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.
 */
 
 /** @addtogroup genericadt
 
 * @{
 */
/**
 * @file
 * @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 – Rev 1704 → 1705

Rev 1704		Rev 1705
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	/** @addtogroup genericadt ADT	29	/** @addtogroup genericadt
30	* @ingroup kernel	-
31	* @{	30	* @{
32	*/	31	*/
33	/**	32	/**
34	* @file	33	* @file
35	* @brief Implementation of bitmap ADT.	34	* @brief Implementation of bitmap ADT.
36	*	35	*
37	* This file implements bitmap ADT and provides functions for	36	* This file implements bitmap ADT and provides functions for
38	* setting and clearing ranges of bits.	37	* setting and clearing ranges of bits.
39	*/	38	*/
40		39
41	#include <adt/bitmap.h>	40	#include <adt/bitmap.h>
42	#include <typedefs.h>	41	#include <typedefs.h>
43	#include <arch/types.h>	42	#include <arch/types.h>
44	#include <align.h>	43	#include <align.h>
45	#include <debug.h>	44	#include <debug.h>
46	#include <macros.h>	45	#include <macros.h>
47		46
48	#define ALL_ONES 0xff	47	#define ALL_ONES 0xff
49	#define ALL_ZEROES 0x00	48	#define ALL_ZEROES 0x00
50		49
51	/** Initialize bitmap.	50	/** Initialize bitmap.
52	*	51	*
53	* No portion of the bitmap is set or cleared by this function.	52	* No portion of the bitmap is set or cleared by this function.
54	*	53	*
55	* @param bitmap Bitmap structure.	54	* @param bitmap Bitmap structure.
56	* @param map Address of the memory used to hold the map.	55	* @param map Address of the memory used to hold the map.
57	* @param bits Number of bits stored in bitmap.	56	* @param bits Number of bits stored in bitmap.
58	*/	57	*/
59	void bitmap_initialize(bitmap_t bitmap, __u8 map, count_t bits)	58	void bitmap_initialize(bitmap_t bitmap, __u8 map, count_t bits)
60	{	59	{
61	bitmap->map = map;	60	bitmap->map = map;
62	bitmap->bits = bits;	61	bitmap->bits = bits;
63	}	62	}
64		63
65	/** Set range of bits.	64	/** Set range of bits.
66	*	65	*
67	* @param bitmap Bitmap structure.	66	* @param bitmap Bitmap structure.
68	* @param start Starting bit.	67	* @param start Starting bit.
69	* @param bits Number of bits to set.	68	* @param bits Number of bits to set.
70	*/	69	*/
71	void bitmap_set_range(bitmap_t *bitmap, index_t start, count_t bits)	70	void bitmap_set_range(bitmap_t *bitmap, index_t start, count_t bits)
72	{	71	{
73	index_t i=0;	72	index_t i=0;
74	index_t aligned_start;	73	index_t aligned_start;
75	count_t lub; /* leading unaligned bits */	74	count_t lub; /* leading unaligned bits */
76	count_t amb; /* aligned middle bits */	75	count_t amb; /* aligned middle bits */
77	count_t tab; /* trailing aligned bits */	76	count_t tab; /* trailing aligned bits */
78		77
79	ASSERT(start + bits <= bitmap->bits);	78	ASSERT(start + bits <= bitmap->bits);
80		79
81	aligned_start = ALIGN_UP(start, 8);	80	aligned_start = ALIGN_UP(start, 8);
82	lub = min(aligned_start - start, bits);	81	lub = min(aligned_start - start, bits);
83	amb = bits > lub ? bits - lub : 0;	82	amb = bits > lub ? bits - lub : 0;
84	tab = amb % 8;	83	tab = amb % 8;
85		84
86	if ( start + bits < aligned_start ) {	85	if ( start + bits < aligned_start ) {
87	/*	86	/*
88	* Set bits in the middle of byte	87	* Set bits in the middle of byte
89	*/	88	*/
90	bitmap->map[start / 8] \|= ((1 << lub)-1) << (start&7);	89	bitmap->map[start / 8] \|= ((1 << lub)-1) << (start&7);
91	return;	90	return;
92	}	91	}
93		92
94	if (lub) {	93	if (lub) {
95	/*	94	/*
96	* Make sure to set any leading unaligned bits.	95	* Make sure to set any leading unaligned bits.
97	*/	96	*/
98	bitmap->map[start / 8] \|= ~((1 << (8 - lub)) - 1);	97	bitmap->map[start / 8] \|= ~((1 << (8 - lub)) - 1);
99	}	98	}
100	for (i = 0; i < amb / 8; i++) {	99	for (i = 0; i < amb / 8; i++) {
101	/*	100	/*
102	* The middle bits can be set byte by byte.	101	* The middle bits can be set byte by byte.
103	*/	102	*/
104	bitmap->map[aligned_start / 8 + i] = ALL_ONES;	103	bitmap->map[aligned_start / 8 + i] = ALL_ONES;
105	}	104	}
