/*
 * File:    nbuf.c
 * Purpose: Implementation of network buffer scheme.
 *
 * Notes:   
 */
#include "queue.h"
#include "net.h"
#include "driver_mem.h"
#include "exceptions.h"
#include "bas_types.h"
#include "bas_printf.h"
/*
 * Queues used for network buffer storage
 */
QUEUE nbuf_queue[NBUF_MAXQ];

/*
 * Some devices require line-aligned buffers.  In order to accomplish
 * this, the nbuf data is over-allocated and adjusted.  The following
 * array keeps track of the original data pointer returned by malloc
 */
uint8_t *unaligned_buffers[NBUF_MAX];

/*
 * Initialize all the network buffer queues
 *
 * Return Value:
 *  0 success
 *  1 failure
 */
int nbuf_init(void)
{
    int i;
    NBUF *nbuf;

    for (i=0; i<NBUF_MAXQ; ++i)
    {
        /* Initialize all the queues */
        queue_init(&nbuf_queue[i]);
    }

    #ifdef DEBUG_PRINT
        printf("Creating %d net buffers of %d bytes\n",NBUF_MAX,NBUF_SZ);
    #endif

    for (i = 0; i < NBUF_MAX; ++i)
    {
        /* Allocate memory for the network buffer structure */
        nbuf = (NBUF *) driver_mem_alloc(sizeof(NBUF));
        if (!nbuf)
        {
            return 1;
        }

        /* Allocate memory for the actual data */
        unaligned_buffers[i] = driver_mem_alloc(NBUF_SZ + 16);
        nbuf->data = (uint8_t *)((uint32_t)(unaligned_buffers[i] + 15) & 0xFFFFFFF0);
		if (!nbuf->data)
        {
			return 1;
        }

        /* Initialize the network buffer */
        nbuf->offset = 0;
        nbuf->length = 0;

        /* Add the network buffer to the free list */
        queue_add(&nbuf_queue[NBUF_FREE], (QNODE *)nbuf);
    }
    
    #ifdef DEBUG_PRINT
        printf("NBUF allocation complete\n");
        nbuf_debug_dump();
    #endif
    
    return 0;
}

/* 
 * Return all the allocated memory to the heap
 */
void nbuf_flush(void)
{
    NBUF *nbuf;
    int i, level = set_ipl(7);
    int n = 0;

    for (i = 0; i < NBUF_MAX; ++i)
        driver_mem_free((uint8_t *) unaligned_buffers[i]);

    for (i = 0; i < NBUF_MAXQ; ++i)
    {
        while ((nbuf = (NBUF *) queue_remove(&nbuf_queue[i])) != NULL)
        {
            driver_mem_free(nbuf);
            ++n;
        }
    }
    set_ipl(level);
}

/* 
 * Allocate a network buffer from the free list
 *
 * Return Value:
 *  Pointer to a free network buffer
 *  NULL if none are available
 */
NBUF *nbuf_alloc(void)
{
    NBUF *nbuf;
    int level = set_ipl(7);

    nbuf = (NBUF *) queue_remove(&nbuf_queue[NBUF_FREE]);
    set_ipl(level);
    
    return nbuf;
}

/*
 * Add the specified network buffer back to the free list
 *
 * Parameters:
 *  nbuf    Buffer to add back to the free list
 */
void nbuf_free(NBUF *nbuf)
{
    int level = set_ipl(7);

    nbuf->offset = 0;
    nbuf->length = NBUF_SZ;
    queue_add(&nbuf_queue[NBUF_FREE],(QNODE *)nbuf);

    set_ipl(level);
}

/*
 * Remove a network buffer from the specified queue
 *
 * Parameters:
 *  q   The index that identifies the queue to pull the buffer from
 */
NBUF *nbuf_remove(int q)
{
    NBUF *nbuf;
    int level = set_ipl(7);

    nbuf = (NBUF *) queue_remove(&nbuf_queue[q]);
    set_ipl(level);
    
    return nbuf;
}

/*
 * Add a network buffer to the specified queue
 *
 * Parameters:
 *  q   The index that identifies the queue to add the buffer to
 */
void nbuf_add(int q, NBUF *nbuf)
{
    int level = set_ipl(7);
    queue_add(&nbuf_queue[q],(QNODE *)nbuf);
    set_ipl(level);
}

/*
 * Put all the network buffers back into the free list 
 */
void nbuf_reset(void)
{
    NBUF *nbuf;
    int i, level = set_ipl(7);

    for (i = 1; i < NBUF_MAXQ; ++i)
    {
        while ((nbuf = nbuf_remove(i)) != NULL)
            nbuf_free(nbuf);
    }
    set_ipl(level);
}

/*
 * Display all the nbuf queues
 */
void nbuf_debug_dump(void)
{
#ifdef DEBUG
    NBUF *nbuf;
    int i, j, level;
    
    level = set_ipl(7);

    for (i = 0; i < NBUF_MAXQ; ++i)
    {
        printf("\n\nQueue #%d\n\n",i);
        printf("\tBuffer Location\tOffset\tLength\n");
        printf("--------------------------------------\n");
        j = 0;
        nbuf = (NBUF *)queue_peek(&nbuf_queue[i]);
        while (nbuf != NULL)
        {
           printf("%d\t  0x%08x\t0x%04x\t0x%04x\n",j++,nbuf->data,
                                                       nbuf->offset,
                                                       nbuf->length);
           nbuf = (NBUF *)nbuf->node.next;
        }
    }

    set_ipl(level);
#endif
}