mirror of
https://github.com/koverstreet/bcachefs-tools.git
synced 2025-02-03 00:00:07 +03:00
131 lines
3.3 KiB
C
131 lines
3.3 KiB
C
#ifndef _LINUX_GENERIC_RADIX_TREE_H
|
|
#define _LINUX_GENERIC_RADIX_TREE_H
|
|
|
|
/*
|
|
* Generic radix trees/sparse arrays:
|
|
*
|
|
* A generic radix tree has all nodes of size PAGE_SIZE - both leaves and
|
|
* interior nodes.
|
|
*/
|
|
|
|
#include <linux/bug.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/log2.h>
|
|
|
|
struct genradix_node;
|
|
|
|
struct __genradix {
|
|
struct genradix_node *root;
|
|
size_t depth;
|
|
};
|
|
|
|
/*
|
|
* NOTE: currently, sizeof(_type) must be a power of two and not larger than
|
|
* PAGE_SIZE:
|
|
*/
|
|
|
|
#define __GENRADIX_INITIALIZER \
|
|
{ \
|
|
.tree = { \
|
|
.root = NULL, \
|
|
.depth = 0, \
|
|
} \
|
|
}
|
|
|
|
/*
|
|
* 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_INITIALIZER
|
|
|
|
#define genradix_init(_radix) \
|
|
do { \
|
|
*(_radix) = (typeof(*_radix)) __GENRADIX_INITIALIZER; \
|
|
} while (0)
|
|
|
|
void __genradix_free(struct __genradix *);
|
|
|
|
#define genradix_free(_radix) __genradix_free(&(_radix)->tree)
|
|
|
|
static inline size_t __idx_to_offset(size_t idx, size_t obj_size)
|
|
{
|
|
BUILD_BUG_ON(obj_size > PAGE_SIZE);
|
|
|
|
if (!is_power_of_2(obj_size)) {
|
|
size_t objs_per_page = PAGE_SIZE / obj_size;
|
|
|
|
return (idx / objs_per_page) * PAGE_SIZE +
|
|
(idx % objs_per_page) * obj_size;
|
|
} else {
|
|
return idx * obj_size;
|
|
}
|
|
}
|
|
|
|
#define __genradix_cast(_radix) (typeof((_radix)->type[0]) *)
|
|
#define __genradix_obj_size(_radix) sizeof((_radix)->type[0])
|
|
#define __genradix_idx_to_offset(_radix, _idx) \
|
|
__idx_to_offset(_idx, __genradix_obj_size(_radix))
|
|
|
|
void *__genradix_ptr(struct __genradix *, size_t);
|
|
|
|
/* Returns a pointer to element at @_idx */
|
|
#define genradix_ptr(_radix, _idx) \
|
|
(__genradix_cast(_radix) \
|
|
__genradix_ptr(&(_radix)->tree, \
|
|
__genradix_idx_to_offset(_radix, _idx)))
|
|
|
|
void *__genradix_ptr_alloc(struct __genradix *, size_t, gfp_t);
|
|
|
|
/* Returns a pointer to element at @_idx, allocating it if necessary */
|
|
#define genradix_ptr_alloc(_radix, _idx, _gfp) \
|
|
(__genradix_cast(_radix) \
|
|
__genradix_ptr_alloc(&(_radix)->tree, \
|
|
__genradix_idx_to_offset(_radix, _idx), \
|
|
_gfp))
|
|
|
|
struct genradix_iter {
|
|
size_t offset;
|
|
size_t pos;
|
|
};
|
|
|
|
static inline void genradix_iter_init(struct genradix_iter *iter)
|
|
{
|
|
iter->offset = 0;
|
|
iter->pos = 0;
|
|
}
|
|
|
|
void *__genradix_iter_peek(struct genradix_iter *, struct __genradix *, size_t);
|
|
|
|
#define genradix_iter_peek(_iter, _radix) \
|
|
(__genradix_cast(_radix) \
|
|
__genradix_iter_peek(_iter, &(_radix)->tree, \
|
|
PAGE_SIZE / __genradix_obj_size(_radix)))
|
|
|
|
static inline void __genradix_iter_advance(struct genradix_iter *iter,
|
|
size_t obj_size)
|
|
{
|
|
iter->offset += obj_size;
|
|
|
|
if (!is_power_of_2(obj_size) &&
|
|
(iter->offset & (PAGE_SIZE - 1)) + obj_size > PAGE_SIZE)
|
|
iter->offset = round_up(iter->offset, PAGE_SIZE);
|
|
|
|
iter->pos++;
|
|
}
|
|
|
|
#define genradix_iter_advance(_iter, _radix) \
|
|
__genradix_iter_advance(_iter, __genradix_obj_size(_radix))
|
|
|
|
#endif /* _LINUX_GENERIC_RADIX_TREE_H */
|