summaryrefslogtreecommitdiffstats
path: root/drivers/isdn/hysdn/hysdn_net.c
blob: 5609deee7cd3f7891076dd474493bcfa91c7ad87 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
/* $Id: hysdn_net.c,v 1.8.6.4 2001/09/23 22:24:54 kai Exp $
 *
 * Linux driver for HYSDN cards, net (ethernet type) handling routines.
 *
 * Author    Werner Cornelius (werner@titro.de) for Hypercope GmbH
 * Copyright 1999 by Werner Cornelius (werner@titro.de)
 *
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 *
 * This net module has been inspired by the skeleton driver from
 * Donald Becker (becker@CESDIS.gsfc.nasa.gov)
 *
 */

#include <linux/module.h>
#include <linux/signal.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/inetdevice.h>

#include "hysdn_defs.h"

unsigned int hynet_enable = 0xffffffff;
module_param(hynet_enable, uint, 0);

#define MAX_SKB_BUFFERS 20	/* number of buffers for keeping TX-data */

/****************************************************************************/
/* structure containing the complete network data. The structure is aligned */
/* in a way that both, the device and statistics are kept inside it.        */
/* for proper access, the device structure MUST be the first var/struct     */
/* inside the definition.                                                   */
/****************************************************************************/
struct net_local {
	/* Tx control lock.  This protects the transmit buffer ring
	 * state along with the "tx full" state of the driver.  This
	 * means all netif_queue flow control actions are protected
	 * by this lock as well.
	 */
	struct net_device *dev;
	spinlock_t lock;
	struct sk_buff *skbs[MAX_SKB_BUFFERS];	/* pointers to tx-skbs */
	int in_idx, out_idx;	/* indexes to buffer ring */
	int sk_count;		/* number of buffers currently in ring */
};				/* net_local */



/*********************************************************************/
/* Open/initialize the board. This is called (in the current kernel) */
/* sometime after booting when the 'ifconfig' program is run.        */
/* This routine should set everything up anew at each open, even     */
/* registers that "should" only need to be set once at boot, so that */
/* there is non-reboot way to recover if something goes wrong.       */
/*********************************************************************/
static int
net_open(struct net_device *dev)
{
	struct in_device *in_dev;
	hysdn_card *card = dev->ml_priv;
	int i;

	netif_start_queue(dev);	/* start tx-queueing */

	/* Fill in the MAC-level header (if not already set) */
	if (!card->mac_addr[0]) {
		for (i = 0; i < ETH_ALEN; i++)
			dev->dev_addr[i] = 0xfc;
		if ((in_dev = dev->ip_ptr) != NULL) {
			struct in_ifaddr *ifa = in_dev->ifa_list;
			if (ifa != NULL)
				memcpy(dev->dev_addr + (ETH_ALEN - sizeof(ifa->ifa_local)), &ifa->ifa_local, sizeof(ifa->ifa_local));
		}
	} else
		memcpy(dev->dev_addr, card->mac_addr, ETH_ALEN);

	return (0);
}				/* net_open */

/*******************************************/
/* flush the currently occupied tx-buffers */
/* must only be called when device closed  */
/*******************************************/
static void
flush_tx_buffers(struct net_local *nl)
{

	while (nl->sk_count) {
		dev_kfree_skb(nl->skbs[nl->out_idx++]);		/* free skb */
		if (nl->out_idx >= MAX_SKB_BUFFERS)
			nl->out_idx = 0;	/* wrap around */
		nl->sk_count--;
	}
}				/* flush_tx_buffers */


/*********************************************************************/
/* close/decativate the device. The device is not removed, but only  */
/* deactivated.                                                      */
/*********************************************************************/
static int
net_close(struct net_device *dev)
{

	netif_stop_queue(dev);	/* disable queueing */

	flush_tx_buffers((struct net_local *) dev);

	return (0);		/* success */
}				/* net_close */

/************************************/
/* send a packet on this interface. */
/* new style for kernel >= 2.3.33   */
/************************************/
static netdev_tx_t
net_send_packet(struct sk_buff *skb, struct net_device *dev)
{
	struct net_local *lp = (struct net_local *) dev;

	spin_lock_irq(&lp->lock);

	lp->skbs[lp->in_idx++] = skb;	/* add to buffer list */
	if (lp->in_idx >= MAX_SKB_BUFFERS)
		lp->in_idx = 0;	/* wrap around */
	lp->sk_count++;		/* adjust counter */
	netif_trans_update(dev);

	/* If we just used up the very last entry in the
	 * TX ring on this device, tell the queueing
	 * layer to send no more.
	 */
	if (lp->sk_count >= MAX_SKB_BUFFERS)
		netif_stop_queue(dev);

	/* When the TX completion hw interrupt arrives, this
	 * is when the transmit statistics are updated.
	 */

	spin_unlock_irq(&lp->lock);

	if (lp->sk_count <= 3) {
		schedule_work(&((hysdn_card *) dev->ml_priv)->irq_queue);
	}
	return NETDEV_TX_OK;	/* success */
}				/* net_send_packet */



