAGS); } static inline bool ida_is_empty(const struct ida *ida) { - return radix_tree_empty(&ida->ida_rt); + return xa_empty(&ida->xa); +} + +static inline bool ida_exists(struct ida *ida, unsigned int id) +{ + return ida_find_first_range(ida, id, id) == id; +} + +static inline int ida_find_first(struct ida *ida) +{ + return ida_find_first_range(ida, 0, ~0); } #endif /* __IDR_H__ */ |