Subversion Repositories HelenOS

/*

 * Copyright (c) 2008 Jakub Jermar 

 * Copyright (c) 2008 Martin Decky 

 * 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.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.

 */

/** @addtogroup libblock 

 * @{

 */ 

/**

 * @file

 * @brief

 */

#include "libblock.h" 

#include "../../srv/vfs/vfs.h"

#include "../../srv/rd/rd.h"

#include <ipc/devmap.h>

#include <ipc/services.h>

#include <errno.h>

#include <sys/mman.h>

#include <async.h>

#include <ipc/ipc.h>

#include <as.h>

#include <assert.h>

#include <futex.h>

#include <libadt/list.h>

#include <libadt/hash_table.h>

/** Lock protecting the device connection list */

static futex_t dcl_lock = FUTEX_INITIALIZER;

/** Device connection list head. */

static LIST_INITIALIZE(dcl_head);

#define CACHE_BUCKETS_LOG2		10

#define CACHE_BUCKETS			(1 << CACHE_BUCKETS_LOG2)

typedef struct {

	futex_t lock;

	size_t block_size;		/**< Block size. */

	unsigned block_count;		/**< Total number of blocks. */

	hash_table_t block_hash;

	link_t free_head;

} cache_t;

typedef struct {

	link_t link;

	int dev_handle;

	int dev_phone;

	void *com_area;

	size_t com_size;

	void *bb_buf;

	off_t bb_off;

	size_t bb_size;

	cache_t *cache;

} devcon_t;

static devcon_t *devcon_search(dev_handle_t dev_handle)

{

	link_t *cur;

	futex_down(&dcl_lock);

	for (cur = dcl_head.next; cur != &dcl_head; cur = cur->next) {

		devcon_t *devcon = list_get_instance(cur, devcon_t, link);

		if (devcon->dev_handle == dev_handle) {

			futex_up(&dcl_lock);

			return devcon;

		}

	}

	futex_up(&dcl_lock);

	return NULL;

}

static int devcon_add(dev_handle_t dev_handle, int dev_phone, void *com_area,

   size_t com_size)

{

	link_t *cur;

	devcon_t *devcon;

	devcon = malloc(sizeof(devcon_t));

	if (!devcon)

		return ENOMEM;

	link_initialize(&devcon->link);

	devcon->dev_handle = dev_handle;

	devcon->dev_phone = dev_phone;

	devcon->com_area = com_area;

	devcon->com_size = com_size;

	devcon->bb_buf = NULL;

	devcon->bb_off = 0;

	devcon->bb_size = 0;

	devcon->cache = NULL;

	futex_down(&dcl_lock);

	for (cur = dcl_head.next; cur != &dcl_head; cur = cur->next) {

		devcon_t *d = list_get_instance(cur, devcon_t, link);

		if (d->dev_handle == dev_handle) {

			futex_up(&dcl_lock);

			free(devcon);

			return EEXIST;

		}

	}

	list_append(&devcon->link, &dcl_head);

	futex_up(&dcl_lock);

	return EOK;

}

static void devcon_remove(devcon_t *devcon)

{

	futex_down(&dcl_lock);

	list_remove(&devcon->link);

	futex_up(&dcl_lock);

}

int block_init(dev_handle_t dev_handle, size_t com_size)

{

	int rc;

	int dev_phone;

	void *com_area;

	com_area = mmap(NULL, com_size, PROTO_READ | PROTO_WRITE,

	    MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);

	if (!com_area) {

		return ENOMEM;

	}

	dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP,

	    DEVMAP_CONNECT_TO_DEVICE, dev_handle);

	if (dev_phone < 0) {

		munmap(com_area, com_size);

		return dev_phone;

	}

	rc = ipc_share_out_start(dev_phone, com_area,

	    AS_AREA_READ | AS_AREA_WRITE);

	if (rc != EOK) {

	    	munmap(com_area, com_size);

		ipc_hangup(dev_phone);

		return rc;

	}

	rc = devcon_add(dev_handle, dev_phone, com_area, com_size);

	if (rc != EOK) {

		munmap(com_area, com_size);

		ipc_hangup(dev_phone);

		return rc;

	}

	return EOK;

}

void block_fini(dev_handle_t dev_handle)

{

	devcon_t *devcon = devcon_search(dev_handle);

	assert(devcon);

	devcon_remove(devcon);

	if (devcon->bb_buf)

		free(devcon->bb_buf);

	if (devcon->cache) {

		hash_table_destroy(&devcon->cache->block_hash);

		free(devcon->cache);

	}

	munmap(devcon->com_area, devcon->com_size);

	ipc_hangup(devcon->dev_phone);

	free(devcon);	

