1/*
2 * meth.c -- O2 Builtin 10/100 Ethernet driver
3 *
4 * Copyright (C) 2001-2003 Ilya Volynets
5 *
6 *	This program is free software; you can redistribute it and/or
7 *	modify it under the terms of the GNU General Public License
8 *	as published by the Free Software Foundation; either version
9 *	2 of the License, or (at your option) any later version.
10 */
11#include <linux/delay.h>
12#include <linux/dma-mapping.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/platform_device.h>
16#include <linux/slab.h>
17#include <linux/errno.h>
18#include <linux/types.h>
19#include <linux/interrupt.h>
20
21#include <linux/in.h>
22#include <linux/in6.h>
23#include <linux/device.h> /* struct device, et al */
24#include <linux/netdevice.h>   /* struct device, and other headers */
25#include <linux/etherdevice.h> /* eth_type_trans */
26#include <linux/ip.h>          /* struct iphdr */
27#include <linux/tcp.h>         /* struct tcphdr */
28#include <linux/skbuff.h>
29#include <linux/mii.h>         /* MII definitions */
30#include <linux/crc32.h>
31
32#include <asm/ip32/mace.h>
33#include <asm/ip32/ip32_ints.h>
34
35#include <asm/io.h>
36
37#include "meth.h"
38
39#ifndef MFE_DEBUG
40#define MFE_DEBUG 0
41#endif
42
43#if MFE_DEBUG>=1
44#define DPRINTK(str,args...) printk(KERN_DEBUG "meth: %s: " str, __func__ , ## args)
45#define MFE_RX_DEBUG 2
46#else
47#define DPRINTK(str,args...)
48#define MFE_RX_DEBUG 0
49#endif
50
51
52static const char *meth_str="SGI O2 Fast Ethernet";
53
54/* The maximum time waited (in jiffies) before assuming a Tx failed. (400ms) */
55#define TX_TIMEOUT (400*HZ/1000)
56
57static int timeout = TX_TIMEOUT;
58module_param(timeout, int, 0);
59
60/*
61 * Maximum number of multicast addresses to filter (vs. Rx-all-multicast).
62 * MACE Ethernet uses a 64 element hash table based on the Ethernet CRC.
63 */
64#define METH_MCF_LIMIT 32
65
66/*
67 * This structure is private to each device. It is used to pass
68 * packets in and out, so there is place for a packet
69 */
70struct meth_private {
71	/* in-memory copy of MAC Control register */
72	u64 mac_ctrl;
73
74	/* in-memory copy of DMA Control register */
75	unsigned long dma_ctrl;
76	/* address of PHY, used by mdio_* functions, initialized in mdio_probe */
77	unsigned long phy_addr;
78	tx_packet *tx_ring;
79	dma_addr_t tx_ring_dma;
80	struct sk_buff *tx_skbs[TX_RING_ENTRIES];
81	dma_addr_t tx_skb_dmas[TX_RING_ENTRIES];
82	unsigned long tx_read, tx_write, tx_count;
83
84	rx_packet *rx_ring[RX_RING_ENTRIES];
85	dma_addr_t rx_ring_dmas[RX_RING_ENTRIES];
86	struct sk_buff *rx_skbs[RX_RING_ENTRIES];
87	unsigned long rx_write;
88
89	/* Multicast filter. */
90	u64 mcast_filter;
91
92	spinlock_t meth_lock;
93};
94
95static void meth_tx_timeout(struct net_device *dev);
96static irqreturn_t meth_interrupt(int irq, void *dev_id);
97
98/* global, initialized in ip32-setup.c */
99char o2meth_eaddr[8]={0,0,0,0,0,0,0,0};
100
101static inline void load_eaddr(struct net_device *dev)
102{
103	int i;
104	u64 macaddr;
105
106	DPRINTK("Loading MAC Address: %pM\n", dev->dev_addr);
107	macaddr = 0;
108	for (i = 0; i < 6; i++)
109		macaddr |= (u64)dev->dev_addr[i] << ((5 - i) * 8);
110
111	mace->eth.mac_addr = macaddr;
112}
113
114/*
115 * Waits for BUSY status of mdio bus to clear
116 */
117#define WAIT_FOR_PHY(___rval)					\
118	while ((___rval = mace->eth.phy_data) & MDIO_BUSY) {	\
119		udelay(25);					\
120	}
121/*read phy register, return value read */
