path: root/drivers/scsi/pm8001/pm8001_sas.c

/*
 * PMC-Sierra PM8001/8081/8088/8089 SAS/SATA based host adapters driver
 *
 * Copyright (c) 2008-2009 USI Co., Ltd.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * 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 MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
 *
 */

#include <linux/slab.h>
#include "pm8001_sas.h"

/**
 * pm8001_find_tag - from sas task to find out  tag that belongs to this task
 * @task: the task sent to the LLDD
 * @tag: the found tag associated with the task
 */
static int pm8001_find_tag(struct sas_task *task, u32 *tag)
{
	if (task->lldd_task) {
		struct pm8001_ccb_info *ccb;
		ccb = task->lldd_task;
		*tag = ccb->ccb_tag;
		return 1;
	}
	return 0;
}

/**
  * pm8001_tag_clear - clear the tags bitmap
  * @pm8001_ha: our hba struct
  * @tag: the found tag associated with the task
  */
static void pm8001_tag_clear(struct pm8001_hba_info *pm8001_ha, u32 tag)
{
	void *bitmap = pm8001_ha->tags;
	clear_bit(tag, bitmap);
}

void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
{
	pm8001_tag_clear(pm8001_ha, tag);
}

static void pm8001_tag_set(struct pm8001_hba_info *pm8001_ha, u32 tag)
{
	void *bitmap = pm8001_ha->tags;
	set_bit(tag, bitmap);
}

/**
  * pm8001_tag_alloc - allocate a empty tag for task used.
  * @pm8001_ha: our hba struct
  * @tag_out: the found empty tag .
  */
inline int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
{
	unsigned int index, tag;
	void *bitmap = pm8001_ha->tags;

	index = find_first_zero_bit(bitmap, pm8001_ha->tags_num);
	tag = index;
	if (tag >= pm8001_ha->tags_num)
		return -SAS_QUEUE_FULL;
	pm8001_tag_set(pm8001_ha, tag);
	*tag_out = tag;
	return 0;
}

void pm8001_tag_init(struct pm8001_hba_info *pm8001_ha)
{
	int i;
	for (i = 0; i < pm8001_ha->tags_num; ++i)
		pm8001_tag_clear(pm8001_ha,