m68k/atari: ARAnyM - Add support for network access

[petr: Second author]
[michael, geert: Cleanups and updates]

Signed-off-by: Milan Jurik <milan.jurik@xylab.cz>
Signed-off-by: Petr Stehlik <pstehlik@sophics.cz>
Signed-off-by: Michael Schmitz <schmitz@debian.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: netdev@vger.kernel.org

arch/m68k/Kconfig

@@ -263,6 +263,14 @@ config NFCON
 	  which allows the console output to be redirected to the stderr
 	  output of ARAnyM.
 
+config NFETH
+	tristate "NatFeat Ethernet support"
+	depends on NET_ETHERNET && NATFEAT
+	help
+	  Say Y to include support for the ARAnyM NatFeat network device
+	  which will emulate a regular ethernet device while presenting an
+	  ethertap device to the host system.
+
 comment "Processor type"
 
 config M68020

arch/m68k/emu/Makefile

@@ -6,3 +6,4 @@ obj-y			+= natfeat.o
 
 obj-$(CONFIG_NFBLOCK)	+= nfblock.o
 obj-$(CONFIG_NFCON)	+= nfcon.o
+obj-$(CONFIG_NFETH)	+= nfeth.o

arch/m68k/emu/nfeth.c

@@ -0,0 +1,270 @@
+/*
+ * atari_nfeth.c - ARAnyM ethernet card driver for GNU/Linux
+ *
+ * Copyright (c) 2005 Milan Jurik, Petr Stehlik of ARAnyM dev team
+ *
+ * Based on ARAnyM driver for FreeMiNT written by Standa Opichal
+ *
+ * This software may be used and distributed according to the terms of
+ * the GNU General Public License (GPL), incorporated herein by reference.
+ */
+
+#define DRV_VERSION	"0.3"
+#define DRV_RELDATE	"10/12/2005"
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/module.h>
+#include <asm/natfeat.h>
+#include <asm/virtconvert.h>
+
+enum {
+	GET_VERSION = 0,/* no parameters, return NFAPI_VERSION in d0 */
+	XIF_INTLEVEL,	/* no parameters, return Interrupt Level in d0 */
+	XIF_IRQ,	/* acknowledge interrupt from host */
+	XIF_START,	/* (ethX), called on 'ifup', start receiver thread */
+	XIF_STOP,	/* (ethX), called on 'ifdown', stop the thread */
+	XIF_READLENGTH,	/* (ethX), return size of network data block to read */
+	XIF_READBLOCK,	/* (ethX, buffer, size), read block of network data */
+	XIF_WRITEBLOCK,	/* (ethX, buffer, size), write block of network data */
+	XIF_GET_MAC,	/* (ethX, buffer, size), return MAC HW addr in buffer */
+	XIF_GET_IPHOST,	/* (ethX, buffer, size), return IP address of host */
+	XIF_GET_IPATARI,/* (ethX, buffer, size), return IP address of atari */
+	XIF_GET_NETMASK	/* (ethX, buffer, size), return IP netmask */
+};
+
+#define MAX_UNIT	8
+
+/* These identify the driver base version and may not be removed. */
+static const char version[] __devinitdata =
+	KERN_INFO KBUILD_MODNAME ".c:v" DRV_VERSION " " DRV_RELDATE
+	" S.Opichal, M.Jurik, P.Stehlik\n"
+	KERN_INFO " http://aranym.org/\n";
+
+MODULE_AUTHOR("Milan Jurik");
+MODULE_DESCRIPTION("Atari NFeth driver");
+MODULE_LICENSE("GPL");
+/*
+MODULE_PARM(nfeth_debug, "i");
+MODULE_PARM_DESC(nfeth_debug, "nfeth_debug level (1-2)");
+*/
+
+
+static long nfEtherID;
+static int nfEtherIRQ;
+
+struct nfeth_private {
+	int ethX;
+};
+
+static struct net_device *nfeth_dev[MAX_UNIT];
+
+static int nfeth_open(struct net_device *dev)
+{
+	struct nfeth_private *priv = netdev_priv(dev);
+	int res;
+
+	res = nf_call(nfEtherID + XIF_START, priv->ethX);
+	netdev_dbg(dev, "%s: %d\n", __func__, res);
+
+	/* Ready for data */
+	netif_start_queue(dev);
+
+	return 0;
+}
+
+static int nfeth_stop(struct net_device *dev)
+{
+	struct nfeth_private *priv = netdev_priv(dev);
+
+	/* No more data */
+	netif_stop_queue(dev);
+
+	nf_call(nfEtherID + XIF_STOP, priv->ethX);
+
+	return 0;
+}
+
+/*
+ * Read a packet out of the adapter and pass it to the upper layers
+ */
+static inline void recv_packet(struct net_device *dev)
+{
+	struct nfeth_private *priv = netdev_priv(dev);
+	unsigned short pktlen;
+	struct sk_buff *skb;
+
+	/* read packet length (excluding 32 bit crc) */
