drivers/io/io_memmap.c - filogic/atf - Gitiles

 /*
  * 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 <debug.h>
 #include <io_driver.h>
 #include <io_storage.h>
 #include <string.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;
 	uintptr_t	base;
 	size_t		file_pos;
 	size_t		size;
 } 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(const uintptr_t dev_spec, io_dev_info_t **dev_info);
 static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec,
 			     io_entity_t *entity);
 static int memmap_block_seek(io_entity_t *entity, int mode,
 			     ssize_t offset);
 static int memmap_block_len(io_entity_t *entity, size_t *length);
 static int memmap_block_read(io_entity_t *entity, uintptr_t buffer,
 			     size_t length, size_t *length_read);
 static int memmap_block_write(io_entity_t *entity, const uintptr_t 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 const io_dev_connector_t memmap_dev_connector = {
 	.dev_open = memmap_dev_open
 };


 static const io_dev_funcs_t memmap_dev_funcs = {
 	.type = device_type_memmap,
 	.open = memmap_block_open,
 	.seek = memmap_block_seek,
 	.size = memmap_block_len,
 	.read = memmap_block_read,
 	.write = memmap_block_write,
 	.close = memmap_block_close,
 	.dev_init = NULL,
 	.dev_close = memmap_dev_close,
 };


 /* No state associated with this device so structure can be const */
 static const io_dev_info_t memmap_dev_info = {
 	.funcs = &memmap_dev_funcs,
 	.info = (uintptr_t)NULL
 };


 /* Open a connection to the memmap device */
 static int memmap_dev_open(const uintptr_t dev_spec __unused,
 			   io_dev_info_t **dev_info)
 {
 	assert(dev_info != NULL);
 	*dev_info = (io_dev_info_t *)&memmap_dev_info; /* cast away const */

 	return 0;
 }


 /* 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 0;
 }


 /* 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 uintptr_t spec,
 			     io_entity_t *entity)
 {
 	int result = -ENOMEM;
 	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;
 		current_file.size = block_spec->length;
 		entity->info = (uintptr_t)&current_file;
 		result = 0;
 	} else {
 		WARN("A Memmap device is already active. Close first.\n");
 	}

 	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 = -ENOENT;

 	/* 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 = 0;
 	}

 	return result;
 }


 /* Return the size of a file on the memmap device */
 static int memmap_block_len(io_entity_t *entity, size_t *length)
 {
 	assert(entity != NULL);
 	assert(length != NULL);

 	*length = ((file_state_t *)entity->info)->size;

 	return 0;
 }


 /* Read data from a file on the memmap device */
 static int memmap_block_read(io_entity_t *entity, uintptr_t buffer,
 			     size_t length, size_t *length_read)
 {
 	file_state_t *fp;

 	assert(entity != NULL);
 	assert(buffer != (uintptr_t)NULL);
 	assert(length_read != NULL);

 	fp = (file_state_t *)entity->info;

 	memcpy((void *)buffer, (void *)(fp->base + fp->file_pos), length);

 	*length_read = length;
 	/* advance the file 'cursor' for incremental reads */
 	fp->file_pos += length;

 	return 0;
 }


 /* Write data to a file on the memmap device */
 static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer,
 			      size_t length, size_t *length_written)
 {
 	file_state_t *fp;

 	assert(entity != NULL);
 	assert(buffer != (uintptr_t)NULL);
 	assert(length_written != NULL);

 	fp = (file_state_t *)entity->info;

 	memcpy((void *)(fp->base + fp->file_pos), (void *)buffer, length);

 	*length_written = length;

