smc91x.c

linux 内核源代码

/*
 * smc91x.c
 * This is a driver for SMSC's 91C9x/91C1xx single-chip Ethernet devices.
 *
 * Copyright (C) 1996 by Erik Stahlman
 * Copyright (C) 2001 Standard Microsystems Corporation
 *	Developed by Simple Network Magic Corporation
 * Copyright (C) 2003 Monta Vista Software, Inc.
 *	Unified SMC91x driver by Nicolas Pitre
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Arguments:
 * 	io	= for the base address
 *	irq	= for the IRQ
 *	nowait	= 0 for normal wait states, 1 eliminates additional wait states
 *
 * original author:
 * 	Erik Stahlman <[e-mail]>
 *
 * hardware multicast code:
 *    Peter Cammaert <[e-mail]>
 *
 * contributors:
 * 	Daris A Nevil <[e-mail]>
 *      Nicolas Pitre <[e-mail]>
 *	Russell King <[e-mail]>
 *
 * History:
 *   08/20/00  Arnaldo Melo       fix kfree(skb) in smc_hardware_send_packet
 *   12/15/00  Christian Jullien  fix "Warning: kfree_skb on hard IRQ"
 *   03/16/01  Daris A Nevil      modified smc9194.c for use with LAN91C111
 *   08/22/01  Scott Anderson     merge changes from smc9194 to smc91111
 *   08/21/01  Pramod B Bhardwaj  added support for RevB of LAN91C111
 *   12/20/01  Jeff Sutherland    initial port to Xscale PXA with DMA support
 *   04/07/03  Nicolas Pitre      unified SMC91x driver, killed irq races,
 *                                more bus abstraction, big cleanup, etc.
 *   29/09/03  Russell King       - add driver model support
 *                                - ethtool support
 *                                - convert to use generic MII interface
 *                                - add link up/down notification
 *                                - don't try to handle full negotiation in
 *                                  smc_phy_configure
 *                                - clean up (and fix stack overrun) in PHY
 *                                  MII read/write functions
 *   22/09/04  Nicolas Pitre      big update (see commit log for details)
 */
static const char version[] =
	"smc91x.c: v1.1, sep 22 2004 by Nicolas Pitre <[e-mail]>\n";

/* Debugging level */
#ifndef SMC_DEBUG
#define SMC_DEBUG		0
#endif


#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/crc32.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/workqueue.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>

#include <asm/io.h>

#include "smc91x.h"

#ifdef CONFIG_ISA
/*
 * the LAN91C111 can be at any of the following port addresses.  To change,
 * for a slightly different card, you can add it to the array.  Keep in
 * mind that the array must end in zero.
 */
static unsigned int smc_portlist[] __initdata = {
	0x200, 0x220, 0x240, 0x260, 0x280, 0x2A0, 0x2C0, 0x2E0,
	0x300, 0x320, 0x340, 0x360, 0x380, 0x3A0, 0x3C0, 0x3E0, 0
};

#ifndef SMC_IOADDR
# define SMC_IOADDR		-1
#endif
static unsigned long io = SMC_IOADDR;
module_param(io, ulong, 0400);
MODULE_PARM_DESC(io, "I/O base address");

#ifndef SMC_IRQ
# define SMC_IRQ		-1
#endif
static int irq = SMC_IRQ;
module_param(irq, int, 0400);
MODULE_PARM_DESC(irq, "IRQ number");

#endif  /* CONFIG_ISA */

#ifndef SMC_NOWAIT
# define SMC_NOWAIT		0
#endif
static int nowait = SMC_NOWAIT;
module_param(nowait, int, 0400);
MODULE_PARM_DESC(nowait, "set to 1 for no wait state");

/*
 * Transmit timeout, default 5 seconds.
 */
static int watchdog = 1000;
module_param(watchdog, int, 0400);
MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");

MODULE_LICENSE("GPL");

/*
 * The internal workings of the driver.  If you are changing anything
 * here with the SMC stuff, you should have the datasheet and know
 * what you are doing.
 */
#define CARDNAME "smc91x"

/*
 * Use power-down feature of the chip
 */
#define POWER_DOWN		1

/*
 * Wait time for memory to be free.  This probably shouldn't be
 * tuned that much, as waiting for this means nothing else happens
 * in the system
 */
#define MEMORY_WAIT_TIME	16

/*
 * The maximum number of processing loops allowed for each call to the
 * IRQ handler.
 */
#define MAX_IRQ_LOOPS		8

/*
 * This selects whether TX packets are sent one by one to the SMC91x internal
 * memory and throttled until transmission completes.  This may prevent
 * RX overruns a litle by keeping much of the memory free for RX packets
 * but to the expense of reduced TX throughput and increased IRQ overhead.
 * Note this is not a cure for a too slow data bus or too high IRQ latency.
 */
#define THROTTLE_TX_PKTS	0

