/*
<:copyright-BRCM:2018:DUAL/GPL:standard

   Copyright (c) 2018 Broadcom 
   All Rights Reserved

Unless you and Broadcom execute a separate written software license
agreement governing use of this software, this software is licensed
to you under the terms of the GNU General Public License version 2
(the "GPL"), available at http://www.broadcom.com/licenses/GPLv2.php,
with the following added to such license:

   As a special exception, the copyright holders of this software give
   you permission to link this software with independent modules, and
   to copy and distribute the resulting executable under terms of your
   choice, provided that you also meet, for each linked independent
   module, the terms and conditions of the license of that module.
   An independent module is a module which is not derived from this
   software.  The special exception does not apply to any modifications
   of the software.

Not withstanding the above, under no circumstances may you combine
this software in any way with any other Broadcom software provided
under a license other than the GPL, without Broadcom's express prior
written consent.

:>
*/

/*
 *******************************************************************************
 * File Name  : bcm_async_queue.h
 *
 *******************************************************************************
 */

#ifndef __BCM_ASYNC_QUEUE_H_INCLUDED__
#define __BCM_ASYNC_QUEUE_H_INCLUDED__

typedef struct {
    uint32_t writes;
    uint64_t write_bytes;
    uint32_t reads;
    uint32_t discards;
    uint64_t discard_bytes;
} bcm_async_queue_stats_t;

typedef struct {
    volatile uint8_t *alloc_p;
    volatile uint16_t write;
    volatile uint16_t read;
    int depth;
    int entry_size;
    bcm_async_queue_stats_t stats;
} bcm_async_queue_t;

#if 1
#define _STATIC_INLINE_ static inline
#define _STATIC_        static
#else
#define _STATIC_INLINE_
#define _STATIC_
#endif

#define bcm_async_queue_not_full(_queue_p) bcm_async_queue_free_entries(_queue_p)
#define bcm_async_queue_not_empty(_queue_p) !bcm_async_queue_empty(_queue_p)
#define bcm_async_queue_empty(_queue_p) ( (_queue_p)->write == (_queue_p)->read )

_STATIC_INLINE_ uint16_t bcm_async_queue_avail_entries(bcm_async_queue_t *queue_p)
{
    return (queue_p->write - queue_p->read);
}

_STATIC_INLINE_ uint16_t bcm_async_queue_free_entries(bcm_async_queue_t *queue_p)
{
    return queue_p->depth - bcm_async_queue_avail_entries(queue_p);
}

_STATIC_INLINE_ volatile uint8_t *bcm_async_queue_entry_read(bcm_async_queue_t *queue_p)
{
    int read_index = queue_p->read & (queue_p->depth - 1);
    int read_offset = read_index * queue_p->entry_size;
    volatile uint8_t *read_p = &queue_p->alloc_p[read_offset];

    return read_p;
}

_STATIC_INLINE_ void bcm_async_queue_entry_dequeue(bcm_async_queue_t *queue_p)
{
#if !defined(CC_BCM_ASYNC_QUEUE_NO_BARRIER)
    smp_rmb();
#endif
    queue_p->read++;
}

_STATIC_INLINE_ volatile uint8_t *bcm_async_queue_entry_write(bcm_async_queue_t *queue_p)
{
    int write_index = queue_p->write & (queue_p->depth - 1);
    int write_offset = write_index * queue_p->entry_size;
    volatile uint8_t *write_p = &queue_p->alloc_p[write_offset];

    return write_p;
}

_STATIC_INLINE_ void bcm_async_queue_entry_enqueue(bcm_async_queue_t *queue_p)
{
#if !defined(CC_BCM_ASYNC_QUEUE_NO_BARRIER)
    smp_wmb();
#endif
    queue_p->write++;
}

_STATIC_INLINE_ int bcm_async_queue_init(bcm_async_queue_t *queue_p, int queue_size, int entry_size)
{
    int alloc_size = entry_size * queue_size;

    memset((void *)queue_p, 0, sizeof(bcm_async_queue_t));
    queue_p->alloc_p = (uint8_t *)kmalloc(alloc_size, GFP_KERNEL);

    if (queue_p->alloc_p == NULL)
    {
        return -1;
    }

    memset((void *)queue_p->alloc_p, 0, alloc_size);

    queue_p->entry_size = entry_size;
    queue_p->depth = queue_size;

    return 0;
}

_STATIC_INLINE_ void bcm_async_queue_uninit(bcm_async_queue_t *queue_p)
{
    if(!bcm_async_queue_empty(queue_p))
    {
        printk("bcm_async_queue_uninit: Warning, Queue is not empty");
    }

    if(queue_p->alloc_p)
    {
        kfree((void *)queue_p->alloc_p);
    }
}

#endif /*__BCM_ASYNC_QUEUE_H_INCLUDED__ */