sonic.c

讲述linux的初始化过程

    int status;

    while (rd->in_use == 0) {
	struct sk_buff *skb;
	int pkt_len;
	unsigned char *pkt_ptr;
	
	status = rd->rx_status;
	if (sonic_debug > 3)
	  printk ("status %x, cur_rx %d, cur_rra %x\n",status,lp->cur_rx,lp->cur_rra);
	if (status & SONIC_RCR_PRX) {	    
	    pkt_len = rd->rx_pktlen;
	    pkt_ptr = (char *)sonic_chiptomem((rd->rx_pktptr_h << 16) +
						      rd->rx_pktptr_l);
	    
	    if (sonic_debug > 3)
	      printk ("pktptr %p (rba %p) h:%x l:%x, bsize h:%x l:%x\n", pkt_ptr,lp->rba,
		      rd->rx_pktptr_h,rd->rx_pktptr_l,
		      SONIC_READ(SONIC_RBWC1),SONIC_READ(SONIC_RBWC0));
	
	    /* Malloc up new buffer. */
	    skb = dev_alloc_skb(pkt_len+2);
	    if (skb == NULL) {
		printk("%s: Memory squeeze, dropping packet.\n", dev->name);
		lp->stats.rx_dropped++;
		break;
	    }
	    skb->dev = dev;
	    skb_reserve(skb,2);	/* 16 byte align */
	    skb_put(skb,pkt_len);	/* Make room */
	    eth_copy_and_sum(skb, pkt_ptr, pkt_len, 0);
	    skb->protocol=eth_type_trans(skb,dev);
	    netif_rx(skb);			/* pass the packet to upper layers */
	    lp->stats.rx_packets++;
	    lp->stats.rx_bytes += pkt_len;
	    
	} else {
	    /* This should only happen, if we enable accepting broken packets. */
	    lp->stats.rx_errors++;
	    if (status & SONIC_RCR_FAER) lp->stats.rx_frame_errors++;
	    if (status & SONIC_RCR_CRCR) lp->stats.rx_crc_errors++;
	}
	
	rd->in_use = 1;
	rd = &lp->rda[(++lp->cur_rx) & SONIC_RDS_MASK];
	/* now give back the buffer to the receive buffer area */
	if (status & SONIC_RCR_LPKT) {
	    /*
	     * this was the last packet out of the current receice buffer
	     * give the buffer back to the SONIC
	     */
	    lp->cur_rra += sizeof(sonic_rr_t);
	    if (lp->cur_rra > (lp->rra_laddr + (SONIC_NUM_RRS-1) * sizeof(sonic_rr_t)))
		lp->cur_rra = lp->rra_laddr;
	    SONIC_WRITE(SONIC_RWP, lp->cur_rra & 0xffff);
	} else
	    printk ("%s: rx desc without RCR_LPKT. Shouldn't happen !?\n",dev->name);
    }
    /*
     * If any worth-while packets have been received, dev_rint()
     * has done a mark_bh(NET_BH) for us and will work on them
     * when we get to the bottom-half routine.
     */
    return;
}


/*
 * Get the current statistics.
 * This may be called with the device open or closed.
 */
static struct net_device_stats *
sonic_get_stats(struct net_device *dev)
{
    struct sonic_local *lp = (struct sonic_local *)dev->priv;
    unsigned int base_addr = dev->base_addr;

    /* read the tally counter from the SONIC and reset them */
    lp->stats.rx_crc_errors += SONIC_READ(SONIC_CRCT);
    SONIC_WRITE(SONIC_CRCT,0xffff);
    lp->stats.rx_frame_errors += SONIC_READ(SONIC_FAET);
    SONIC_WRITE(SONIC_FAET,0xffff);
    lp->stats.rx_missed_errors += SONIC_READ(SONIC_MPT);
    SONIC_WRITE(SONIC_MPT,0xffff);
    
    return &lp->stats;
}


/*
 * Set or clear the multicast filter for this adaptor.
 */
static void
sonic_multicast_list(struct net_device *dev)
{
    struct sonic_local *lp = (struct sonic_local *)dev->priv;    
    unsigned int base_addr = dev->base_addr;    
    unsigned int rcr;
    struct dev_mc_list *dmi = dev->mc_list;
    unsigned char *addr;
    int i;

    rcr = SONIC_READ(SONIC_RCR) & ~(SONIC_RCR_PRO | SONIC_RCR_AMC);
    rcr |= SONIC_RCR_BRD; /* accept broadcast packets */
    
