WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/adt/bitmap.c


/*
 * Copyright (C) 2006 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/**
 * @file    bitmap.c
 * @brief   Implementation of bitmap ADT.
 *
 * This file implements bitmap ADT and provides functions for
 * setting and clearing ranges of bits.
 */
 
#include <adt/bitmap.h>
#include <typedefs.h>
#include <arch/types.h>
#include <align.h>
#include <debug.h>
#include <macros.h>
 
#define ALL_ONES    0xff
#define ALL_ZEROES  0x00
 
/** Initialize bitmap.
 *
 * No portion of the bitmap is set or cleared by this function.
 *
 * @param bitmap Bitmap structure.
 * @param map Address of the memory used to hold the map.
 * @param bits Number of bits stored in bitmap.
 */
void bitmap_initialize(bitmap_t *bitmap, __u8 *map, count_t bits)
{
    bitmap->map = map;
    bitmap->bits = bits;
}
 
/** Set range of bits.
 *
 * @param bitmap Bitmap structure.
 * @param start Starting bit.
 * @param bits Number of bits to set.
 */
void bitmap_set_range(bitmap_t *bitmap, index_t start, count_t bits)
{
    index_t i=0;
    index_t aligned_start;
    count_t lub;        /* leading unaligned bits */
    count_t amb;        /* aligned middle bits */
    count_t tab;        /* trailing aligned bits */
   
    ASSERT(start + bits <= bitmap->bits);
   
    aligned_start = ALIGN_UP(start, 8);
    lub = min(aligned_start - start, bits);
    amb = bits > lub ? bits - lub : 0;
    tab = amb % 8;
   
    if ( start + bits < aligned_start ) {
        /*
        * Set bits in the middle of byte
        */
        bitmap->map[start / 8] |= ((1 << lub)-1) << (start&7);
        return;
    }
   
    if (lub) {
        /*
         * Make sure to set any leading unaligned bits.
         */
        bitmap->map[start / 8] |= ~((1 << (8 - lub)) - 1);
    }
    for (i = 0; i < amb / 8; i++) {
        /*
         * The middle bits can be set byte by byte.
         */
        bitmap->map[aligned_start / 8 + i] = ALL_ONES;
    }
    if (tab) {
        /*
         * Make sure to set any trailing aligned bits.
         */
        bitmap->map[aligned_start / 8 + i] |= (1 << tab) - 1;
    }
   
}
 
/** Clear range of bits.
 *
 * @param bitmap Bitmap structure.
 * @param start Starting bit.
 * @param bits Number of bits to clear.
 */
void bitmap_clear_range(bitmap_t *bitmap, index_t start, count_t bits)
{
    index_t i=0;
    index_t aligned_start;
    count_t lub;        /* leading unaligned bits */
    count_t amb;        /* aligned middle bits */
    count_t tab;        /* trailing aligned bits */
   
    ASSERT(start + bits <= bitmap->bits);
   
    aligned_start = ALIGN_UP(start, 8);
    lub = min(aligned_start - start, bits);
    amb = bits > lub ? bits - lub : 0;
    tab = amb % 8;
 
    if ( start + bits < aligned_start )
    {
        /*
        * Set bits in the middle of byte
        */
        bitmap->map[start / 8] &= ~(((1 << lub)-1) << (start&7));
        return;
    }
 
 
    if (lub) {
        /*
         * Make sure to clear any leading unaligned bits.
         */
        bitmap->map[start / 8] &= (1 << (8 - lub)) - 1;
    }
    for (i = 0; i < amb / 8; i++) {
        /*
         * The middle bits can be cleared byte by byte.
         */
        bitmap->map[aligned_start / 8 + i] = ALL_ZEROES;
    }
    if (tab) {
        /*
         * Make sure to clear any trailing aligned bits.
         */
        bitmap->map[aligned_start / 8 + i] &= ~((1 << tab) - 1);
    }
 
}
 
/** Copy portion of one bitmap into another bitmap.
 *
 * @param dst Destination bitmap.
 * @param src Source bitmap.
 * @param bits Number of bits to copy.
 */
void bitmap_copy(bitmap_t *dst, bitmap_t *src, count_t bits)
{
    index_t i;
   
    ASSERT(bits <= dst->bits);
    ASSERT(bits <= src->bits);
   
    for (i = 0; i < bits / 8; i++)
        dst->map[i] = src->map[i];
   
    if (bits % 8) {
        bitmap_clear_range(dst, i * 8, bits % 8);
        dst->map[i] |= src->map[i] & ((1 << (bits % 8)) - 1);
    }
}
 

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/adt/bitmap.c @ 1757 – Rev 1262 → 1549

