i2o_lan.c

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/*
 *	drivers/i2o/i2o_lan.c
 *
 * 	I2O LAN CLASS OSM 		May 26th 2000
 *
 *	(C) Copyright 1999, 2000 	University of Helsinki,
 *		      			Department of Computer Science
 *
 * 	This code is still under development / test.
 *
 *	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.
 *
 *	Authors: 	Auvo H鋕kinen <[e-mail]>
 *	Fixes:		Juha Siev鋘en <[e-mail]>
 *	 		Taneli V鋒鋕angas <[e-mail]>
 *			Deepak Saxena <[e-mail]>
 *
 *	Tested:		in FDDI environment (using SysKonnect's DDM)
 *			in Gigabit Eth environment (using SysKonnect's DDM)
 *			in Fast Ethernet environment (using Intel 82558 DDM)
 *
 *	TODO:		tests for other LAN classes (Token Ring, Fibre Channel)
 */

#include <linux/config.h>
#include <linux/module.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/fddidevice.h>
#include <linux/trdevice.h>
#include <linux/fcdevice.h>

#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/malloc.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/tqueue.h>
#include <asm/io.h>

#include <linux/errno.h>

#include <linux/i2o.h>
#include "i2o_lan.h"

//#define DRIVERDEBUG
#ifdef DRIVERDEBUG
#define dprintk(s, args...) printk(s, ## args)
#else
#define dprintk(s, args...)
#endif

/* The following module parameters are used as default values
 * for per interface values located in the net_device private area.
 * Private values are changed via /proc filesystem.
 */
static u32 max_buckets_out = I2O_LAN_MAX_BUCKETS_OUT;
static u32 bucket_thresh   = I2O_LAN_BUCKET_THRESH;
static u32 rx_copybreak    = I2O_LAN_RX_COPYBREAK;
static u8  tx_batch_mode   = I2O_LAN_TX_BATCH_MODE;
static u32 i2o_event_mask  = I2O_LAN_EVENT_MASK;

#define MAX_LAN_CARDS 16
static struct net_device *i2o_landevs[MAX_LAN_CARDS+1];
static int unit = -1; 	  /* device unit number */

static void i2o_lan_reply(struct i2o_handler *h, struct i2o_controller *iop, struct i2o_message *m);
static void i2o_lan_send_post_reply(struct i2o_handler *h, struct i2o_controller *iop, struct i2o_message *m);
static int i2o_lan_receive_post(struct net_device *dev);
static void i2o_lan_receive_post_reply(struct i2o_handler *h, struct i2o_controller *iop, struct i2o_message *m);
static void i2o_lan_release_buckets(struct net_device *dev, u32 *msg);

static int i2o_lan_reset(struct net_device *dev);
static void i2o_lan_handle_event(struct net_device *dev, u32 *msg);

/* Structures to register handlers for the incoming replies. */

static struct i2o_handler i2o_lan_send_handler = {
	i2o_lan_send_post_reply, 	// For send replies
	NULL,
	NULL,
	NULL,
	"I2O LAN OSM send",
	-1,
	I2O_CLASS_LAN
};
static int lan_send_context;

static struct i2o_handler i2o_lan_receive_handler = {
	i2o_lan_receive_post_reply,	// For receive replies
	NULL,
	NULL,
	NULL,
	"I2O LAN OSM receive",
	-1,
	I2O_CLASS_LAN
};
static int lan_receive_context;

static struct i2o_handler i2o_lan_handler = {
	i2o_lan_reply,			// For other replies
	NULL,
	NULL,
	NULL,
	"I2O LAN OSM",
	-1,
	I2O_CLASS_LAN
};
static int lan_context;

DECLARE_TASK_QUEUE(i2o_post_buckets_task);
struct tq_struct run_i2o_post_buckets_task = {
	routine: (void (*)(void *)) run_task_queue,
	data: (void *) 0
};

/* Functions to handle message failures and transaction errors:
==============================================================*/

/*
 * i2o_lan_handle_failure(): Fail bit has been set since IOP's message
 * layer cannot deliver the request to the target, or the target cannot
 * process the request.
 */
static void i2o_lan_handle_failure(struct net_device *dev, u32 *msg)
{
	struct i2o_lan_local *priv = (struct i2o_lan_local *)dev->priv;
	struct i2o_device *i2o_dev = priv->i2o_dev;
	struct i2o_controller *iop = i2o_dev->controller;

	u32 *preserved_msg = (u32*)(iop->mem_offset + msg[7]);
	u32 *sgl_elem = &preserved_msg[4];
	struct sk_buff *skb = NULL;
	u8 le_flag;

	i2o_report_status(KERN_INFO, dev->name, msg);

