1/* $Id: hysdn_net.c,v 1.1.1.1 2007/08/03 18:52:36 Exp $
2 *
3 * Linux driver for HYSDN cards, net (ethernet type) handling routines.
4 *
5 * Author    Werner Cornelius (werner@titro.de) for Hypercope GmbH
6 * Copyright 1999 by Werner Cornelius (werner@titro.de)
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * This net module has been inspired by the skeleton driver from
12 * Donald Becker (becker@CESDIS.gsfc.nasa.gov)
13 *
14 */
15
16#include <linux/module.h>
17#include <linux/signal.h>
18#include <linux/kernel.h>
19#include <linux/netdevice.h>
20#include <linux/etherdevice.h>
21#include <linux/skbuff.h>
22#include <linux/inetdevice.h>
23
24#include "hysdn_defs.h"
25
26unsigned int hynet_enable = 0xffffffff;
27module_param(hynet_enable, uint, 0);
28
29/* store the actual version for log reporting */
30char *hysdn_net_revision = "$Revision: 1.1.1.1 $";
31
32#define MAX_SKB_BUFFERS 20	/* number of buffers for keeping TX-data */
33
34/****************************************************************************/
35/* structure containing the complete network data. The structure is aligned */
36/* in a way that both, the device and statistics are kept inside it.        */
37/* for proper access, the device structure MUST be the first var/struct     */
38/* inside the definition.                                                   */
39/****************************************************************************/
40struct net_local {
41	struct net_device netdev;	/* the network device */
42	struct net_device_stats stats;
43	/* additional vars may be added here */
44	char dev_name[9];	/* our own device name */
45
46	/* Tx control lock.  This protects the transmit buffer ring
47	 * state along with the "tx full" state of the driver.  This
48	 * means all netif_queue flow control actions are protected
49	 * by this lock as well.
50	 */
51	spinlock_t lock;
52	struct sk_buff *skbs[MAX_SKB_BUFFERS];	/* pointers to tx-skbs */
53	int in_idx, out_idx;	/* indexes to buffer ring */
54	int sk_count;		/* number of buffers currently in ring */
55};				/* net_local */
56
57
58/*****************************************************/
59/* Get the current statistics for this card.         */
60/* This may be called with the card open or closed ! */
61/*****************************************************/
62static struct net_device_stats *
63net_get_stats(struct net_device *dev)
64{
65	return (&((struct net_local *) dev)->stats);
66}				/* net_device_stats */
67
68/*********************************************************************/
69/* Open/initialize the board. This is called (in the current kernel) */
70/* sometime after booting when the 'ifconfig' program is run.        */
71/* This routine should set everything up anew at each open, even     */
72/* registers that "should" only need to be set once at boot, so that */
73/* there is non-reboot way to recover if something goes wrong.       */
74/*********************************************************************/
75static int
76net_open(struct net_device *dev)
77{
78	struct in_device *in_dev;
79	hysdn_card *card = dev->priv;
80	int i;
81
82	netif_start_queue(dev);	/* start tx-queueing */
83
84	/* Fill in the MAC-level header (if not already set) */
85	if (!card->mac_addr[0]) {
86		for (i = 0; i < ETH_ALEN - sizeof(unsigned long); i++)
87			dev->dev_addr[i] = 0xfc;
88		if ((in_dev = dev->ip_ptr) != NULL) {
89			struct in_ifaddr *ifa = in_dev->ifa_list;
90			if (ifa != NULL)
91				memcpy(dev->dev_addr + (ETH_ALEN - sizeof(unsigned long)), &ifa->ifa_local, sizeof(unsigned long));
92		}
93	} else
94		memcpy(dev->dev_addr, card->mac_addr, ETH_ALEN);
95
96	return (0);
97}				/* net_open */
98
99/*******************************************/
100/* flush the currently occupied tx-buffers */
101/* must only be called when device closed  */
102/*******************************************/
103static void
104flush_tx_buffers(struct net_local *nl)
