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      1 /*	$NetBSD: xarray.h,v 1.9 2021/12/19 12:05:25 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2020 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #ifndef	_LINUX_XARRAY_H_
     30 #define	_LINUX_XARRAY_H_
     31 
     32 #include <sys/rbtree.h>
     33 
     34 #include <linux/slab.h>
     35 
     36 struct xarray;
     37 struct xa_limit;
     38 
     39 struct xa_limit {
     40 	uint32_t	max;
     41 	uint32_t	min;
     42 };
     43 
     44 struct xarray {
     45 	kmutex_t		xa_lock;
     46 	struct rb_tree		xa_tree;
     47 	gfp_t			xa_gfp;
     48 };
     49 
     50 #define	xa_for_each(XA, INDEX, ENTRY)					      \
     51 	for ((INDEX) = 0, (ENTRY) = xa_find((XA), &(INDEX), ULONG_MAX, -1);   \
     52 		(ENTRY) != NULL;					      \
     53 		(ENTRY) = xa_find_after((XA), &(INDEX), ULONG_MAX, -1))
     54 
     55 #define	XA_ERROR(error)	((void *)(((uintptr_t)error << 2) | 2))
     56 
     57 static inline int
     58 xa_err(void *cookie)
     59 {
     60 
     61 	if (((uintptr_t)cookie & 3) != 2)
     62 		return 0;
     63 
     64 	return (uintptr_t)cookie >> 2;
     65 }
     66 
     67 #define	XA_FLAGS_ALLOC	0
     68 
     69 #define	xa_alloc	linux_xa_alloc
     70 #define	xa_destroy	linux_xa_destroy
     71 #define	xa_erase	linux_xa_erase
     72 #define	xa_find		linux_xa_find
     73 #define	xa_find_after	linux_xa_find_after
     74 #define	xa_init_flags	linux_xa_init_flags
     75 #define	xa_limit_32b	linux_xa_limit_32b
     76 #define	xa_load		linux_xa_load
     77 #define	xa_store	linux_xa_store
     78 
     79 void	xa_init_flags(struct xarray *, gfp_t);
     80 void	xa_destroy(struct xarray *);
     81 
     82 void *	xa_load(struct xarray *, unsigned long);
     83 void *	xa_store(struct xarray *, unsigned long, void *, gfp_t);
     84 void *	xa_erase(struct xarray *, unsigned long);
     85 
     86 int	xa_alloc(struct xarray *, uint32_t *, void *, struct xa_limit, gfp_t);
     87 void *	xa_find(struct xarray *, unsigned long *, unsigned long, unsigned);
     88 void *	xa_find_after(struct xarray *, unsigned long *, unsigned long,
     89 	    unsigned);
     90 
     91 extern const struct xa_limit xa_limit_32b;
     92 
     93 #endif	/* _LINUX_XARRAY_H_ */
     94