122static unsigned long mdio_read(struct meth_private *priv, unsigned long phyreg)
123{
124	unsigned long rval;
125	WAIT_FOR_PHY(rval);
126	mace->eth.phy_regs = (priv->phy_addr << 5) | (phyreg & 0x1f);
127	udelay(25);
128	mace->eth.phy_trans_go = 1;
129	udelay(25);
130	WAIT_FOR_PHY(rval);
131	return rval & MDIO_DATA_MASK;
132}
133
134static int mdio_probe(struct meth_private *priv)
135{
136	int i;
137	unsigned long p2, p3, flags;
138	/* check if phy is detected already */
139	if(priv->phy_addr>=0&&priv->phy_addr<32)
140		return 0;
141	spin_lock_irqsave(&priv->meth_lock, flags);
142	for (i=0;i<32;++i){
143		priv->phy_addr=i;
144		p2=mdio_read(priv,2);
145		p3=mdio_read(priv,3);
146#if MFE_DEBUG>=2
147		switch ((p2<<12)|(p3>>4)){
148		case PHY_QS6612X:
149			DPRINTK("PHY is QS6612X\n");
150			break;
151		case PHY_ICS1889:
152			DPRINTK("PHY is ICS1889\n");
153			break;
154		case PHY_ICS1890:
155			DPRINTK("PHY is ICS1890\n");
156			break;
157		case PHY_DP83840:
158			DPRINTK("PHY is DP83840\n");
159			break;
160		}
161#endif
162		if(p2!=0xffff&&p2!=0x0000){
163			DPRINTK("PHY code: %x\n",(p2<<12)|(p3>>4));
164			break;
165		}
166	}
167	spin_unlock_irqrestore(&priv->meth_lock, flags);
168	if(priv->phy_addr<32) {
169		return 0;
170	}
171	DPRINTK("Oopsie! PHY is not known!\n");
172	priv->phy_addr=-1;
173	return -ENODEV;
174}
175
176static void meth_check_link(struct net_device *dev)
177{
178	struct meth_private *priv = netdev_priv(dev);
179	unsigned long mii_advertising = mdio_read(priv, 4);
180	unsigned long mii_partner = mdio_read(priv, 5);
181	unsigned long negotiated = mii_advertising & mii_partner;
182	unsigned long duplex, speed;
183
184	if (mii_partner == 0xffff)
185		return;
186
187	speed = (negotiated & 0x0380) ? METH_100MBIT : 0;
188	duplex = ((negotiated & 0x0100) || (negotiated & 0x01C0) == 0x0040) ?
189		 METH_PHY_FDX : 0;
190
191	if ((priv->mac_ctrl & METH_PHY_FDX) ^ duplex) {
192		DPRINTK("Setting %s-duplex\n", duplex ? "full" : "half");
193		if (duplex)
194			priv->mac_ctrl |= METH_PHY_FDX;
195		else
196			priv->mac_ctrl &= ~METH_PHY_FDX;
197		mace->eth.mac_ctrl = priv->mac_ctrl;
198	}
199
200	if ((priv->mac_ctrl & METH_100MBIT) ^ speed) {
201		DPRINTK("Setting %dMbs mode\n", speed ? 100 : 10);
202		if (duplex)
203			priv->mac_ctrl |= METH_100MBIT;
204		else
205			priv->mac_ctrl &= ~METH_100MBIT;
206		mace->eth.mac_ctrl = priv->mac_ctrl;
207	}
208}
209
210
211static int meth_init_tx_ring(struct meth_private *priv)
212{
213	/* Init TX ring */
214	priv->tx_ring = dma_zalloc_coherent(NULL, TX_RING_BUFFER_SIZE,
215					    &priv->tx_ring_dma, GFP_ATOMIC);
216	if (!priv->tx_ring)
217		return -ENOMEM;
218
219	priv->tx_count = priv->tx_read = priv->tx_write = 0;
220	mace->eth.tx_ring_base = priv->tx_ring_dma;
221	/* Now init skb save area */
222	memset(priv->tx_skbs, 0, sizeof(priv->tx_skbs));
223	memset(priv->tx_skb_dmas, 0, sizeof(priv->tx_skb_dmas));
224	return 0;
225}
226
227static int meth_init_rx_ring(struct meth_private *priv)
228{
229	int i;
230
231	for (i = 0; i < RX_RING_ENTRIES; i++) {
232		priv->rx_skbs[i] = alloc_skb(METH_RX_BUFF_SIZE, 0);
233		/* 8byte status vector + 3quad padding + 2byte padding,
234		 * to put data on 64bit aligned boundary */
235		skb_reserve(priv->rx_skbs[i],METH_RX_HEAD);
236		priv->rx_ring[i]=(rx_packet*)(priv->rx_skbs[i]->head);
237		/* I'll need to re-sync it after each RX */
238		priv->rx_ring_dmas[i] =
239			dma_map_single(NULL, priv->rx_ring[i],
240				       METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
