sgiseeq.c

powerpc内核mpc8241linux系统下net驱动程序

		hregs->tx_ndptr = PHYSADDR(td);
		hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
	}
}

static inline void sgiseeq_tx(struct device *dev, struct sgiseeq_private *sp,
			      volatile struct hpc3_ethregs *hregs,
			      volatile struct sgiseeq_regs *sregs)
{
	struct sgiseeq_tx_desc *td;
	unsigned long status = hregs->tx_ctrl;
	int j;

	tx_maybe_reset_collisions(sp, sregs);

	if(!(status & (HPC3_ETXCTRL_ACTIVE | SEEQ_TSTAT_PTRANS))) {
		/* Oops, HPC detected some sort of error. */
		if(status & SEEQ_TSTAT_R16)
			sp->stats.tx_aborted_errors++;
		if(status & SEEQ_TSTAT_UFLOW)
			sp->stats.tx_fifo_errors++;
		if(status & SEEQ_TSTAT_LCLS)
			sp->stats.collisions++;
	}

	/* Ack 'em... */
	for(j = sp->tx_old; j != sp->tx_new; j = NEXT_TX(j)) {
		td = &sp->srings.tx_desc[j];

		if(!(td->tdma.cntinfo & (HPCDMA_XIU)))
			break;
		if(!(td->tdma.cntinfo & (HPCDMA_ETXD))) {
			if(!(status & HPC3_ETXCTRL_ACTIVE)) {
				hregs->tx_ndptr = PHYSADDR(td);
				hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
			}
			break;
		}
		sp->stats.tx_packets++;
		sp->tx_old = NEXT_TX(sp->tx_old);
		td->tdma.cntinfo &= ~(HPCDMA_XIU | HPCDMA_XIE);
		td->tdma.cntinfo |= HPCDMA_EOX;
	}
}

static inline void tx_maybe_unbusy(struct sgiseeq_private *sp,
				   struct device *dev)
{
	if((TX_BUFFS_AVAIL(sp) >= 0) && dev->tbusy) {
		dev->tbusy = 0;
		mark_bh(NET_BH);
	}
}

static void sgiseeq_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct device *dev = (struct device *) dev_id;
	struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;
	volatile struct hpc3_ethregs *hregs = sp->hregs;
	volatile struct sgiseeq_regs *sregs = sp->sregs;

	/* Ack the IRQ and set software state. */
	hregs->rx_reset = HPC3_ERXRST_CLRIRQ;
	dev->interrupt = 1;

	/* Always check for received packets. */
	sgiseeq_rx(dev, sp, hregs, sregs);

	/* Only check for tx acks iff we have something queued. */
	if(sp->tx_old != sp->tx_new)
		sgiseeq_tx(dev, sp, hregs, sregs);

	tx_maybe_unbusy(sp, dev);
	dev->interrupt = 0;
}

static int sgiseeq_open(struct device *dev)
{
	struct sgiseeq_private *sp = (struct sgiseeq_private *)dev->priv;
	volatile struct sgiseeq_regs *sregs = sp->sregs;
	unsigned long flags;

	save_flags(flags); cli();
	if(request_irq(dev->irq, sgiseeq_interrupt, 0, sgiseeqstr, (void *) dev)) {
		printk("Seeq8003: Can't get irq %d\n", dev->irq);
		restore_flags(flags);
		return -EAGAIN;
	}

	init_seeq(dev, sp, sregs);

	dev->tbusy = 0;
	dev->interrupt = 0;
	dev->start = 1;
	restore_flags(flags);
	return 0;
}

static int sgiseeq_close(struct device *dev)
{
	struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;
	volatile struct sgiseeq_regs *sregs = sp->sregs;

	dev->start = 0;
	dev->tbusy = 1;

