fcc_enet.c

自己根据lkd和情境分析

/*
 * BK Id: SCCS/s.fcc_enet.c 1.7 05/17/01 18:14:20 cort
 */
/*
 * Fast Ethernet Controller (FCC) driver for Motorola MPC8260.
 * Copyright (c) 2000 MontaVista Software, Inc.   Dan Malek ([e-mail])
 *
 * This version of the driver is a combination of the 8xx fec and
 * 8260 SCC Ethernet drivers.  People seem to be choosing common I/O
 * configurations, so this driver will work on the EST8260 boards and
 * others yet to be announced.
 *
 * Right now, I am very watseful with the buffers.  I allocate memory
 * pages and then divide them into 2K frame buffers.  This way I know I
 * have buffers large enough to hold one frame within one buffer descriptor.
 * Once I get this working, I will use 64 or 128 byte CPM buffers, which
 * will be much more memory efficient and will easily handle lots of
 * small packets.
 *
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>

#include <asm/immap_8260.h>
#include <asm/pgtable.h>
#include <asm/mpc8260.h>
#include <asm/irq.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <asm/cpm_8260.h>

/* The transmitter timeout
 */
#define TX_TIMEOUT	(2*HZ)

/* The number of Tx and Rx buffers.  These are allocated from the page
 * pool.  The code may assume these are power of two, so it is best
 * to keep them that size.
 * We don't need to allocate pages for the transmitter.  We just use
 * the skbuffer directly.
 */
#define FCC_ENET_RX_PAGES	16
#define FCC_ENET_RX_FRSIZE	2048
#define FCC_ENET_RX_FRPPG	(PAGE_SIZE / FCC_ENET_RX_FRSIZE)
#define RX_RING_SIZE		(FCC_ENET_RX_FRPPG * FCC_ENET_RX_PAGES)
#define TX_RING_SIZE		16	/* Must be power of two */
#define TX_RING_MOD_MASK	15	/*   for this to work */

/* The FCC stores dest/src/type, data, and checksum for receive packets.
 */
#define PKT_MAXBUF_SIZE		1518
#define PKT_MINBUF_SIZE		64

/* Maximum input DMA size.  Must be a should(?) be a multiple of 4.
*/
#define PKT_MAXDMA_SIZE		1520

/* Maximum input buffer size.  Must be a multiple of 32.
*/
#define PKT_MAXBLR_SIZE		1536

static int fcc_enet_open(struct net_device *dev);
static int fcc_enet_start_xmit(struct sk_buff *skb, struct net_device *dev);
static int fcc_enet_rx(struct net_device *dev);
static void fcc_enet_mii(struct net_device *dev);
static	void fcc_enet_interrupt(int irq, void * dev_id, struct pt_regs * regs);
static int fcc_enet_close(struct net_device *dev);
static struct net_device_stats *fcc_enet_get_stats(struct net_device *dev);
static void set_multicast_list(struct net_device *dev);
static void restart_fcc(struct net_device *dev);

/* These will be configurable for the FCC choice.
 * Multiple ports can be configured.  There is little choice among the
 * I/O pins to the PHY, except the clocks.  We will need some board
 * dependent clock selection.
 * Why in the hell did I put these inside #ifdef's?  I dunno, maybe to
 * help show what pins are used for each device.
 */

/* I/O Pin assignment for FCC1.  I don't yet know the best way to do this,
 * but there is little variation among the choices.
 */
#define PA1_COL		((uint)0x00000001)
#define PA1_CRS		((uint)0x00000002)
#define PA1_TXER	((uint)0x00000004)
#define PA1_TXEN	((uint)0x00000008)
#define PA1_RXDV	((uint)0x00000010)
#define PA1_RXER	((uint)0x00000020)
#define PA1_TXDAT	((uint)0x00003c00)
#define PA1_RXDAT	((uint)0x0003c000)
#define PA1_PSORA0	(PA1_RXDAT | PA1_TXDAT)
#define PA1_PSORA1	(PA1_COL | PA1_CRS | PA1_TXER | PA1_TXEN | \
				PA1_RXDV | PA1_RXER)
#define PA1_DIRA0	(PA1_RXDAT | PA1_CRS | PA1_COL | PA1_RXER | PA1_RXDV)
#define PA1_DIRA1	(PA1_TXDAT | PA1_TXEN | PA1_TXER)