241		mace->eth.rx_fifo = priv->rx_ring_dmas[i];
242	}
243        priv->rx_write = 0;
244	return 0;
245}
246static void meth_free_tx_ring(struct meth_private *priv)
247{
248	int i;
249
250	/* Remove any pending skb */
251	for (i = 0; i < TX_RING_ENTRIES; i++) {
252		if (priv->tx_skbs[i])
253			dev_kfree_skb(priv->tx_skbs[i]);
254		priv->tx_skbs[i] = NULL;
255	}
256	dma_free_coherent(NULL, TX_RING_BUFFER_SIZE, priv->tx_ring,
257	                  priv->tx_ring_dma);
258}
259
260/* Presumes RX DMA engine is stopped, and RX fifo ring is reset */
261static void meth_free_rx_ring(struct meth_private *priv)
262{
263	int i;
264
265	for (i = 0; i < RX_RING_ENTRIES; i++) {
266		dma_unmap_single(NULL, priv->rx_ring_dmas[i],
267				 METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
268		priv->rx_ring[i] = 0;
269		priv->rx_ring_dmas[i] = 0;
270		kfree_skb(priv->rx_skbs[i]);
271	}
272}
273
274int meth_reset(struct net_device *dev)
275{
276	struct meth_private *priv = netdev_priv(dev);
277
278	/* Reset card */
279	mace->eth.mac_ctrl = SGI_MAC_RESET;
280	udelay(1);
281	mace->eth.mac_ctrl = 0;
282	udelay(25);
283
284	/* Load ethernet address */
285	load_eaddr(dev);
286	/* Should load some "errata", but later */
287
288	/* Check for device */
289	if (mdio_probe(priv) < 0) {
290		DPRINTK("Unable to find PHY\n");
291		return -ENODEV;
292	}
293
294	/* Initial mode: 10 | Half-duplex | Accept normal packets */
295	priv->mac_ctrl = METH_ACCEPT_MCAST | METH_DEFAULT_IPG;
296	if (dev->flags & IFF_PROMISC)
297		priv->mac_ctrl |= METH_PROMISC;
298	mace->eth.mac_ctrl = priv->mac_ctrl;
299
300	/* Autonegotiate speed and duplex mode */
301	meth_check_link(dev);
302
303	/* Now set dma control, but don't enable DMA, yet */
304	priv->dma_ctrl = (4 << METH_RX_OFFSET_SHIFT) |
305			 (RX_RING_ENTRIES << METH_RX_DEPTH_SHIFT);
306	mace->eth.dma_ctrl = priv->dma_ctrl;
307
308	return 0;
309}
310
311/*============End Helper Routines=====================*/
312
313/*
314 * Open and close
315 */
316static int meth_open(struct net_device *dev)
317{
318	struct meth_private *priv = netdev_priv(dev);
319	int ret;
320
321	priv->phy_addr = -1;    /* No PHY is known yet... */
322
323	/* Initialize the hardware */
324	ret = meth_reset(dev);
325	if (ret < 0)
326		return ret;
327
328	/* Allocate the ring buffers */
329	ret = meth_init_tx_ring(priv);
330	if (ret < 0)
331		return ret;
332	ret = meth_init_rx_ring(priv);
333	if (ret < 0)
334		goto out_free_tx_ring;
335
336	ret = request_irq(dev->irq, meth_interrupt, 0, meth_str, dev);
337	if (ret) {
338		printk(KERN_ERR "%s: Can't get irq %d\n", dev->name, dev->irq);
339		goto out_free_rx_ring;
340	}
341
342	/* Start DMA */
343	priv->dma_ctrl |= METH_DMA_TX_EN | /*METH_DMA_TX_INT_EN |*/
344			  METH_DMA_RX_EN | METH_DMA_RX_INT_EN;
345	mace->eth.dma_ctrl = priv->dma_ctrl;
346
347	DPRINTK("About to start queue\n");
348	netif_start_queue(dev);
349
350	return 0;
351
352out_free_rx_ring:
353	meth_free_rx_ring(priv);
354out_free_tx_ring:
355	meth_free_tx_ring(priv);
356
357	return ret;
358}
359
360static int meth_release(struct net_device *dev)
361{
362	struct meth_private *priv = netdev_priv(dev);
363
364	DPRINTK("Stopping queue\n");
365	netif_stop_queue(dev); /* can't transmit any more */
366	/* shut down DMA */
367	priv->dma_ctrl &= ~(METH_DMA_TX_EN | METH_DMA_TX_INT_EN |
368			    METH_DMA_RX_EN | METH_DMA_RX_INT_EN);
369	mace->eth.dma_ctrl = priv->dma_ctrl;
370	free_irq(dev->irq, dev);
371	meth_free_tx_ring(priv);
