1/* $Id: hysdn_net.c,v 1.8.6.4 2001/09/23 22:24:54 kai 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#define MAX_SKB_BUFFERS 20	/* number of buffers for keeping TX-data */
30
31/****************************************************************************/
32/* structure containing the complete network data. The structure is aligned */
33/* in a way that both, the device and statistics are kept inside it.        */
34/* for proper access, the device structure MUST be the first var/struct     */
35/* inside the definition.                                                   */
36/****************************************************************************/
37struct net_local {
38	/* Tx control lock.  This protects the transmit buffer ring
39	 * state along with the "tx full" state of the driver.  This
40	 * means all netif_queue flow control actions are protected
41	 * by this lock as well.
42	 */
43	struct net_device *dev;
44	spinlock_t lock;
45	struct sk_buff *skbs[MAX_SKB_BUFFERS];	/* pointers to tx-skbs */
46	int in_idx, out_idx;	/* indexes to buffer ring */
47	int sk_count;		/* number of buffers currently in ring */
48};				/* net_local */
49
50
51
52/*********************************************************************/
53/* Open/initialize the board. This is called (in the current kernel) */
54/* sometime after booting when the 'ifconfig' program is run.        */
55/* This routine should set everything up anew at each open, even     */
56/* registers that "should" only need to be set once at boot, so that */
57/* there is non-reboot way to recover if something goes wrong.       */
58/*********************************************************************/
59static int
60net_open(struct net_device *dev)
61{
62	struct in_device *in_dev;
63	hysdn_card *card = dev->ml_priv;
64	int i;
65
66	netif_start_queue(dev);	/* start tx-queueing */
67
68	/* Fill in the MAC-level header (if not already set) */
69	if (!card->mac_addr[0]) {
70		for (i = 0; i < ETH_ALEN; i++)
71			dev->dev_addr[i] = 0xfc;
72		if ((in_dev = dev->ip_ptr) != NULL) {
73			struct in_ifaddr *ifa = in_dev->ifa_list;
74			if (ifa != NULL)
75				memcpy(dev->dev_addr + (ETH_ALEN - sizeof(ifa->ifa_local)), &ifa->ifa_local, sizeof(ifa->ifa_local));
76		}
77	} else
78		memcpy(dev->dev_addr, card->mac_addr, ETH_ALEN);
79
80	return (0);
81}				/* net_open */
82
83/*******************************************/
84/* flush the currently occupied tx-buffers */
85/* must only be called when device closed  */
86/*******************************************/
87static void
88flush_tx_buffers(struct net_local *nl)
89{
90
91	while (nl->sk_count) {
92		dev_kfree_skb(nl->skbs[nl->out_idx++]);		/* free skb */
93		if (nl->out_idx >= MAX_SKB_BUFFERS)
94			nl->out_idx = 0;	/* wrap around */
95		nl->sk_count--;
96	}
97}				/* flush_tx_buffers */
98
99
100/*********************************************************************/
101/* close/decativate the device. The device is not removed, but only  */
102/* deactivated.                                                      */
103/*********************************************************************/
104static int
105net_close(struct net_device *dev)
106{
107
108	netif_stop_queue(dev);	/* disable queueing */
109
110	flush_tx_buffers((struct net_local *) dev);
111
112	return (0);		/* success */
113}				/* net_close */
114
115/************************************/
116/* send a packet on this interface. */
117/* new style for kernel >= 2.3.33   */
118/************************************/
119static netdev_tx_t
120net_send_packet(struct sk_buff *skb, struct net_device *dev)
121{
122	struct net_local *lp = (struct net_local *) dev;
123
124	spin_lock_irq(&lp->lock);
125
126	lp->skbs[lp->in_idx++] = skb;	/* add to buffer list */
127	if (lp->in_idx >= MAX_SKB_BUFFERS)
128		lp->in_idx = 0;	/* wrap around */
129	lp->sk_count++;		/* adjust counter */
130	dev->trans_start = jiffies;
131
132	/* If we just used up the very last entry in the
133	 * TX ring on this device, tell the queueing
134	 * layer to send no more.
135	 */
136	if (lp->sk_count >= MAX_SKB_BUFFERS)
137		netif_stop_queue(dev);
138
139	/* When the TX completion hw interrupt arrives, this
140	 * is when the transmit statistics are updated.