/* CLK12 is receive, CLK11 is transmit.  These are board specific.
*/
#define PC_F1RXCLK	((uint)0x00000800)
#define PC_F1TXCLK	((uint)0x00000400)
#define CMX1_CLK_ROUTE	((uint)0x3e000000)
#define CMX1_CLK_MASK	((uint)0xff000000)

/* I/O Pin assignment for FCC2.  I don't yet know the best way to do this,
 * but there is little variation among the choices.
 */
#define PB2_TXER	((uint)0x00000001)
#define PB2_RXDV	((uint)0x00000002)
#define PB2_TXEN	((uint)0x00000004)
#define PB2_RXER	((uint)0x00000008)
#define PB2_COL		((uint)0x00000010)
#define PB2_CRS		((uint)0x00000020)
#define PB2_TXDAT	((uint)0x000003c0)
#define PB2_RXDAT	((uint)0x00003c00)
#define PB2_PSORB0	(PB2_RXDAT | PB2_TXDAT | PB2_CRS | PB2_COL | \
				PB2_RXER | PB2_RXDV | PB2_TXER)
#define PB2_PSORB1	(PB2_TXEN)
#define PB2_DIRB0	(PB2_RXDAT | PB2_CRS | PB2_COL | PB2_RXER | PB2_RXDV)
#define PB2_DIRB1	(PB2_TXDAT | PB2_TXEN | PB2_TXER)

/* CLK13 is receive, CLK14 is transmit.  These are board dependent.
*/
#define PC_F2RXCLK	((uint)0x00001000)
#define PC_F2TXCLK	((uint)0x00002000)
#define CMX2_CLK_ROUTE	((uint)0x00250000)
#define CMX2_CLK_MASK	((uint)0x00ff0000)

/* I/O Pin assignment for FCC3.  I don't yet know the best way to do this,
 * but there is little variation among the choices.
 */
#define PB3_RXDV	((uint)0x00004000)
#define PB3_RXER	((uint)0x00008000)
#define PB3_TXER	((uint)0x00010000)
#define PB3_TXEN	((uint)0x00020000)
#define PB3_COL		((uint)0x00040000)
#define PB3_CRS		((uint)0x00080000)
#define PB3_TXDAT	((uint)0x0f000000)
#define PB3_RXDAT	((uint)0x00f00000)
#define PB3_PSORB0	(PB3_RXDAT | PB3_TXDAT | PB3_CRS | PB3_COL | \
				PB3_RXER | PB3_RXDV | PB3_TXER | PB3_TXEN)
#define PB3_PSORB1	(0)
#define PB3_DIRB0	(PB3_RXDAT | PB3_CRS | PB3_COL | PB3_RXER | PB3_RXDV)
#define PB3_DIRB1	(PB3_TXDAT | PB3_TXEN | PB3_TXER)

/* CLK15 is receive, CLK16 is transmit.  These are board dependent.
*/
#define PC_F3RXCLK	((uint)0x00004000)
#define PC_F3TXCLK	((uint)0x00008000)
#define CMX3_CLK_ROUTE	((uint)0x00003700)
#define CMX3_CLK_MASK	((uint)0x0000ff00)

/* MII status/control serial interface.
*/
#define PC_MDIO		((uint)0x00400000)
#define PC_MDCK		((uint)0x00200000)

/* A table of information for supporting FCCs.  This does two things.
 * First, we know how many FCCs we have and they are always externally
 * numbered from zero.  Second, it holds control register and I/O
 * information that could be different among board designs.
 */
typedef struct fcc_info {
	uint	fc_fccnum;
	uint	fc_cpmblock;
	uint	fc_cpmpage;
	uint	fc_proff;
	uint	fc_interrupt;
	uint	fc_trxclocks;
	uint	fc_clockroute;
	uint	fc_clockmask;
	uint	fc_mdio;
	uint	fc_mdck;
} fcc_info_t;