372	meth_free_rx_ring(priv);
373
374	return 0;
375}
376
377/*
378 * Receive a packet: retrieve, encapsulate and pass over to upper levels
379 */
380static void meth_rx(struct net_device* dev, unsigned long int_status)
381{
382	struct sk_buff *skb;
383	unsigned long status, flags;
384	struct meth_private *priv = netdev_priv(dev);
385	unsigned long fifo_rptr = (int_status & METH_INT_RX_RPTR_MASK) >> 8;
386
387	spin_lock_irqsave(&priv->meth_lock, flags);
388	priv->dma_ctrl &= ~METH_DMA_RX_INT_EN;
389	mace->eth.dma_ctrl = priv->dma_ctrl;
390	spin_unlock_irqrestore(&priv->meth_lock, flags);
391
392	if (int_status & METH_INT_RX_UNDERFLOW) {
393		fifo_rptr = (fifo_rptr - 1) & 0x0f;
394	}
395	while (priv->rx_write != fifo_rptr) {
396		dma_unmap_single(NULL, priv->rx_ring_dmas[priv->rx_write],
397				 METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
398		status = priv->rx_ring[priv->rx_write]->status.raw;
399#if MFE_DEBUG
400		if (!(status & METH_RX_ST_VALID)) {
401			DPRINTK("Not received? status=%016lx\n",status);
402		}
403#endif
404		if ((!(status & METH_RX_STATUS_ERRORS)) && (status & METH_RX_ST_VALID)) {
405			int len = (status & 0xffff) - 4; /* omit CRC */
406			/* length sanity check */
407			if (len < 60 || len > 1518) {
408				printk(KERN_DEBUG "%s: bogus packet size: %ld, status=%#2Lx.\n",
409				       dev->name, priv->rx_write,
410				       priv->rx_ring[priv->rx_write]->status.raw);
411				dev->stats.rx_errors++;
412				dev->stats.rx_length_errors++;
413				skb = priv->rx_skbs[priv->rx_write];
414			} else {
415				skb = alloc_skb(METH_RX_BUFF_SIZE, GFP_ATOMIC);
416				if (!skb) {
417					/* Ouch! No memory! Drop packet on the floor */
418					DPRINTK("No mem: dropping packet\n");
419					dev->stats.rx_dropped++;
420					skb = priv->rx_skbs[priv->rx_write];
421				} else {
422					struct sk_buff *skb_c = priv->rx_skbs[priv->rx_write];
423					/* 8byte status vector + 3quad padding + 2byte padding,
424					 * to put data on 64bit aligned boundary */
425					skb_reserve(skb, METH_RX_HEAD);
426					/* Write metadata, and then pass to the receive level */
427					skb_put(skb_c, len);
428					priv->rx_skbs[priv->rx_write] = skb;
429					skb_c->protocol = eth_type_trans(skb_c, dev);
430					dev->stats.rx_packets++;
431					dev->stats.rx_bytes += len;
432					netif_rx(skb_c);
433				}
434			}
435		} else {
436			dev->stats.rx_errors++;
437			skb=priv->rx_skbs[priv->rx_write];
438#if MFE_DEBUG>0
439			printk(KERN_WARNING "meth: RX error: status=0x%016lx\n",status);
440			if(status&METH_RX_ST_RCV_CODE_VIOLATION)
441				printk(KERN_WARNING "Receive Code Violation\n");
442			if(status&METH_RX_ST_CRC_ERR)
443				printk(KERN_WARNING "CRC error\n");
444			if(status&METH_RX_ST_INV_PREAMBLE_CTX)
445				printk(KERN_WARNING "Invalid Preamble Context\n");
446			if(status&METH_RX_ST_LONG_EVT_SEEN)
447				printk(KERN_WARNING "Long Event Seen...\n");
448			if(status&METH_RX_ST_BAD_PACKET)
449				printk(KERN_WARNING "Bad Packet\n");
450			if(status&METH_RX_ST_CARRIER_EVT_SEEN)
451				printk(KERN_WARNING "Carrier Event Seen\n");
452#endif
453		}
454		priv->rx_ring[priv->rx_write] = (rx_packet*)skb->head;
455		priv->rx_ring[priv->rx_write]->status.raw = 0;
456		priv->rx_ring_dmas[priv->rx_write] =
457			dma_map_single(NULL, priv->rx_ring[priv->rx_write],
458				       METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
459		mace->eth.rx_fifo = priv->rx_ring_dmas[priv->rx_write];
460		ADVANCE_RX_PTR(priv->rx_write);
