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 */ 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 */ 98 static int memmap_dev_open(const uintptr_t dev_spec __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 0; 105 } 106 107 108 109 /* Close a connection to the memmap device */ 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 0; 115 } 116 117 118 /* Open a file on the memmap device */ 119 /* TODO: Can we do any sensible limit checks on requested memory */ 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 = -ENOMEM; 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 = 0; 140 } else { 141 WARN("A Memmap device is already active. Close first.\n"); 142 } 143 144 return result; 145 } 146 147 148 /* Seek to a particular file offset on the memmap device */ 149 static int memmap_block_seek(io_entity_t *entity, int mode, ssize_t offset) 150 { 151 int result = -ENOENT; 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_t *)entity->info)->file_pos = offset; 159 result = 0; 160 } 161 162 return result; 163 } 164 165 166 /* Read data from a file on the memmap device */ 167 static int memmap_block_read(io_entity_t *entity, uintptr_t buffer, 168 size_t length, size_t *length_read) 169 { 170 file_state_t *fp; 171 172 assert(entity != NULL); 173 assert(buffer != (uintptr_t)NULL); 174 assert(length_read != NULL); 175 176 fp = (file_state_t *)entity->info; 177 178 memcpy((void *)buffer, (void *)(fp->base + fp->file_pos), length); 179 180 *length_read = length; 181 /* advance the file 'cursor' for incremental reads */ 182 fp->file_pos += length; 183 184 return 0; 185 } 186 187 188 /* Write data to a file on the memmap device */ 189 static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer, 190 size_t length, size_t *length_written) 191 { 192 file_state_t *fp; 193 194 assert(entity != NULL); 195 assert(buffer != (uintptr_t)NULL); 196 assert(length_written != NULL); 197 198 fp = (file_state_t *)entity->info; 199 200 memcpy((void *)(fp->base + fp->file_pos), (void *)buffer, length); 201 202 *length_written = length; 203 204 /* advance the file 'cursor' for incremental writes */ 205 fp->file_pos += length; 206 207 return 0; 208 } 209 210 211 /* Close a file on the memmap device */ 212 static int memmap_block_close(io_entity_t *entity) 213 { 214 assert(entity != NULL); 215 216 entity->info = 0; 217 218 /* This would be a mem free() if we had malloc.*/ 219 memset((void *)¤t_file, 0, sizeof(current_file)); 220 221 return 0; 222 } 223 224 225 /* Exported functions */ 226 227 /* Register the memmap driver with the IO abstraction */ 228 int register_io_dev_memmap(const io_dev_connector_t **dev_con) 229 { 230 int result; 231 assert(dev_con != NULL); 232 233 result = io_register_device(&memmap_dev_info); 234 if (result == 0) 235 *dev_con = &memmap_dev_connector; 236 237 return result; 238 } 239