static fcc_info_t fcc_ports[] = {
#ifdef CONFIG_FCC1_ENET
	{ 0, CPM_CR_FCC1_SBLOCK, CPM_CR_FCC1_PAGE, PROFF_FCC1, SIU_INT_FCC1,
		(PC_F1RXCLK | PC_F1TXCLK), CMX1_CLK_ROUTE, CMX1_CLK_MASK,
		PC_MDIO, PC_MDCK },
#endif
#ifdef CONFIG_FCC2_ENET
	{ 1, CPM_CR_FCC2_SBLOCK, CPM_CR_FCC2_PAGE, PROFF_FCC2, SIU_INT_FCC2,
		(PC_F2RXCLK | PC_F2TXCLK), CMX2_CLK_ROUTE, CMX2_CLK_MASK,
		PC_MDIO, PC_MDCK },
#endif
#ifdef CONFIG_FCC3_ENET
	{ 2, CPM_CR_FCC3_SBLOCK, CPM_CR_FCC3_PAGE, PROFF_FCC3, SIU_INT_FCC3,
		(PC_F3RXCLK | PC_F3TXCLK), CMX3_CLK_ROUTE, CMX3_CLK_MASK,
		PC_MDIO, PC_MDCK },
#endif
};

/* The FCC buffer descriptors track the ring buffers.  The rx_bd_base and
 * tx_bd_base always point to the base of the buffer descriptors.  The
 * cur_rx and cur_tx point to the currently available buffer.
 * The dirty_tx tracks the current buffer that is being sent by the
 * controller.  The cur_tx and dirty_tx are equal under both completely
 * empty and completely full conditions.  The empty/ready indicator in
 * the buffer descriptor determines the actual condition.
 */
struct fcc_enet_private {
	/* The saved address of a sent-in-place packet/buffer, for skfree(). */
	struct	sk_buff* tx_skbuff[TX_RING_SIZE];
	ushort	skb_cur;
	ushort	skb_dirty;

	/* CPM dual port RAM relative addresses.
	*/
	cbd_t	*rx_bd_base;		/* Address of Rx and Tx buffers. */
	cbd_t	*tx_bd_base;
	cbd_t	*cur_rx, *cur_tx;		/* The next free ring entry */
	cbd_t	*dirty_tx;	/* The ring entries to be free()ed. */
	volatile fcc_t	*fccp;
	volatile fcc_enet_t	*ep;
	struct	net_device_stats stats;
	uint	tx_full;
	spinlock_t lock;
	uint	phy_address;
	uint	phy_type;
	uint	phy_duplex;
	fcc_info_t	*fip;
};

static void init_fcc_shutdown(fcc_info_t *fip, struct fcc_enet_private *cep,
	volatile immap_t *immap);
static void init_fcc_startup(fcc_info_t *fip, struct net_device *dev);
static void init_fcc_ioports(fcc_info_t *fip, volatile iop8260_t *io,
	volatile immap_t *immap);
static void init_fcc_param(fcc_info_t *fip, struct net_device *dev,
	volatile immap_t *immap);

/* MII processing.  We keep this as simple as possible.  Requests are
 * placed on the list (if there is room).  When the request is finished
 * by the MII, an optional function may be called.
 */
typedef struct mii_list {
	uint	mii_regval;
	void	(*mii_func)(uint val, struct net_device *dev);
	struct	mii_list *mii_next;
} mii_list_t;

#define		NMII	20
mii_list_t	mii_cmds[NMII];
mii_list_t	*mii_free;
mii_list_t	*mii_head;
mii_list_t	*mii_tail;

static	int	phyaddr;
static	uint	phytype;

static int	mii_queue(int request, void (*func)(uint, struct net_device *));
static void	mii_startup_cmds(void);
static uint	mii_send_receive(fcc_info_t *fip, uint cmd);

/* Make MII read/write commands for the FCC.
*/

#define mk_mii_phyaddr(ADDR)	(0x60020000 | ((ADDR) << 23) | (2 << 18))

#define mk_mii_read(REG)	(0x60020000 | ((phyaddr << 23) | \
						(REG & 0x1f) << 18))

#define mk_mii_write(REG, VAL)	(0x50020000 | ((phyaddr << 23) | \
						(REG & 0x1f) << 18) | \
						(VAL & 0xffff))


static int
fcc_enet_open(struct net_device *dev)
{
	netif_start_queue(dev);
	return 0;					/* Always succeed */
}

static int
fcc_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct fcc_enet_private *cep = (struct fcc_enet_private *)dev->priv;
	volatile cbd_t	*bdp;