461	}
462	spin_lock_irqsave(&priv->meth_lock, flags);
463	/* In case there was underflow, and Rx DMA was disabled */
464	priv->dma_ctrl |= METH_DMA_RX_INT_EN | METH_DMA_RX_EN;
465	mace->eth.dma_ctrl = priv->dma_ctrl;
466	mace->eth.int_stat = METH_INT_RX_THRESHOLD;
467	spin_unlock_irqrestore(&priv->meth_lock, flags);
468}
469
470static int meth_tx_full(struct net_device *dev)
471{
472	struct meth_private *priv = netdev_priv(dev);
473
474	return priv->tx_count >= TX_RING_ENTRIES - 1;
475}
476
477static void meth_tx_cleanup(struct net_device* dev, unsigned long int_status)
478{
479	struct meth_private *priv = netdev_priv(dev);
480	unsigned long status, flags;
481	struct sk_buff *skb;
482	unsigned long rptr = (int_status&TX_INFO_RPTR) >> 16;
483
484	spin_lock_irqsave(&priv->meth_lock, flags);
485
486	/* Stop DMA notification */
487	priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
488	mace->eth.dma_ctrl = priv->dma_ctrl;
489
490	while (priv->tx_read != rptr) {
491		skb = priv->tx_skbs[priv->tx_read];
492		status = priv->tx_ring[priv->tx_read].header.raw;
493#if MFE_DEBUG>=1
494		if (priv->tx_read == priv->tx_write)
495			DPRINTK("Auchi! tx_read=%d,tx_write=%d,rptr=%d?\n", priv->tx_read, priv->tx_write,rptr);
496#endif
497		if (status & METH_TX_ST_DONE) {
498			if (status & METH_TX_ST_SUCCESS){
499				dev->stats.tx_packets++;
500				dev->stats.tx_bytes += skb->len;
501			} else {
502				dev->stats.tx_errors++;
503#if MFE_DEBUG>=1
504				DPRINTK("TX error: status=%016lx <",status);
505				if(status & METH_TX_ST_SUCCESS)
506					printk(" SUCCESS");
507				if(status & METH_TX_ST_TOOLONG)
508					printk(" TOOLONG");
509				if(status & METH_TX_ST_UNDERRUN)
510					printk(" UNDERRUN");
511				if(status & METH_TX_ST_EXCCOLL)
512					printk(" EXCCOLL");
513				if(status & METH_TX_ST_DEFER)
514					printk(" DEFER");
515				if(status & METH_TX_ST_LATECOLL)
516					printk(" LATECOLL");
517				printk(" >\n");
518#endif
519			}
520		} else {
521			DPRINTK("RPTR points us here, but packet not done?\n");
522			break;
523		}
524		dev_kfree_skb_irq(skb);
525		priv->tx_skbs[priv->tx_read] = NULL;
526		priv->tx_ring[priv->tx_read].header.raw = 0;
527		priv->tx_read = (priv->tx_read+1)&(TX_RING_ENTRIES-1);
528		priv->tx_count--;
529	}
530
531	/* wake up queue if it was stopped */
532	if (netif_queue_stopped(dev) && !meth_tx_full(dev)) {
533		netif_wake_queue(dev);
534	}
535
536	mace->eth.int_stat = METH_INT_TX_EMPTY | METH_INT_TX_PKT;
537	spin_unlock_irqrestore(&priv->meth_lock, flags);
538}
539
540static void meth_error(struct net_device* dev, unsigned status)
541{
542	struct meth_private *priv = netdev_priv(dev);
543	unsigned long flags;
544
545	printk(KERN_WARNING "meth: error status: 0x%08x\n",status);
546	/* check for errors too... */
547	if (status & (METH_INT_TX_LINK_FAIL))
548		printk(KERN_WARNING "meth: link failure\n");
549	/* Should I do full reset in this case? */
550	if (status & (METH_INT_MEM_ERROR))
551		printk(KERN_WARNING "meth: memory error\n");
552	if (status & (METH_INT_TX_ABORT))
553		printk(KERN_WARNING "meth: aborted\n");
554	if (status & (METH_INT_RX_OVERFLOW))
555		printk(KERN_WARNING "meth: Rx overflow\n");
556	if (status & (METH_INT_RX_UNDERFLOW)) {
557		printk(KERN_WARNING "meth: Rx underflow\n");
558		spin_lock_irqsave(&priv->meth_lock, flags);
559		mace->eth.int_stat = METH_INT_RX_UNDERFLOW;
560		/* more underflow interrupts will be delivered,
561		 * effectively throwing us into an infinite loop.
