1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * meth.c -- O2 Builtin 10/100 Ethernet driver
4 *
5 * Copyright (C) 2001-2003 Ilya Volynets
6 */
7#include <linux/delay.h>
8#include <linux/dma-mapping.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/platform_device.h>
12#include <linux/slab.h>
13#include <linux/errno.h>
14#include <linux/types.h>
15#include <linux/interrupt.h>
16
17#include <linux/in.h>
18#include <linux/in6.h>
19#include <linux/device.h> /* struct device, et al */
20#include <linux/netdevice.h>   /* struct device, and other headers */
21#include <linux/etherdevice.h> /* eth_type_trans */
22#include <linux/ip.h>          /* struct iphdr */
23#include <linux/tcp.h>         /* struct tcphdr */
24#include <linux/skbuff.h>
25#include <linux/mii.h>         /* MII definitions */
26#include <linux/crc32.h>
27
28#include <asm/ip32/mace.h>
29#include <asm/ip32/ip32_ints.h>
30
31#include <asm/io.h>
32
33#include "meth.h"
34
35#ifndef MFE_DEBUG
36#define MFE_DEBUG 0
37#endif
38
39#if MFE_DEBUG>=1
40#define DPRINTK(str,args...) printk(KERN_DEBUG "meth: %s: " str, __func__ , ## args)
41#define MFE_RX_DEBUG 2
42#else
43#define DPRINTK(str,args...)
44#define MFE_RX_DEBUG 0
45#endif
46
47
48static const char *meth_str="SGI O2 Fast Ethernet";
49
50/* The maximum time waited (in jiffies) before assuming a Tx failed. (400ms) */
51#define TX_TIMEOUT (400*HZ/1000)
52
53static int timeout = TX_TIMEOUT;
54module_param(timeout, int, 0);
55
56/*
57 * Maximum number of multicast addresses to filter (vs. Rx-all-multicast).
58 * MACE Ethernet uses a 64 element hash table based on the Ethernet CRC.
59 */
60#define METH_MCF_LIMIT 32
61
62/*
63 * This structure is private to each device. It is used to pass
64 * packets in and out, so there is place for a packet
65 */
66struct meth_private {
67	struct platform_device *pdev;
68
69	/* in-memory copy of MAC Control register */
70	u64 mac_ctrl;
71
72	/* in-memory copy of DMA Control register */
73	unsigned long dma_ctrl;
74	/* address of PHY, used by mdio_* functions, initialized in mdio_probe */
75	unsigned long phy_addr;
76	tx_packet *tx_ring;
77	dma_addr_t tx_ring_dma;
78	struct sk_buff *tx_skbs[TX_RING_ENTRIES];
79	dma_addr_t tx_skb_dmas[TX_RING_ENTRIES];
80	unsigned long tx_read, tx_write, tx_count;
81
82	rx_packet *rx_ring[RX_RING_ENTRIES];
83	dma_addr_t rx_ring_dmas[RX_RING_ENTRIES];
84	struct sk_buff *rx_skbs[RX_RING_ENTRIES];
85	unsigned long rx_write;
86
87	/* Multicast filter. */
88	u64 mcast_filter;
89
90	spinlock_t meth_lock;
91};
92
93static void meth_tx_timeout(struct net_device *dev, unsigned int txqueue);
94static irqreturn_t meth_interrupt(int irq, void *dev_id);
95
96/* global, initialized in ip32-setup.c */
97char o2meth_eaddr[8]={0,0,0,0,0,0,0,0};
98
99static inline void load_eaddr(struct net_device *dev)
100{
101	int i;
102	u64 macaddr;
103
104	DPRINTK("Loading MAC Address: %pM\n", dev->dev_addr);
105	macaddr = 0;
106	for (i = 0; i < 6; i++)
107		macaddr |= (u64)dev->dev_addr[i] << ((5 - i) * 8);
108
109	mace->eth.mac_addr = macaddr;
110}
111
112/*
113 * Waits for BUSY status of mdio bus to clear
114 */
115#define WAIT_FOR_PHY(___rval)					\
116	while ((___rval = mace->eth.phy_data) & MDIO_BUSY) {	\
117		udelay(25);					\
118	}
119/*read phy register, return value read */
120static unsigned long mdio_read(struct meth_private *priv, unsigned long phyreg)
121{
122	unsigned long rval;
123	WAIT_FOR_PHY(rval);