	/* If PacketSend failed, free sk_buffs reserved by upper layers */

	if (msg[1] >> 24 == LAN_PACKET_SEND) {
		do {
			skb = (struct sk_buff *)(sgl_elem[1]);
			dev_kfree_skb_irq(skb);

			atomic_dec(&priv->tx_out);

			le_flag = *sgl_elem >> 31;
			sgl_elem +=3;
		} while (le_flag == 0); /* Last element flag not set */

		if (netif_queue_stopped(dev))
			netif_wake_queue(dev);
	}

	/* If ReceivePost failed, free sk_buffs we have reserved */

	if (msg[1] >> 24 == LAN_RECEIVE_POST) {
		do {
			skb = (struct sk_buff *)(sgl_elem[1]);
			dev_kfree_skb_irq(skb);

			atomic_dec(&priv->buckets_out);

			le_flag = *sgl_elem >> 31;
			sgl_elem +=3;
		} while (le_flag == 0); /* Last element flag not set */
	}

	/* Release the preserved msg frame by resubmitting it as a NOP */

	preserved_msg[0] = THREE_WORD_MSG_SIZE | SGL_OFFSET_0;
	preserved_msg[1] = I2O_CMD_UTIL_NOP << 24 | HOST_TID << 12 | 0;
	preserved_msg[2] = 0;
	i2o_post_message(iop, msg[7]);
}
/*
 * i2o_lan_handle_transaction_error(): IOP or DDM has rejected the request
 * for general cause (format error, bad function code, insufficient resources,
 * etc.). We get one transaction_error for each failed transaction.
 */
static void i2o_lan_handle_transaction_error(struct net_device *dev, u32 *msg)
{
	struct i2o_lan_local *priv = (struct i2o_lan_local *)dev->priv;
	struct sk_buff *skb;

	i2o_report_status(KERN_INFO, dev->name, msg);

	/* If PacketSend was rejected, free sk_buff reserved by upper layers */

	if (msg[1] >> 24 == LAN_PACKET_SEND) {
		skb = (struct sk_buff *)(msg[3]); // TransactionContext
		dev_kfree_skb_irq(skb);
		atomic_dec(&priv->tx_out);

		if (netif_queue_stopped(dev))
			netif_wake_queue(dev);
 	}

	/* If ReceivePost was rejected, free sk_buff we have reserved */

	if (msg[1] >> 24 == LAN_RECEIVE_POST) {
		skb = (struct sk_buff *)(msg[3]);
		dev_kfree_skb_irq(skb);
		atomic_dec(&priv->buckets_out);
	}
}

/*
 * i2o_lan_handle_status(): Common parts of handling a not succeeded request
 * (status != SUCCESS).
 */
static int i2o_lan_handle_status(struct net_device *dev, u32 *msg)
{
	/* Fail bit set? */

	if (msg[0] & MSG_FAIL) {
		i2o_lan_handle_failure(dev, msg);
		return -1;
	}

	/* Message rejected for general cause? */

	if ((msg[4]>>24) == I2O_REPLY_STATUS_TRANSACTION_ERROR) {
		i2o_lan_handle_transaction_error(dev, msg);
		return -1;
	}

	/* Else have to handle it in the callback function */

	return 0;
}

/* Callback functions called from the interrupt routine:
=======================================================*/

/*
 * i2o_lan_send_post_reply(): Callback function to handle PostSend replies.
 */
static void i2o_lan_send_post_reply(struct i2o_handler *h,
			struct i2o_controller *iop, struct i2o_message *m)
{
	u32 *msg = (u32 *)m;
	u8 unit  = (u8)(msg[2]>>16); // InitiatorContext
	struct net_device *dev = i2o_landevs[unit];
	struct i2o_lan_local *priv = (struct i2o_lan_local *)dev->priv;
	u8 trl_count  = msg[3] & 0x000000FF;

	if ((msg[4] >> 24) != I2O_REPLY_STATUS_SUCCESS) {
		if (i2o_lan_handle_status(dev, msg))
			return;
	}

#ifdef DRIVERDEBUG
	i2o_report_status(KERN_INFO, dev->name, msg);
#endif

	/* DDM has handled transmit request(s), free sk_buffs.
	 * We get similar single transaction reply also in error cases 
	 * (except if msg failure or transaction error).
	 */
	while (trl_count) {
		dev_kfree_skb_irq((struct sk_buff *)msg[4 + trl_count]);
		dprintk(KERN_INFO "%s: tx skb freed (trl_count=%d).\n",
			dev->name, trl_count);
		atomic_dec(&priv->tx_out);
		trl_count--;
	}