141	 */
142
143	spin_unlock_irq(&lp->lock);
144
145	if (lp->sk_count <= 3) {
146		schedule_work(&((hysdn_card *) dev->ml_priv)->irq_queue);
147	}
148	return NETDEV_TX_OK;	/* success */
149}				/* net_send_packet */
150
151
152
153/***********************************************************************/
154/* acknowlegde a packet send. The network layer will be informed about */
155/* completion                                                          */
156/***********************************************************************/
157void
158hysdn_tx_netack(hysdn_card *card)
159{
160	struct net_local *lp = card->netif;
161
162	if (!lp)
163		return;		/* non existing device */
164
165
166	if (!lp->sk_count)
167		return;		/* error condition */
168
169	lp->dev->stats.tx_packets++;
170	lp->dev->stats.tx_bytes += lp->skbs[lp->out_idx]->len;
171
172	dev_kfree_skb(lp->skbs[lp->out_idx++]);		/* free skb */
173	if (lp->out_idx >= MAX_SKB_BUFFERS)
174		lp->out_idx = 0;	/* wrap around */
175
176	if (lp->sk_count-- == MAX_SKB_BUFFERS)	/* dec usage count */
177		netif_start_queue((struct net_device *) lp);
178}				/* hysdn_tx_netack */
179
180/*****************************************************/
181/* we got a packet from the network, go and queue it */
182/*****************************************************/
183void
184hysdn_rx_netpkt(hysdn_card *card, unsigned char *buf, unsigned short len)
185{
186	struct net_local *lp = card->netif;
187	struct net_device *dev;
188	struct sk_buff *skb;
189
190	if (!lp)
191		return;		/* non existing device */
192
193	dev = lp->dev;
194	dev->stats.rx_bytes += len;
195
196	skb = dev_alloc_skb(len);
197	if (skb == NULL) {
198		printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n",
199		       dev->name);
200		dev->stats.rx_dropped++;
201		return;
202	}
203	/* copy the data */
204	memcpy(skb_put(skb, len), buf, len);
205
206	/* determine the used protocol */
207	skb->protocol = eth_type_trans(skb, dev);
208
209	dev->stats.rx_packets++;	/* adjust packet count */
210
211	netif_rx(skb);
212}				/* hysdn_rx_netpkt */
213
214/*****************************************************/
215/* return the pointer to a network packet to be send */
216/*****************************************************/
217struct sk_buff *
218hysdn_tx_netget(hysdn_card *card)
219{
220	struct net_local *lp = card->netif;
221
222	if (!lp)
223		return (NULL);	/* non existing device */
224
225	if (!lp->sk_count)
226		return (NULL);	/* nothing available */
227
228	return (lp->skbs[lp->out_idx]);		/* next packet to send */
229}				/* hysdn_tx_netget */
230
231static const struct net_device_ops hysdn_netdev_ops = {
232	.ndo_open		= net_open,
233	.ndo_stop		= net_close,
234	.ndo_start_xmit		= net_send_packet,
235	.ndo_change_mtu		= eth_change_mtu,
236	.ndo_set_mac_address	= eth_mac_addr,
237	.ndo_validate_addr	= eth_validate_addr,
238};
239
240
241/*****************************************************************************/
242/* hysdn_net_create creates a new net device for the given card. If a device */
243/* already exists, it will be deleted and created a new one. The return value */
244/* 0 announces success, else a negative error code will be returned.         */
245/*****************************************************************************/
246int
247hysdn_net_create(hysdn_card *card)
248{
249	struct net_device *dev;
250	int i;
251	struct net_local *lp;
252
253	if (!card) {
254		printk(KERN_WARNING "No card-pt in hysdn_net_create!\n");
255		return (-ENOMEM);
256	}
257	hysdn_net_release(card);	/* release an existing net device */
258
259	dev = alloc_etherdev(sizeof(struct net_local));
260	if (!dev) {
261		printk(KERN_WARNING "HYSDN: unable to allocate mem\n");
262		return (-ENOMEM);
263	}
264
265	lp = netdev_priv(dev);
266	lp->dev = dev;
267
268	dev->netdev_ops = &hysdn_netdev_ops;
269	spin_lock_init(&((struct net_local *) dev)->lock);
270
271	/* initialise necessary or informing fields */
272	dev->base_addr = card->iobase;	/* IO address */
273	dev->irq = card->irq;	/* irq */
274
275	dev->netdev_ops = &hysdn_netdev_ops;
276	if ((i = register_netdev(dev))) {
277		printk(KERN_WARNING "HYSDN: unable to create network device\n");
278		free_netdev(dev);
279		return (i);
280	}
281	dev->ml_priv = card;	/* remember pointer to own data structure */
282	card->netif = dev;	/* setup the local pointer */
283
284	if (card->debug_flags & LOG_NET_INIT)
285		hysdn_addlog(card, "network device created");
286	return (0);		/* and return success */
287}				/* hysdn_net_create */
288
289/***************************************************************************/
290/* hysdn_net_release deletes the net device for the given card. The return */
291/* value 0 announces success, else a negative error code will be returned. */
292/***************************************************************************/
293int
294hysdn_net_release(hysdn_card *card)
295{
296	struct net_device *dev = card->netif;
297
298	if (!dev)
299		return (0);	/* non existing */
300
301	card->netif = NULL;	/* clear out pointer */
302	net_close(dev);
303
304	flush_tx_buffers((struct net_local *) dev);	/* empty buffers */
305
306	unregister_netdev(dev);	/* release the device */
307	free_netdev(dev);	/* release the memory allocated */
308	if (card->debug_flags & LOG_NET_INIT)
309		hysdn_addlog(card, "network device deleted");
310
311	return (0);		/* always successful */
312}				/* hysdn_net_release */
313
314/*****************************************************************************/
315/* hysdn_net_getname returns a pointer to the name of the network interface. */
316/* if the interface is not existing, a "-" is returned.                      */
317/*****************************************************************************/
318char *
319hysdn_net_getname(hysdn_card *card)
320{
321	struct net_device *dev = card->netif;
322
323	if (!dev)
324		return ("-");	/* non existing */
325
326	return (dev->name);
327}				/* hysdn_net_getname */
328