124	mace->eth.phy_regs = (priv->phy_addr << 5) | (phyreg & 0x1f);
125	udelay(25);
126	mace->eth.phy_trans_go = 1;
127	udelay(25);
128	WAIT_FOR_PHY(rval);
129	return rval & MDIO_DATA_MASK;
130}
131
132static int mdio_probe(struct meth_private *priv)
133{
134	int i;
135	unsigned long p2, p3, flags;
136	/* check if phy is detected already */
137	if(priv->phy_addr>=0&&priv->phy_addr<32)
138		return 0;
139	spin_lock_irqsave(&priv->meth_lock, flags);
140	for (i=0;i<32;++i){
141		priv->phy_addr=i;
142		p2=mdio_read(priv,2);
143		p3=mdio_read(priv,3);
144#if MFE_DEBUG>=2
145		switch ((p2<<12)|(p3>>4)){
146		case PHY_QS6612X:
147			DPRINTK("PHY is QS6612X\n");
148			break;
149		case PHY_ICS1889:
150			DPRINTK("PHY is ICS1889\n");
151			break;
152		case PHY_ICS1890:
153			DPRINTK("PHY is ICS1890\n");
154			break;
155		case PHY_DP83840:
156			DPRINTK("PHY is DP83840\n");
157			break;
158		}
159#endif
160		if(p2!=0xffff&&p2!=0x0000){
161			DPRINTK("PHY code: %x\n",(p2<<12)|(p3>>4));
162			break;
163		}
164	}
165	spin_unlock_irqrestore(&priv->meth_lock, flags);
166	if(priv->phy_addr<32) {
167		return 0;
168	}
169	DPRINTK("Oopsie! PHY is not known!\n");
170	priv->phy_addr=-1;
171	return -ENODEV;
172}
173
174static void meth_check_link(struct net_device *dev)
175{
176	struct meth_private *priv = netdev_priv(dev);
177	unsigned long mii_advertising = mdio_read(priv, 4);
178	unsigned long mii_partner = mdio_read(priv, 5);
179	unsigned long negotiated = mii_advertising & mii_partner;
180	unsigned long duplex, speed;
181
182	if (mii_partner == 0xffff)
183		return;
184
185	speed = (negotiated & 0x0380) ? METH_100MBIT : 0;
186	duplex = ((negotiated & 0x0100) || (negotiated & 0x01C0) == 0x0040) ?
187		 METH_PHY_FDX : 0;
188
189	if ((priv->mac_ctrl & METH_PHY_FDX) ^ duplex) {
190		DPRINTK("Setting %s-duplex\n", duplex ? "full" : "half");
191		if (duplex)
192			priv->mac_ctrl |= METH_PHY_FDX;
193		else
194			priv->mac_ctrl &= ~METH_PHY_FDX;
195		mace->eth.mac_ctrl = priv->mac_ctrl;
196	}
197
198	if ((priv->mac_ctrl & METH_100MBIT) ^ speed) {
199		DPRINTK("Setting %dMbs mode\n", speed ? 100 : 10);
200		if (duplex)
201			priv->mac_ctrl |= METH_100MBIT;
202		else
203			priv->mac_ctrl &= ~METH_100MBIT;
204		mace->eth.mac_ctrl = priv->mac_ctrl;
205	}
206}
207
208
209static int meth_init_tx_ring(struct meth_private *priv)
210{
211	/* Init TX ring */
212	priv->tx_ring = dma_alloc_coherent(&priv->pdev->dev,
213			TX_RING_BUFFER_SIZE, &priv->tx_ring_dma, GFP_ATOMIC);
214	if (!priv->tx_ring)
215		return -ENOMEM;
216
217	priv->tx_count = priv->tx_read = priv->tx_write = 0;
218	mace->eth.tx_ring_base = priv->tx_ring_dma;
219	/* Now init skb save area */
220	memset(priv->tx_skbs, 0, sizeof(priv->tx_skbs));
221	memset(priv->tx_skb_dmas, 0, sizeof(priv->tx_skb_dmas));
222	return 0;
223}
224
225static int meth_init_rx_ring(struct meth_private *priv)
226{
227	int i;
228
229	for (i = 0; i < RX_RING_ENTRIES; i++) {
230		priv->rx_skbs[i] = alloc_skb(METH_RX_BUFF_SIZE, 0);
231		/* 8byte status vector + 3quad padding + 2byte padding,
232		 * to put data on 64bit aligned boundary */
233		skb_reserve(priv->rx_skbs[i],METH_RX_HEAD);
234		priv->rx_ring[i]=(rx_packet*)(priv->rx_skbs[i]->head);
235		/* I'll need to re-sync it after each RX */
236		priv->rx_ring_dmas[i] =
237			dma_map_single(&priv->pdev->dev, priv->rx_ring[i],
238				       METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
239		mace->eth.rx_fifo = priv->rx_ring_dmas[i];
240	}
241        priv->rx_write = 0;