562		 *  Thus I stop processing Rx in this case. */
563		priv->dma_ctrl &= ~METH_DMA_RX_EN;
564		mace->eth.dma_ctrl = priv->dma_ctrl;
565		DPRINTK("Disabled meth Rx DMA temporarily\n");
566		spin_unlock_irqrestore(&priv->meth_lock, flags);
567	}
568	mace->eth.int_stat = METH_INT_ERROR;
569}
570
571/*
572 * The typical interrupt entry point
573 */
574static irqreturn_t meth_interrupt(int irq, void *dev_id)
575{
576	struct net_device *dev = (struct net_device *)dev_id;
577	struct meth_private *priv = netdev_priv(dev);
578	unsigned long status;
579
580	status = mace->eth.int_stat;
581	while (status & 0xff) {
582		/* First handle errors - if we get Rx underflow,
583		 * Rx DMA will be disabled, and Rx handler will reenable
584		 * it. I don't think it's possible to get Rx underflow,
585		 * without getting Rx interrupt */
586		if (status & METH_INT_ERROR) {
587			meth_error(dev, status);
588		}
589		if (status & (METH_INT_TX_EMPTY | METH_INT_TX_PKT)) {
590			/* a transmission is over: free the skb */
591			meth_tx_cleanup(dev, status);
592		}
593		if (status & METH_INT_RX_THRESHOLD) {
594			if (!(priv->dma_ctrl & METH_DMA_RX_INT_EN))
595				break;
596			/* send it to meth_rx for handling */
597			meth_rx(dev, status);
598		}
599		status = mace->eth.int_stat;
600	}
601
602	return IRQ_HANDLED;
603}
604
605/*
606 * Transmits packets that fit into TX descriptor (are <=120B)
607 */
608static void meth_tx_short_prepare(struct meth_private *priv,
609				  struct sk_buff *skb)
610{
611	tx_packet *desc = &priv->tx_ring[priv->tx_write];
612	int len = (skb->len < ETH_ZLEN) ? ETH_ZLEN : skb->len;
613
614	desc->header.raw = METH_TX_CMD_INT_EN | (len-1) | ((128-len) << 16);
615	/* maybe I should set whole thing to 0 first... */
616	skb_copy_from_linear_data(skb, desc->data.dt + (120 - len), skb->len);
617	if (skb->len < len)
618		memset(desc->data.dt + 120 - len + skb->len, 0, len-skb->len);
619}
620#define TX_CATBUF1 BIT(25)
621static void meth_tx_1page_prepare(struct meth_private *priv,
622				  struct sk_buff *skb)
623{
624	tx_packet *desc = &priv->tx_ring[priv->tx_write];
625	void *buffer_data = (void *)(((unsigned long)skb->data + 7) & ~7);
626	int unaligned_len = (int)((unsigned long)buffer_data - (unsigned long)skb->data);
627	int buffer_len = skb->len - unaligned_len;
628	dma_addr_t catbuf;
629
630	desc->header.raw = METH_TX_CMD_INT_EN | TX_CATBUF1 | (skb->len - 1);
631
632	/* unaligned part */
633	if (unaligned_len) {
634		skb_copy_from_linear_data(skb, desc->data.dt + (120 - unaligned_len),
635			      unaligned_len);
636		desc->header.raw |= (128 - unaligned_len) << 16;
637	}
638
639	/* first page */
640	catbuf = dma_map_single(NULL, buffer_data, buffer_len,
641				DMA_TO_DEVICE);
642	desc->data.cat_buf[0].form.start_addr = catbuf >> 3;
643	desc->data.cat_buf[0].form.len = buffer_len - 1;
644}
645#define TX_CATBUF2 BIT(26)
646static void meth_tx_2page_prepare(struct meth_private *priv,