    if (dev->flags & IFF_PROMISC) {         /* set promiscuous mode */
	rcr |= SONIC_RCR_PRO;
    } else {
	if ((dev->flags & IFF_ALLMULTI) || (dev->mc_count > 15)) {
	    rcr |= SONIC_RCR_AMC;
	} else {
	    if (sonic_debug > 2)
	      printk ("sonic_multicast_list: mc_count %d\n",dev->mc_count);
	    lp->cda.cam_enable = 1; /* always enable our own address */
	    for (i = 1; i <= dev->mc_count; i++) {
		addr = dmi->dmi_addr;
		dmi = dmi->next;
		lp->cda.cam_desc[i].cam_cap0 = addr[1] << 8 | addr[0];
		lp->cda.cam_desc[i].cam_cap1 = addr[3] << 8 | addr[2];
		lp->cda.cam_desc[i].cam_cap2 = addr[5] << 8 | addr[4];
		lp->cda.cam_enable |= (1 << i);
	    }
	    SONIC_WRITE(SONIC_CDC,16);
	    /* issue Load CAM command */
	    SONIC_WRITE(SONIC_CDP, lp->cda_laddr & 0xffff);	    
	    SONIC_WRITE(SONIC_CMD,SONIC_CR_LCAM);
	}
    }
    
    if (sonic_debug > 2)
      printk("sonic_multicast_list: setting RCR=%x\n",rcr);
    
    SONIC_WRITE(SONIC_RCR,rcr);
}


/*
 * Initialize the SONIC ethernet controller.
 */
static int sonic_init(struct net_device *dev)
{
    unsigned int base_addr = dev->base_addr;
    unsigned int cmd;
    struct sonic_local *lp = (struct sonic_local *)dev->priv;
    unsigned int rra_start;
    unsigned int rra_end;
    int i;
    
    /*
     * put the Sonic into software-reset mode and
     * disable all interrupts
     */
    SONIC_WRITE(SONIC_ISR,0x7fff);
    SONIC_WRITE(SONIC_IMR,0);
    SONIC_WRITE(SONIC_CMD,SONIC_CR_RST);
  
    /*
     * clear software reset flag, disable receiver, clear and
     * enable interrupts, then completely initialize the SONIC
     */
    SONIC_WRITE(SONIC_CMD,0);
    SONIC_WRITE(SONIC_CMD,SONIC_CR_RXDIS);

    /*
     * initialize the receive resource area
     */
    if (sonic_debug > 2)
      printk ("sonic_init: initialize receive resource area\n");
    
    rra_start = lp->rra_laddr & 0xffff;
    rra_end   = (rra_start + (SONIC_NUM_RRS * sizeof(sonic_rr_t))) & 0xffff;
  
    for (i = 0; i < SONIC_NUM_RRS; i++) {
	lp->rra[i].rx_bufadr_l = (lp->rba_laddr + i * SONIC_RBSIZE) & 0xffff;
	lp->rra[i].rx_bufadr_h = (lp->rba_laddr + i * SONIC_RBSIZE) >> 16;
	lp->rra[i].rx_bufsize_l = SONIC_RBSIZE >> 1;
	lp->rra[i].rx_bufsize_h = 0;
    }

    /* initialize all RRA registers */
    SONIC_WRITE(SONIC_RSA,rra_start);
    SONIC_WRITE(SONIC_REA,rra_end);
    SONIC_WRITE(SONIC_RRP,rra_start);
    SONIC_WRITE(SONIC_RWP,rra_end);
    SONIC_WRITE(SONIC_URRA,lp->rra_laddr >> 16);
    SONIC_WRITE(SONIC_EOBC,(SONIC_RBSIZE-2) >> 1);
    
    lp->cur_rra = lp->rra_laddr + (SONIC_NUM_RRS-1) * sizeof(sonic_rr_t);

    /* load the resource pointers */
    if (sonic_debug > 3)
      printk("sonic_init: issueing RRRA command\n");
  
    SONIC_WRITE(SONIC_CMD,SONIC_CR_RRRA);
    i = 0;
    while (i++ < 100) {
	if (SONIC_READ(SONIC_CMD) & SONIC_CR_RRRA)
	  break;
    }
    
    if (sonic_debug > 2)
      printk("sonic_init: status=%x\n",SONIC_READ(SONIC_CMD));
    