242	return 0;
243}
244static void meth_free_tx_ring(struct meth_private *priv)
245{
246	int i;
247
248	/* Remove any pending skb */
249	for (i = 0; i < TX_RING_ENTRIES; i++) {
250		dev_kfree_skb(priv->tx_skbs[i]);
251		priv->tx_skbs[i] = NULL;
252	}
253	dma_free_coherent(&priv->pdev->dev, TX_RING_BUFFER_SIZE, priv->tx_ring,
254	                  priv->tx_ring_dma);
255}
256
257/* Presumes RX DMA engine is stopped, and RX fifo ring is reset */
258static void meth_free_rx_ring(struct meth_private *priv)
259{
260	int i;
261
262	for (i = 0; i < RX_RING_ENTRIES; i++) {
263		dma_unmap_single(&priv->pdev->dev, priv->rx_ring_dmas[i],
264				 METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
265		priv->rx_ring[i] = 0;
266		priv->rx_ring_dmas[i] = 0;
267		kfree_skb(priv->rx_skbs[i]);
268	}
269}
270
271int meth_reset(struct net_device *dev)
272{
273	struct meth_private *priv = netdev_priv(dev);
274
275	/* Reset card */
276	mace->eth.mac_ctrl = SGI_MAC_RESET;
277	udelay(1);
278	mace->eth.mac_ctrl = 0;
279	udelay(25);
280
281	/* Load ethernet address */
282	load_eaddr(dev);
283	/* Should load some "errata", but later */
284
285	/* Check for device */
286	if (mdio_probe(priv) < 0) {
287		DPRINTK("Unable to find PHY\n");
288		return -ENODEV;
289	}
290
291	/* Initial mode: 10 | Half-duplex | Accept normal packets */
292	priv->mac_ctrl = METH_ACCEPT_MCAST | METH_DEFAULT_IPG;
293	if (dev->flags & IFF_PROMISC)
294		priv->mac_ctrl |= METH_PROMISC;
295	mace->eth.mac_ctrl = priv->mac_ctrl;
296
297	/* Autonegotiate speed and duplex mode */
298	meth_check_link(dev);
299
300	/* Now set dma control, but don't enable DMA, yet */
301	priv->dma_ctrl = (4 << METH_RX_OFFSET_SHIFT) |
302			 (RX_RING_ENTRIES << METH_RX_DEPTH_SHIFT);
303	mace->eth.dma_ctrl = priv->dma_ctrl;
304
305	return 0;
306}
307
308/*============End Helper Routines=====================*/
309
310/*
311 * Open and close
312 */
313static int meth_open(struct net_device *dev)
314{
315	struct meth_private *priv = netdev_priv(dev);
316	int ret;
317
318	priv->phy_addr = -1;    /* No PHY is known yet... */
319
320	/* Initialize the hardware */
321	ret = meth_reset(dev);
322	if (ret < 0)
323		return ret;
324
325	/* Allocate the ring buffers */
326	ret = meth_init_tx_ring(priv);
327	if (ret < 0)
328		return ret;
329	ret = meth_init_rx_ring(priv);
330	if (ret < 0)
331		goto out_free_tx_ring;
332
333	ret = request_irq(dev->irq, meth_interrupt, 0, meth_str, dev);
334	if (ret) {
335		printk(KERN_ERR "%s: Can't get irq %d\n", dev->name, dev->irq);
336		goto out_free_rx_ring;
337	}
338
339	/* Start DMA */
340	priv->dma_ctrl |= METH_DMA_TX_EN | /*METH_DMA_TX_INT_EN |*/
341			  METH_DMA_RX_EN | METH_DMA_RX_INT_EN;
342	mace->eth.dma_ctrl = priv->dma_ctrl;
343
344	DPRINTK("About to start queue\n");
345	netif_start_queue(dev);
346
347	return 0;
348
349out_free_rx_ring:
350	meth_free_rx_ring(priv);
351out_free_tx_ring:
352	meth_free_tx_ring(priv);
353
354	return ret;
355}
356
357static int meth_release(struct net_device *dev)
358{
359	struct meth_private *priv = netdev_priv(dev);
360
361	DPRINTK("Stopping queue\n");
362	netif_stop_queue(dev); /* can't transmit any more */
363	/* shut down DMA */
364	priv->dma_ctrl &= ~(METH_DMA_TX_EN | METH_DMA_TX_INT_EN |
365			    METH_DMA_RX_EN | METH_DMA_RX_INT_EN);
366	mace->eth.dma_ctrl = priv->dma_ctrl;
367	free_irq(dev->irq, dev);
368	meth_free_tx_ring(priv);
369	meth_free_rx_ring(priv);
370
371	return 0;
372}
373
374/*