647				  struct sk_buff *skb)
648{
649	tx_packet *desc = &priv->tx_ring[priv->tx_write];
650	void *buffer1_data = (void *)(((unsigned long)skb->data + 7) & ~7);
651	void *buffer2_data = (void *)PAGE_ALIGN((unsigned long)skb->data);
652	int unaligned_len = (int)((unsigned long)buffer1_data - (unsigned long)skb->data);
653	int buffer1_len = (int)((unsigned long)buffer2_data - (unsigned long)buffer1_data);
654	int buffer2_len = skb->len - buffer1_len - unaligned_len;
655	dma_addr_t catbuf1, catbuf2;
656
657	desc->header.raw = METH_TX_CMD_INT_EN | TX_CATBUF1 | TX_CATBUF2| (skb->len - 1);
658	/* unaligned part */
659	if (unaligned_len){
660		skb_copy_from_linear_data(skb, desc->data.dt + (120 - unaligned_len),
661			      unaligned_len);
662		desc->header.raw |= (128 - unaligned_len) << 16;
663	}
664
665	/* first page */
666	catbuf1 = dma_map_single(NULL, buffer1_data, buffer1_len,
667				 DMA_TO_DEVICE);
668	desc->data.cat_buf[0].form.start_addr = catbuf1 >> 3;
669	desc->data.cat_buf[0].form.len = buffer1_len - 1;
670	/* second page */
671	catbuf2 = dma_map_single(NULL, buffer2_data, buffer2_len,
672				 DMA_TO_DEVICE);
673	desc->data.cat_buf[1].form.start_addr = catbuf2 >> 3;
674	desc->data.cat_buf[1].form.len = buffer2_len - 1;
675}
676
677static void meth_add_to_tx_ring(struct meth_private *priv, struct sk_buff *skb)
678{
679	/* Remember the skb, so we can free it at interrupt time */
680	priv->tx_skbs[priv->tx_write] = skb;
681	if (skb->len <= 120) {
682		/* Whole packet fits into descriptor */
683		meth_tx_short_prepare(priv, skb);
684	} else if (PAGE_ALIGN((unsigned long)skb->data) !=
685		   PAGE_ALIGN((unsigned long)skb->data + skb->len - 1)) {
686		/* Packet crosses page boundary */
687		meth_tx_2page_prepare(priv, skb);
688	} else {
689		/* Packet is in one page */
690		meth_tx_1page_prepare(priv, skb);
691	}
692	priv->tx_write = (priv->tx_write + 1) & (TX_RING_ENTRIES - 1);
693	mace->eth.tx_info = priv->tx_write;
694	priv->tx_count++;
695}
696
697/*
698 * Transmit a packet (called by the kernel)
699 */
700static int meth_tx(struct sk_buff *skb, struct net_device *dev)
701{
702	struct meth_private *priv = netdev_priv(dev);
703	unsigned long flags;
704
705	spin_lock_irqsave(&priv->meth_lock, flags);
706	/* Stop DMA notification */
707	priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
708	mace->eth.dma_ctrl = priv->dma_ctrl;
709
710	meth_add_to_tx_ring(priv, skb);
711	dev->trans_start = jiffies; /* save the timestamp */
712
713	/* If TX ring is full, tell the upper layer to stop sending packets */
714	if (meth_tx_full(dev)) {
715	        printk(KERN_DEBUG "TX full: stopping\n");
716		netif_stop_queue(dev);
717	}
718
719	/* Restart DMA notification */
720	priv->dma_ctrl |= METH_DMA_TX_INT_EN;
721	mace->eth.dma_ctrl = priv->dma_ctrl;
722
723	spin_unlock_irqrestore(&priv->meth_lock, flags);
724
725	return NETDEV_TX_OK;
726}
727
728/*
729 * Deal with a transmit timeout.