106	if (tab) {	105	if (tab) {
107	/*	106	/*
108	* Make sure to set any trailing aligned bits.	107	* Make sure to set any trailing aligned bits.
109	*/	108	*/
110	bitmap->map[aligned_start / 8 + i] \|= (1 << tab) - 1;	109	bitmap->map[aligned_start / 8 + i] \|= (1 << tab) - 1;
111	}	110	}
112		111
113	}	112	}
114		113
115	/** Clear range of bits.	114	/** Clear range of bits.
116	*	115	*
117	* @param bitmap Bitmap structure.	116	* @param bitmap Bitmap structure.
118	* @param start Starting bit.	117	* @param start Starting bit.
119	* @param bits Number of bits to clear.	118	* @param bits Number of bits to clear.
120	*/	119	*/
121	void bitmap_clear_range(bitmap_t *bitmap, index_t start, count_t bits)	120	void bitmap_clear_range(bitmap_t *bitmap, index_t start, count_t bits)
122	{	121	{
123	index_t i=0;	122	index_t i=0;
124	index_t aligned_start;	123	index_t aligned_start;
125	count_t lub; /* leading unaligned bits */	124	count_t lub; /* leading unaligned bits */
126	count_t amb; /* aligned middle bits */	125	count_t amb; /* aligned middle bits */
127	count_t tab; /* trailing aligned bits */	126	count_t tab; /* trailing aligned bits */
128		127
129	ASSERT(start + bits <= bitmap->bits);	128	ASSERT(start + bits <= bitmap->bits);
130		129
131	aligned_start = ALIGN_UP(start, 8);	130	aligned_start = ALIGN_UP(start, 8);
132	lub = min(aligned_start - start, bits);	131	lub = min(aligned_start - start, bits);
133	amb = bits > lub ? bits - lub : 0;	132	amb = bits > lub ? bits - lub : 0;
134	tab = amb % 8;	133	tab = amb % 8;
135		134
136	if ( start + bits < aligned_start )	135	if ( start + bits < aligned_start )
137	{	136	{
138	/*	137	/*
139	* Set bits in the middle of byte	138	* Set bits in the middle of byte
140	*/	139	*/
141	bitmap->map[start / 8] &= ~(((1 << lub)-1) << (start&7));	140	bitmap->map[start / 8] &= ~(((1 << lub)-1) << (start&7));
142	return;	141	return;
143	}	142	}
144		143
145		144
146	if (lub) {	145	if (lub) {
147	/*	146	/*
148	* Make sure to clear any leading unaligned bits.	147	* Make sure to clear any leading unaligned bits.
149	*/	148	*/
150	bitmap->map[start / 8] &= (1 << (8 - lub)) - 1;	149	bitmap->map[start / 8] &= (1 << (8 - lub)) - 1;
151	}	150	}
152	for (i = 0; i < amb / 8; i++) {	151	for (i = 0; i < amb / 8; i++) {
153	/*	152	/*
154	* The middle bits can be cleared byte by byte.	153	* The middle bits can be cleared byte by byte.
155	*/	154	*/
156	bitmap->map[aligned_start / 8 + i] = ALL_ZEROES;	155	bitmap->map[aligned_start / 8 + i] = ALL_ZEROES;
157	}	156	}
158	if (tab) {	157	if (tab) {
159	/*	158	/*
160	* Make sure to clear any trailing aligned bits.	159	* Make sure to clear any trailing aligned bits.
161	*/	160	*/
162	bitmap->map[aligned_start / 8 + i] &= ~((1 << tab) - 1);	161	bitmap->map[aligned_start / 8 + i] &= ~((1 << tab) - 1);
163	}	162	}
164		163
165	}	164	}
166		165
167	/** Copy portion of one bitmap into another bitmap.	166	/** Copy portion of one bitmap into another bitmap.
168	*	167	*
169	* @param dst Destination bitmap.	168	* @param dst Destination bitmap.
170	* @param src Source bitmap.	169	* @param src Source bitmap.
171	* @param bits Number of bits to copy.	170	* @param bits Number of bits to copy.
172	*/	171	*/
173	void bitmap_copy(bitmap_t dst, bitmap_t src, count_t bits)	172	void bitmap_copy(bitmap_t dst, bitmap_t src, count_t bits)
174	{	173	{
175	index_t i;	174	index_t i;
176		175
177	ASSERT(bits <= dst->bits);	176	ASSERT(bits <= dst->bits);
178	ASSERT(bits <= src->bits);	177	ASSERT(bits <= src->bits);
179		178
180	for (i = 0; i < bits / 8; i++)	179	for (i = 0; i < bits / 8; i++)
181	dst->map[i] = src->map[i];	180	dst->map[i] = src->map[i];
182		181
183	if (bits % 8) {	182	if (bits % 8) {
184	bitmap_clear_range(dst, i * 8, bits % 8);	183	bitmap_clear_range(dst, i * 8, bits % 8);
185	dst->map[i] \|= src->map[i] & ((1 << (bits % 8)) - 1);	184	dst->map[i] \|= src->map[i] & ((1 << (bits % 8)) - 1);
186	}	185	}
187	}	186	}
188		187
189	/** @}	188	/** @}
190	*/	189	*/
191		190
192		191