375 * Receive a packet: retrieve, encapsulate and pass over to upper levels
376 */
377static void meth_rx(struct net_device* dev, unsigned long int_status)
378{
379	struct sk_buff *skb;
380	unsigned long status, flags;
381	struct meth_private *priv = netdev_priv(dev);
382	unsigned long fifo_rptr = (int_status & METH_INT_RX_RPTR_MASK) >> 8;
383
384	spin_lock_irqsave(&priv->meth_lock, flags);
385	priv->dma_ctrl &= ~METH_DMA_RX_INT_EN;
386	mace->eth.dma_ctrl = priv->dma_ctrl;
387	spin_unlock_irqrestore(&priv->meth_lock, flags);
388
389	if (int_status & METH_INT_RX_UNDERFLOW) {
390		fifo_rptr = (fifo_rptr - 1) & 0x0f;
391	}
392	while (priv->rx_write != fifo_rptr) {
393		dma_unmap_single(&priv->pdev->dev,
394				 priv->rx_ring_dmas[priv->rx_write],
395				 METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
396		status = priv->rx_ring[priv->rx_write]->status.raw;
397#if MFE_DEBUG
398		if (!(status & METH_RX_ST_VALID)) {
399			DPRINTK("Not received? status=%016lx\n",status);
400		}
401#endif
402		if ((!(status & METH_RX_STATUS_ERRORS)) && (status & METH_RX_ST_VALID)) {
403			int len = (status & 0xffff) - 4; /* omit CRC */
404			/* length sanity check */
405			if (len < 60 || len > 1518) {
406				printk(KERN_DEBUG "%s: bogus packet size: %ld, status=%#2Lx.\n",
407				       dev->name, priv->rx_write,
408				       priv->rx_ring[priv->rx_write]->status.raw);
409				dev->stats.rx_errors++;
410				dev->stats.rx_length_errors++;
411				skb = priv->rx_skbs[priv->rx_write];
412			} else {
413				skb = alloc_skb(METH_RX_BUFF_SIZE, GFP_ATOMIC);
414				if (!skb) {
415					/* Ouch! No memory! Drop packet on the floor */
416					DPRINTK("No mem: dropping packet\n");
417					dev->stats.rx_dropped++;
418					skb = priv->rx_skbs[priv->rx_write];
419				} else {
420					struct sk_buff *skb_c = priv->rx_skbs[priv->rx_write];
421					/* 8byte status vector + 3quad padding + 2byte padding,
422					 * to put data on 64bit aligned boundary */
423					skb_reserve(skb, METH_RX_HEAD);
424					/* Write metadata, and then pass to the receive level */
425					skb_put(skb_c, len);
426					priv->rx_skbs[priv->rx_write] = skb;
427					skb_c->protocol = eth_type_trans(skb_c, dev);
428					dev->stats.rx_packets++;
429					dev->stats.rx_bytes += len;
430					netif_rx(skb_c);
431				}
432			}
433		} else {
434			dev->stats.rx_errors++;
435			skb=priv->rx_skbs[priv->rx_write];
436#if MFE_DEBUG>0
437			printk(KERN_WARNING "meth: RX error: status=0x%016lx\n",status);
438			if(status&METH_RX_ST_RCV_CODE_VIOLATION)
439				printk(KERN_WARNING "Receive Code Violation\n");
440			if(status&METH_RX_ST_CRC_ERR)
441				printk(KERN_WARNING "CRC error\n");
442			if(status&METH_RX_ST_INV_PREAMBLE_CTX)
443				printk(KERN_WARNING "Invalid Preamble Context\n");
444			if(status&METH_RX_ST_LONG_EVT_SEEN)
445				printk(KERN_WARNING "Long Event Seen...\n");
446			if(status&METH_RX_ST_BAD_PACKET)
447				printk(KERN_WARNING "Bad Packet\n");
448			if(status&METH_RX_ST_CARRIER_EVT_SEEN)
449				printk(KERN_WARNING "Carrier Event Seen\n");
450#endif
451		}
452		priv->rx_ring[priv->rx_write] = (rx_packet*)skb->head;
453		priv->rx_ring[priv->rx_write]->status.raw = 0;
454		priv->rx_ring_dmas[priv->rx_write] =
455			dma_map_single(&priv->pdev->dev,
456				       priv->rx_ring[priv->rx_write],
457				       METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
458		mace->eth.rx_fifo = priv->rx_ring_dmas[priv->rx_write];
459		ADVANCE_RX_PTR(priv->rx_write);
460	}