730 */
731static void meth_tx_timeout(struct net_device *dev)
732{
733	struct meth_private *priv = netdev_priv(dev);
734	unsigned long flags;
735
736	printk(KERN_WARNING "%s: transmit timed out\n", dev->name);
737
738	/* Protect against concurrent rx interrupts */
739	spin_lock_irqsave(&priv->meth_lock,flags);
740
741	/* Try to reset the interface. */
742	meth_reset(dev);
743
744	dev->stats.tx_errors++;
745
746	/* Clear all rings */
747	meth_free_tx_ring(priv);
748	meth_free_rx_ring(priv);
749	meth_init_tx_ring(priv);
750	meth_init_rx_ring(priv);
751
752	/* Restart dma */
753	priv->dma_ctrl |= METH_DMA_TX_EN | METH_DMA_RX_EN | METH_DMA_RX_INT_EN;
754	mace->eth.dma_ctrl = priv->dma_ctrl;
755
756	/* Enable interrupt */
757	spin_unlock_irqrestore(&priv->meth_lock, flags);
758
759	dev->trans_start = jiffies; /* prevent tx timeout */
760	netif_wake_queue(dev);
761}
762
763/*
764 * Ioctl commands
765 */
766static int meth_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
767{
768	/* XXX Not yet implemented */
769	switch(cmd) {
770	case SIOCGMIIPHY:
771	case SIOCGMIIREG:
772	case SIOCSMIIREG:
773	default:
774		return -EOPNOTSUPP;
775	}
776}
777
778static void meth_set_rx_mode(struct net_device *dev)
779{
780	struct meth_private *priv = netdev_priv(dev);
781	unsigned long flags;
782
783	netif_stop_queue(dev);
784	spin_lock_irqsave(&priv->meth_lock, flags);
785	priv->mac_ctrl &= ~METH_PROMISC;
786
787	if (dev->flags & IFF_PROMISC) {
788		priv->mac_ctrl |= METH_PROMISC;
789		priv->mcast_filter = 0xffffffffffffffffUL;
790	} else if ((netdev_mc_count(dev) > METH_MCF_LIMIT) ||
791		   (dev->flags & IFF_ALLMULTI)) {
792		priv->mac_ctrl |= METH_ACCEPT_AMCAST;
793		priv->mcast_filter = 0xffffffffffffffffUL;
794	} else {
795		struct netdev_hw_addr *ha;
796		priv->mac_ctrl |= METH_ACCEPT_MCAST;
797
798		netdev_for_each_mc_addr(ha, dev)
799			set_bit((ether_crc(ETH_ALEN, ha->addr) >> 26),
800			        (volatile unsigned long *)&priv->mcast_filter);
801	}
802
803	/* Write the changes to the chip registers. */
804	mace->eth.mac_ctrl = priv->mac_ctrl;
805	mace->eth.mcast_filter = priv->mcast_filter;
806
807	/* Done! */
808	spin_unlock_irqrestore(&priv->meth_lock, flags);
809	netif_wake_queue(dev);
810}
811
812static const struct net_device_ops meth_netdev_ops = {
813	.ndo_open		= meth_open,
814	.ndo_stop		= meth_release,
815	.ndo_start_xmit		= meth_tx,
816	.ndo_do_ioctl		= meth_ioctl,
817	.ndo_tx_timeout		= meth_tx_timeout,
818	.ndo_change_mtu		= eth_change_mtu,
819	.ndo_validate_addr	= eth_validate_addr,
820	.ndo_set_mac_address	= eth_mac_addr,
821	.ndo_set_rx_mode    	= meth_set_rx_mode,
822};
823
824/*
825 * The init function.
826 */
827static int meth_probe(struct platform_device *pdev)
828{
829	struct net_device *dev;
830	struct meth_private *priv;
831	int err;
832
833	dev = alloc_etherdev(sizeof(struct meth_private));
834	if (!dev)
835		return -ENOMEM;
836
837	dev->netdev_ops		= &meth_netdev_ops;
838	dev->watchdog_timeo	= timeout;
839	dev->irq		= MACE_ETHERNET_IRQ;
840	dev->base_addr		= (unsigned long)&mace->eth;
841	memcpy(dev->dev_addr, o2meth_eaddr, ETH_ALEN);
842
843	priv = netdev_priv(dev);
844	spin_lock_init(&priv->meth_lock);
845	SET_NETDEV_DEV(dev, &pdev->dev);
846
847	err = register_netdev(dev);
848	if (err) {
849		free_netdev(dev);
850		return err;
851	}
852
853	printk(KERN_INFO "%s: SGI MACE Ethernet rev. %d\n",
854	       dev->name, (unsigned int)(mace->eth.mac_ctrl >> 29));
855	return 0;
856}
857
858static int __exit meth_remove(struct platform_device *pdev)
859{
860	struct net_device *dev = platform_get_drvdata(pdev);
861
862	unregister_netdev(dev);
863	free_netdev(dev);
864
865	return 0;
866}
867
868static struct platform_driver meth_driver = {
869	.probe	= meth_probe,
870	.remove	= __exit_p(meth_remove),
871	.driver = {
872		.name	= "meth",
873	}
874};
875
876module_platform_driver(meth_driver);
877
878MODULE_AUTHOR("Ilya Volynets <ilya@theIlya.com>");
879MODULE_DESCRIPTION("SGI O2 Builtin Fast Ethernet driver");
880MODULE_LICENSE("GPL");
881MODULE_ALIAS("platform:meth");
882