Rev 1262		Rev 1549
1	/*	1	/*
2	* Copyright (C) 2006 Jakub Jermar	2	* Copyright (C) 2006 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/**	29	/**
30	* @file bitmap.c	30	* @file bitmap.c
31	* @brief Implementation of bitmap ADT.	31	* @brief Implementation of bitmap ADT.
32	*	32	*
33	* This file implements bitmap ADT and provides functions for	33	* This file implements bitmap ADT and provides functions for
34	* setting and clearing ranges of bits.	34	* setting and clearing ranges of bits.
35	*/	35	*/
36		36
37	#include <adt/bitmap.h>	37	#include <adt/bitmap.h>
38	#include <typedefs.h>	38	#include <typedefs.h>
39	#include <arch/types.h>	39	#include <arch/types.h>
40	#include <align.h>	40	#include <align.h>
41	#include <debug.h>	41	#include <debug.h>
42	#include <macros.h>	42	#include <macros.h>
43		43
44	#define ALL_ONES 0xff	44	#define ALL_ONES 0xff
45	#define ALL_ZEROES 0x00	45	#define ALL_ZEROES 0x00
46		46
47	/** Initialize bitmap.	47	/** Initialize bitmap.
48	*	48	*
49	* No portion of the bitmap is set or cleared by this function.	49	* No portion of the bitmap is set or cleared by this function.
50	*	50	*
51	* @param bitmap Bitmap structure.	51	* @param bitmap Bitmap structure.
52	* @param map Address of the memory used to hold the map.	52	* @param map Address of the memory used to hold the map.
53	* @param bits Number of bits stored in bitmap.	53	* @param bits Number of bits stored in bitmap.
54	*/	54	*/
55	void bitmap_initialize(bitmap_t bitmap, __u8 map, count_t bits)	55	void bitmap_initialize(bitmap_t bitmap, __u8 map, count_t bits)
56	{	56	{
57	bitmap->map = map;	57	bitmap->map = map;
58	bitmap->bits = bits;	58	bitmap->bits = bits;
59	}	59	}
60		60
61	/** Set range of bits.	61	/** Set range of bits.
62	*	62	*
63	* @param bitmap Bitmap structure.	63	* @param bitmap Bitmap structure.
64	* @param start Starting bit.	64	* @param start Starting bit.
65	* @param bits Number of bits to set.	65	* @param bits Number of bits to set.
66	*/	66	*/
67	void bitmap_set_range(bitmap_t *bitmap, index_t start, count_t bits)	67	void bitmap_set_range(bitmap_t *bitmap, index_t start, count_t bits)
68	{	68	{
69	index_t i;	69	index_t i=0;
70	index_t aligned_start;	70	index_t aligned_start;
71	count_t lub; /* leading unaligned bits */	71	count_t lub; /* leading unaligned bits */
72	count_t amb; /* aligned middle bits */	72	count_t amb; /* aligned middle bits */
73	count_t tab; /* trailing aligned bits */	73	count_t tab; /* trailing aligned bits */
74		74
75	ASSERT(start + bits <= bitmap->bits);	75	ASSERT(start + bits <= bitmap->bits);
76		76
77	aligned_start = ALIGN_UP(start, 8);	77	aligned_start = ALIGN_UP(start, 8);
78	lub = min(aligned_start - start, bits);	78	lub = min(aligned_start - start, bits);
79	amb = bits > lub ? bits - lub : 0;	79	amb = bits > lub ? bits - lub : 0;
80	tab = amb % 8;	80	tab = amb % 8;
81		81
-		82	if ( start + bits < aligned_start ) {
-		83	/*
-		84	* Set bits in the middle of byte
-		85	*/
-		86	bitmap->map[start / 8] \|= ((1 << lub)-1) << (start&7);
-		87	return;
-		88	}
-		89
82	if (lub) {	90	if (lub) {
83	/*	91	/*
84	* Make sure to set any leading unaligned bits.	92	* Make sure to set any leading unaligned bits.
85	*/	93	*/
86	bitmap->map[start / 8] \|= ~((1 << (8 - lub)) - 1);	94	bitmap->map[start / 8] \|= ~((1 << (8 - lub)) - 1);
87	}	95	}
88	for (i = 0; i < amb / 8; i++) {	96	for (i = 0; i < amb / 8; i++) {
89	/*	97	/*
90	* The middle bits can be set byte by byte.	98	* The middle bits can be set byte by byte.
91	*/	99	*/
92	bitmap->map[aligned_start / 8 + i] = ALL_ONES;	100	bitmap->map[aligned_start / 8 + i] = ALL_ONES;
93	}	101	}
94	if (tab) {	102	if (tab) {
95	/*	103	/*
