0,0 → 1,144 |
/* |
* 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 <types.h> |
#include <errno-base.h> |
|
//#include <linux/bitops.h> |
//#include <linux/init.h> |
//#include <linux/rcupdate.h> |
|
struct rcu_head { |
struct rcu_head *next; |
void (*func)(struct rcu_head *head); |
}; |
|
|
# define IDR_BITS 5 |
# define IDR_FULL 0xfffffffful |
/* We can only use two of the bits in the top level because there is |
only one possible bit in the top level (5 bits * 7 levels = 35 |
bits, but you only use 31 bits in the id). */ |
# define TOP_LEVEL_FULL (IDR_FULL >> 30) |
|
#define IDR_SIZE (1 << IDR_BITS) |
#define IDR_MASK ((1 << IDR_BITS)-1) |
|
#define MAX_ID_SHIFT (sizeof(int)*8 - 1) |
#define MAX_ID_BIT (1U << MAX_ID_SHIFT) |
#define MAX_ID_MASK (MAX_ID_BIT - 1) |
|
/* Leave the possibility of an incomplete final layer */ |
#define MAX_LEVEL (MAX_ID_SHIFT + IDR_BITS - 1) / IDR_BITS |
|
/* Number of id_layer structs to leave in free list */ |
#define IDR_FREE_MAX MAX_LEVEL + MAX_LEVEL |
|
struct idr_layer { |
unsigned long bitmap; /* A zero bit means "space here" */ |
struct idr_layer *ary[1<<IDR_BITS]; |
int count; /* When zero, we can release it */ |
int layer; /* distance from leaf */ |
struct rcu_head rcu_head; |
}; |
|
struct idr { |
struct idr_layer *top; |
struct idr_layer *id_free; |
int layers; /* only valid without concurrent changes */ |
int id_free_cnt; |
// spinlock_t lock; |
}; |
|
#define IDR_INIT(name) \ |
{ \ |
.top = NULL, \ |
.id_free = NULL, \ |
.layers = 0, \ |
.id_free_cnt = 0, \ |
// .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ |
} |
#define DEFINE_IDR(name) struct idr name = IDR_INIT(name) |
|
/* Actions to be taken after a call to _idr_sub_alloc */ |
#define IDR_NEED_TO_GROW -2 |
#define IDR_NOMORE_SPACE -3 |
|
#define _idr_rc_to_errno(rc) ((rc) == -1 ? -EAGAIN : -ENOSPC) |
|
/** |
* 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). |
*/ |
|
/* |
* This is what we export. |
*/ |
|
void *idr_find(struct idr *idp, int id); |
int idr_pre_get(struct idr *idp, u32_t gfp_mask); |
int idr_get_new(struct idr *idp, void *ptr, int *id); |
int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id); |
int idr_for_each(struct idr *idp, |
int (*fn)(int id, void *p, void *data), void *data); |
void *idr_get_next(struct idr *idp, int *nextid); |
void *idr_replace(struct idr *idp, void *ptr, int id); |
void idr_remove(struct idr *idp, int id); |
void idr_remove_all(struct idr *idp); |
void idr_destroy(struct idr *idp); |
void idr_init(struct idr *idp); |
|
|
/* |
* 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 (128 / sizeof(long) - 1) |
#define IDA_BITMAP_BITS (IDA_BITMAP_LONGS * sizeof(long) * 8) |
|
struct ida_bitmap { |
long nr_busy; |
unsigned long bitmap[IDA_BITMAP_LONGS]; |
}; |
|
struct ida { |
struct idr idr; |
struct ida_bitmap *free_bitmap; |
}; |
|
#define IDA_INIT(name) { .idr = IDR_INIT(name), .free_bitmap = NULL, } |
#define DEFINE_IDA(name) struct ida name = IDA_INIT(name) |
|
int ida_pre_get(struct ida *ida, u32_t gfp_mask); |
int ida_get_new_above(struct ida *ida, int starting_id, int *p_id); |
int ida_get_new(struct ida *ida, int *p_id); |
void ida_remove(struct ida *ida, int id); |
void ida_destroy(struct ida *ida); |
void ida_init(struct ida *ida); |
|
void idr_init_cache(void); |
|
#endif /* __IDR_H__ */ |