461	spin_lock_irqsave(&priv->meth_lock, flags);
462	/* In case there was underflow, and Rx DMA was disabled */
463	priv->dma_ctrl |= METH_DMA_RX_INT_EN | METH_DMA_RX_EN;
464	mace->eth.dma_ctrl = priv->dma_ctrl;
465	mace->eth.int_stat = METH_INT_RX_THRESHOLD;
466	spin_unlock_irqrestore(&priv->meth_lock, flags);
467}
468
469static int meth_tx_full(struct net_device *dev)
470{
471	struct meth_private *priv = netdev_priv(dev);
472
473	return priv->tx_count >= TX_RING_ENTRIES - 1;
474}
475
476static void meth_tx_cleanup(struct net_device* dev, unsigned long int_status)
477{
478	struct meth_private *priv = netdev_priv(dev);
479	unsigned long status, flags;
480	struct sk_buff *skb;
481	unsigned long rptr = (int_status&TX_INFO_RPTR) >> 16;
482
483	spin_lock_irqsave(&priv->meth_lock, flags);
484
485	/* Stop DMA notification */
486	priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
487	mace->eth.dma_ctrl = priv->dma_ctrl;
488
489	while (priv->tx_read != rptr) {
490		skb = priv->tx_skbs[priv->tx_read];
491		status = priv->tx_ring[priv->tx_read].header.raw;
492#if MFE_DEBUG>=1
493		if (priv->tx_read == priv->tx_write)
494			DPRINTK("Auchi! tx_read=%d,tx_write=%d,rptr=%d?\n", priv->tx_read, priv->tx_write,rptr);
495#endif
496		if (status & METH_TX_ST_DONE) {
497			if (status & METH_TX_ST_SUCCESS){
498				dev->stats.tx_packets++;
499				dev->stats.tx_bytes += skb->len;
500			} else {
501				dev->stats.tx_errors++;
502#if MFE_DEBUG>=1
503				DPRINTK("TX error: status=%016lx <",status);
504				if(status & METH_TX_ST_SUCCESS)
505					printk(" SUCCESS");
506				if(status & METH_TX_ST_TOOLONG)
507					printk(" TOOLONG");
508				if(status & METH_TX_ST_UNDERRUN)
509					printk(" UNDERRUN");
510				if(status & METH_TX_ST_EXCCOLL)
511					printk(" EXCCOLL");
512				if(status & METH_TX_ST_DEFER)
513					printk(" DEFER");
514				if(status & METH_TX_ST_LATECOLL)
515					printk(" LATECOLL");
516				printk(" >\n");
517#endif
518			}
519		} else {
520			DPRINTK("RPTR points us here, but packet not done?\n");
521			break;
522		}
523		dev_consume_skb_irq(skb);
524		priv->tx_skbs[priv->tx_read] = NULL;
525		priv->tx_ring[priv->tx_read].header.raw = 0;
526		priv->tx_read = (priv->tx_read+1)&(TX_RING_ENTRIES-1);
527		priv->tx_count--;
528	}
529
530	/* wake up queue if it was stopped */
531	if (netif_queue_stopped(dev) && !meth_tx_full(dev)) {
532		netif_wake_queue(dev);
533	}
534
535	mace->eth.int_stat = METH_INT_TX_EMPTY | METH_INT_TX_PKT;
536	spin_unlock_irqrestore(&priv->meth_lock, flags);
537}
538
539static void meth_error(struct net_device* dev, unsigned status)
540{
541	struct meth_private *priv = netdev_priv(dev);
542	unsigned long flags;
543
544	printk(KERN_WARNING "meth: error status: 0x%08x\n",status);
545	/* check for errors too... */
546	if (status & (METH_INT_TX_LINK_FAIL))
547		printk(KERN_WARNING "meth: link failure\n");
548	/* Should I do full reset in this case? */
549	if (status & (METH_INT_MEM_ERROR))
550		printk(KERN_WARNING "meth: memory error\n");
551	if (status & (METH_INT_TX_ABORT))
552		printk(KERN_WARNING "meth: aborted\n");
553	if (status & (METH_INT_RX_OVERFLOW))
554		printk(KERN_WARNING "meth: Rx overflow\n");
555	if (status & (METH_INT_RX_UNDERFLOW)) {
556		printk(KERN_WARNING "meth: Rx underflow\n");
557		spin_lock_irqsave(&priv->meth_lock, flags);
558		mace->eth.int_stat = METH_INT_RX_UNDERFLOW;
559		/* more underflow interrupts will be delivered,
560		 * effectively throwing us into an infinite loop.
