1 /* 2 * Copyright (c) 2014-2017, 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 #include <utils.h> 37 38 /* As we need to be able to keep state for seek, only one file can be open 39 * at a time. Make this a structure and point to the entity->info. When we 40 * can malloc memory we can change this to support more open files. 41 */ 42 typedef struct { 43 /* Use the 'in_use' flag as any value for base and file_pos could be 44 * valid. 45 */ 46 int in_use; 47 uintptr_t base; 48 size_t file_pos; 49 size_t size; 50 } file_state_t; 51 52 static file_state_t current_file = {0}; 53 54 /* Identify the device type as memmap */ 55 io_type_t device_type_memmap(void) 56 { 57 return IO_TYPE_MEMMAP; 58 } 59 60 /* Memmap device functions */ 61 static int memmap_dev_open(const uintptr_t dev_spec, io_dev_info_t **dev_info); 62 static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec, 63 io_entity_t *entity); 64 static int memmap_block_seek(io_entity_t *entity, int mode, 65 ssize_t offset); 66 static int memmap_block_len(io_entity_t *entity, size_t *length); 67 static int memmap_block_read(io_entity_t *entity, uintptr_t buffer, 68 size_t length, size_t *length_read); 69 static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer, 70 size_t length, size_t *length_written); 71 static int memmap_block_close(io_entity_t *entity); 72 static int memmap_dev_close(io_dev_info_t *dev_info); 73 74 75 static const io_dev_connector_t memmap_dev_connector = { 76 .dev_open = memmap_dev_open 77 }; 78 79 80 static const io_dev_funcs_t memmap_dev_funcs = { 81 .type = device_type_memmap, 82 .open = memmap_block_open, 83 .seek = memmap_block_seek, 84 .size = memmap_block_len, 85 .read = memmap_block_read, 86 .write = memmap_block_write, 87 .close = memmap_block_close, 88 .dev_init = NULL, 89 .dev_close = memmap_dev_close, 90 }; 91 92 93 /* No state associated with this device so structure can be const */ 94 static const io_dev_info_t memmap_dev_info = { 95 .funcs = &memmap_dev_funcs, 96 .info = (uintptr_t)NULL 97 }; 98 99 100 /* Open a connection to the memmap device */ 101 static int memmap_dev_open(const uintptr_t dev_spec __unused, 102 io_dev_info_t **dev_info) 103 { 104 assert(dev_info != NULL); 105 *dev_info = (io_dev_info_t *)&memmap_dev_info; /* cast away const */ 106 107 return 0; 108 } 109 110 111 112 /* Close a connection to the memmap device */ 113 static int memmap_dev_close(io_dev_info_t *dev_info) 114 { 115 /* NOP */ 116 /* TODO: Consider tracking open files and cleaning them up here */ 117 return 0; 118 } 119 120 121 /* Open a file on the memmap device */ 122 /* TODO: Can we do any sensible limit checks on requested memory */ 123 static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec, 124 io_entity_t *entity) 125 { 126 int result = -ENOMEM; 127 const io_block_spec_t *block_spec = (io_block_spec_t *)spec; 128 129 /* Since we need to track open state for seek() we only allow one open 130 * spec at a time. When we have dynamic memory we can malloc and set 131 * entity->info. 132 */ 133 if (current_file.in_use == 0) { 134 assert(block_spec != NULL); 135 assert(entity != NULL); 136 137 current_file.in_use = 1; 138 current_file.base = block_spec->offset; 139 /* File cursor offset for seek and incremental reads etc. */ 140 current_file.file_pos = 0; 141 current_file.size = block_spec->length; 142 entity->info = (uintptr_t)¤t_file; 143 result = 0; 144 } else { 145 WARN("A Memmap device is already active. Close first.\n"); 146 } 147 148 return result; 149 } 150 151 152 /* Seek to a particular file offset on the memmap device */ 153 static int memmap_block_seek(io_entity_t *entity, int mode, ssize_t offset) 154 { 155 int result = -ENOENT; 156 157 /* We only support IO_SEEK_SET for the moment. */ 158 if (mode == IO_SEEK_SET) { 159 assert(entity != NULL); 160 161 /* TODO: can we do some basic limit checks on seek? */ 162 ((file_state_t *)entity->info)->file_pos = offset; 163 result = 0; 164 } 165 166 return result; 167 } 168 169 170 /* Return the size of a file on the memmap device */ 171 static int memmap_block_len(io_entity_t *entity, size_t *length) 172 { 173 assert(entity != NULL); 174 assert(length != NULL); 175 176 *length = ((file_state_t *)entity->info)->size; 177 178 return 0; 179 } 180 181 182 /* Read data from a file on the memmap device */ 183 static int memmap_block_read(io_entity_t *entity, uintptr_t buffer, 184 size_t length, size_t *length_read) 185 { 186 file_state_t *fp; 187 188 assert(entity != NULL); 189 assert(buffer != (uintptr_t)NULL); 190 assert(length_read != NULL); 191 192 fp = (file_state_t *)entity->info; 193 194 memcpy((void *)buffer, (void *)(fp->base + fp->file_pos), length); 195 196 *length_read = length; 197 /* advance the file 'cursor' for incremental reads */ 198 fp->file_pos += length; 199 200 return 0; 201 } 202 203 204 /* Write data to a file on the memmap device */ 205 static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer, 206 size_t length, size_t *length_written) 207 { 208 file_state_t *fp; 209 210 assert(entity != NULL); 211 assert(buffer != (uintptr_t)NULL); 212 assert(length_written != NULL); 213 214 fp = (file_state_t *)entity->info; 215 216 memcpy((void *)(fp->base + fp->file_pos), (void *)buffer, length); 217 218 *length_written = length; 219 220 /* advance the file 'cursor' for incremental writes */ 221 fp->file_pos += length; 222 223 return 0; 224 } 225 226 227 /* Close a file on the memmap device */ 228 static int memmap_block_close(io_entity_t *entity) 229 { 230 assert(entity != NULL); 231 232 entity->info = 0; 233 234 /* This would be a mem free() if we had malloc.*/ 235 zeromem((void *)¤t_file, sizeof(current_file)); 236 237 return 0; 238 } 239 240 241 /* Exported functions */ 242 243 /* Register the memmap driver with the IO abstraction */ 244 int register_io_dev_memmap(const io_dev_connector_t **dev_con) 245 { 246 int result; 247 assert(dev_con != NULL); 248 249 result = io_register_device(&memmap_dev_info); 250 if (result == 0) 251 *dev_con = &memmap_dev_connector; 252 253 return result; 254 } 255