96	* Make sure to set any trailing aligned bits.	104	* Make sure to set any trailing aligned bits.
97	*/	105	*/
98	bitmap->map[aligned_start / 8 + i] \|= (1 << tab) - 1;	106	bitmap->map[aligned_start / 8 + i] \|= (1 << tab) - 1;
99	}	107	}
100		108
101	}	109	}
102		110
103	/** Clear range of bits.	111	/** Clear range of bits.
104	*	112	*
105	* @param bitmap Bitmap structure.	113	* @param bitmap Bitmap structure.
106	* @param start Starting bit.	114	* @param start Starting bit.
107	* @param bits Number of bits to clear.	115	* @param bits Number of bits to clear.
108	*/	116	*/
109	void bitmap_clear_range(bitmap_t *bitmap, index_t start, count_t bits)	117	void bitmap_clear_range(bitmap_t *bitmap, index_t start, count_t bits)
110	{	118	{
111	index_t i;	119	index_t i=0;
112	index_t aligned_start;	120	index_t aligned_start;
113	count_t lub; /* leading unaligned bits */	121	count_t lub; /* leading unaligned bits */
114	count_t amb; /* aligned middle bits */	122	count_t amb; /* aligned middle bits */
115	count_t tab; /* trailing aligned bits */	123	count_t tab; /* trailing aligned bits */
116		124
117	ASSERT(start + bits <= bitmap->bits);	125	ASSERT(start + bits <= bitmap->bits);
118		126
119	aligned_start = ALIGN_UP(start, 8);	127	aligned_start = ALIGN_UP(start, 8);
120	lub = min(aligned_start - start, bits);	128	lub = min(aligned_start - start, bits);
121	amb = bits > lub ? bits - lub : 0;	129	amb = bits > lub ? bits - lub : 0;
122	tab = amb % 8;	130	tab = amb % 8;
123		131
-		132	if ( start + bits < aligned_start )
-		133	{
-		134	/*
-		135	* Set bits in the middle of byte
-		136	*/
-		137	bitmap->map[start / 8] &= ~(((1 << lub)-1) << (start&7));
-		138	return;
-		139	}
-		140
-		141
124	if (lub) {	142	if (lub) {
125	/*	143	/*
126	* Make sure to clear any leading unaligned bits.	144	* Make sure to clear any leading unaligned bits.
127	*/	145	*/
128	bitmap->map[start / 8] &= (1 << (8 - lub)) - 1;	146	bitmap->map[start / 8] &= (1 << (8 - lub)) - 1;
129	}	147	}
130	for (i = 0; i < amb / 8; i++) {	148	for (i = 0; i < amb / 8; i++) {
131	/*	149	/*
132	* The middle bits can be cleared byte by byte.	150	* The middle bits can be cleared byte by byte.
133	*/	151	*/
134	bitmap->map[aligned_start / 8 + i] = ALL_ZEROES;	152	bitmap->map[aligned_start / 8 + i] = ALL_ZEROES;
135	}	153	}
136	if (tab) {	154	if (tab) {
137	/*	155	/*
138	* Make sure to clear any trailing aligned bits.	156	* Make sure to clear any trailing aligned bits.
139	*/	157	*/
140	bitmap->map[aligned_start / 8 + i] &= ~((1 << tab) - 1);	158	bitmap->map[aligned_start / 8 + i] &= ~((1 << tab) - 1);
141	}	159	}
142		160
143	}	161	}
144		162
145	/** Copy portion of one bitmap into another bitmap.	163	/** Copy portion of one bitmap into another bitmap.
146	*	164	*
147	* @param dst Destination bitmap.	165	* @param dst Destination bitmap.
148	* @param src Source bitmap.	166	* @param src Source bitmap.
149	* @param bits Number of bits to copy.	167	* @param bits Number of bits to copy.
150	*/	168	*/
151	void bitmap_copy(bitmap_t dst, bitmap_t src, count_t bits)	169	void bitmap_copy(bitmap_t dst, bitmap_t src, count_t bits)
152	{	170	{
153	index_t i;	171	index_t i;
154		172
155	ASSERT(bits <= dst->bits);	173	ASSERT(bits <= dst->bits);
156	ASSERT(bits <= src->bits);	174	ASSERT(bits <= src->bits);
157		175
158	for (i = 0; i < bits / 8; i++)	176	for (i = 0; i < bits / 8; i++)
159	dst->map[i] = src->map[i];	177	dst->map[i] = src->map[i];
160		178
161	if (bits % 8) {	179	if (bits % 8) {
162	bitmap_clear_range(dst, i * 8, bits % 8);	180	bitmap_clear_range(dst, i * 8, bits % 8);
163	dst->map[i] \|= src->map[i] & ((1 << (bits % 8)) - 1);	181	dst->map[i] \|= src->map[i] & ((1 << (bits % 8)) - 1);
164	}	182	}
165	}	183	}
166		184