1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
|
/****************************************************************************
* mm/mm_granalloc.c
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <nuttx/gran.h>
#include "mm_gran.h"
#ifdef CONFIG_GRAN
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Name: gran_common_alloc
*
* Description:
* Allocate memory from the granule heap.
*
* Input Parameters:
* priv - The granule heap state structure.
* alloc - The adress of the allocation.
* ngranules - The number of granules allocated
*
* Returned Value:
* None
*
****************************************************************************/
static inline void gran_mark_allocated(FAR struct gran_s *priv, uintptr_t alloc, unsigned int ngranules)
{
unsigned int granno;
unsigned int gatidx;
unsigned int gatbit;
unsigned int avail;
uint32_t mask;
/* Determine the granule number of the allocation */
granno = (alloc - priv->heapstart) >> priv->log2gran;
/* Determine the GAT table index associated with the allocation */
gatidx = granno >> 5;
gatbit = granno & 31;
/* Mark bits in the first GAT entry */
avail = 32 - gatbit;
if (ngranules > avail)
{
priv->gat[gatidx] |= (0xffffffff << gatbit);
ngranules -= avail;
}
/* Handle the case where where all of the granules come from one entry */
else
{
mask = 0xffffffff >> (32 - ngranules);
priv->gat[gatidx] |= (mask << gatbit);
return;
}
/* Mark bits in the second GAT entry */
mask = 0xffffffff >> (32 - ngranules);
priv->gat[gatidx+1] |= (mask << gatbit);
}
/****************************************************************************
* Name: gran_common_alloc
*
* Description:
* Allocate memory from the granule heap.
*
* Input Parameters:
* priv - The granule heap state structure.
* size - The size of the memory region to allocate.
*
* Returned Value:
* On success, a non-NULL pointer to the allocated memory is returned.
*
****************************************************************************/
static inline FAR void *gran_common_alloc(FAR struct gran_s *priv, size_t size)
{
unsigned int ngranules;
size_t tmpmask;
uintptr_t alloc;
uint32_t curr;
uint32_t next;
uint32_t mask;
int i;
int j;
DEBUGASSERT(priv && size <= 32 * (1 << priv->log2gran));
if (priv && size > 0)
{
/* Get exclusive access to the GAT */
gran_semtake(priv);
/* How many contiguous granules we we need to find? */
tmpmask = (1 << priv->log2gran) - 1;
ngranules = (size + tmpmask) >> priv->log2gran;
/* Then create mask for that number of granules */
DEBUGASSERT(ngranules <= 32);
mask = 0xffffffff >> (32 - ngranules);
/* Now search the granule allocation table for that number of contiguous */
alloc = priv->heapstart;
for (i = 0; i < priv->ngranules; i += 32)
{
/* Get the GAT index associated with the granule (i) */
j = i >> 5;
curr = priv->gat[j];
/* Get the next entry from the GAT to support a 64 bit shift */
if (i < priv->ngranules)
{
next = priv->gat[j + 1];
}
/* Use all zeroes when are at the last entry in the GAT */
else
{
next = 0;
}
for (j = 0; j < 32; j++)
{
/* Check if we have the allocation at this bit position (0
* means unallocated).
*/
if ((curr & mask) == 0)
{
/* Yes.. mark these granules allocated */
gran_mark_allocated(priv, alloc, ngranules);
/* And return the allocation address */
gran_semgive(priv);
return (FAR void *)alloc;
}
/* Set up for the next time through the loop. Perform a 64
* bit shift to move to the next gram position.
*/
curr >>= 1;
if ((next & 1) != 0)
{
curr |= 0x80000000;
}
next >>= 1;
/* Increment the next candidate allocation address */
alloc += (1 << priv->log2gran);
}
}
}
gran_semgive(priv);
return NULL;
}
/****************************************************************************
* Global Functions
****************************************************************************/
/****************************************************************************
* Name: gran_alloc
*
* Description:
* Allocate memory from the granule heap.
*
* NOTE: The current implementation also restricts the maximum allocation
* size to 32 granaules. That restriction could be eliminated with some
* additional coding effort.
*
* Input Parameters:
* handle - The handle previously returned by gran_initialize
* size - The size of the memory region to allocate.
*
* Returned Value:
* On success, either a non-NULL pointer to the allocated memory (if
* CONFIG_GRAN_SINGLE) or zero (if !CONFIG_GRAN_SINGLE) is returned.
*
****************************************************************************/
#ifdef CONFIG_GRAN_SINGLE
FAR void *gran_alloc(size_t size)
{
return gran_common_alloc(g_graninfo, size);
}
#else
FAR void *gran_alloc(GRAN_HANDLE handle, size_t size)
{
return gran_common_alloc((FAR struct gran_s *)handle, size);
}
#endif
#endif /* CONFIG_GRAN */
|