105{
106
107	while (nl->sk_count) {
108		dev_kfree_skb(nl->skbs[nl->out_idx++]);		/* free skb */
109		if (nl->out_idx >= MAX_SKB_BUFFERS)
110			nl->out_idx = 0;	/* wrap around */
111		nl->sk_count--;
112	}
113}				/* flush_tx_buffers */
114
115
116/*********************************************************************/
117/* close/decativate the device. The device is not removed, but only  */
118/* deactivated.                                                      */
119/*********************************************************************/
120static int
121net_close(struct net_device *dev)
122{
123
124	netif_stop_queue(dev);	/* disable queueing */
125
126	flush_tx_buffers((struct net_local *) dev);
127
128	return (0);		/* success */
129}				/* net_close */
130
131/************************************/
132/* send a packet on this interface. */
133/* new style for kernel >= 2.3.33   */
134/************************************/
135static int
136net_send_packet(struct sk_buff *skb, struct net_device *dev)
137{
138	struct net_local *lp = (struct net_local *) dev;
139
140	spin_lock_irq(&lp->lock);
141
142	lp->skbs[lp->in_idx++] = skb;	/* add to buffer list */
143	if (lp->in_idx >= MAX_SKB_BUFFERS)
144		lp->in_idx = 0;	/* wrap around */
145	lp->sk_count++;		/* adjust counter */
146	dev->trans_start = jiffies;
147
148	/* If we just used up the very last entry in the
149	 * TX ring on this device, tell the queueing
150	 * layer to send no more.
151	 */
152	if (lp->sk_count >= MAX_SKB_BUFFERS)
153		netif_stop_queue(dev);
154
155	/* When the TX completion hw interrupt arrives, this
156	 * is when the transmit statistics are updated.
157	 */
158
159	spin_unlock_irq(&lp->lock);
160
161	if (lp->sk_count <= 3) {
162		schedule_work(&((hysdn_card *) dev->priv)->irq_queue);
163	}
164	return (0);		/* success */
165}				/* net_send_packet */
166
167
168
169/***********************************************************************/
170/* acknowlegde a packet send. The network layer will be informed about */
171/* completion                                                          */
172/***********************************************************************/
173void
174hysdn_tx_netack(hysdn_card * card)
175{
176	struct net_local *lp = card->netif;
177
178	if (!lp)
179		return;		/* non existing device */
180
181
182	if (!lp->sk_count)
183		return;		/* error condition */
184
185	lp->stats.tx_packets++;
186	lp->stats.tx_bytes += lp->skbs[lp->out_idx]->len;
187
188	dev_kfree_skb(lp->skbs[lp->out_idx++]);		/* free skb */
189	if (lp->out_idx >= MAX_SKB_BUFFERS)
190		lp->out_idx = 0;	/* wrap around */
191
192	if (lp->sk_count-- == MAX_SKB_BUFFERS)	/* dec usage count */
193		netif_start_queue((struct net_device *) lp);
194}				/* hysdn_tx_netack */
195
196/*****************************************************/
197/* we got a packet from the network, go and queue it */
198/*****************************************************/
199void
200hysdn_rx_netpkt(hysdn_card * card, unsigned char *buf, unsigned short len)
201{
202	struct net_local *lp = card->netif;
203	struct sk_buff *skb;
204
205	if (!lp)
206		return;		/* non existing device */
207
208	lp->stats.rx_bytes += len;
209
210	skb = dev_alloc_skb(len);
211	if (skb == NULL) {
212		printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n",
213		       lp->netdev.name);
214		lp->stats.rx_dropped++;
215		return;
216	}
217	/* copy the data */
218	memcpy(skb_put(skb, len), buf, len);
219
220	/* determine the used protocol */
221	skb->protocol = eth_type_trans(skb, &lp->netdev);
222
223	netif_rx(skb);
224	lp->stats.rx_packets++;	/* adjust packet count */
225
226}				/* hysdn_rx_netpkt */
227
228/*****************************************************/
229/* return the pointer to a network packet to be send */
230/*****************************************************/
231struct sk_buff *
232hysdn_tx_netget(hysdn_card * card)
233{