561		 *  Thus I stop processing Rx in this case. */
562		priv->dma_ctrl &= ~METH_DMA_RX_EN;
563		mace->eth.dma_ctrl = priv->dma_ctrl;
564		DPRINTK("Disabled meth Rx DMA temporarily\n");
565		spin_unlock_irqrestore(&priv->meth_lock, flags);
566	}
567	mace->eth.int_stat = METH_INT_ERROR;
568}
569
570/*
571 * The typical interrupt entry point
572 */
573static irqreturn_t meth_interrupt(int irq, void *dev_id)
574{
575	struct net_device *dev = (struct net_device *)dev_id;
576	struct meth_private *priv = netdev_priv(dev);
577	unsigned long status;
578
579	status = mace->eth.int_stat;
580	while (status & 0xff) {
581		/* First handle errors - if we get Rx underflow,
582		 * Rx DMA will be disabled, and Rx handler will reenable
583		 * it. I don't think it's possible to get Rx underflow,
584		 * without getting Rx interrupt */
585		if (status & METH_INT_ERROR) {
586			meth_error(dev, status);
587		}
588		if (status & (METH_INT_TX_EMPTY | METH_INT_TX_PKT)) {
589			/* a transmission is over: free the skb */
590			meth_tx_cleanup(dev, status);
591		}
592		if (status & METH_INT_RX_THRESHOLD) {
593			if (!(priv->dma_ctrl & METH_DMA_RX_INT_EN))
594				break;
595			/* send it to meth_rx for handling */
596			meth_rx(dev, status);
597		}
598		status = mace->eth.int_stat;
599	}
600
601	return IRQ_HANDLED;
602}
603
604/*
605 * Transmits packets that fit into TX descriptor (are <=120B)
606 */
607static void meth_tx_short_prepare(struct meth_private *priv,
608				  struct sk_buff *skb)
609{
610	tx_packet *desc = &priv->tx_ring[priv->tx_write];
611	int len = (skb->len < ETH_ZLEN) ? ETH_ZLEN : skb->len;
612
613	desc->header.raw = METH_TX_CMD_INT_EN | (len-1) | ((128-len) << 16);
614	/* maybe I should set whole thing to 0 first... */
615	skb_copy_from_linear_data(skb, desc->data.dt + (120 - len), skb->len);
616	if (skb->len < len)
617		memset(desc->data.dt + 120 - len + skb->len, 0, len-skb->len);
618}
619#define TX_CATBUF1 BIT(25)
620static void meth_tx_1page_prepare(struct meth_private *priv,
621				  struct sk_buff *skb)
622{
623	tx_packet *desc = &priv->tx_ring[priv->tx_write];
624	void *buffer_data = (void *)(((unsigned long)skb->data + 7) & ~7);
625	int unaligned_len = (int)((unsigned long)buffer_data - (unsigned long)skb->data);
626	int buffer_len = skb->len - unaligned_len;
627	dma_addr_t catbuf;
628
629	desc->header.raw = METH_TX_CMD_INT_EN | TX_CATBUF1 | (skb->len - 1);
630
631	/* unaligned part */
632	if (unaligned_len) {
633		skb_copy_from_linear_data(skb, desc->data.dt + (120 - unaligned_len),
634			      unaligned_len);
635		desc->header.raw |= (128 - unaligned_len) << 16;
636	}
637
638	/* first page */
639	catbuf = dma_map_single(&priv->pdev->dev, buffer_data, buffer_len,
640				DMA_TO_DEVICE);
641	desc->data.cat_buf[0].form.start_addr = catbuf >> 3;
642	desc->data.cat_buf[0].form.len = buffer_len - 1;
643}
644#define TX_CATBUF2 BIT(26)
645static void meth_tx_2page_prepare(struct meth_private *priv,