    /*
     * Initialize the receive descriptors so that they
     * become a circular linked list, ie. let the last
     * descriptor point to the first again.
     */
    if (sonic_debug > 2)
      printk ("sonic_init: initialize receive descriptors\n");      
    for (i=0; i<SONIC_NUM_RDS; i++) {
	lp->rda[i].rx_status = 0;
	lp->rda[i].rx_pktlen = 0;
	lp->rda[i].rx_pktptr_l = 0;
	lp->rda[i].rx_pktptr_h = 0;
	lp->rda[i].rx_seqno = 0;
	lp->rda[i].in_use = 1;		       	
	lp->rda[i].link = lp->rda_laddr + (i+1) * sizeof (sonic_rd_t);
    }
    /* fix last descriptor */
    lp->rda[SONIC_NUM_RDS-1].link = lp->rda_laddr;
    lp->cur_rx = 0;
    SONIC_WRITE(SONIC_URDA,lp->rda_laddr >> 16);
    SONIC_WRITE(SONIC_CRDA,lp->rda_laddr & 0xffff);
    
    /* 
     * initialize transmit descriptors
     */
    if (sonic_debug > 2)
      printk ("sonic_init: initialize transmit descriptors\n");
    for (i = 0; i < SONIC_NUM_TDS; i++) {
	lp->tda[i].tx_status = 0;
	lp->tda[i].tx_config = 0;
	lp->tda[i].tx_pktsize = 0;
	lp->tda[i].tx_frag_count = 0;
	lp->tda[i].link = (lp->tda_laddr + (i+1) * sizeof (sonic_td_t)) | SONIC_END_OF_LINKS;
    }
    lp->tda[SONIC_NUM_TDS-1].link = (lp->tda_laddr & 0xffff) | SONIC_END_OF_LINKS;    

    SONIC_WRITE(SONIC_UTDA,lp->tda_laddr >> 16);
    SONIC_WRITE(SONIC_CTDA,lp->tda_laddr & 0xffff);
    lp->cur_tx = lp->dirty_tx = 0;
    
    /*
     * put our own address to CAM desc[0]
     */
    lp->cda.cam_desc[0].cam_cap0 = dev->dev_addr[1] << 8 | dev->dev_addr[0];
    lp->cda.cam_desc[0].cam_cap1 = dev->dev_addr[3] << 8 | dev->dev_addr[2];
    lp->cda.cam_desc[0].cam_cap2 = dev->dev_addr[5] << 8 | dev->dev_addr[4];
    lp->cda.cam_enable = 1;
    
    for (i=0; i < 16; i++)
      lp->cda.cam_desc[i].cam_entry_pointer = i;

    /*
     * initialize CAM registers
     */
    SONIC_WRITE(SONIC_CDP, lp->cda_laddr & 0xffff);
    SONIC_WRITE(SONIC_CDC,16);
    
    /*
     * load the CAM
     */
    SONIC_WRITE(SONIC_CMD,SONIC_CR_LCAM);
    
    i = 0;
    while (i++ < 100) {
	if (SONIC_READ(SONIC_ISR) & SONIC_INT_LCD)
	  break;
    }
    if (sonic_debug > 2) {
	printk("sonic_init: CMD=%x, ISR=%x\n",
	       SONIC_READ(SONIC_CMD),
	       SONIC_READ(SONIC_ISR));
    }

    /*
     * enable receiver, disable loopback
     * and enable all interrupts
     */
    SONIC_WRITE(SONIC_CMD,SONIC_CR_RXEN | SONIC_CR_STP);
    SONIC_WRITE(SONIC_RCR,SONIC_RCR_DEFAULT);
    SONIC_WRITE(SONIC_TCR,SONIC_TCR_DEFAULT);
    SONIC_WRITE(SONIC_ISR,0x7fff);
    SONIC_WRITE(SONIC_IMR,SONIC_IMR_DEFAULT);

    cmd = SONIC_READ(SONIC_CMD);
    if ((cmd & SONIC_CR_RXEN) == 0 ||
	(cmd & SONIC_CR_STP) == 0)
      printk("sonic_init: failed, status=%x\n",cmd);

    if (sonic_debug > 2)
      printk("sonic_init: new status=%x\n",SONIC_READ(SONIC_CMD));

    return(0);
}


/*
 * Local variables:
 *  compile-command: "mipsel-linux-gcc -D__KERNEL__ -D__mips64 -I/usr/src/linux/net/inet -Wall -Wstrict-prototypes -O2 -mcpu=r4000 -c sonic.c"
 *  version-control: t
 *  kept-new-versions: 5
 *  tab-width: 4
 * End:
 */