packets.c

/*
# _____     ___ ____     ___ ____
#  ____|   |    ____|   |        | |____|
# |     ___|   |____ ___|    ____| |    \    PS2DEV Open Source Project.
#-----------------------------------------------------------------------
# (c) 2009 Lion
# Licenced under Academic Free License version 2.0
# Review ps2sdk README & LICENSE files for further details.
*/
 
#include <errno.h>
#include <stdio.h>
#include <kernel.h>
#include <libgs.h>
 
#include "internal.h"
 
QWORD GsPrimWorkArea[64] __attribute__((aligned(64))); // Align to a 64-byte boundary.
 
QWORD *GsGifPacketsAlloc(GS_PACKET_TABLE *table, u32 num_qwords)
{
    void *pointer;
    GS_GIF_PACKET *packet;
 
    if(num_qwords <= (GS_PACKET_DATA_QWORD_MAX-table->qword_offset))            //check if we can alloc in current packet
    {
        pointer=&table->packets[table->packet_offset].data[table->qword_offset];
        table->qword_offset += num_qwords;
    }
    else    //couldnt fit so we going to have to try to jump to next packet
    {
        if(table->packet_offset+1 == table->packet_count) //no more packet available so we return error;
        {
            pointer=NULL;
        }
        else //there is another pocket available so we can jump to it
        {
            //before we jup to this packet then we got to end current packet and point it to the new one
            packet=(GS_GIF_PACKET*)UNCACHED_SEG(&table->packets[table->packet_offset]);
            packet->tag.qwc=table->qword_offset;
            packet->tag.pad1=0;
            packet->tag.pce=0;
            packet->tag.id=0x02; //next = tag.addr
            packet->tag.irq =0;
            packet->tag.addr=(unsigned int)&((GS_GIF_PACKET*)UNCACHED_SEG(&table->packets[table->packet_offset + 1]))->tag;
            packet->tag.spr     =0;
            packet->tag.pad2    =0;
 
            //now reset qwords offset in this packet & update packet offset
            table->qword_offset= 0;
            table->packet_offset++;
 
            //now we use the new packet
            // but we still got to check if enough mem is available
            if( num_qwords <= (GS_PACKET_DATA_QWORD_MAX-table->qword_offset) )
            {
                pointer=&table->packets[table->packet_offset].data[table->qword_offset];
                table->qword_offset += num_qwords;
            }
            else //not enough
            {
                pointer=NULL;
            }
        }
    }
 
    return pointer;
}
 
void GsGifPacketsClear(GS_PACKET_TABLE *table)
{
    table->packet_offset=0;
    table->qword_offset=0;
}
 
int GsGifPacketsExecute(GS_PACKET_TABLE *table, u16 wait)
{
    GS_GIF_PACKET *packet;
 
    if(table->packet_offset==0    &&   table->qword_offset==0)
        return 0;
 
    if(table->packets == NULL)
        return -1;
 
    //close the current pocket
    packet=(GS_GIF_PACKET*)UNCACHED_SEG(&table->packets[table->packet_offset]);
    packet->tag.qwc     =table->qword_offset;
    packet->tag.pad1    =0;
    packet->tag.pce     =0;
    packet->tag.id      =0x07; //end
    packet->tag.irq     =0;
    packet->tag.addr    =(u32)0;
    packet->tag.spr     =0;
    packet->tag.pad2    =0;
 
    GsDmaSend_tag(0, 0, &table->packets[0].tag);
    if(wait)
        GsDmaWait();
 
    return 0;
}