646				  struct sk_buff *skb)
647{
648	tx_packet *desc = &priv->tx_ring[priv->tx_write];
649	void *buffer1_data = (void *)(((unsigned long)skb->data + 7) & ~7);
650	void *buffer2_data = (void *)PAGE_ALIGN((unsigned long)skb->data);
651	int unaligned_len = (int)((unsigned long)buffer1_data - (unsigned long)skb->data);
652	int buffer1_len = (int)((unsigned long)buffer2_data - (unsigned long)buffer1_data);
653	int buffer2_len = skb->len - buffer1_len - unaligned_len;
654	dma_addr_t catbuf1, catbuf2;
655
656	desc->header.raw = METH_TX_CMD_INT_EN | TX_CATBUF1 | TX_CATBUF2| (skb->len - 1);
657	/* unaligned part */
658	if (unaligned_len){
659		skb_copy_from_linear_data(skb, desc->data.dt + (120 - unaligned_len),
660			      unaligned_len);
661		desc->header.raw |= (128 - unaligned_len) << 16;
662	}
663
664	/* first page */
665	catbuf1 = dma_map_single(&priv->pdev->dev, buffer1_data, buffer1_len,
666				 DMA_TO_DEVICE);
667	desc->data.cat_buf[0].form.start_addr = catbuf1 >> 3;
668	desc->data.cat_buf[0].form.len = buffer1_len - 1;
669	/* second page */
670	catbuf2 = dma_map_single(&priv->pdev->dev, buffer2_data, buffer2_len,
671				 DMA_TO_DEVICE);
672	desc->data.cat_buf[1].form.start_addr = catbuf2 >> 3;
673	desc->data.cat_buf[1].form.len = buffer2_len - 1;
674}
675
676static void meth_add_to_tx_ring(struct meth_private *priv, struct sk_buff *skb)
677{
678	/* Remember the skb, so we can free it at interrupt time */
679	priv->tx_skbs[priv->tx_write] = skb;
680	if (skb->len <= 120) {
681		/* Whole packet fits into descriptor */
682		meth_tx_short_prepare(priv, skb);
683	} else if (PAGE_ALIGN((unsigned long)skb->data) !=
684		   PAGE_ALIGN((unsigned long)skb->data + skb->len - 1)) {
685		/* Packet crosses page boundary */
686		meth_tx_2page_prepare(priv, skb);
687	} else {
688		/* Packet is in one page */
689		meth_tx_1page_prepare(priv, skb);
690	}
691	priv->tx_write = (priv->tx_write + 1) & (TX_RING_ENTRIES - 1);
692	mace->eth.tx_info = priv->tx_write;
693	priv->tx_count++;
694}
695
696/*
697 * Transmit a packet (called by the kernel)
698 */
699static netdev_tx_t meth_tx(struct sk_buff *skb, struct net_device *dev)
700{
701	struct meth_private *priv = netdev_priv(dev);
702	unsigned long flags;
703
704	spin_lock_irqsave(&priv->meth_lock, flags);
705	/* Stop DMA notification */
706	priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
707	mace->eth.dma_ctrl = priv->dma_ctrl;
708
709	meth_add_to_tx_ring(priv, skb);
710	netif_trans_update(dev); /* save the timestamp */
711
712	/* If TX ring is full, tell the upper layer to stop sending packets */
713	if (meth_tx_full(dev)) {
714	        printk(KERN_DEBUG "TX full: stopping\n");
715		netif_stop_queue(dev);
716	}
717
718	/* Restart DMA notification */
719	priv->dma_ctrl |= METH_DMA_TX_INT_EN;
720	mace->eth.dma_ctrl = priv->dma_ctrl;
721
722	spin_unlock_irqrestore(&priv->meth_lock, flags);
723
724	return NETDEV_TX_OK;
725}
726
727/*
728 * Deal with a transmit timeout.
