[mirror_ubuntu-focal-kernel.git] / include / linux / flex_array.h

#ifndef _FLEX_ARRAY_H
#define _FLEX_ARRAY_H

#include <linux/types.h>
#include <asm/page.h>

#define FLEX_ARRAY_PART_SIZE PAGE_SIZE
#define FLEX_ARRAY_BASE_SIZE PAGE_SIZE

struct flex_array_part;

/*
 * This is meant to replace cases where an array-like
 * structure has gotten too big to fit into kmalloc()
 * and the developer is getting tempted to use
 * vmalloc().
 */

struct flex_array {
	union {
		struct {
			int element_size;
			int total_nr_elements;
			struct flex_array_part *parts[];
		};
		/*
		 * This little trick makes sure that
		 * sizeof(flex_array) == PAGE_SIZE
		 */
		char padding[FLEX_ARRAY_BASE_SIZE];
	};
};

#define FLEX_ARRAY_INIT(size, total) { { {\
	.element_size = (size),		\
	.total_nr_elements = (total),	\
} } }

struct flex_array *flex_array_alloc(int element_size, unsigned int total,
		gfp_t flags);
int flex_array_prealloc(struct flex_array *fa, unsigned int start,
		unsigned int end, gfp_t flags);
void flex_array_free(struct flex_array *fa);
void flex_array_free_parts(struct flex_array *fa);
int flex_array_put(struct flex_array *fa, unsigned int element_nr, void *src,
		gfp_t flags);
void *flex_array_get(struct flex_array *fa, unsigned int element_nr);

#endif /* _FLEX_ARRAY_H */
Commit	Line	Data
534acc05 DH	1	#ifndef _FLEX_ARRAY_H
	2	#define _FLEX_ARRAY_H
	3
	4	#include <linux/types.h>
	5	#include <asm/page.h>
	6
	7	#define FLEX_ARRAY_PART_SIZE PAGE_SIZE
	8	#define FLEX_ARRAY_BASE_SIZE PAGE_SIZE
	9
	10	struct flex_array_part;
	11
	12	/*
	13	* This is meant to replace cases where an array-like
	14	* structure has gotten too big to fit into kmalloc()
	15	* and the developer is getting tempted to use
	16	* vmalloc().
	17	*/
	18
	19	struct flex_array {
	20	union {
	21	struct {
	22	int element_size;
	23	int total_nr_elements;
8e7ee270	24	struct flex_array_part *parts[];
534acc05 DH	25	};
	26	/*
	27	* This little trick makes sure that
	28	* sizeof(flex_array) == PAGE_SIZE
	29	*/
	30	char padding[FLEX_ARRAY_BASE_SIZE];
	31	};
	32	};
	33
	34	#define FLEX_ARRAY_INIT(size, total) { { {\
	35	.element_size = (size), \
	36	.total_nr_elements = (total), \
	37	} } }
	38
b62e408c DR	39	struct flex_array *flex_array_alloc(int element_size, unsigned int total,
	40	gfp_t flags);
	41	int flex_array_prealloc(struct flex_array *fa, unsigned int start,
	42	unsigned int end, gfp_t flags);
534acc05 DH	43	void flex_array_free(struct flex_array *fa);
534acc05 DH	44	void flex_array_free_parts(struct flex_array *fa);
b62e408c	45	int flex_array_put(struct flex_array fa, unsigned int element_nr, void src,
534acc05	46	gfp_t flags);
b62e408c	47	void flex_array_get(struct flex_array fa, unsigned int element_nr);
534acc05 DH	48
534acc05 DH	49	#endif /* _FLEX_ARRAY_H */