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Index of /anon_sym/anon/sys/dev/char/189:2/1-2:1.0/0003:0627:0001.0002/driver
Index of /anon_sym/anon/sys/dev/char/189:2/1-2:1.0/0003:0627:0001.0002/driver
#ifndef _LINUX_GENERIC_RADIX_TREE_H
#define _LINUX_GENERIC_RADIX_TREE_H
/**
* DOC: Generic radix trees/sparse arrays
*
* Very simple and minimalistic, supporting arbitrary size entries up to
* PAGE_SIZE.
*
* A genradix is defined with the type it will store, like so:
*
* static GENRADIX(struct foo) foo_genradix;
*
* The main operations are:
*
* - genradix_init(radix) - initialize an empty genradix
*
* - genradix_free(radix) - free all memory owned by the genradix and
* reinitialize it
*
* - genradix_ptr(radix, idx) - gets a pointer to the entry at idx, returning
* NULL if that entry does not exist
*
* - genradix_ptr_alloc(radix, idx, gfp) - gets a pointer to an entry,
* allocating it if necessary
*
* - genradix_for_each(radix, iter, p) - iterate over each entry in a genradix
*
* The radix tree allocates one page of entries at a time, so entries may exist
* that were never explicitly allocated - they will be initialized to all
* zeroes.
*
* Internally, a genradix is just a radix tree of pages, and indexing works in
* terms of byte offsets. The wrappers in this header file use sizeof on the
* type the radix contains to calculate a byte offset from the index - see
* __idx_to_offset.
*/
#include
#include
#include
#include
#include
#include
struct genradix_root;
struct __genradix {
struct genradix_root *root;
};
/*
* NOTE: currently, sizeof(_type) must not be larger than PAGE_SIZE:
*/
#define __GENRADIX_INITIALIZER \
{ \
.tree = { \
.root = NULL, \
} \
}
/*
* We use a 0 size array to stash the type we're storing without taking any
* space at runtime - then the various accessor macros can use typeof() to get
* to it for casts/sizeof - we also force the alignment so that storing a type
* with a ridiculous alignment doesn't blow up the alignment or size of the
* genradix.
*/
#define GENRADIX(_type) \
struct { \
struct __genradix tree; \
_type type[0] __aligned(1); \
}
#define DEFINE_GENRADIX(_name, _type) \
GENRADIX(_type) _name = __GENRADIX_INITIALIZ