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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/init.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/slab.h>
18 #include <linux/errno.h>
19 #include <linux/types.h>
20 #include <linux/interrupt.h>
21 
22 #include <linux/in.h>
23 #include <linux/in6.h>
24 #include <linux/device.h> /* struct device, et al */
25 #include <linux/netdevice.h>   /* struct device, and other headers */
26 #include <linux/etherdevice.h> /* eth_type_trans */
27 #include <linux/ip.h>          /* struct iphdr */
28 #include <linux/tcp.h>         /* struct tcphdr */
29 #include <linux/skbuff.h>
30 #include <linux/mii.h>         /* MII definitions */
31 #include <linux/crc32.h>
32 
33 #include <asm/ip32/mace.h>
34 #include <asm/ip32/ip32_ints.h>
35 
36 #include <asm/io.h>
37 
38 #include "meth.h"
39 
40 #ifndef MFE_DEBUG
41 #define MFE_DEBUG 0
42 #endif
43 
44 #if MFE_DEBUG>=1
45 #define DPRINTK(str,args...) printk(KERN_DEBUG "meth: %s: " str, __func__ , ## args)
46 #define MFE_RX_DEBUG 2
47 #else
48 #define DPRINTK(str,args...)
49 #define MFE_RX_DEBUG 0
50 #endif
51 
52 
53 static const char *meth_str="SGI O2 Fast Ethernet";
54 
55 /* The maximum time waited (in jiffies) before assuming a Tx failed. (400ms) */
56 #define TX_TIMEOUT (400*HZ/1000)
57 
58 static int timeout = TX_TIMEOUT;
59 module_param(timeout, int, 0);
60 
61 /*
62  * Maximum number of multicast addresses to filter (vs. Rx-all-multicast).
63  * MACE Ethernet uses a 64 element hash table based on the Ethernet CRC.
64  */
65 #define METH_MCF_LIMIT 32
66 
67 /*
68  * This structure is private to each device. It is used to pass
69  * packets in and out, so there is place for a packet
70  */
71 struct meth_private {
72 	/* in-memory copy of MAC Control register */
73 	u64 mac_ctrl;
74 
75 	/* in-memory copy of DMA Control register */
76 	unsigned long dma_ctrl;
77 	/* address of PHY, used by mdio_* functions, initialized in mdio_probe */
78 	unsigned long phy_addr;
79 	tx_packet *tx_ring;
80 	dma_addr_t tx_ring_dma;
81 	struct sk_buff *tx_skbs[TX_RING_ENTRIES];
82 	dma_addr_t tx_skb_dmas[TX_RING_ENTRIES];
83 	unsigned long tx_read, tx_write, tx_count;
84 
85 	rx_packet *rx_ring[RX_RING_ENTRIES];
86 	dma_addr_t rx_ring_dmas[RX_RING_ENTRIES];
87 	struct sk_buff *rx_skbs[RX_RING_ENTRIES];
88 	unsigned long rx_write;
89 
90 	/* Multicast filter. */
91 	u64 mcast_filter;
92 
93 	spinlock_t meth_lock;
94 };
95 
96 static void meth_tx_timeout(struct net_device *dev);
97 static irqreturn_t meth_interrupt(int irq, void *dev_id);
98 
99 /* global, initialized in ip32-setup.c */
100 char o2meth_eaddr[8]={0,0,0,0,0,0,0,0};
101 
load_eaddr(struct net_device * dev)102 static inline void load_eaddr(struct net_device *dev)
103 {
104 	int i;
105 	u64 macaddr;
106 
107 	DPRINTK("Loading MAC Address: %pM\n", dev->dev_addr);
108 	macaddr = 0;
109 	for (i = 0; i < 6; i++)
110 		macaddr |= (u64)dev->dev_addr[i] << ((5 - i) * 8);
111 
112 	mace->eth.mac_addr = macaddr;
113 }
114 
115 /*
116  * Waits for BUSY status of mdio bus to clear
117  */
118 #define WAIT_FOR_PHY(___rval)					\
119 	while ((___rval = mace->eth.phy_data) & MDIO_BUSY) {	\
120 		udelay(25);					\
121 	}
122 /*read phy register, return value read */