	/* If priv->tx_out had reached tx_max_out, the queue was stopped */

	if (netif_queue_stopped(dev))
 		netif_wake_queue(dev);
}

/*
 * i2o_lan_receive_post_reply(): Callback function to process incoming packets.
 */
static void i2o_lan_receive_post_reply(struct i2o_handler *h,
			struct i2o_controller *iop, struct i2o_message *m)
{
	u32 *msg = (u32 *)m;
	u8 unit  = (u8)(msg[2]>>16); // InitiatorContext
	struct net_device *dev = i2o_landevs[unit];

	struct i2o_lan_local *priv = (struct i2o_lan_local *)dev->priv;
	struct i2o_bucket_descriptor *bucket = (struct i2o_bucket_descriptor *)&msg[6];
	struct i2o_packet_info *packet;
	u8 trl_count = msg[3] & 0x000000FF;
	struct sk_buff *skb, *old_skb;
	unsigned long flags = 0;

	if ((msg[4] >> 24) != I2O_REPLY_STATUS_SUCCESS) {
		if (i2o_lan_handle_status(dev, msg))
			return;

		i2o_lan_release_buckets(dev, msg);
		return;
	}

#ifdef DRIVERDEBUG
	i2o_report_status(KERN_INFO, dev->name, msg);
#endif

	/* Else we are receiving incoming post. */

	while (trl_count--) {
		skb = (struct sk_buff *)bucket->context;
		packet = (struct i2o_packet_info *)bucket->packet_info;
		atomic_dec(&priv->buckets_out);

		/* Sanity checks: Any weird characteristics in bucket? */

		if (packet->flags & 0x0f || ! packet->flags & 0x40) {
			if (packet->flags & 0x01)
				printk(KERN_WARNING "%s: packet with errors, error code=0x%02x.\n",
					dev->name, packet->status & 0xff);

			/* The following shouldn't happen, unless parameters in
			 * LAN_OPERATION group are changed during the run time.
			 */
			 if (packet->flags & 0x0c)
				printk(KERN_DEBUG "%s: multi-bucket packets not supported!\n", 
					dev->name);
					
			if (! packet->flags & 0x40)
				printk(KERN_DEBUG "%s: multiple packets in a bucket not supported!\n", 
					dev->name);

			dev_kfree_skb_irq(skb);

			bucket++;
			continue;
		}

		/* Copy short packet to a new skb */
		
		if (packet->len < priv->rx_copybreak) {
			old_skb = skb;
			skb = (struct sk_buff *)dev_alloc_skb(packet->len+2);
			if (skb == NULL) {
				printk(KERN_ERR "%s: Can't allocate skb.\n", dev->name);
				return;
			}
			skb_reserve(skb, 2);
			memcpy(skb_put(skb, packet->len), old_skb->data, packet->len);

			spin_lock_irqsave(&priv->fbl_lock, flags);
			if (priv->i2o_fbl_tail < I2O_LAN_MAX_BUCKETS_OUT)
				priv->i2o_fbl[++priv->i2o_fbl_tail] = old_skb;
			else
				dev_kfree_skb_irq(old_skb);

			spin_unlock_irqrestore(&priv->fbl_lock, flags);
		} else
			skb_put(skb, packet->len);

		/* Deliver to upper layers */

		skb->dev = dev;
		skb->protocol = priv->type_trans(skb, dev);
		netif_rx(skb);

		dev->last_rx = jiffies;

		dprintk(KERN_INFO "%s: Incoming packet (%d bytes) delivered "
			"to upper level.\n", dev->name, packet->len);

		bucket++; // to next Packet Descriptor Block
	}

#ifdef DRIVERDEBUG
	if (msg[5] == 0)
		printk(KERN_INFO "%s: DDM out of buckets (priv->count = %d)!\n",
		       dev->name, atomic_read(&priv->buckets_out));
#endif

	/* If DDM has already consumed bucket_thresh buckets, post new ones */

	if (atomic_read(&priv->buckets_out) <= priv->max_buckets_out - priv->bucket_thresh) {
		run_i2o_post_buckets_task.data = (void *)dev;
		queue_task(&run_i2o_post_buckets_task, &tq_immediate);
		mark_bh(IMMEDIATE_BH);
	}

	return;
}

/*
 * i2o_lan_reply(): Callback function to handle other incoming messages
 * except SendPost and ReceivePost.