729 */
730static void meth_tx_timeout(struct net_device *dev, unsigned int txqueue)
731{
732	struct meth_private *priv = netdev_priv(dev);
733	unsigned long flags;
734
735	printk(KERN_WARNING "%s: transmit timed out\n", dev->name);
736
737	/* Protect against concurrent rx interrupts */
738	spin_lock_irqsave(&priv->meth_lock,flags);
739
740	/* Try to reset the interface. */
741	meth_reset(dev);
742
743	dev->stats.tx_errors++;
744
745	/* Clear all rings */
746	meth_free_tx_ring(priv);
747	meth_free_rx_ring(priv);
748	meth_init_tx_ring(priv);
749	meth_init_rx_ring(priv);
750
751	/* Restart dma */
752	priv->dma_ctrl |= METH_DMA_TX_EN | METH_DMA_RX_EN | METH_DMA_RX_INT_EN;
753	mace->eth.dma_ctrl = priv->dma_ctrl;
754
755	/* Enable interrupt */
756	spin_unlock_irqrestore(&priv->meth_lock, flags);
757
758	netif_trans_update(dev); /* prevent tx timeout */
759	netif_wake_queue(dev);
760}
761
762/*
763 * Ioctl commands
764 */
765static int meth_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
766{
767	/* XXX Not yet implemented */
768	switch(cmd) {
769	case SIOCGMIIPHY:
770	case SIOCGMIIREG:
771	case SIOCSMIIREG:
772	default:
773		return -EOPNOTSUPP;
774	}
775}
776
777static void meth_set_rx_mode(struct net_device *dev)
778{
779	struct meth_private *priv = netdev_priv(dev);
780	unsigned long flags;
781
782	netif_stop_queue(dev);
783	spin_lock_irqsave(&priv->meth_lock, flags);
784	priv->mac_ctrl &= ~METH_PROMISC;
785
786	if (dev->flags & IFF_PROMISC) {
787		priv->mac_ctrl |= METH_PROMISC;
788		priv->mcast_filter = 0xffffffffffffffffUL;
789	} else if ((netdev_mc_count(dev) > METH_MCF_LIMIT) ||
790		   (dev->flags & IFF_ALLMULTI)) {
791		priv->mac_ctrl |= METH_ACCEPT_AMCAST;
792		priv->mcast_filter = 0xffffffffffffffffUL;
793	} else {
794		struct netdev_hw_addr *ha;
795		priv->mac_ctrl |= METH_ACCEPT_MCAST;
796
797		netdev_for_each_mc_addr(ha, dev)
798			set_bit((ether_crc(ETH_ALEN, ha->addr) >> 26),
799			        (volatile unsigned long *)&priv->mcast_filter);
800	}
801
802	/* Write the changes to the chip registers. */
803	mace->eth.mac_ctrl = priv->mac_ctrl;
804	mace->eth.mcast_filter = priv->mcast_filter;
805
806	/* Done! */
807	spin_unlock_irqrestore(&priv->meth_lock, flags);
808	netif_wake_queue(dev);
809}
810
811static const struct net_device_ops meth_netdev_ops = {
812	.ndo_open		= meth_open,
813	.ndo_stop		= meth_release,
814	.ndo_start_xmit		= meth_tx,
815	.ndo_eth_ioctl		= meth_ioctl,
816	.ndo_tx_timeout		= meth_tx_timeout,
817	.ndo_validate_addr	= eth_validate_addr,
818	.ndo_set_mac_address	= eth_mac_addr,
819	.ndo_set_rx_mode    	= meth_set_rx_mode,
820};
821
822/*
823 * The init function.
824 */
825static int meth_probe(struct platform_device *pdev)
826{
827	struct net_device *dev;
828	struct meth_private *priv;
829	int err;
830
831	dev = alloc_etherdev(sizeof(struct meth_private));
832	if (!dev)
833		return -ENOMEM;
834
835	dev->netdev_ops		= &meth_netdev_ops;
836	dev->watchdog_timeo	= timeout;
837	dev->irq		= MACE_ETHERNET_IRQ;
838	dev->base_addr		= (unsigned long)&mace->eth;
839	eth_hw_addr_set(dev, o2meth_eaddr);
840
841	priv = netdev_priv(dev);
842	priv->pdev = pdev;
843	spin_lock_init(&priv->meth_lock);
844	SET_NETDEV_DEV(dev, &pdev->dev);
845
846	err = register_netdev(dev);
847	if (err) {
848		free_netdev(dev);
849		return err;
850	}
851
852	printk(KERN_INFO "%s: SGI MACE Ethernet rev. %d\n",
853	       dev->name, (unsigned int)(mace->eth.mac_ctrl >> 29));
854	return 0;
855}
856
857static void meth_remove(struct platform_device *pdev)
858{
859	struct net_device *dev = platform_get_drvdata(pdev);
860
861	unregister_netdev(dev);
862	free_netdev(dev);
863}
864
865static struct platform_driver meth_driver = {
866	.probe	= meth_probe,
867	.remove_new = meth_remove,
868	.driver = {
869		.name	= "meth",
870	}
871};
872
873module_platform_driver(meth_driver);
874
875MODULE_AUTHOR("Ilya Volynets <ilya@theIlya.com>");
876MODULE_DESCRIPTION("SGI O2 Builtin Fast Ethernet driver");
877MODULE_LICENSE("GPL");
878MODULE_ALIAS("platform:meth");
879