	/* Shutdown the Seeq. */
	reset_hpc3_and_seeq(sp->hregs, sregs);

	free_irq(dev->irq, dev);

	return 0;
}

static inline int sgiseeq_reset(struct device *dev)
{
	struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;
	volatile struct sgiseeq_regs *sregs = sp->sregs;

	init_seeq(dev, sp, sregs);

	dev->trans_start = jiffies;
	dev->interrupt = 0;
	dev->start = 1;
	dev->tbusy = 0;

	return 0;
}

void sgiseeq_my_reset(void)
{
	printk("RESET!\n");
	sgiseeq_reset(gdev);
}

static inline int verify_tx(struct sgiseeq_private *sp,
			    struct device *dev,
			    struct sk_buff *skb)
{
	/* Are we bolixed? */
	if(dev->tbusy) {
		int tickssofar = jiffies - dev->trans_start;
		if (tickssofar < 20)
			return 1;

		printk("%s: transmit timed out, ticks=%d resetting\n",
		       dev->name, tickssofar);
		sgiseeq_reset(dev);
		return 0;
	}
	/* Are we getting in someone else's way? */
	if(test_and_set_bit(0, (void *) &dev->tbusy) != 0) {
		printk("%s: Transmitter access conflict.\n", dev->name);
		return -1;
	}

	/* Can we even send anything? */
	if(!TX_BUFFS_AVAIL(sp))
		return -1;

	return 0;
}

static int sgiseeq_start_xmit(struct sk_buff *skb, struct device *dev)
{
	struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;
	volatile struct hpc3_ethregs *hregs = sp->hregs;
	unsigned long flags;
	struct sgiseeq_tx_desc *td;
	int skblen, len, entry;

	if(verify_tx(sp, dev, skb))
		return -1; /* Yeee... */

	save_flags(flags); cli();

	/* Setup... */
	skblen = skb->len;
	len = (skblen <= ETH_ZLEN) ? ETH_ZLEN : skblen;
	entry = sp->tx_new;
	td = &sp->srings.tx_desc[entry];

	/* Create entry.  There are so many races with adding a new
	 * descriptor to the chain:
	 * 1) Assume that the HPC is off processing a DMA chain while
	 *    we are changing all of the following.
	 * 2) Do no allow the HPC to look at a new descriptor until
	 *    we have completely set up it's state.  This means, do
	 *    not clear HPCDMA_EOX in the current last descritptor
	 *    until the one we are adding looks consistant and could
	 *    be processes right now.
	 * 3) The tx interrupt code must notice when we've added a new
	 *    entry and the HPC got to the end of the chain before we
	 *    added this new entry and restarted it.
	 */
	memcpy((char *)td->buf_vaddr, skb->data, skblen);
	td->tdma.cntinfo = ((len) & HPCDMA_BCNT) |
		(HPCDMA_XIU | HPCDMA_EOXP | HPCDMA_XIE | HPCDMA_EOX);
	if(sp->tx_old != sp->tx_new) {
		struct sgiseeq_tx_desc *backend;

		backend = &sp->srings.tx_desc[PREV_TX(sp->tx_new)];
		backend->tdma.cntinfo &= ~(HPCDMA_EOX);
	}
	sp->tx_new = NEXT_TX(sp->tx_new); /* Advance. */

	/* Maybe kick the HPC back into motion. */
	if(!(hregs->tx_ctrl & HPC3_ETXCTRL_ACTIVE))
		kick_tx(&sp->srings.tx_desc[sp->tx_old], hregs);

	dev->trans_start = jiffies;
	dev_kfree_skb(skb);

	if(TX_BUFFS_AVAIL(sp))
		dev->tbusy = 0;
	restore_flags(flags);
	return 0;
}

static struct enet_statistics *sgiseeq_get_stats(struct device *dev)
{
	struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;

	return &sp->stats;
}

static void sgiseeq_set_multicast(struct device *dev)
{
}

static inline void setup_tx_ring(struct sgiseeq_tx_desc *buf, int nbufs)
{
	int i = 0;

	while(i < (nbufs - 1)) {
		buf[i].tdma.pnext = PHYSADDR(&buf[i + 1]);
		buf[i].tdma.pbuf = 0;
		i++;
	}
	buf[i].tdma.pnext = PHYSADDR(&buf[0]);
}

static inline void setup_rx_ring(struct sgiseeq_rx_desc *buf, int nbufs)
{
	int i = 0;

	while(i < (nbufs - 1)) {
		buf[i].rdma.pnext = PHYSADDR(&buf[i + 1]);
		buf[i].rdma.pbuf = 0;
		i++;
	}
	buf[i].rdma.pbuf = 0;
	buf[i].rdma.pnext = PHYSADDR(&buf[0]);
}

static char onboard_eth_addr[6];