234	struct net_local *lp = card->netif;
235
236	if (!lp)
237		return (NULL);	/* non existing device */
238
239	if (!lp->sk_count)
240		return (NULL);	/* nothing available */
241
242	return (lp->skbs[lp->out_idx]);		/* next packet to send */
243}				/* hysdn_tx_netget */
244
245
246/*******************************************/
247/* init function called by register device */
248/*******************************************/
249static int
250net_init(struct net_device *dev)
251{
252	/* setup the function table */
253	dev->open = net_open;
254	dev->stop = net_close;
255	dev->hard_start_xmit = net_send_packet;
256	dev->get_stats = net_get_stats;
257
258	/* Fill in the fields of the device structure with ethernet values. */
259	ether_setup(dev);
260
261	return (0);		/* success */
262}				/* net_init */
263
264/*****************************************************************************/
265/* hysdn_net_create creates a new net device for the given card. If a device */
266/* already exists, it will be deleted and created a new one. The return value */
267/* 0 announces success, else a negative error code will be returned.         */
268/*****************************************************************************/
269int
270hysdn_net_create(hysdn_card * card)
271{
272	struct net_device *dev;
273	int i;
274	if(!card) {
275		printk(KERN_WARNING "No card-pt in hysdn_net_create!\n");
276		return (-ENOMEM);
277	}
278	hysdn_net_release(card);	/* release an existing net device */
279	if ((dev = kzalloc(sizeof(struct net_local), GFP_KERNEL)) == NULL) {
280		printk(KERN_WARNING "HYSDN: unable to allocate mem\n");
281		return (-ENOMEM);
282	}
283
284	spin_lock_init(&((struct net_local *) dev)->lock);
285
286	/* initialise necessary or informing fields */
287	dev->base_addr = card->iobase;	/* IO address */
288	dev->irq = card->irq;	/* irq */
289	dev->init = net_init;	/* the init function of the device */
290	if(dev->name) {
291		strcpy(dev->name, ((struct net_local *) dev)->dev_name);
292	}
293	if ((i = register_netdev(dev))) {
294		printk(KERN_WARNING "HYSDN: unable to create network device\n");
295		kfree(dev);
296		return (i);
297	}
298	dev->priv = card;	/* remember pointer to own data structure */
299	card->netif = dev;	/* setup the local pointer */
300
301	if (card->debug_flags & LOG_NET_INIT)
302		hysdn_addlog(card, "network device created");
303	return (0);		/* and return success */
304}				/* hysdn_net_create */
305
306/***************************************************************************/
307/* hysdn_net_release deletes the net device for the given card. The return */
308/* value 0 announces success, else a negative error code will be returned. */
309/***************************************************************************/
310int
311hysdn_net_release(hysdn_card * card)
312{
313	struct net_device *dev = card->netif;
314
315	if (!dev)
316		return (0);	/* non existing */
317
318	card->netif = NULL;	/* clear out pointer */
319	dev->stop(dev);		/* close the device */
320
321	flush_tx_buffers((struct net_local *) dev);	/* empty buffers */
322
323	unregister_netdev(dev);	/* release the device */
324	free_netdev(dev);	/* release the memory allocated */
325	if (card->debug_flags & LOG_NET_INIT)
326		hysdn_addlog(card, "network device deleted");
327
328	return (0);		/* always successful */
329}				/* hysdn_net_release */
330
331/*****************************************************************************/
332/* hysdn_net_getname returns a pointer to the name of the network interface. */
333/* if the interface is not existing, a "-" is returned.                      */
334/*****************************************************************************/
335char *
336hysdn_net_getname(hysdn_card * card)
337{
338	struct net_device *dev = card->netif;
339
340	if (!dev)
341		return ("-");	/* non existing */
342
343	return (dev->name);
344}				/* hysdn_net_getname */
345