mdio_read(struct meth_private * priv,unsigned long phyreg)123 static unsigned long mdio_read(struct meth_private *priv, unsigned long phyreg)
124 {
125 	unsigned long rval;
126 	WAIT_FOR_PHY(rval);
127 	mace->eth.phy_regs = (priv->phy_addr << 5) | (phyreg & 0x1f);
128 	udelay(25);
129 	mace->eth.phy_trans_go = 1;
130 	udelay(25);
131 	WAIT_FOR_PHY(rval);
132 	return rval & MDIO_DATA_MASK;
133 }
134 
mdio_probe(struct meth_private * priv)135 static int mdio_probe(struct meth_private *priv)
136 {
137 	int i;
138 	unsigned long p2, p3, flags;
139 	/* check if phy is detected already */
140 	if(priv->phy_addr>=0&&priv->phy_addr<32)
141 		return 0;
142 	spin_lock_irqsave(&priv->meth_lock, flags);
143 	for (i=0;i<32;++i){
144 		priv->phy_addr=i;
145 		p2=mdio_read(priv,2);
146 		p3=mdio_read(priv,3);
147 #if MFE_DEBUG>=2
148 		switch ((p2<<12)|(p3>>4)){
149 		case PHY_QS6612X:
150 			DPRINTK("PHY is QS6612X\n");
151 			break;
152 		case PHY_ICS1889:
153 			DPRINTK("PHY is ICS1889\n");
154 			break;
155 		case PHY_ICS1890:
156 			DPRINTK("PHY is ICS1890\n");
157 			break;
158 		case PHY_DP83840:
159 			DPRINTK("PHY is DP83840\n");
160 			break;
161 		}
162 #endif
163 		if(p2!=0xffff&&p2!=0x0000){
164 			DPRINTK("PHY code: %x\n",(p2<<12)|(p3>>4));
165 			break;
166 		}
167 	}
168 	spin_unlock_irqrestore(&priv->meth_lock, flags);
169 	if(priv->phy_addr<32) {
170 		return 0;
171 	}
172 	DPRINTK("Oopsie! PHY is not known!\n");
173 	priv->phy_addr=-1;
174 	return -ENODEV;
175 }
176 
meth_check_link(struct net_device * dev)177 static void meth_check_link(struct net_device *dev)
178 {
179 	struct meth_private *priv = netdev_priv(dev);
180 	unsigned long mii_advertising = mdio_read(priv, 4);
181 	unsigned long mii_partner = mdio_read(priv, 5);
182 	unsigned long negotiated = mii_advertising & mii_partner;
183 	unsigned long duplex, speed;
184 
185 	if (mii_partner == 0xffff)
186 		return;
187 
188 	speed = (negotiated & 0x0380) ? METH_100MBIT : 0;
189 	duplex = ((negotiated & 0x0100) || (negotiated & 0x01C0) == 0x0040) ?
190 		 METH_PHY_FDX : 0;
191 
192 	if ((priv->mac_ctrl & METH_PHY_FDX) ^ duplex) {
193 		DPRINTK("Setting %s-duplex\n", duplex ? "full" : "half");
194 		if (duplex)
195 			priv->mac_ctrl |= METH_PHY_FDX;
196 		else
197 			priv->mac_ctrl &= ~METH_PHY_FDX;
198 		mace->eth.mac_ctrl = priv->mac_ctrl;
199 	}
200 
201 	if ((priv->mac_ctrl & METH_100MBIT) ^ speed) {
202 		DPRINTK("Setting %dMbs mode\n", speed ? 100 : 10);
203 		if (duplex)
204 			priv->mac_ctrl |= METH_100MBIT;
205 		else
206 			priv->mac_ctrl &= ~METH_100MBIT;
207 		mace->eth.mac_ctrl = priv->mac_ctrl;
208 	}
209 }
210 
211 
meth_init_tx_ring(struct meth_private * priv)212 static int meth_init_tx_ring(struct meth_private *priv)
213 {
214 	/* Init TX ring */
215 	priv->tx_ring = dma_alloc_coherent(NULL, TX_RING_BUFFER_SIZE,
216 	                                   &priv->tx_ring_dma,
217 					   GFP_ATOMIC | __GFP_ZERO);
218 	if (!priv->tx_ring)
219 		return -ENOMEM;
220 
221 	priv->tx_count = priv->tx_read = priv->tx_write = 0;
222 	mace->eth.tx_ring_base = priv->tx_ring_dma;
223 	/* Now init skb save area */
224 	memset(priv->tx_skbs, 0, sizeof(priv->tx_skbs));
225 	memset(priv->tx_skb_dmas, 0, sizeof(priv->tx_skb_dmas));
226 	return 0;
227 }
