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Release 4.16 include/linux/idr.h

Directory: include/linux
/*
 * 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.
 */

#ifndef __IDR_H__

#define __IDR_H__

#include <linux/radix-tree.h>
#include <linux/gfp.h>
#include <linux/percpu.h>


struct idr {
	
struct radix_tree_root	idr_rt;
	
unsigned int		idr_base;
	
unsigned int		idr_next;
};

/*
 * The IDR API does not expose the tagging functionality of the radix tree
 * to users.  Use tag 0 to track whether a node has free space below it.
 */

#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_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

/**
 * idr_get_cursor - Return the current position of the cyclic allocator
 * @idr: idr handle
 *
 * The value returned is the value that will be next returned from
 * idr_alloc_cyclic() if it is free (otherwise the search will start from
 * this position).
 */

static inline unsigned int idr_get_cursor(const struct idr *idr) { return READ_ONCE(idr->idr_next); }

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/** * idr_set_cursor - Set the current position of the cyclic allocator * @idr: idr handle * @val: new position * * The next call to idr_alloc_cyclic() will return @val if it is free * (otherwise the search will start from this position). */
static inline void idr_set_cursor(struct idr *idr, unsigned int val) { WRITE_ONCE(idr->idr_next, val); }

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/** * DOC: idr sync * idr synchronization (stolen from radix-tree.h) * * idr_find() is able to be called locklessly, using RCU. The caller must * ensure calls to this function are made within rcu_read_lock() regions. * Other readers (lock-free or otherwise) and modifications may be running * concurrently. * * It is still required that the caller manage the synchronization and * lifetimes of the items. So if RCU lock-free lookups are used, typically * this would mean that the items have their own locks, or are amenable to * lock-free access; and that the items are freed by RCU (or only freed after * having been deleted from the idr tree *and* a synchronize_rcu() grace * period). */ void idr_preload(gfp_t gfp_mask); 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_ul(struct idr *, unsigned long *nextid); void *idr_replace(struct idr *, void *, unsigned long id); void idr_destroy(struct idr *); /** * 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) { INIT_RADIX_TREE(&idr->idr_rt, IDR_RT_MARKER); idr->idr_base = base; idr->idr_next = 0; }

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Matthew Wilcox3183.78%266.67%
Kristian Högsberg616.22%133.33%
Total37100.00%3100.00%

/** * 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) { idr_init_base(idr, 0); }

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Matthew Wilcox1263.16%240.00%
Andrew Morton526.32%120.00%
Tejun Heo15.26%120.00%
George Anzinger15.26%120.00%
Total19100.00%5100.00%

/** * 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) && radix_tree_tagged(&idr->idr_rt, IDR_FREE); }

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Matthew Wilcox2578.12%150.00%
Andreas Gruenbacher721.88%150.00%
Total32100.00%2100.00%

/** * idr_preload_end - end preload section started with idr_preload() * * Each idr_preload() should be matched with an invocation of this * function. See idr_preload() for details. */
static inline void idr_preload_end(void) { preempt_enable(); }

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Tejun Heo12100.00%1100.00%
Total12100.00%1100.00%

/** * 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. * * @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. */ #define idr_for_each_entry(idr, entry, id) \ for (id = 0; ((entry) = idr_get_next(idr, &(id))) != NULL; ++id) /** * 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 termination @entry is left with the value NULL. This * is convenient for a "not found" value. */ #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 a cursor. * @id: Entry ID. * * 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))) /* * IDA - IDR based 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)) #define IDA_BITMAP_BITS (IDA_BITMAP_LONGS * sizeof(long) * 8) 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; }; #define IDA_INIT { \ .ida_rt = RADIX_TREE_INIT(IDR_RT_MARKER | GFP_NOWAIT), \ } #define DEFINE_IDA(name) struct ida name = IDA_INIT 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); 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);
static inline void ida_init(struct ida *ida) { INIT_RADIX_TREE(&ida->ida_rt, IDR_RT_MARKER | GFP_NOWAIT); }

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/** * ida_get_new - allocate new ID * @ida: idr handle * @p_id: pointer to the allocated handle * * Simple wrapper around ida_get_new_above() w/ @starting_id of zero. */
static inline int ida_get_new(struct ida *ida, int *p_id) { return ida_get_new_above(ida, 0, p_id); }

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Tejun Heo26100.00%1100.00%
Total26100.00%1100.00%


static inline bool ida_is_empty(const struct ida *ida) { return radix_tree_empty(&ida->ida_rt); }

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Matthew Wilcox22100.00%2100.00%
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#endif /* __IDR_H__ */

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Matthew Wilcox29044.75%931.03%
Tejun Heo16425.31%517.24%
Kristian Högsberg365.56%26.90%
Rusty Russell335.09%13.45%
Chris Mi304.63%13.45%
Jeff Layton192.93%13.45%
Andreas Gruenbacher172.62%26.90%
George Anzinger162.47%13.45%
Kamezawa Hiroyuki132.01%13.45%
Jeff Mahoney101.54%13.45%
Andrew Morton91.39%26.90%
Luben Tuikov91.39%13.45%
Geert Uytterhoeven10.15%13.45%
Randy Dunlap10.15%13.45%
Total648100.00%29100.00%
Directory: include/linux
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