 	/* advance the file 'cursor' for incremental writes */
 	fp->file_pos += length;

 	return 0;
 }


 /* 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 *)&current_file, 0, sizeof(current_file));

 	return 0;
 }


 /* Exported functions */

 /* Register the memmap driver with the IO abstraction */
 int register_io_dev_memmap(const io_dev_connector_t **dev_con)
 {
 	int result;
 	assert(dev_con != NULL);

 	result = io_register_device(&memmap_dev_info);
 	if (result == 0)
 		*dev_con = &memmap_dev_connector;

 	return result;
 }
	/*
	* 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 <debug.h>
	#include <io_driver.h>
	#include <io_storage.h>
	#include <string.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;
	uintptr_t base;
	size_t file_pos;
	size_t size;
	} 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(const uintptr_t dev_spec, io_dev_info_t **dev_info);
	static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec,
	io_entity_t *entity);
	static int memmap_block_seek(io_entity_t *entity, int mode,
	ssize_t offset);
	static int memmap_block_len(io_entity_t entity, size_t length);
	static int memmap_block_read(io_entity_t *entity, uintptr_t buffer,
	size_t length, size_t *length_read);
	static int memmap_block_write(io_entity_t *entity, const uintptr_t 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 const io_dev_connector_t memmap_dev_connector = {
	.dev_open = memmap_dev_open
	};


	static const io_dev_funcs_t memmap_dev_funcs = {
	.type = device_type_memmap,
	.open = memmap_block_open,
	.seek = memmap_block_seek,
	.size = memmap_block_len,
	.read = memmap_block_read,
	.write = memmap_block_write,
	.close = memmap_block_close,
	.dev_init = NULL,
	.dev_close = memmap_dev_close,
	};


	/* No state associated with this device so structure can be const */
	static const io_dev_info_t memmap_dev_info = {
	.funcs = &memmap_dev_funcs,
	.info = (uintptr_t)NULL
	};


	/* Open a connection to the memmap device */
	static int memmap_dev_open(const uintptr_t dev_spec __unused,
	io_dev_info_t **dev_info)
	{
	assert(dev_info != NULL);
	dev_info = (io_dev_info_t )&memmap_dev_info; /* cast away const */

	return 0;
	}



	/* 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 0;
	}


	/* 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 uintptr_t spec,
	io_entity_t *entity)
	{
	int result = -ENOMEM;
	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;
	current_file.size = block_spec->length;
	entity->info = (uintptr_t)&current_file;
	result = 0;
	} else {
	WARN("A Memmap device is already active. Close first.\n");
	}

	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 = -ENOENT;

	/* 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 = 0;
	}

	return result;
	}


	/* Return the size of a file on the memmap device */
	static int memmap_block_len(io_entity_t entity, size_t length)
	{
	assert(entity != NULL);
	assert(length != NULL);

	length = ((file_state_t )entity->info)->size;

	return 0;
	}


	/* Read data from a file on the memmap device */
	static int memmap_block_read(io_entity_t *entity, uintptr_t buffer,
	size_t length, size_t *length_read)
	{
	file_state_t *fp;

	assert(entity != NULL);
	assert(buffer != (uintptr_t)NULL);
	assert(length_read != NULL);

	fp = (file_state_t *)entity->info;

	memcpy((void )buffer, (void )(fp->base + fp->file_pos), length);

	*length_read = length;
	/* advance the file 'cursor' for incremental reads */
	fp->file_pos += length;

	return 0;
	}


	/* Write data to a file on the memmap device */
	static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer,
	size_t length, size_t *length_written)
	{
	file_state_t *fp;

	assert(entity != NULL);
	assert(buffer != (uintptr_t)NULL);
	assert(length_written != NULL);

	fp = (file_state_t *)entity->info;

	memcpy((void )(fp->base + fp->file_pos), (void )buffer, length);

	*length_written = length;

	/* advance the file 'cursor' for incremental writes */
	fp->file_pos += length;

	return 0;
	}


	/* 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 *)&current_file, 0, sizeof(current_file));

	return 0;
	}


	/* Exported functions */

	/* Register the memmap driver with the IO abstraction */
	int register_io_dev_memmap(const io_dev_connector_t **dev_con)
	{
	int result;
	assert(dev_con != NULL);

	result = io_register_device(&memmap_dev_info);
	if (result == 0)
	*dev_con = &memmap_dev_connector;

	return result;
	}