228 
meth_init_rx_ring(struct meth_private * priv)229 static int meth_init_rx_ring(struct meth_private *priv)
230 {
231 	int i;
232 
233 	for (i = 0; i < RX_RING_ENTRIES; i++) {
234 		priv->rx_skbs[i] = alloc_skb(METH_RX_BUFF_SIZE, 0);
235 		/* 8byte status vector + 3quad padding + 2byte padding,
236 		 * to put data on 64bit aligned boundary */
237 		skb_reserve(priv->rx_skbs[i],METH_RX_HEAD);
238 		priv->rx_ring[i]=(rx_packet*)(priv->rx_skbs[i]->head);
239 		/* I'll need to re-sync it after each RX */
240 		priv->rx_ring_dmas[i] =
241 			dma_map_single(NULL, priv->rx_ring[i],
242 				       METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
243 		mace->eth.rx_fifo = priv->rx_ring_dmas[i];
244 	}
245         priv->rx_write = 0;
246 	return 0;
247 }
meth_free_tx_ring(struct meth_private * priv)248 static void meth_free_tx_ring(struct meth_private *priv)
249 {
250 	int i;
251 
252 	/* Remove any pending skb */
253 	for (i = 0; i < TX_RING_ENTRIES; i++) {
254 		if (priv->tx_skbs[i])
255 			dev_kfree_skb(priv->tx_skbs[i]);
256 		priv->tx_skbs[i] = NULL;
257 	}
258 	dma_free_coherent(NULL, TX_RING_BUFFER_SIZE, priv->tx_ring,
259 	                  priv->tx_ring_dma);
260 }
261 
262 /* Presumes RX DMA engine is stopped, and RX fifo ring is reset */
meth_free_rx_ring(struct meth_private * priv)263 static void meth_free_rx_ring(struct meth_private *priv)
264 {
265 	int i;
266 
267 	for (i = 0; i < RX_RING_ENTRIES; i++) {
268 		dma_unmap_single(NULL, priv->rx_ring_dmas[i],
269 				 METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
270 		priv->rx_ring[i] = 0;
271 		priv->rx_ring_dmas[i] = 0;
272 		kfree_skb(priv->rx_skbs[i]);
273 	}
274 }
275 
meth_reset(struct net_device * dev)276 int meth_reset(struct net_device *dev)
277 {
278 	struct meth_private *priv = netdev_priv(dev);
279 
280 	/* Reset card */
281 	mace->eth.mac_ctrl = SGI_MAC_RESET;
282 	udelay(1);
283 	mace->eth.mac_ctrl = 0;
284 	udelay(25);
285 
286 	/* Load ethernet address */
287 	load_eaddr(dev);
288 	/* Should load some "errata", but later */
289 
290 	/* Check for device */
291 	if (mdio_probe(priv) < 0) {
292 		DPRINTK("Unable to find PHY\n");
293 		return -ENODEV;
294 	}
295 
296 	/* Initial mode: 10 | Half-duplex | Accept normal packets */
297 	priv->mac_ctrl = METH_ACCEPT_MCAST | METH_DEFAULT_IPG;
298 	if (dev->flags & IFF_PROMISC)
299 		priv->mac_ctrl |= METH_PROMISC;
300 	mace->eth.mac_ctrl = priv->mac_ctrl;
301 
302 	/* Autonegotiate speed and duplex mode */
303 	meth_check_link(dev);
304 
305 	/* Now set dma control, but don't enable DMA, yet */
306 	priv->dma_ctrl = (4 << METH_RX_OFFSET_SHIFT) |
307 			 (RX_RING_ENTRIES << METH_RX_DEPTH_SHIFT);
308 	mace->eth.dma_ctrl = priv->dma_ctrl;
309 
310 	return 0;
311 }
312 
313 /*============End Helper Routines=====================*/
314 
315 /*
316  * Open and close
317  */
meth_open(struct net_device * dev)318 static int meth_open(struct net_device *dev)
319 {
320 	struct meth_private *priv = netdev_priv(dev);
321 	int ret;
322 
323 	priv->phy_addr = -1;    /* No PHY is known yet... */
324 
325 	/* Initialize the hardware */
326 	ret = meth_reset(dev);
327 	if (ret < 0)
328 		return ret;
329 
330 	/* Allocate the ring buffers */
331 	ret = meth_init_tx_ring(priv);
