1 /*
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 <debug.h>
33 #include <io_driver.h>
34 #include <io_storage.h>
35 #include <string.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 */
41 typedef 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 uintptr_t base;
47 size_t file_pos;
48 } file_state_t;
49
50 static file_state_t current_file = {0};
51
52 /* Identify the device type as memmap */
device_type_memmap(void)53 io_type_t device_type_memmap(void)
54 {
55 return IO_TYPE_MEMMAP;
56 }
57
58 /* Memmap device functions */
59 static int memmap_dev_open(const uintptr_t dev_spec, io_dev_info_t **dev_info);
60 static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec,
61 io_entity_t *entity);
62 static int memmap_block_seek(io_entity_t *entity, int mode,
63 ssize_t offset);
64 static int memmap_block_read(io_entity_t *entity, uintptr_t buffer,
65 size_t length, size_t *length_read);
66 static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer,
67 size_t length, size_t *length_written);
68 static int memmap_block_close(io_entity_t *entity);
69 static int memmap_dev_close(io_dev_info_t *dev_info);
70
71
72 static const io_dev_connector_t memmap_dev_connector = {
73 .dev_open = memmap_dev_open
74 };
75
76
77 static const io_dev_funcs_t 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
90 /* No state associated with this device so structure can be const */
91 static const io_dev_info_t memmap_dev_info = {
92 .funcs = &memmap_dev_funcs,
93 .info = (uintptr_t)NULL
94 };
95
96
97 /* Open a connection to the memmap device */
memmap_dev_open(const uintptr_t dev_spec,io_dev_info_t ** dev_info)98 static int memmap_dev_open(const uintptr_t dev_spec __attribute__((unused)),
99 io_dev_info_t **dev_info)
100 {
101 assert(dev_info != NULL);
102 *dev_info = (io_dev_info_t *)&memmap_dev_info; /* cast away const */
103
104 return IO_SUCCESS;
105 }
106
107
108
109 /* Close a connection to the memmap device */
memmap_dev_close(io_dev_info_t * dev_info)110 static int memmap_dev_close(io_dev_info_t *dev_info)
111 {
112 /* NOP */
113 /* TODO: Consider tracking open files and cleaning them up here */
114 return IO_SUCCESS;
115 }
116
117
118 /* Open a file on the memmap device */
119 /* TODO: Can we do any sensible limit checks on requested memory */
memmap_block_open(io_dev_info_t * dev_info,const uintptr_t spec,io_entity_t * entity)120 static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec,
121 io_entity_t *entity)
122 {
123 int result = IO_FAIL;
124 const io_block_spec_t *block_spec = (io_block_spec_t *)spec;
125
126 /* Since we need to track open state for seek() we only allow one open
127 * spec at a time. When we have dynamic memory we can malloc and set
128 * entity->info.
129 */
130 if (current_file.in_use == 0) {
131 assert(block_spec != NULL);
132 assert(entity != NULL);
133
134 current_file.in_use = 1;
135 current_file.base = block_spec->offset;
136 /* File cursor offset for seek and incremental reads etc. */
137 current_file.file_pos = 0;
138 entity->info = (uintptr_t)¤t_file;
139 result = IO_SUCCESS;
140 } else {
141 WARN("A Memmap device is already active. Close first.\n");
142 result = IO_RESOURCES_EXHAUSTED;
143 }
144
145 return result;
146 }
147
148
149 /* Seek to a particular file offset on the memmap device */
memmap_block_seek(io_entity_t * entity,int mode,ssize_t offset)150 static int memmap_block_seek(io_entity_t *entity, int mode, ssize_t offset)
151 {
152 int result = IO_FAIL;
153
154 /* We only support IO_SEEK_SET for the moment. */
155 if (mode == IO_SEEK_SET) {
156 assert(entity != NULL);
157
158 /* TODO: can we do some basic limit checks on seek? */
159 ((file_state_t *)entity->info)->file_pos = offset;
160 result = IO_SUCCESS;
161 } else {
162 result = IO_FAIL;
163 }
164
165 return result;
166 }
167
168
169 /* Read data from a file on the memmap device */
memmap_block_read(io_entity_t * entity,uintptr_t buffer,size_t length,size_t * length_read)170 static int memmap_block_read(io_entity_t *entity, uintptr_t buffer,
171 size_t length, size_t *length_read)
172 {
173 file_state_t *fp;
174
175 assert(entity != NULL);
176 assert(buffer != (uintptr_t)NULL);
177 assert(length_read != NULL);
178
179 fp = (file_state_t *)entity->info;
180
181 memcpy((void *)buffer, (void *)(fp->base + fp->file_pos), length);
182
183 *length_read = length;
184 /* advance the file 'cursor' for incremental reads */
185 fp->file_pos += length;
186
187 return IO_SUCCESS;
188 }
189
190
191 /* Write data to a file on the memmap device */
memmap_block_write(io_entity_t * entity,const uintptr_t buffer,size_t length,size_t * length_written)192 static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer,
193 size_t length, size_t *length_written)
194 {
195 file_state_t *fp;
196
197 assert(entity != NULL);
198 assert(buffer != (uintptr_t)NULL);
199 assert(length_written != NULL);
200
201 fp = (file_state_t *)entity->info;
202
203 memcpy((void *)(fp->base + fp->file_pos), (void *)buffer, length);
204
205 *length_written = length;
206
207 /* advance the file 'cursor' for incremental writes */
208 fp->file_pos += length;
209
210 return IO_SUCCESS;
211 }
212
213
214 /* Close a file on the memmap device */
memmap_block_close(io_entity_t * entity)215 static int memmap_block_close(io_entity_t *entity)
216 {
217 assert(entity != NULL);
218
219 entity->info = 0;
220
221 /* This would be a mem free() if we had malloc.*/
222 memset((void *)¤t_file, 0, sizeof(current_file));
223
224 return IO_SUCCESS;
225 }
226
227
228 /* Exported functions */
229
230 /* Register the memmap driver with the IO abstraction */
register_io_dev_memmap(const io_dev_connector_t ** dev_con)231 int register_io_dev_memmap(const io_dev_connector_t **dev_con)
232 {
233 int result = IO_FAIL;
234 assert(dev_con != NULL);
235
236 result = io_register_device(&memmap_dev_info);
237 if (result == IO_SUCCESS)
238 *dev_con = &memmap_dev_connector;
239
240 return result;
241 }
242