/*
 * The MII clock high/low times.  2x this number gives the MII clock period
 * in microseconds. (was 50, but this gives 6.4ms for each MII transaction!)
 */
#define MII_DELAY		1

#if SMC_DEBUG > 0
#define DBG(n, args...)					\
	do {						\
		if (SMC_DEBUG >= (n))			\
			printk(args);	\
	} while (0)

#define PRINTK(args...)   printk(args)
#else
#define DBG(n, args...)   do { } while(0)
#define PRINTK(args...)   printk(KERN_DEBUG args)
#endif

#if SMC_DEBUG > 3
static void PRINT_PKT(u_char *buf, int length)
{
	int i;
	int remainder;
	int lines;

	lines = length / 16;
	remainder = length % 16;

	for (i = 0; i < lines ; i ++) {
		int cur;
		for (cur = 0; cur < 8; cur++) {
			u_char a, b;
			a = *buf++;
			b = *buf++;
			printk("%02x%02x ", a, b);
		}
		printk("\n");
	}
	for (i = 0; i < remainder/2 ; i++) {
		u_char a, b;
		a = *buf++;
		b = *buf++;
		printk("%02x%02x ", a, b);
	}
	printk("\n");
}
#else
#define PRINT_PKT(x...)  do { } while(0)
#endif


/* this enables an interrupt in the interrupt mask register */
#define SMC_ENABLE_INT(x) do {						\
	unsigned char mask;						\
	spin_lock_irq(&lp->lock);					\
	mask = SMC_GET_INT_MASK();					\
	mask |= (x);							\
	SMC_SET_INT_MASK(mask);						\
	spin_unlock_irq(&lp->lock);					\
} while (0)

/* this disables an interrupt from the interrupt mask register */
#define SMC_DISABLE_INT(x) do {						\
	unsigned char mask;						\
	spin_lock_irq(&lp->lock);					\
	mask = SMC_GET_INT_MASK();					\
	mask &= ~(x);							\
	SMC_SET_INT_MASK(mask);						\
	spin_unlock_irq(&lp->lock);					\
} while (0)

/*
 * Wait while MMU is busy.  This is usually in the order of a few nanosecs
 * if at all, but let's avoid deadlocking the system if the hardware
 * decides to go south.
 */
#define SMC_WAIT_MMU_BUSY() do {					\
	if (unlikely(SMC_GET_MMU_CMD() & MC_BUSY)) {			\
		unsigned long timeout = jiffies + 2;			\
		while (SMC_GET_MMU_CMD() & MC_BUSY) {			\
			if (time_after(jiffies, timeout)) {		\
				printk("%s: timeout %s line %d\n",	\
					dev->name, __FILE__, __LINE__);	\
				break;					\
			}						\
			cpu_relax();					\
		}							\
	}								\
} while (0)


/*
 * this does a soft reset on the device
 */
static void smc_reset(struct net_device *dev)
{
	struct smc_local *lp = netdev_priv(dev);
	void __iomem *ioaddr = lp->base;
	unsigned int ctl, cfg;
	struct sk_buff *pending_skb;

	DBG(2, "%s: %s\n", dev->name, __FUNCTION__);

	/* Disable all interrupts, block TX tasklet */
	spin_lock_irq(&lp->lock);
	SMC_SELECT_BANK(2);
	SMC_SET_INT_MASK(0);
	pending_skb = lp->pending_tx_skb;
	lp->pending_tx_skb = NULL;
	spin_unlock_irq(&lp->lock);

	/* free any pending tx skb */
	if (pending_skb) {
		dev_kfree_skb(pending_skb);
		dev->stats.tx_errors++;
		dev->stats.tx_aborted_errors++;
	}

	/*
	 * This resets the registers mostly to defaults, but doesn't
	 * affect EEPROM.  That seems unnecessary
	 */
	SMC_SELECT_BANK(0);
	SMC_SET_RCR(RCR_SOFTRST);

	/*
	 * Setup the Configuration Register
	 * This is necessary because the CONFIG_REG is not affected
	 * by a soft reset
	 */
	SMC_SELECT_BANK(1);

	cfg = CONFIG_DEFAULT;

	/*
	 * Setup for fast accesses if requested.  If the card/system
	 * can't handle it then there will be no recovery except for
	 * a hard reset or power cycle
	 */
	if (nowait)
		cfg |= CONFIG_NO_WAIT;

	/*
	 * Release from possible power-down state
	 * Configuration register is not affected by Soft Reset
	 */
	cfg |= CONFIG_EPH_POWER_EN;