332 	if (ret < 0)
333 		return ret;
334 	ret = meth_init_rx_ring(priv);
335 	if (ret < 0)
336 		goto out_free_tx_ring;
337 
338 	ret = request_irq(dev->irq, meth_interrupt, 0, meth_str, dev);
339 	if (ret) {
340 		printk(KERN_ERR "%s: Can't get irq %d\n", dev->name, dev->irq);
341 		goto out_free_rx_ring;
342 	}
343 
344 	/* Start DMA */
345 	priv->dma_ctrl |= METH_DMA_TX_EN | /*METH_DMA_TX_INT_EN |*/
346 			  METH_DMA_RX_EN | METH_DMA_RX_INT_EN;
347 	mace->eth.dma_ctrl = priv->dma_ctrl;
348 
349 	DPRINTK("About to start queue\n");
350 	netif_start_queue(dev);
351 
352 	return 0;
353 
354 out_free_rx_ring:
355 	meth_free_rx_ring(priv);
356 out_free_tx_ring:
357 	meth_free_tx_ring(priv);
358 
359 	return ret;
360 }
361 
meth_release(struct net_device * dev)362 static int meth_release(struct net_device *dev)
363 {
364 	struct meth_private *priv = netdev_priv(dev);
365 
366 	DPRINTK("Stopping queue\n");
367 	netif_stop_queue(dev); /* can't transmit any more */
368 	/* shut down DMA */
369 	priv->dma_ctrl &= ~(METH_DMA_TX_EN | METH_DMA_TX_INT_EN |
370 			    METH_DMA_RX_EN | METH_DMA_RX_INT_EN);
371 	mace->eth.dma_ctrl = priv->dma_ctrl;
372 	free_irq(dev->irq, dev);
373 	meth_free_tx_ring(priv);
374 	meth_free_rx_ring(priv);
375 
376 	return 0;
377 }
378 
379 /*
380  * Receive a packet: retrieve, encapsulate and pass over to upper levels
381  */
meth_rx(struct net_device * dev,unsigned long int_status)382 static void meth_rx(struct net_device* dev, unsigned long int_status)
383 {
384 	struct sk_buff *skb;
385 	unsigned long status, flags;
386 	struct meth_private *priv = netdev_priv(dev);
387 	unsigned long fifo_rptr = (int_status & METH_INT_RX_RPTR_MASK) >> 8;
388 
389 	spin_lock_irqsave(&priv->meth_lock, flags);
390 	priv->dma_ctrl &= ~METH_DMA_RX_INT_EN;
391 	mace->eth.dma_ctrl = priv->dma_ctrl;
392 	spin_unlock_irqrestore(&priv->meth_lock, flags);
393 
394 	if (int_status & METH_INT_RX_UNDERFLOW) {
395 		fifo_rptr = (fifo_rptr - 1) & 0x0f;
396 	}
397 	while (priv->rx_write != fifo_rptr) {
398 		dma_unmap_single(NULL, priv->rx_ring_dmas[priv->rx_write],
399 				 METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
400 		status = priv->rx_ring[priv->rx_write]->status.raw;
401 #if MFE_DEBUG
402 		if (!(status & METH_RX_ST_VALID)) {
403 			DPRINTK("Not received? status=%016lx\n",status);
404 		}
405 #endif
406 		if ((!(status & METH_RX_STATUS_ERRORS)) && (status & METH_RX_ST_VALID)) {
407 			int len = (status & 0xffff) - 4; /* omit CRC */
408 			/* length sanity check */
409 			if (len < 60 || len > 1518) {
410 				printk(KERN_DEBUG "%s: bogus packet size: %ld, status=%#2Lx.\n",
411 				       dev->name, priv->rx_write,
412 				       priv->rx_ring[priv->rx_write]->status.raw);
413 				dev->stats.rx_errors++;
414 				dev->stats.rx_length_errors++;
415 				skb = priv->rx_skbs[priv->rx_write];
416 			} else {
417 				skb = alloc_skb(METH_RX_BUFF_SIZE, GFP_ATOMIC);
418 				if (!skb) {
419 					/* Ouch! No memory! Drop packet on the floor */
420 					DPRINTK("No mem: dropping packet\n");
421 					dev->stats.rx_dropped++;
422 					skb = priv->rx_skbs[priv->rx_write];
423 				} else {
424 					struct sk_buff *skb_c = priv->rx_skbs[priv->rx_write];
425 					/* 8byte status vector + 3quad padding + 2byte padding,
