blob: 40b8e9abcaedffba540e1e05d2e2f5506238cc9c [file] [log] [blame]
Harry Liebel561cd332014-02-14 14:42:48 +00001/*
2 * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * Neither the name of ARM nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without specific
16 * prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <assert.h>
32#include <string.h>
33#include "io_storage.h"
34#include "io_driver.h"
35#include "debug.h"
36
37/* As we need to be able to keep state for seek, only one file can be open
38 * at a time. Make this a structure and point to the entity->info. When we
39 * can malloc memory we can change this to support more open files.
40 */
41typedef struct {
42 /* Use the 'in_use' flag as any value for base and file_pos could be
43 * valid.
44 */
45 int in_use;
46 size_t base;
47 size_t file_pos;
48} file_state;
49
50static file_state current_file = {0};
51
52/* Identify the device type as memmap */
53io_type device_type_memmap(void)
54{
55 return IO_TYPE_MEMMAP;
56}
57
58/* Memmap device functions */
59static int memmap_dev_open(void *spec, struct io_dev_info **dev_info);
60static int memmap_block_open(struct io_dev_info *dev_info, const void *spec,
61 struct io_entity *entity);
62static int memmap_block_seek(struct io_entity *entity, int mode,
63 ssize_t offset);
64static int memmap_block_read(struct io_entity *entity, void *buffer,
65 size_t length, size_t *length_read);
66static int memmap_block_write(struct io_entity *entity, const void *buffer,
67 size_t length, size_t *length_written);
68static int memmap_block_close(struct io_entity *entity);
69static int memmap_dev_close(struct io_dev_info *dev_info);
70
71
72static struct io_dev_connector memmap_dev_connector = {
73 .dev_open = memmap_dev_open
74};
75
76
77static struct io_dev_funcs memmap_dev_funcs = {
78 .type = device_type_memmap,
79 .open = memmap_block_open,
80 .seek = memmap_block_seek,
81 .size = NULL,
82 .read = memmap_block_read,
83 .write = memmap_block_write,
84 .close = memmap_block_close,
85 .dev_init = NULL,
86 .dev_close = memmap_dev_close,
87};
88
89
90static struct io_dev_info memmap_dev_info = {
91 .funcs = &memmap_dev_funcs,
92 .info = (uintptr_t)NULL
93};
94
95
96/* Open a connection to the memmap device */
97static int memmap_dev_open(void *spec __attribute__((unused)),
98 struct io_dev_info **dev_info)
99{
100 assert(dev_info != NULL);
101 *dev_info = &memmap_dev_info;
102
103 return IO_SUCCESS;
104}
105
106
107
108/* Close a connection to the memmap device */
109static int memmap_dev_close(struct io_dev_info *dev_info)
110{
111 /* NOP */
112 /* TODO: Consider tracking open files and cleaning them up here */
113 return IO_SUCCESS;
114}
115
116
117/* Open a file on the memmap device */
118/* TODO: Can we do any sensible limit checks on requested memory */
119static int memmap_block_open(struct io_dev_info *dev_info, const void *spec,
120 struct io_entity *entity)
121{
122 int result = IO_FAIL;
123 const io_block_spec *block_spec = (io_block_spec *)spec;
124
125 /* Since we need to track open state for seek() we only allow one open
126 * spec at a time. When we have dynamic memory we can malloc and set
127 * entity->info.
128 */
129 if (current_file.in_use == 0) {
130 assert(block_spec != NULL);
131 assert(entity != NULL);
132
133 current_file.in_use = 1;
134 current_file.base = block_spec->offset;
135 /* File cursor offset for seek and incremental reads etc. */
136 current_file.file_pos = 0;
137 entity->info = (uintptr_t)&current_file;
138 result = IO_SUCCESS;
139 } else {
Jeenu Viswambharan08c28d52014-02-20 12:03:31 +0000140 WARN("A Memmap device is already active. Close first.\n");
Harry Liebel561cd332014-02-14 14:42:48 +0000141 result = IO_RESOURCES_EXHAUSTED;
142 }
143
144 return result;
145}
146
147
148/* Seek to a particular file offset on the memmap device */
149static int memmap_block_seek(struct io_entity *entity, int mode, ssize_t offset)
150{
151 int result = IO_FAIL;
152
153 /* We only support IO_SEEK_SET for the moment. */
154 if (mode == IO_SEEK_SET) {
155 assert(entity != NULL);
156
157 /* TODO: can we do some basic limit checks on seek? */
158 ((file_state *)entity->info)->file_pos = offset;
159 result = IO_SUCCESS;
160 } else {
161 result = IO_FAIL;
162 }
163
164 return result;
165}
166
167
168/* Read data from a file on the memmap device */
169static int memmap_block_read(struct io_entity *entity, void *buffer,
170 size_t length, size_t *length_read)
171{
172 file_state *fp;
173
174 assert(entity != NULL);
175 assert(buffer != NULL);
176 assert(length_read != NULL);
177
178 fp = (file_state *)entity->info;
179
180 memcpy(buffer, (void *)(fp->base + fp->file_pos), length);
181
182 *length_read = length;
183 /* advance the file 'cursor' for incremental reads */
184 fp->file_pos += length;
185
186 return IO_SUCCESS;
187}
188
189
190/* Write data to a file on the memmap device */
191static int memmap_block_write(struct io_entity *entity, const void *buffer,
192 size_t length, size_t *length_written)
193{
194 file_state *fp;
195
196 assert(entity != NULL);
197 assert(buffer != NULL);
198 assert(length_written != NULL);
199
200 fp = (file_state *)entity->info;
201
202 memcpy((void *)(fp->base + fp->file_pos), buffer, length);
203
204 *length_written = length;
205
206 /* advance the file 'cursor' for incremental writes */
207 fp->file_pos += length;
208
209 return IO_SUCCESS;
210}
211
212
213/* Close a file on the memmap device */
214static int memmap_block_close(struct io_entity *entity)
215{
216 assert(entity != NULL);
217
218 entity->info = 0;
219
220 /* This would be a mem free() if we had malloc.*/
221 memset((void *)&current_file, 0, sizeof(current_file));
222
223 return IO_SUCCESS;
224}
225
226
227/* Exported functions */
228
229/* Register the memmap driver with the IO abstraction */
230int register_io_dev_memmap(struct io_dev_connector **dev_con)
231{
232 int result = IO_FAIL;
233 assert(dev_con != NULL);
234
235 result = io_register_device(&memmap_dev_info);
236 if (result == IO_SUCCESS)
237 *dev_con = &memmap_dev_connector;
238
239 return result;
240}