/***********************************************************************/
/* acknowlegde a packet send. The network layer will be informed about */
/* completion                                                          */
/***********************************************************************/
void
hysdn_tx_netack(hysdn_card *card)
{
	struct net_local *lp = card->netif;

	if (!lp)
		return;		/* non existing device */


	if (!lp->sk_count)
		return;		/* error condition */

	lp->dev->stats.tx_packets++;
	lp->dev->stats.tx_bytes += lp->skbs[lp->out_idx]->len;

	dev_kfree_skb(lp->skbs[lp->out_idx++]);		/* free skb */
	if (lp->out_idx >= MAX_SKB_BUFFERS)
		lp->out_idx = 0;	/* wrap around */

	if (lp->sk_count-- == MAX_SKB_BUFFERS)	/* dec usage count */
		netif_start_queue((struct net_device *) lp);
}				/* hysdn_tx_netack */

/*****************************************************/
/* we got a packet from the network, go and queue it */
/*****************************************************/
void
hysdn_rx_netpkt(hysdn_card *card, unsigned char *buf, unsigned short len)
{
	struct net_local *lp = card->netif;
	struct net_device *dev;
	struct sk_buff *skb;

	if (!lp)
		return;		/* non existing device */

	dev = lp->dev;
	dev->stats.rx_bytes += len;

	skb = dev_alloc_skb(len);
	if (skb == NULL) {
		printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n",
		       dev->name);
		dev->stats.rx_dropped++;
		return;
	}
	/* copy the data */
	memcpy(skb_put(skb, len), buf, len);

	/* determine the used protocol */
	skb->protocol = eth_type_trans(skb, dev);

	dev->stats.rx_packets++;	/* adjust packet count */

	netif_rx(skb);
}				/* hysdn_rx_netpkt */

/*****************************************************/
/* return the pointer to a network packet to be send */
/*****************************************************/
struct sk_buff *
hysdn_tx_netget(hysdn_card *card)
{
	struct net_local *lp = card->netif;

	if (!lp)
		return (NULL);	/* non existing device */

	if (!lp->sk_count)
		return (NULL);	/* nothing available */

	return (lp->skbs[lp->out_idx]);		/* next packet to send */
}				/* hysdn_tx_netget */

static const struct net_device_ops hysdn_netdev_ops = {
	.ndo_open		= net_open,
	.ndo_stop		= net_close,
	.ndo_start_xmit		= net_send_packet,
	.ndo_change_mtu		= eth_change_mtu,
	.ndo_set_mac_address	= eth_mac_addr,
	.ndo_validate_addr	= eth_validate_addr,
};


/*****************************************************************************/
/* hysdn_net_create creates a new net device for the given card. If a device */
/* already exists, it will be deleted and created a new one. The return value */
/* 0 announces success, else a negative error code will be returned.         */
/*****************************************************************************/
int
hysdn_net_create(hysdn_card *card)
{
	struct net_device *dev;
	int i;
	struct net_local *lp;

	if (!card) {
		printk(KERN_WARNING "No card-pt in hysdn_net_create!\n");
		return (-ENOMEM);
	}
	hysdn_net_release(card);	/* release an existing net device */

	dev = alloc_etherdev(sizeof(struct net_local));
	if (!dev) {
		printk(KERN_WARNING "HYSDN: unable to allocate mem\n");
		return (-ENOMEM);
	}

	lp = netdev_priv(dev);
	lp->dev = dev;

	dev->netdev_ops = &hysdn_netdev_ops;
	spin_lock_init(&((struct net_local *) dev)->lock);

	/* initialise necessary or informing fields */
	dev->base_addr = card->iobase;	/* IO address */
	dev->irq = card->irq;	/* irq */

	dev->netdev_ops = &hysdn_netdev_ops;
	if ((i = register_netdev(dev))) {
		printk(KERN_WARNING "HYSDN: unable to create network device\n");
		free_netdev(dev);
		return (i);
	}
	dev->ml_priv = card;	/* remember pointer to own data structure */
	card->netif = dev;	/* setup the local pointer */

	if (card->debug_flags & LOG_NET_INIT)
		hysdn_addlog(card, "network device created");
	return (0);		/* and return success */
}				/* hysdn_net_create */

/***************************************************************************/
/* hysdn_net_release deletes the net device for the given card. The return */
/* value 0 announces success, else a negative error code will be returned. */
/***************************************************************************/
int
hysdn_net_release(hysdn_card *card)
{
	struct net_device *dev = card->netif;

	if (!dev)
		return (0);	/* non existing */

	card->netif = NULL;	/* clear out pointer */
	net_close(dev);

	flush_tx_buffers((struct net_local *) dev);	/* empty buffers */

	unregister_netdev(dev);	/* release the device */
	free_netdev(dev);	/* release the memory allocated */
	if (card->debug_flags & LOG_NET_INIT)
		hysdn_addlog(card, "network device deleted");

	return (0);		/* always successful */
}				/* hysdn_net_release */

/*****************************************************************************/
/* hysdn_net_getname returns a pointer to the name of the network interface. */
/* if the interface is not existing, a "-" is returned.                      */
/*****************************************************************************/
char *
hysdn_net_getname(hysdn_card *card)
{
	struct net_device *dev = card->netif;

	if (!dev)
		return ("-");	/* non existing */

	return (dev->name);
}				/* hysdn_net_getname */
OpenPOWER on IntegriCloud