426 					 * to put data on 64bit aligned boundary */
427 					skb_reserve(skb, METH_RX_HEAD);
428 					/* Write metadata, and then pass to the receive level */
429 					skb_put(skb_c, len);
430 					priv->rx_skbs[priv->rx_write] = skb;
431 					skb_c->protocol = eth_type_trans(skb_c, dev);
432 					dev->stats.rx_packets++;
433 					dev->stats.rx_bytes += len;
434 					netif_rx(skb_c);
435 				}
436 			}
437 		} else {
438 			dev->stats.rx_errors++;
439 			skb=priv->rx_skbs[priv->rx_write];
440 #if MFE_DEBUG>0
441 			printk(KERN_WARNING "meth: RX error: status=0x%016lx\n",status);
442 			if(status&METH_RX_ST_RCV_CODE_VIOLATION)
443 				printk(KERN_WARNING "Receive Code Violation\n");
444 			if(status&METH_RX_ST_CRC_ERR)
445 				printk(KERN_WARNING "CRC error\n");
446 			if(status&METH_RX_ST_INV_PREAMBLE_CTX)
447 				printk(KERN_WARNING "Invalid Preamble Context\n");
448 			if(status&METH_RX_ST_LONG_EVT_SEEN)
449 				printk(KERN_WARNING "Long Event Seen...\n");
450 			if(status&METH_RX_ST_BAD_PACKET)
451 				printk(KERN_WARNING "Bad Packet\n");
452 			if(status&METH_RX_ST_CARRIER_EVT_SEEN)
453 				printk(KERN_WARNING "Carrier Event Seen\n");
454 #endif
455 		}
456 		priv->rx_ring[priv->rx_write] = (rx_packet*)skb->head;
457 		priv->rx_ring[priv->rx_write]->status.raw = 0;
458 		priv->rx_ring_dmas[priv->rx_write] =
459 			dma_map_single(NULL, priv->rx_ring[priv->rx_write],
460 				       METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
461 		mace->eth.rx_fifo = priv->rx_ring_dmas[priv->rx_write];
462 		ADVANCE_RX_PTR(priv->rx_write);
463 	}
464 	spin_lock_irqsave(&priv->meth_lock, flags);
465 	/* In case there was underflow, and Rx DMA was disabled */
466 	priv->dma_ctrl |= METH_DMA_RX_INT_EN | METH_DMA_RX_EN;
467 	mace->eth.dma_ctrl = priv->dma_ctrl;
468 	mace->eth.int_stat = METH_INT_RX_THRESHOLD;
469 	spin_unlock_irqrestore(&priv->meth_lock, flags);
470 }
471 
meth_tx_full(struct net_device * dev)472 static int meth_tx_full(struct net_device *dev)
473 {
474 	struct meth_private *priv = netdev_priv(dev);
475 
476 	return priv->tx_count >= TX_RING_ENTRIES - 1;
477 }
478 
meth_tx_cleanup(struct net_device * dev,unsigned long int_status)479 static void meth_tx_cleanup(struct net_device* dev, unsigned long int_status)
480 {
481 	struct meth_private *priv = netdev_priv(dev);
482 	unsigned long status, flags;
483 	struct sk_buff *skb;
484 	unsigned long rptr = (int_status&TX_INFO_RPTR) >> 16;
485 
486 	spin_lock_irqsave(&priv->meth_lock, flags);
487 
488 	/* Stop DMA notification */
489 	priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
490 	mace->eth.dma_ctrl = priv->dma_ctrl;
491 
492 	while (priv->tx_read != rptr) {
493 		skb = priv->tx_skbs[priv->tx_read];
494 		status = priv->tx_ring[priv->tx_read].header.raw;
495 #if MFE_DEBUG>=1
496 		if (priv->tx_read == priv->tx_write)
497 			DPRINTK("Auchi! tx_read=%d,tx_write=%d,rptr=%d?\n", priv->tx_read, priv->tx_write,rptr);
498 #endif
499 		if (status & METH_TX_ST_DONE) {
500 			if (status & METH_TX_ST_SUCCESS){
501 				dev->stats.tx_packets++;
502 				dev->stats.tx_bytes += skb->len;
503 			} else {
504 				dev->stats.tx_errors++;
505 #if MFE_DEBUG>=1
506 				DPRINTK("TX error: status=%016lx <",status);
507 				if(status & METH_TX_ST_SUCCESS)
