blob: 40b8e9abcaedffba540e1e05d2e2f5506238cc9c [file] [log] [blame]
/*
* 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 <assert.h>
#include <string.h>
#include "io_storage.h"
#include "io_driver.h"
#include "debug.h"
/* 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;
static file_state current_file = {0};
/* Identify the device type as memmap */
io_type device_type_memmap(void)
{
return IO_TYPE_MEMMAP;
}
/* Memmap device functions */
static int memmap_dev_open(void *spec, struct io_dev_info **dev_info);
static int memmap_block_open(struct io_dev_info *dev_info, const void *spec,
struct io_entity *entity);
static int memmap_block_seek(struct io_entity *entity, int mode,
ssize_t offset);
static int memmap_block_read(struct io_entity *entity, void *buffer,
size_t length, size_t *length_read);
static int memmap_block_write(struct io_entity *entity, const void *buffer,
size_t length, size_t *length_written);
static int memmap_block_close(struct io_entity *entity);
static int memmap_dev_close(struct io_dev_info *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)),
struct io_dev_info **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(struct io_dev_info *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(struct io_dev_info *dev_info, const void *spec,
struct io_entity *entity)
{
int result = IO_FAIL;
const io_block_spec *block_spec = (io_block_spec *)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)&current_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(struct io_entity *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 *)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(struct io_entity *entity, void *buffer,
size_t length, size_t *length_read)
{
file_state *fp;
assert(entity != NULL);
assert(buffer != NULL);
assert(length_read != NULL);
fp = (file_state *)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(struct io_entity *entity, const void *buffer,
size_t length, size_t *length_written)
{
file_state *fp;
assert(entity != NULL);
assert(buffer != NULL);
assert(length_written != NULL);
fp = (file_state *)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(struct io_entity *entity)
{
assert(entity != NULL);
entity->info = 0;
/* This would be a mem free() if we had malloc.*/
memset((void *)&current_file, 0, sizeof(current_file));
return IO_SUCCESS;
}
/* Exported functions */
/* Register the memmap driver with the IO abstraction */
int register_io_dev_memmap(struct io_dev_connector **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;
}