	/* Fill in a Tx ring entry */
	bdp = cep->cur_tx;

#ifndef final_version
	if (bdp->cbd_sc & BD_ENET_TX_READY) {
		/* Ooops.  All transmit buffers are full.  Bail out.
		 * This should not happen, since cep->tx_full should be set.
		 */
		printk("%s: tx queue full!.\n", dev->name);
		return 1;
	}
#endif

	/* Clear all of the status flags.
	 */
	bdp->cbd_sc &= ~BD_ENET_TX_STATS;

	/* If the frame is short, tell CPM to pad it.
	*/
	if (skb->len <= ETH_ZLEN)
		bdp->cbd_sc |= BD_ENET_TX_PAD;
	else
		bdp->cbd_sc &= ~BD_ENET_TX_PAD;

	/* Set buffer length and buffer pointer.
	*/
	bdp->cbd_datlen = skb->len;
	bdp->cbd_bufaddr = __pa(skb->data);

	/* Save skb pointer.
	*/
	cep->tx_skbuff[cep->skb_cur] = skb;

	cep->stats.tx_bytes += skb->len;
	cep->skb_cur = (cep->skb_cur+1) & TX_RING_MOD_MASK;

	spin_lock_irq(&cep->lock);

	/* Send it on its way.  Tell CPM its ready, interrupt when done,
	 * its the last BD of the frame, and to put the CRC on the end.
	 */
	bdp->cbd_sc |= (BD_ENET_TX_READY | BD_ENET_TX_INTR | BD_ENET_TX_LAST | BD_ENET_TX_TC);

#if 0
	/* Errata says don't do this.
	*/
	cep->fccp->fcc_ftodr = 0x8000;
#endif
	dev->trans_start = jiffies;

	/* If this was the last BD in the ring, start at the beginning again.
	*/
	if (bdp->cbd_sc & BD_ENET_TX_WRAP)
		bdp = cep->tx_bd_base;
	else
		bdp++;

	if (bdp->cbd_sc & BD_ENET_TX_READY) {
		netif_stop_queue(dev);
		cep->tx_full = 1;
	}

	cep->cur_tx = (cbd_t *)bdp;

	spin_unlock_irq(&cep->lock);

	return 0;
}


static void
fcc_enet_timeout(struct net_device *dev)
{
	struct fcc_enet_private *cep = (struct fcc_enet_private *)dev->priv;

	printk("%s: transmit timed out.\n", dev->name);
	cep->stats.tx_errors++;
#ifndef final_version
	{
		int	i;
		cbd_t	*bdp;
		printk(" Ring data dump: cur_tx %p%s cur_rx %p.\n",
		       cep->cur_tx, cep->tx_full ? " (full)" : "",
		       cep->cur_rx);
		bdp = cep->tx_bd_base;
		printk(" Tx @base %p :\n", bdp);
		for (i = 0 ; i < TX_RING_SIZE; i++, bdp++)
			printk("%04x %04x %08x\n",
			       bdp->cbd_sc,
			       bdp->cbd_datlen,
			       bdp->cbd_bufaddr);
		bdp = cep->rx_bd_base;
		printk(" Rx @base %p :\n", bdp);
		for (i = 0 ; i < RX_RING_SIZE; i++, bdp++)
			printk("%04x %04x %08x\n",
			       bdp->cbd_sc,
			       bdp->cbd_datlen,
			       bdp->cbd_bufaddr);
	}
#endif
	if (!cep->tx_full)
		netif_wake_queue(dev);
}

/* The interrupt handler.
 */
static void
fcc_enet_interrupt(int irq, void * dev_id, struct pt_regs * regs)
{
	struct	net_device *dev = dev_id;
	volatile struct	fcc_enet_private *cep;
	volatile cbd_t	*bdp;
	ushort	int_events;
	int	must_restart;

	cep = (struct fcc_enet_private *)dev->priv;

	/* Get the interrupt events that caused us to be here.
	*/
	int_events = cep->fccp->fcc_fcce;
	cep->fccp->fcc_fcce = int_events;
	must_restart = 0;

	/* Handle receive event in its own function.
	*/
	if (int_events & FCC_ENET_RXF)
		fcc_enet_rx(dev_id);