#define ALIGNED(x)  ((((unsigned long)(x)) + 0xf) & ~(0xf))

int sgiseeq_init(struct device *dev, struct sgiseeq_regs *sregs,
		 struct hpc3_ethregs *hregs, int irq)
{
	static unsigned version_printed = 0;
	int i;
	struct sgiseeq_private *sp;

	if(dev == NULL) {
		dev = init_etherdev(0, sizeof(struct sgiseeq_private));
	} else {
		dev->priv = (struct sgiseeq_private *) get_free_page(GFP_KERNEL);
		if(dev->priv == NULL)
			return -ENOMEM;
	}

	if(!version_printed++)
		printk(version);

	printk("%s: SGI Seeq8003 ", dev->name);

	for(i = 0; i < 6; i++)
		printk("%2.2x%c",
		       dev->dev_addr[i] = onboard_eth_addr[i],
		       i == 5 ? ' ': ':');

	printk("\n");

	sp = (struct sgiseeq_private *) dev->priv;
#ifdef DEBUG
	gpriv = sp;
	gdev = dev;
#endif
	memset((char *)dev->priv, 0, sizeof(struct sgiseeq_private));
	sp->sregs = sregs;
	sp->hregs = hregs;
	sp->name = sgiseeqstr;

	sp->srings.rx_desc = (struct sgiseeq_rx_desc *)
	                     (KSEG1ADDR(ALIGNED(&sp->srings.rxvector[0])));
	dma_cache_wback_inv((unsigned long)&sp->srings.rxvector,
	                    sizeof(sp->srings.rxvector));
	sp->srings.tx_desc = (struct sgiseeq_tx_desc *)
	                     (KSEG1ADDR(ALIGNED(&sp->srings.txvector[0])));
	dma_cache_wback_inv((unsigned long)&sp->srings.txvector,
	                    sizeof(sp->srings.txvector));

	/* A couple calculations now, saves many cycles later. */
	setup_rx_ring(sp->srings.rx_desc, SEEQ_RX_BUFFERS);
	setup_tx_ring(sp->srings.tx_desc, SEEQ_TX_BUFFERS);

	/* Reset the chip. */
	hpc3_eth_reset((volatile struct hpc3_ethregs *) hregs);

	sp->is_edlc = !(sregs->rw.rregs.collision_tx[0] & 0xff);
	if(sp->is_edlc) {
		sp->control = (SEEQ_CTRL_XCNT | SEEQ_CTRL_ACCNT |
			       SEEQ_CTRL_SFLAG | SEEQ_CTRL_ESHORT |
			       SEEQ_CTRL_ENCARR);
	}

	dev->open                 = sgiseeq_open;
	dev->stop                 = sgiseeq_close;
	dev->hard_start_xmit      = sgiseeq_start_xmit;
	dev->get_stats            = sgiseeq_get_stats;
	dev->set_multicast_list   = sgiseeq_set_multicast;
	dev->irq                  = irq;
	dev->dma                  = 0;
	ether_setup(dev);
	return 0;
}

static inline unsigned char str2hexnum(unsigned char c)
{
	if(c >= '0' && c <= '9')
		return c - '0';
	if(c >= 'a' && c <= 'f')
		return c - 'a' + 10;
	return 0; /* foo */
}

static inline void str2eaddr(unsigned char *ea, unsigned char *str)
{
	int i;

	for(i = 0; i < 6; i++) {
		unsigned char num;

		if(*str == ':')
			str++;
		num = str2hexnum(*str++) << 4;
		num |= (str2hexnum(*str++));
		ea[i] = num;
	}
}

int sgiseeq_probe(struct device *dev)
{
	char *ep;

	/* First get the ethernet address of the onboard
	 * interface from ARCS.
	 */
	ep = romvec->get_evar("eaddr");
	str2eaddr(onboard_eth_addr, ep);
	return sgiseeq_init(dev,
			    (struct sgiseeq_regs *) (KSEG1ADDR(0x1fbd4000)),
			    &hpc3c0->ethregs, 3);

}