	SMC_SET_CONFIG(cfg);

	/* this should pause enough for the chip to be happy */
	/*
	 * elaborate?  What does the chip _need_? --jgarzik
	 *
	 * This seems to be undocumented, but something the original
	 * driver(s) have always done.  Suspect undocumented timing
	 * info/determined empirically. --rmk
	 */
	udelay(1);

	/* Disable transmit and receive functionality */
	SMC_SELECT_BANK(0);
	SMC_SET_RCR(RCR_CLEAR);
	SMC_SET_TCR(TCR_CLEAR);

	SMC_SELECT_BANK(1);
	ctl = SMC_GET_CTL() | CTL_LE_ENABLE;

	/*
	 * Set the control register to automatically release successfully
	 * transmitted packets, to make the best use out of our limited
	 * memory
	 */
	if(!THROTTLE_TX_PKTS)
		ctl |= CTL_AUTO_RELEASE;
	else
		ctl &= ~CTL_AUTO_RELEASE;
	SMC_SET_CTL(ctl);

	/* Reset the MMU */
	SMC_SELECT_BANK(2);
	SMC_SET_MMU_CMD(MC_RESET);
	SMC_WAIT_MMU_BUSY();
}

/*
 * Enable Interrupts, Receive, and Transmit
 */
static void smc_enable(struct net_device *dev)
{
	struct smc_local *lp = netdev_priv(dev);
	void __iomem *ioaddr = lp->base;
	int mask;

	DBG(2, "%s: %s\n", dev->name, __FUNCTION__);

	/* see the header file for options in TCR/RCR DEFAULT */
	SMC_SELECT_BANK(0);
	SMC_SET_TCR(lp->tcr_cur_mode);
	SMC_SET_RCR(lp->rcr_cur_mode);

	SMC_SELECT_BANK(1);
	SMC_SET_MAC_ADDR(dev->dev_addr);

	/* now, enable interrupts */
	mask = IM_EPH_INT|IM_RX_OVRN_INT|IM_RCV_INT;
	if (lp->version >= (CHIP_91100 << 4))
		mask |= IM_MDINT;
	SMC_SELECT_BANK(2);
	SMC_SET_INT_MASK(mask);

	/*
	 * From this point the register bank must _NOT_ be switched away
	 * to something else than bank 2 without proper locking against
	 * races with any tasklet or interrupt handlers until smc_shutdown()
	 * or smc_reset() is called.
	 */
}

/*
 * this puts the device in an inactive state
 */
static void smc_shutdown(struct net_device *dev)
{
	struct smc_local *lp = netdev_priv(dev);
	void __iomem *ioaddr = lp->base;
	struct sk_buff *pending_skb;

	DBG(2, "%s: %s\n", CARDNAME, __FUNCTION__);

	/* no more interrupts for me */
	spin_lock_irq(&lp->lock);
	SMC_SELECT_BANK(2);
	SMC_SET_INT_MASK(0);
	pending_skb = lp->pending_tx_skb;
	lp->pending_tx_skb = NULL;
	spin_unlock_irq(&lp->lock);
	if (pending_skb)
		dev_kfree_skb(pending_skb);

	/* and tell the card to stay away from that nasty outside world */
	SMC_SELECT_BANK(0);
	SMC_SET_RCR(RCR_CLEAR);
	SMC_SET_TCR(TCR_CLEAR);

#ifdef POWER_DOWN
	/* finally, shut the chip down */
	SMC_SELECT_BANK(1);
	SMC_SET_CONFIG(SMC_GET_CONFIG() & ~CONFIG_EPH_POWER_EN);
#endif
}

/*
 * This is the procedure to handle the receipt of a packet.
 */
static inline void  smc_rcv(struct net_device *dev)
{
	struct smc_local *lp = netdev_priv(dev);
	void __iomem *ioaddr = lp->base;
	unsigned int packet_number, status, packet_len;

	DBG(3, "%s: %s\n", dev->name, __FUNCTION__);

	packet_number = SMC_GET_RXFIFO();
	if (unlikely(packet_number & RXFIFO_REMPTY)) {
		PRINTK("%s: smc_rcv with nothing on FIFO.\n", dev->name);
		return;
	}

	/* read from start of packet */
	SMC_SET_PTR(PTR_READ | PTR_RCV | PTR_AUTOINC);

