diff options
Diffstat (limited to 'include/linux/idr.h')
| -rw-r--r-- | include/linux/idr.h | 174 |
1 files changed, 75 insertions, 99 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h index fa14f834e4ed..7d6a6313f0ab 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -15,10 +15,10 @@ #include <linux/radix-tree.h> #include <linux/gfp.h> #include <linux/percpu.h> -#include <linux/bug.h> struct idr { struct radix_tree_root idr_rt; + unsigned int idr_base; unsigned int idr_next; }; @@ -31,10 +31,26 @@ struct idr { /* Set the IDR flag and the IDR_FREE tag */ #define IDR_RT_MARKER ((__force gfp_t)(3 << __GFP_BITS_SHIFT)) -#define IDR_INIT \ -{ \ - .idr_rt = RADIX_TREE_INIT(IDR_RT_MARKER) \ +#define IDR_INIT_BASE(base) { \ + .idr_rt = RADIX_TREE_INIT(IDR_RT_MARKER), \ + .idr_base = (base), \ + .idr_next = 0, \ } + +/** + * IDR_INIT() - Initialise an IDR. + * + * A freshly-initialised IDR contains no IDs. + */ +#define IDR_INIT IDR_INIT_BASE(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 /** @@ -82,80 +98,52 @@ static inline void idr_set_cursor(struct idr *idr, unsigned int val) void idr_preload(gfp_t gfp_mask); -int idr_alloc_cmn(struct idr *idr, void *ptr, unsigned long *index, - unsigned long start, unsigned long end, gfp_t gfp, - bool ext); - -/** - * idr_alloc - allocate an id - * @idr: idr handle - * @ptr: pointer to be associated with the new id - * @start: the minimum id (inclusive) - * @end: the maximum id (exclusive) - * @gfp: memory allocation flags - * - * Allocates an unused ID in the range [start, end). Returns -ENOSPC - * if there are no unused IDs in that range. - * - * Note that @end is treated as max when <= 0. This is to always allow - * using @start + N as @end as long as N is inside integer range. - * - * Simultaneous modifications to the @idr are not allowed and should be - * prevented by the user, usually with a lock. idr_alloc() may be called - * concurrently with read-only accesses to the @idr, such as idr_find() and - * idr_for_each_entry(). - */ -static inline int idr_alloc(struct idr *idr, void *ptr, - int start, int end, gfp_t gfp) -{ - unsigned long id; - int ret; - - if (WARN_ON_ONCE(start < 0)) - return -EINVAL; - - ret = idr_alloc_cmn(idr, ptr, &id, start, end, gfp, false); - - if (ret) - return ret; - - return id; -} - -static inline int idr_alloc_ext(struct idr *idr, void *ptr, - unsigned long *index, - unsigned long start, - unsigned long end, - gfp_t gfp) -{ - return idr_alloc_cmn(idr, ptr, index, start, end, gfp, true); -} - -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_get_next_ext(struct idr *idr, unsigned long *nextid); -void *idr_replace(struct idr *, void *, int id); -void *idr_replace_ext(struct idr *idr, void *ptr, unsigned long 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_ext(struct idr *idr, unsigned long id) -{ - return radix_tree_delete_item(&idr->idr_rt, id, NULL); -} - -static inline void *idr_remove(struct idr *idr, int id) +/** + * 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 idr_remove_ext(idr, id); + 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) && @@ -174,50 +162,38 @@ static inline void idr_preload_end(void) } /** - * idr_find - return pointer for given id - * @idr: idr handle - * @id: lookup key - * - * 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(). + * 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. * - * 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_ext(const struct idr *idr, unsigned long id) -{ - return radix_tree_lookup(&idr->idr_rt, id); -} - -static inline void *idr_find(const struct idr *idr, int id) -{ - return idr_find_ext(idr, id); -} +#define idr_for_each_entry(idr, entry, id) \ + for (id = 0; ((entry) = idr_get_next(idr, &(id))) != NULL; ++id) /** - * 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. + * @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_ext(idr, entry, id) \ - for (id = 0; ((entry) = idr_get_next_ext(idr, &(id))) != NULL; ++id) +#define idr_for_each_entry_ul(idr, entry, id) \ + for (id = 0; ((entry) = idr_get_next_ul(idr, &(id))) != NULL; ++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)); \ |