	/* Check for a transmit error.  The manual is a little unclear
	 * about this, so the debug code until I get it figured out.  It
	 * appears that if TXE is set, then TXB is not set.  However,
	 * if carrier sense is lost during frame transmission, the TXE
	 * bit is set, "and continues the buffer transmission normally."
	 * I don't know if "normally" implies TXB is set when the buffer
	 * descriptor is closed.....trial and error :-).
	 */

	/* Transmit OK, or non-fatal error.  Update the buffer descriptors.
	*/
	if (int_events & (FCC_ENET_TXE | FCC_ENET_TXB)) {
	    spin_lock(&cep->lock);
	    bdp = cep->dirty_tx;
	    while ((bdp->cbd_sc&BD_ENET_TX_READY)==0) {
		if ((bdp==cep->cur_tx) && (cep->tx_full == 0))
		    break;

		if (bdp->cbd_sc & BD_ENET_TX_HB)	/* No heartbeat */
			cep->stats.tx_heartbeat_errors++;
		if (bdp->cbd_sc & BD_ENET_TX_LC)	/* Late collision */
			cep->stats.tx_window_errors++;
		if (bdp->cbd_sc & BD_ENET_TX_RL)	/* Retrans limit */
			cep->stats.tx_aborted_errors++;
		if (bdp->cbd_sc & BD_ENET_TX_UN)	/* Underrun */
			cep->stats.tx_fifo_errors++;
		if (bdp->cbd_sc & BD_ENET_TX_CSL)	/* Carrier lost */
			cep->stats.tx_carrier_errors++;


		/* No heartbeat or Lost carrier are not really bad errors.
		 * The others require a restart transmit command.
		 */
		if (bdp->cbd_sc &
		    (BD_ENET_TX_LC | BD_ENET_TX_RL | BD_ENET_TX_UN)) {
			must_restart = 1;
			cep->stats.tx_errors++;
		}

		cep->stats.tx_packets++;

		/* Deferred means some collisions occurred during transmit,
		 * but we eventually sent the packet OK.
		 */
		if (bdp->cbd_sc & BD_ENET_TX_DEF)
			cep->stats.collisions++;

		/* Free the sk buffer associated with this last transmit.
		*/
		dev_kfree_skb_irq(cep->tx_skbuff[cep->skb_dirty]);
		cep->skb_dirty = (cep->skb_dirty + 1) & TX_RING_MOD_MASK;

		/* Update pointer to next buffer descriptor to be transmitted.
		*/
		if (bdp->cbd_sc & BD_ENET_TX_WRAP)
			bdp = cep->tx_bd_base;
		else
			bdp++;

		/* I don't know if we can be held off from processing these
		 * interrupts for more than one frame time.  I really hope
		 * not.  In such a case, we would now want to check the
		 * currently available BD (cur_tx) and determine if any
		 * buffers between the dirty_tx and cur_tx have also been
		 * sent.  We would want to process anything in between that
		 * does not have BD_ENET_TX_READY set.
		 */

		/* Since we have freed up a buffer, the ring is no longer
		 * full.
		 */
		if (cep->tx_full) {
			cep->tx_full = 0;
			if (netif_queue_stopped(dev)) {
				netif_wake_queue(dev);
			}
		}

		cep->dirty_tx = (cbd_t *)bdp;
	    }

	    if (must_restart) {
		volatile cpm8260_t *cp;

		/* Some transmit errors cause the transmitter to shut
		 * down.  We now issue a restart transmit.  Since the
		 * errors close the BD and update the pointers, the restart
		 * _should_ pick up without having to reset any of our
		 * pointers either.
		 */

		cp = cpmp;
		cp->cp_cpcr =
		    mk_cr_cmd(cep->fip->fc_cpmpage, cep->fip->fc_cpmblock,
		    		0x0c, CPM_CR_RESTART_TX) | CPM_CR_FLG;
		while (cp->cp_cpcr & CPM_CR_FLG);
	    }
	    spin_unlock(&cep->lock);
	}

	/* Check for receive busy, i.e. packets coming but no place to
	 * put them.
	 */
	if (int_events & FCC_ENET_BSY) {
		cep->stats.rx_dropped++;
	}
	return;
}

/* During a receive, the cur_rx points to the current incoming buffer.
 * When we update through the ring, if the next incoming buffer has
 * not been given to the system, we just set the empty indicator,