}

int block_bb_read(dev_handle_t dev_handle, off_t off, size_t size)

{

	void *bb_buf;

	int rc;

	devcon_t *devcon = devcon_search(dev_handle);

	if (!devcon)

		return ENOENT;

	if (devcon->bb_buf)

		return EEXIST;

	bb_buf = malloc(size);

	if (!bb_buf)

		return ENOMEM;

	off_t bufpos = 0;

	size_t buflen = 0;

	rc = block_read(dev_handle, &bufpos, &buflen, &off,

	    bb_buf, size, size);

	if (rc != EOK) {

	    	free(bb_buf);

		return rc;

	}

	devcon->bb_buf = bb_buf;

	devcon->bb_off = off;

	devcon->bb_size = size;

	return EOK;

}

void *block_bb_get(dev_handle_t dev_handle)

{

	devcon_t *devcon = devcon_search(dev_handle);

	assert(devcon);

	return devcon->bb_buf;

}

static hash_index_t cache_hash(unsigned long *key)

{

	return *key & (CACHE_BUCKETS - 1);

}

static int cache_compare(unsigned long *key, hash_count_t keys, link_t *item)

{

	block_t *b = hash_table_get_instance(item, block_t, hash_link);

	return b->boff == *key;

}

static void cache_remove_callback(link_t *item)

{

}

static hash_table_operations_t cache_ops = {

	.hash = cache_hash,

	.compare = cache_compare,

	.remove_callback = cache_remove_callback

};

int block_cache_init(dev_handle_t dev_handle, size_t size, unsigned blocks)

{

	devcon_t *devcon = devcon_search(dev_handle);

	cache_t *cache;

	if (!devcon)

		return ENOENT;

	if (devcon->cache)

		return EEXIST;

	cache = malloc(sizeof(cache_t));

	if (!cache)

		return ENOMEM;

	futex_initialize(&cache->lock, 0);

	list_initialize(&cache->free_head);

	cache->block_size = size;

	cache->block_count = blocks;

	if (!hash_table_create(&cache->block_hash, CACHE_BUCKETS, 1,

	    &cache_ops)) {

		free(cache);

		return ENOMEM;

	}

	devcon->cache = cache;

	return EOK;

}

/** Read data from a block device.

 *

 * @param dev_handle	Device handle of the block device.

 * @param bufpos	Pointer to the first unread valid offset within the

 * 			communication buffer.

 * @param buflen	Pointer to the number of unread bytes that are ready in

 * 			the communication buffer.

 * @param pos		Device position to be read.

 * @param dst		Destination buffer.

 * @param size		Size of the destination buffer.

 * @param block_size	Block size to be used for the transfer.

 *

 * @return		EOK on success or a negative return code on failure.

 */

int

block_read(int dev_handle, off_t *bufpos, size_t *buflen, off_t *pos, void *dst,

    size_t size, size_t block_size)

{

	off_t offset = 0;

	size_t left = size;

	devcon_t *devcon = devcon_search(dev_handle);

	assert(devcon);

	while (left > 0) {

		size_t rd;

		if (*bufpos + left < *buflen)

			rd = left;

		else

			rd = *buflen - *bufpos;

		if (rd > 0) {

			/*

			 * Copy the contents of the communication buffer to the

			 * destination buffer.

			 */

			memcpy(dst + offset, devcon->com_area + *bufpos, rd);

			offset += rd;

			*bufpos += rd;

			*pos += rd;

			left -= rd;

		}

		if (*bufpos == *buflen) {

			/* Refill the communication buffer with a new block. */

			ipcarg_t retval;

			int rc = async_req_2_1(devcon->dev_phone, RD_READ_BLOCK,

			    *pos / block_size, block_size, &retval);

			if ((rc != EOK) || (retval != EOK))

				return (rc != EOK ? rc : retval);

			*bufpos = 0;

			*buflen = block_size;

		}

	}

	return EOK;

}

block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs)

{

	/* FIXME */

	block_t *b;

	off_t bufpos = 0;

	size_t buflen = 0;

	off_t pos = offset * bs;

	b = malloc(sizeof(block_t));

	if (!b)

		return NULL;

	b->data = malloc(bs);

	if (!b->data) {

		free(b);

		return NULL;

	}

	b->size = bs;

	if (block_read(dev_handle, &bufpos, &buflen, &pos, b->data,

	    bs, bs) != EOK) {

		free(b->data);

		free(b);

		return NULL;

	}

	return b;

}

void block_put(block_t *block)

{

	/* FIXME */

	free(block->data);

	free(block);

}

/** @}

 */