	/* First two words are status and packet length */
	SMC_GET_PKT_HDR(status, packet_len);
	packet_len &= 0x07ff;  /* mask off top bits */
	DBG(2, "%s: RX PNR 0x%x STATUS 0x%04x LENGTH 0x%04x (%d)\n",
		dev->name, packet_number, status,
		packet_len, packet_len);

	back:
	if (unlikely(packet_len < 6 || status & RS_ERRORS)) {
		if (status & RS_TOOLONG && packet_len <= (1514 + 4 + 6)) {
			/* accept VLAN packets */
			status &= ~RS_TOOLONG;
			goto back;
		}
		if (packet_len < 6) {
			/* bloody hardware */
			printk(KERN_ERR "%s: fubar (rxlen %u status %x\n",
					dev->name, packet_len, status);
			status |= RS_TOOSHORT;
		}
		SMC_WAIT_MMU_BUSY();
		SMC_SET_MMU_CMD(MC_RELEASE);
		dev->stats.rx_errors++;
		if (status & RS_ALGNERR)
			dev->stats.rx_frame_errors++;
		if (status & (RS_TOOSHORT | RS_TOOLONG))
			dev->stats.rx_length_errors++;
		if (status & RS_BADCRC)
			dev->stats.rx_crc_errors++;
	} else {
		struct sk_buff *skb;
		unsigned char *data;
		unsigned int data_len;

		/* set multicast stats */
		if (status & RS_MULTICAST)
			dev->stats.multicast++;

		/*
		 * Actual payload is packet_len - 6 (or 5 if odd byte).
		 * We want skb_reserve(2) and the final ctrl word
		 * (2 bytes, possibly containing the payload odd byte).
		 * Furthermore, we add 2 bytes to allow rounding up to
		 * multiple of 4 bytes on 32 bit buses.
		 * Hence packet_len - 6 + 2 + 2 + 2.
		 */
		skb = dev_alloc_skb(packet_len);
		if (unlikely(skb == NULL)) {
			printk(KERN_NOTICE "%s: Low memory, packet dropped.\n",
				dev->name);
			SMC_WAIT_MMU_BUSY();
			SMC_SET_MMU_CMD(MC_RELEASE);
			dev->stats.rx_dropped++;
			return;
		}

		/* Align IP header to 32 bits */
		skb_reserve(skb, 2);

		/* BUG: the LAN91C111 rev A never sets this bit. Force it. */
		if (lp->version == 0x90)
			status |= RS_ODDFRAME;

		/*
		 * If odd length: packet_len - 5,
		 * otherwise packet_len - 6.
		 * With the trailing ctrl byte it's packet_len - 4.
		 */
		data_len = packet_len - ((status & RS_ODDFRAME) ? 5 : 6);
		data = skb_put(skb, data_len);
		SMC_PULL_DATA(data, packet_len - 4);

		SMC_WAIT_MMU_BUSY();
		SMC_SET_MMU_CMD(MC_RELEASE);

		PRINT_PKT(data, packet_len - 4);

		dev->last_rx = jiffies;
		skb->protocol = eth_type_trans(skb, dev);
		netif_rx(skb);
		dev->stats.rx_packets++;
		dev->stats.rx_bytes += data_len;
	}
}

#ifdef CONFIG_SMP
/*
 * On SMP we have the following problem:
 *
 * 	A = smc_hardware_send_pkt()
 * 	B = smc_hard_start_xmit()
 * 	C = smc_interrupt()
 *
 * A and B can never be executed simultaneously.  However, at least on UP,
 * it is possible (and even desirable) for C to interrupt execution of
 * A or B in order to have better RX reliability and avoid overruns.
 * C, just like A and B, must have exclusive access to the chip and
 * each of them must lock against any other concurrent access.
 * Unfortunately this is not possible to have C suspend execution of A or
 * B taking place on another CPU. On UP this is no an issue since A and B
 * are run from softirq context and C from hard IRQ context, and there is
 * no other CPU where concurrent access can happen.
 * If ever there is a way to force at least B and C to always be executed
 * on the same CPU then we could use read/write locks to protect against
 * any other concurrent access and C would always interrupt B. But life
 * isn't that easy in a SMP world...
 */
#define smc_special_trylock(lock)					\
({									\
	int __ret;							\
	local_irq_disable();						\
	__ret = spin_trylock(lock);					\
	if (!__ret)							\
		local_irq_enable();					\
	__ret;								\
})
#define smc_special_lock(lock)		spin_lock_irq(lock)
#define smc_special_unlock(lock)	spin_unlock_irq(lock)
#else
#define smc_special_trylock(lock)	(1)
#define smc_special_lock(lock)		do { } while (0)
#define smc_special_unlock(lock)	do { } while (0)
#endif

/*
 * This is called to actually send a packet to the chip.
 */
static void smc_hardware_send_pkt(unsigned long data)
{
	struct net_device *dev = (struct net_device *)data;
	struct smc_local *lp = netdev_priv(dev);
	void __iomem *ioaddr = lp->base;
	struct sk_buff *skb;
	unsigned int packet_no, len;