Subversion Repositories HelenOS-historic

Rev

Rev 1509 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
978 jermar 1 
/*
2 
 * Copyright (C) 2006 Jakub Jermar
3 
 * All rights reserved.
4 
 *
5 
 * Redistribution and use in source and binary forms, with or without
6 
 * modification, are permitted provided that the following conditions
7 
 * are met:
8 
 *
9 
 * - Redistributions of source code must retain the above copyright
10 
 *   notice, this list of conditions and the following disclaimer.
11 
 * - Redistributions in binary form must reproduce the above copyright
12 
 *   notice, this list of conditions and the following disclaimer in the
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
15 
 *   derived from this software without specific prior written permission.
16 
 *
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
19 
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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
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
26 
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1653 cejka 27 
 */
28 
 
29 
 /** @addtogroup libc
30 
 * @{
31 
 */
32 
/** @file
978 jermar 33 
 */
34 
 
1250 jermar 35 
#include <as.h>
978 jermar 36 
#include <libc.h>
37 
#include <unistd.h>
1501 palkovsky 38 
#include <align.h>
978 jermar 39 
 
1228 jermar 40 
/** Create address space area.
1033 jermar 41 
 *
42 
 * @param address Virtual address where to place new address space area.
43 
 * @param size Size of the area.
44 
 * @param flags Flags describing type of the area.
45 
 *
46 
 * @return address on success, (void *) -1 otherwise.
47 
 */
1228 jermar 48 
void *as_area_create(void *address, size_t size, int flags)
978 jermar 49 
{
1228 jermar 50 
    return (void *) __SYSCALL3(SYS_AS_AREA_CREATE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
1033 jermar 51 
}
52 
 
1228 jermar 53 
/** Resize address space area.
1033 jermar 54 
 *
55 
 * @param address Virtual address pointing into already existing address space area.
56 
 * @param size New requested size of the area.
57 
 * @param flags Currently unused.
58 
 *
1307 jermar 59 
 * @return Zero on success or a code from @ref errno.h on failure.
1033 jermar 60 
 */
1307 jermar 61 
int as_area_resize(void *address, size_t size, int flags)
1033 jermar 62 
{
1307 jermar 63 
    return __SYSCALL3(SYS_AS_AREA_RESIZE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
978 jermar 64 
}
985 palkovsky 65 
 
1307 jermar 66 
/** Destroy address space area.
67 
 *
68 
 * @param address Virtual address pointing into the address space area being destroyed.
69 
 *
70 
 * @return Zero on success or a code from @ref errno.h on failure.
71 
 */
72 
int as_area_destroy(void *address)
73 
{
74 
    return __SYSCALL1(SYS_AS_AREA_DESTROY, (sysarg_t ) address);
75 
}
76 
 
985 palkovsky 77 
static size_t heapsize = 0;
1363 vana 78 
static size_t maxheapsize = (size_t)(-1);
1501 palkovsky 79 
 
80 
static void * last_allocated = 0;
81 
 
985 palkovsky 82 
/* Start of heap linker symbol */
83 
extern char _heap;
84 
 
85 
/** Sbrk emulation
86 
 *
1653 cejka 87 
 * @param incr New area that should be allocated or negative,
985 palkovsky 88 
               if it should be shrinked
89 
 * @return Pointer to newly allocated area
90 
 */
91 
void *sbrk(ssize_t incr)
92 
{
1307 jermar 93 
    int rc;
985 palkovsky 94 
    void *res;
95 
    /* Check for invalid values */
96 
    if (incr < 0 && -incr > heapsize)
97 
        return NULL;
98 
    /* Check for too large value */
99 
    if (incr > 0 && incr+heapsize < heapsize)
100 
        return NULL;
101 
    /* Check for too small values */
102 
    if (incr < 0 && incr+heapsize > heapsize)
103 
        return NULL;
1363 vana 104 
    /* Check for user limit */
105 
    if ((maxheapsize!=(size_t)(-1)) && (heapsize + incr)>maxheapsize) return NULL;
985 palkovsky 106 
 
1307 jermar 107 
    rc = as_area_resize(&_heap, heapsize + incr,0);
108 
    if (rc != 0)
985 palkovsky 109 
        return NULL;
999 palkovsky 110 
 
111 
    /* Compute start of new area */
112 
    res = (void *)&_heap + heapsize;
113 
 
985 palkovsky 114 
    heapsize += incr;
999 palkovsky 115 
 
985 palkovsky 116 
    return res;
117 
}
1363 vana 118 
 
1501 palkovsky 119 
/** Set maximum heap size and return pointer just after the heap */
1363 vana 120 
void *set_maxheapsize(size_t mhs)
121 
{
122 
    maxheapsize=mhs;
123 
    /* Return pointer to area not managed by sbrk */
124 
    return (void *)&_heap + maxheapsize;
125 
 
126 
}
1501 palkovsky 127 
 
128 
/** Return pointer to some unmapped area, where fits new as_area
129 
 *
130 
 * TODO: make some first_fit/... algorithm, we are now just incrementing
131 
 *       the pointer to last area
132 
 */
133 
void * as_get_mappable_page(size_t sz)
134 
{
135 
    void *res;
136 
 
137 
    /* Set heapsize to some meaningful value */
138 
    if (maxheapsize == -1)
139 
        set_maxheapsize(ALIGN_UP(USER_ADDRESS_SPACE_SIZE_ARCH>>1,PAGE_SIZE));
140 
    if (!last_allocated)
141 
        last_allocated = ALIGN_UP((void *)&_heap + maxheapsize, PAGE_SIZE);
142 
 
143 
    sz = ALIGN_UP(sz, PAGE_SIZE);
144 
    res = last_allocated;
145 
    last_allocated += sz;
146 
 
147 
    return res;
148 
}
1653 cejka 149 
 
150 
 
151 
 /** @}
152 
 */
153 
 
154