+	pktlen = nf_call(nfEtherID + XIF_READLENGTH, priv->ethX);
+
+	netdev_dbg(dev, "%s: %u\n", __func__, pktlen);
+
+	if (!pktlen) {
+		netdev_dbg(dev, "%s: pktlen == 0\n", __func__);
+		dev->stats.rx_errors++;
+		return;
+	}
+
+	skb = dev_alloc_skb(pktlen + 2);
+	if (!skb) {
+		netdev_dbg(dev, "%s: out of mem (buf_alloc failed)\n",
+			   __func__);
+		dev->stats.rx_dropped++;
+		return;
+	}
+
+	skb->dev = dev;
+	skb_reserve(skb, 2);		/* 16 Byte align  */
+	skb_put(skb, pktlen);		/* make room */
+	nf_call(nfEtherID + XIF_READBLOCK, priv->ethX, virt_to_phys(skb->data),
+		pktlen);
+
+	skb->protocol = eth_type_trans(skb, dev);
+	netif_rx(skb);
+	dev->last_rx = jiffies;
+	dev->stats.rx_packets++;
+	dev->stats.rx_bytes += pktlen;
+
+	/* and enqueue packet */
+	return;
+}
+
+static irqreturn_t nfeth_interrupt(int irq, void *dev_id)
+{
+	int i, m, mask;
+
+	mask = nf_call(nfEtherID + XIF_IRQ, 0);
+	for (i = 0, m = 1; i < MAX_UNIT; m <<= 1, i++) {
+		if (mask & m && nfeth_dev[i]) {
+			recv_packet(nfeth_dev[i]);
+			nf_call(nfEtherID + XIF_IRQ, m);
+		}
+	}
+	return IRQ_HANDLED;
+}
+
+static int nfeth_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	unsigned int len;
+	char *data, shortpkt[ETH_ZLEN];
+	struct nfeth_private *priv = netdev_priv(dev);
+
+	data = skb->data;
+	len = skb->len;
+	if (len < ETH_ZLEN) {
+		memset(shortpkt, 0, ETH_ZLEN);
+		memcpy(shortpkt, data, len);
+		data = shortpkt;
+		len = ETH_ZLEN;
+	}
+
+	netdev_dbg(dev, "%s: send %u bytes\n", __func__, len);
+	nf_call(nfEtherID + XIF_WRITEBLOCK, priv->ethX, virt_to_phys(data),
+		len);
+
+	dev->stats.tx_packets++;
+	dev->stats.tx_bytes += len;
+
+	dev_kfree_skb(skb);
+	return 0;
+}
+
+static void nfeth_tx_timeout(struct net_device *dev)
+{
+	dev->stats.tx_errors++;
+	netif_wake_queue(dev);
+}
+
+static const struct net_device_ops nfeth_netdev_ops = {
+	.ndo_open		= nfeth_open,
+	.ndo_stop		= nfeth_stop,
+	.ndo_start_xmit		= nfeth_xmit,
+	.ndo_tx_timeout		= nfeth_tx_timeout,
+	.ndo_validate_addr	= eth_validate_addr,
+	.ndo_change_mtu		= eth_change_mtu,
+	.ndo_set_mac_address	= eth_mac_addr,
+};
+
+static struct net_device * __init nfeth_probe(int unit)
+{
+	struct net_device *dev;
+	struct nfeth_private *priv;
+	char mac[ETH_ALEN], host_ip[32], local_ip[32];
+	int err;
+
+	if (!nf_call(nfEtherID + XIF_GET_MAC, unit, mac, ETH_ALEN))
+		return NULL;
+
+	dev = alloc_etherdev(sizeof(struct nfeth_private));
+	if (!dev)
+		return NULL;
+
+	dev->irq = nfEtherIRQ;
+	dev->netdev_ops = &nfeth_netdev_ops;
+
+	dev->flags |= NETIF_F_NO_CSUM;
+	memcpy(dev->dev_addr, mac, ETH_ALEN);
+
+	priv = netdev_priv(dev);
+	priv->ethX = unit;
+
+	err = register_netdev(dev);
+	if (err) {
+		free_netdev(dev);
+		return NULL;
+	}
+
+	nf_call(nfEtherID + XIF_GET_IPHOST, unit,
+		host_ip, sizeof(host_ip));
+	nf_call(nfEtherID + XIF_GET_IPATARI, unit,
+		local_ip, sizeof(local_ip));
+
+	netdev_info(dev, KBUILD_MODNAME " addr:%s (%s) HWaddr:%pM\n", host_ip,
+		    local_ip, mac);
+
+	return dev;
+}
+
+static int __init nfeth_init(void)
+{
+	long ver;
+	int error, i;
+
+	nfEtherID = nf_get_id("ETHERNET");
+	if (!nfEtherID)
+		return -ENODEV;
+
+	ver = nf_call(nfEtherID + GET_VERSION);
+	pr_info("API %lu\n", ver);
+
+	nfEtherIRQ = nf_call(nfEtherID + XIF_INTLEVEL);
+	error = request_irq(nfEtherIRQ, nfeth_interrupt, IRQF_SHARED,
+			    "eth emu", nfeth_interrupt);
+	if (error) {
+		pr_err("request for irq %d failed %d", nfEtherIRQ, error);
+		return error;
+	}
+
+	for (i = 0; i < MAX_UNIT; i++)
+		nfeth_dev[i] = nfeth_probe(i);
+
+	return 0;
+}
+
+static void __exit nfeth_cleanup(void)
+{
+	int i;
+
+	for (i = 0; i < MAX_UNIT; i++) {
+		if (nfeth_dev[i]) {
+			unregister_netdev(nfeth_dev[0]);
+			free_netdev(nfeth_dev[0]);
+		}
+	}
+	free_irq(nfEtherIRQ, nfeth_interrupt);
+}
+
+module_init(nfeth_init);
+module_exit(nfeth_cleanup);