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 <string.h> 9 10 #include <platform_def.h> 11 12 #include <common/debug.h> 13 #include <drivers/io/io_driver.h> 14 #include <drivers/io/io_memmap.h> 15 #include <drivers/io/io_storage.h> 16 #include <lib/utils.h> 17 18 /* As we need to be able to keep state for seek, only one file can be open 19 * at a time. Make this a structure and point to the entity->info. When we 20 * can malloc memory we can change this to support more open files. 21 */ 22 typedef struct { 23 /* Use the 'in_use' flag as any value for base and file_pos could be 24 * valid. 25 */ 26 int in_use; 27 uintptr_t base; 28 size_t file_pos; 29 size_t size; 30 } file_state_t; 31 32 static file_state_t current_file = {0}; 33 34 /* Identify the device type as memmap */ 35 static io_type_t device_type_memmap(void) 36 { 37 return IO_TYPE_MEMMAP; 38 } 39 40 /* Memmap device functions */ 41 static int memmap_dev_open(const uintptr_t dev_spec, io_dev_info_t **dev_info); 42 static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec, 43 io_entity_t *entity); 44 static int memmap_block_seek(io_entity_t *entity, int mode, 45 ssize_t offset); 46 static int memmap_block_len(io_entity_t *entity, size_t *length); 47 static int memmap_block_read(io_entity_t *entity, uintptr_t buffer, 48 size_t length, size_t *length_read); 49 static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer, 50 size_t length, size_t *length_written); 51 static int memmap_block_close(io_entity_t *entity); 52 static int memmap_dev_close(io_dev_info_t *dev_info); 53 54 55 static const io_dev_connector_t memmap_dev_connector = { 56 .dev_open = memmap_dev_open 57 }; 58 59 60 static const io_dev_funcs_t memmap_dev_funcs = { 61 .type = device_type_memmap, 62 .open = memmap_block_open, 63 .seek = memmap_block_seek, 64 .size = memmap_block_len, 65 .read = memmap_block_read, 66 .write = memmap_block_write, 67 .close = memmap_block_close, 68 .dev_init = NULL, 69 .dev_close = memmap_dev_close, 70 }; 71 72 73 /* No state associated with this device so structure can be const */ 74 static const io_dev_info_t memmap_dev_info = { 75 .funcs = &memmap_dev_funcs, 76 .info = (uintptr_t)NULL 77 }; 78 79 80 /* Open a connection to the memmap device */ 81 static int memmap_dev_open(const uintptr_t dev_spec __unused, 82 io_dev_info_t **dev_info) 83 { 84 assert(dev_info != NULL); 85 *dev_info = (io_dev_info_t *)&memmap_dev_info; /* cast away const */ 86 87 return 0; 88 } 89 90 91 92 /* Close a connection to the memmap device */ 93 static int memmap_dev_close(io_dev_info_t *dev_info) 94 { 95 /* NOP */ 96 /* TODO: Consider tracking open files and cleaning them up here */ 97 return 0; 98 } 99 100 101 /* Open a file on the memmap device */ 102 static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec, 103 io_entity_t *entity) 104 { 105 int result = -ENOMEM; 106 const io_block_spec_t *block_spec = (io_block_spec_t *)spec; 107 108 /* Since we need to track open state for seek() we only allow one open 109 * spec at a time. When we have dynamic memory we can malloc and set 110 * entity->info. 111 */ 112 if (current_file.in_use == 0) { 113 assert(block_spec != NULL); 114 assert(entity != NULL); 115 116 current_file.in_use = 1; 117 current_file.base = block_spec->offset; 118 /* File cursor offset for seek and incremental reads etc. */ 119 current_file.file_pos = 0; 120 current_file.size = block_spec->length; 121 entity->info = (uintptr_t)¤t_file; 122 result = 0; 123 } else { 124 WARN("A Memmap device is already active. Close first.\n"); 125 } 126 127 return result; 128 } 129 130 131 /* Seek to a particular file offset on the memmap device */ 132 static int memmap_block_seek(io_entity_t *entity, int mode, ssize_t offset) 133 { 134 int result = -ENOENT; 135 file_state_t *fp; 136 137 /* We only support IO_SEEK_SET for the moment. */ 138 if (mode == IO_SEEK_SET) { 139 assert(entity != NULL); 140 141 fp = (file_state_t *) entity->info; 142 143 /* Assert that new file position is valid */ 144 assert((offset >= 0) && (offset < fp->size)); 145 146 /* Reset file position */ 147 fp->file_pos = offset; 148 result = 0; 149 } 150 151 return result; 152 } 153 154 155 /* Return the size of a file on the memmap device */ 156 static int memmap_block_len(io_entity_t *entity, size_t *length) 157 { 158 assert(entity != NULL); 159 assert(length != NULL); 160 161 *length = ((file_state_t *)entity->info)->size; 162 163 return 0; 164 } 165 166 167 /* Read data from a file on the memmap device */ 168 static int memmap_block_read(io_entity_t *entity, uintptr_t buffer, 169 size_t length, size_t *length_read) 170 { 171 file_state_t *fp; 172 size_t pos_after; 173 174 assert(entity != NULL); 175 assert(length_read != NULL); 176 177 fp = (file_state_t *) entity->info; 178 179 /* Assert that file position is valid for this read operation */ 180 pos_after = fp->file_pos + length; 181 assert((pos_after >= fp->file_pos) && (pos_after <= fp->size)); 182 183 memcpy((void *)buffer, (void *)(fp->base + fp->file_pos), length); 184 185 *length_read = length; 186 187 /* Set file position after read */ 188 fp->file_pos = pos_after; 189 190 return 0; 191 } 192 193 194 /* Write data to a file on the memmap device */ 195 static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer, 196 size_t length, size_t *length_written) 197 { 198 file_state_t *fp; 199 size_t pos_after; 200 201 assert(entity != NULL); 202 assert(length_written != NULL); 203 204 fp = (file_state_t *) entity->info; 205 206 /* Assert that file position is valid for this write operation */ 207 pos_after = fp->file_pos + length; 208 assert((pos_after >= fp->file_pos) && (pos_after <= fp->size)); 209 210 memcpy((void *)(fp->base + fp->file_pos), (void *)buffer, length); 211 212 *length_written = length; 213 214 /* Set file position after write */ 215 fp->file_pos = pos_after; 216 217 return 0; 218 } 219 220 221 /* Close a file on the memmap device */ 222 static int memmap_block_close(io_entity_t *entity) 223 { 224 assert(entity != NULL); 225 226 entity->info = 0; 227 228 /* This would be a mem free() if we had malloc.*/ 229 zeromem((void *)¤t_file, sizeof(current_file)); 230 231 return 0; 232 } 233 234 235 /* Exported functions */ 236 237 /* Register the memmap driver with the IO abstraction */ 238 int register_io_dev_memmap(const io_dev_connector_t **dev_con) 239 { 240 int result; 241 assert(dev_con != NULL); 242 243 result = io_register_device(&memmap_dev_info); 244 if (result == 0) 245 *dev_con = &memmap_dev_connector; 246 247 return result; 248 } 249