1 /* 2 * Copyright (c) 2014-2018, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <assert.h> 8 #include <debug.h> 9 #include <io_driver.h> 10 #include <io_memmap.h> 11 #include <io_storage.h> 12 #include <platform_def.h> 13 #include <string.h> 14 #include <utils.h> 15 16 /* As we need to be able to keep state for seek, only one file can be open 17 * at a time. Make this a structure and point to the entity->info. When we 18 * can malloc memory we can change this to support more open files. 19 */ 20 typedef struct { 21 /* Use the 'in_use' flag as any value for base and file_pos could be 22 * valid. 23 */ 24 int in_use; 25 uintptr_t base; 26 size_t file_pos; 27 size_t size; 28 } file_state_t; 29 30 static file_state_t current_file = {0}; 31 32 /* Identify the device type as memmap */ 33 static io_type_t device_type_memmap(void) 34 { 35 return IO_TYPE_MEMMAP; 36 } 37 38 /* Memmap device functions */ 39 static int memmap_dev_open(const uintptr_t dev_spec, io_dev_info_t **dev_info); 40 static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec, 41 io_entity_t *entity); 42 static int memmap_block_seek(io_entity_t *entity, int mode, 43 ssize_t offset); 44 static int memmap_block_len(io_entity_t *entity, size_t *length); 45 static int memmap_block_read(io_entity_t *entity, uintptr_t buffer, 46 size_t length, size_t *length_read); 47 static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer, 48 size_t length, size_t *length_written); 49 static int memmap_block_close(io_entity_t *entity); 50 static int memmap_dev_close(io_dev_info_t *dev_info); 51 52 53 static const io_dev_connector_t memmap_dev_connector = { 54 .dev_open = memmap_dev_open 55 }; 56 57 58 static const io_dev_funcs_t memmap_dev_funcs = { 59 .type = device_type_memmap, 60 .open = memmap_block_open, 61 .seek = memmap_block_seek, 62 .size = memmap_block_len, 63 .read = memmap_block_read, 64 .write = memmap_block_write, 65 .close = memmap_block_close, 66 .dev_init = NULL, 67 .dev_close = memmap_dev_close, 68 }; 69 70 71 /* No state associated with this device so structure can be const */ 72 static const io_dev_info_t memmap_dev_info = { 73 .funcs = &memmap_dev_funcs, 74 .info = (uintptr_t)NULL 75 }; 76 77 78 /* Open a connection to the memmap device */ 79 static int memmap_dev_open(const uintptr_t dev_spec __unused, 80 io_dev_info_t **dev_info) 81 { 82 assert(dev_info != NULL); 83 *dev_info = (io_dev_info_t *)&memmap_dev_info; /* cast away const */ 84 85 return 0; 86 } 87 88 89 90 /* Close a connection to the memmap device */ 91 static int memmap_dev_close(io_dev_info_t *dev_info) 92 { 93 /* NOP */ 94 /* TODO: Consider tracking open files and cleaning them up here */ 95 return 0; 96 } 97 98 99 /* Open a file on the memmap device */ 100 static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec, 101 io_entity_t *entity) 102 { 103 int result = -ENOMEM; 104 const io_block_spec_t *block_spec = (io_block_spec_t *)spec; 105 106 /* Since we need to track open state for seek() we only allow one open 107 * spec at a time. When we have dynamic memory we can malloc and set 108 * entity->info. 109 */ 110 if (current_file.in_use == 0) { 111 assert(block_spec != NULL); 112 assert(entity != NULL); 113 114 current_file.in_use = 1; 115 current_file.base = block_spec->offset; 116 /* File cursor offset for seek and incremental reads etc. */ 117 current_file.file_pos = 0; 118 current_file.size = block_spec->length; 119 entity->info = (uintptr_t)¤t_file; 120 result = 0; 121 } else { 122 WARN("A Memmap device is already active. Close first.\n"); 123 } 124 125 return result; 126 } 127 128 129 /* Seek to a particular file offset on the memmap device */ 130 static int memmap_block_seek(io_entity_t *entity, int mode, ssize_t offset) 131 { 132 int result = -ENOENT; 133 file_state_t *fp; 134 135 /* We only support IO_SEEK_SET for the moment. */ 136 if (mode == IO_SEEK_SET) { 137 assert(entity != NULL); 138 139 fp = (file_state_t *) entity->info; 140 141 /* Assert that new file position is valid */ 142 assert((offset >= 0) && (offset < fp->size)); 143 144 /* Reset file position */ 145 fp->file_pos = offset; 146 result = 0; 147 } 148 149 return result; 150 } 151 152 153 /* Return the size of a file on the memmap device */ 154 static int memmap_block_len(io_entity_t *entity, size_t *length) 155 { 156 assert(entity != NULL); 157 assert(length != NULL); 158 159 *length = ((file_state_t *)entity->info)->size; 160 161 return 0; 162 } 163 164 165 /* Read data from a file on the memmap device */ 166 static int memmap_block_read(io_entity_t *entity, uintptr_t buffer, 167 size_t length, size_t *length_read) 168 { 169 file_state_t *fp; 170 size_t pos_after; 171 172 assert(entity != NULL); 173 assert(length_read != NULL); 174 175 fp = (file_state_t *) entity->info; 176 177 /* Assert that file position is valid for this read operation */ 178 pos_after = fp->file_pos + length; 179 assert((pos_after >= fp->file_pos) && (pos_after <= fp->size)); 180 181 memcpy((void *)buffer, (void *)(fp->base + fp->file_pos), length); 182 183 *length_read = length; 184 185 /* Set file position after read */ 186 fp->file_pos = pos_after; 187 188 return 0; 189 } 190 191 192 /* Write data to a file on the memmap device */ 193 static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer, 194 size_t length, size_t *length_written) 195 { 196 file_state_t *fp; 197 size_t pos_after; 198 199 assert(entity != NULL); 200 assert(length_written != NULL); 201 202 fp = (file_state_t *) entity->info; 203 204 /* Assert that file position is valid for this write operation */ 205 pos_after = fp->file_pos + length; 206 assert((pos_after >= fp->file_pos) && (pos_after <= fp->size)); 207 208 memcpy((void *)(fp->base + fp->file_pos), (void *)buffer, length); 209 210 *length_written = length; 211 212 /* Set file position after write */ 213 fp->file_pos = pos_after; 214 215 return 0; 216 } 217 218 219 /* Close a file on the memmap device */ 220 static int memmap_block_close(io_entity_t *entity) 221 { 222 assert(entity != NULL); 223 224 entity->info = 0; 225 226 /* This would be a mem free() if we had malloc.*/ 227 zeromem((void *)¤t_file, sizeof(current_file)); 228 229 return 0; 230 } 231 232 233 /* Exported functions */ 234 235 /* Register the memmap driver with the IO abstraction */ 236 int register_io_dev_memmap(const io_dev_connector_t **dev_con) 237 { 238 int result; 239 assert(dev_con != NULL); 240 241 result = io_register_device(&memmap_dev_info); 242 if (result == 0) 243 *dev_con = &memmap_dev_connector; 244 245 return result; 246 } 247