/* * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of ARM nor the names of its contributors may be used * to endorse or promote products derived from this software without specific * prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include /* As we need to be able to keep state for seek, only one file can be open * at a time. Make this a structure and point to the entity->info. When we * can malloc memory we can change this to support more open files. */ typedef struct { /* Use the 'in_use' flag as any value for base and file_pos could be * valid. */ int in_use; size_t base; size_t file_pos; } file_state_t; static file_state_t current_file = {0}; /* Identify the device type as memmap */ io_type_t device_type_memmap(void) { return IO_TYPE_MEMMAP; } /* Memmap device functions */ static int memmap_dev_open(void *spec, io_dev_info_t **dev_info); static int memmap_block_open(io_dev_info_t *dev_info, const void *spec, io_entity_t *entity); static int memmap_block_seek(io_entity_t *entity, int mode, ssize_t offset); static int memmap_block_read(io_entity_t *entity, void *buffer, size_t length, size_t *length_read); static int memmap_block_write(io_entity_t *entity, const void *buffer, size_t length, size_t *length_written); static int memmap_block_close(io_entity_t *entity); static int memmap_dev_close(io_dev_info_t *dev_info); static struct io_dev_connector memmap_dev_connector = { .dev_open = memmap_dev_open }; static struct io_dev_funcs memmap_dev_funcs = { .type = device_type_memmap, .open = memmap_block_open, .seek = memmap_block_seek, .size = NULL, .read = memmap_block_read, .write = memmap_block_write, .close = memmap_block_close, .dev_init = NULL, .dev_close = memmap_dev_close, }; static struct io_dev_info memmap_dev_info = { .funcs = &memmap_dev_funcs, .info = (uintptr_t)NULL }; /* Open a connection to the memmap device */ static int memmap_dev_open(void *spec __attribute__((unused)), io_dev_info_t **dev_info) { assert(dev_info != NULL); *dev_info = &memmap_dev_info; return IO_SUCCESS; } /* Close a connection to the memmap device */ static int memmap_dev_close(io_dev_info_t *dev_info) { /* NOP */ /* TODO: Consider tracking open files and cleaning them up here */ return IO_SUCCESS; } /* Open a file on the memmap device */ /* TODO: Can we do any sensible limit checks on requested memory */ static int memmap_block_open(io_dev_info_t *dev_info, const void *spec, io_entity_t *entity) { int result = IO_FAIL; const io_block_spec_t *block_spec = (io_block_spec_t *)spec; /* Since we need to track open state for seek() we only allow one open * spec at a time. When we have dynamic memory we can malloc and set * entity->info. */ if (current_file.in_use == 0) { assert(block_spec != NULL); assert(entity != NULL); current_file.in_use = 1; current_file.base = block_spec->offset; /* File cursor offset for seek and incremental reads etc. */ current_file.file_pos = 0; entity->info = (uintptr_t)¤t_file; result = IO_SUCCESS; } else { WARN("A Memmap device is already active. Close first.\n"); result = IO_RESOURCES_EXHAUSTED; } return result; } /* Seek to a particular file offset on the memmap device */ static int memmap_block_seek(io_entity_t *entity, int mode, ssize_t offset) { int result = IO_FAIL; /* We only support IO_SEEK_SET for the moment. */ if (mode == IO_SEEK_SET) { assert(entity != NULL); /* TODO: can we do some basic limit checks on seek? */ ((file_state_t *)entity->info)->file_pos = offset; result = IO_SUCCESS; } else { result = IO_FAIL; } return result; } /* Read data from a file on the memmap device */ static int memmap_block_read(io_entity_t *entity, void *buffer, size_t length, size_t *length_read) { file_state_t *fp; assert(entity != NULL); assert(buffer != NULL); assert(length_read != NULL); fp = (file_state_t *)entity->info; memcpy(buffer, (void *)(fp->base + fp->file_pos), length); *length_read = length; /* advance the file 'cursor' for incremental reads */ fp->file_pos += length; return IO_SUCCESS; } /* Write data to a file on the memmap device */ static int memmap_block_write(io_entity_t *entity, const void *buffer, size_t length, size_t *length_written) { file_state_t *fp; assert(entity != NULL); assert(buffer != NULL); assert(length_written != NULL); fp = (file_state_t *)entity->info; memcpy((void *)(fp->base + fp->file_pos), buffer, length); *length_written = length; /* advance the file 'cursor' for incremental writes */ fp->file_pos += length; return IO_SUCCESS; } /* Close a file on the memmap device */ static int memmap_block_close(io_entity_t *entity) { assert(entity != NULL); entity->info = 0; /* This would be a mem free() if we had malloc.*/ memset((void *)¤t_file, 0, sizeof(current_file)); return IO_SUCCESS; } /* Exported functions */ /* Register the memmap driver with the IO abstraction */ int register_io_dev_memmap(io_dev_connector_t **dev_con) { int result = IO_FAIL; assert(dev_con != NULL); result = io_register_device(&memmap_dev_info); if (result == IO_SUCCESS) *dev_con = &memmap_dev_connector; return result; }