cregit-Linux how code gets into the kernel

Release 4.12 include/linux/idr.h

Directory: include/linux
 * include/linux/idr.h
 * 2002-10-18  written by Jim Houston
 *      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_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							\
{                                                                       \
        .idr_rt = RADIX_TREE_INIT(IDR_RT_MARKER)                        \

#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); }


Matthew Wilcox22100.00%2100.00%

/** * 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); }


Matthew Wilcox25100.00%2100.00%

/** * 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 *entry, int start, int end, gfp_t); int idr_alloc_cyclic(struct idr *, void *entry, int start, int end, gfp_t); 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_destroy(struct idr *);
static inline void *idr_remove(struct idr *idr, int id) { return radix_tree_delete_item(&idr->idr_rt, id, NULL); }


Matthew Wilcox2379.31%266.67%
Kristian Högsberg620.69%133.33%

static inline void idr_init(struct idr *idr) { INIT_RADIX_TREE(&idr->idr_rt, IDR_RT_MARKER); idr->idr_next = 0; }


Matthew Wilcox2175.00%125.00%
Andrew Morton517.86%125.00%
Tejun Heo13.57%125.00%
George Anzinger13.57%125.00%

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); }


Matthew Wilcox2578.12%150.00%
Andreas Gruenbacher721.88%150.00%

/** * 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(); }


Tejun Heo12100.00%1100.00%

/** * 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(). * * This function can be called under rcu_read_lock(), given that the leaf * pointers lifetimes are correctly managed. */
static inline void *idr_find(const struct idr *idr, int id) { return radix_tree_lookup(&idr->idr_rt, id); }


Tejun Heo2485.71%150.00%
Matthew Wilcox414.29%150.00%

/** * 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: id entry's key * * @entry and @id do not need to be initialized before the loop, and * after normal terminatinon @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_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 * * Continue to iterate over list of given type, 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); }


Matthew Wilcox24100.00%1100.00%

/** * 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); }


Tejun Heo26100.00%1100.00%

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


Matthew Wilcox22100.00%2100.00%

#endif /* __IDR_H__ */

Overall Contributors

Matthew Wilcox21937.44%519.23%
Tejun Heo19032.48%623.08%
Kristian Högsberg376.32%27.69%
Rusty Russell335.64%13.85%
Jeff Layton193.25%13.85%
Andreas Gruenbacher172.91%27.69%
Jeff Mahoney152.56%13.85%
George Anzinger152.56%13.85%
Andrew Morton152.56%27.69%
Kamezawa Hiroyuki132.22%13.85%
Luben Tuikov91.54%13.85%
Randy Dunlap20.34%27.69%
Geert Uytterhoeven10.17%13.85%
Directory: include/linux
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.