508 					printk(" SUCCESS");
509 				if(status & METH_TX_ST_TOOLONG)
510 					printk(" TOOLONG");
511 				if(status & METH_TX_ST_UNDERRUN)
512 					printk(" UNDERRUN");
513 				if(status & METH_TX_ST_EXCCOLL)
514 					printk(" EXCCOLL");
515 				if(status & METH_TX_ST_DEFER)
516 					printk(" DEFER");
517 				if(status & METH_TX_ST_LATECOLL)
518 					printk(" LATECOLL");
519 				printk(" >\n");
520 #endif
521 			}
522 		} else {
523 			DPRINTK("RPTR points us here, but packet not done?\n");
524 			break;
525 		}
526 		dev_kfree_skb_irq(skb);
527 		priv->tx_skbs[priv->tx_read] = NULL;
528 		priv->tx_ring[priv->tx_read].header.raw = 0;
529 		priv->tx_read = (priv->tx_read+1)&(TX_RING_ENTRIES-1);
530 		priv->tx_count--;
531 	}
532 
533 	/* wake up queue if it was stopped */
534 	if (netif_queue_stopped(dev) && !meth_tx_full(dev)) {
535 		netif_wake_queue(dev);
536 	}
537 
538 	mace->eth.int_stat = METH_INT_TX_EMPTY | METH_INT_TX_PKT;
539 	spin_unlock_irqrestore(&priv->meth_lock, flags);
540 }
541 
meth_error(struct net_device * dev,unsigned status)542 static void meth_error(struct net_device* dev, unsigned status)
543 {
544 	struct meth_private *priv = netdev_priv(dev);
545 	unsigned long flags;
546 
547 	printk(KERN_WARNING "meth: error status: 0x%08x\n",status);
548 	/* check for errors too... */
549 	if (status & (METH_INT_TX_LINK_FAIL))
550 		printk(KERN_WARNING "meth: link failure\n");
551 	/* Should I do full reset in this case? */
552 	if (status & (METH_INT_MEM_ERROR))
553 		printk(KERN_WARNING "meth: memory error\n");
554 	if (status & (METH_INT_TX_ABORT))
555 		printk(KERN_WARNING "meth: aborted\n");
556 	if (status & (METH_INT_RX_OVERFLOW))
557 		printk(KERN_WARNING "meth: Rx overflow\n");
558 	if (status & (METH_INT_RX_UNDERFLOW)) {
559 		printk(KERN_WARNING "meth: Rx underflow\n");
560 		spin_lock_irqsave(&priv->meth_lock, flags);
561 		mace->eth.int_stat = METH_INT_RX_UNDERFLOW;
562 		/* more underflow interrupts will be delivered,
563 		 * effectively throwing us into an infinite loop.
564 		 *  Thus I stop processing Rx in this case. */
565 		priv->dma_ctrl &= ~METH_DMA_RX_EN;
566 		mace->eth.dma_ctrl = priv->dma_ctrl;
567 		DPRINTK("Disabled meth Rx DMA temporarily\n");
568 		spin_unlock_irqrestore(&priv->meth_lock, flags);
569 	}
570 	mace->eth.int_stat = METH_INT_ERROR;
571 }
572 
573 /*
574  * The typical interrupt entry point
575  */
meth_interrupt(int irq,void * dev_id)576 static irqreturn_t meth_interrupt(int irq, void *dev_id)
577 {
578 	struct net_device *dev = (struct net_device *)dev_id;
579 	struct meth_private *priv = netdev_priv(dev);
580 	unsigned long status;
581 
582 	status = mace->eth.int_stat;
583 	while (status & 0xff) {
584 		/* First handle errors - if we get Rx underflow,
585 		 * Rx DMA will be disabled, and Rx handler will reenable
586 		 * it. I don't think it's possible to get Rx underflow,
587 		 * without getting Rx interrupt */
588 		if (status & METH_INT_ERROR) {
589 			meth_error(dev, status);
590 		}
591 		if (status & (METH_INT_TX_EMPTY | METH_INT_TX_PKT)) {
592 			/* a transmission is over: free the skb */
593 			meth_tx_cleanup(dev, status);
594 		}
595 		if (status & METH_INT_RX_THRESHOLD) {
596 			if (!(priv->dma_ctrl & METH_DMA_RX_INT_EN))
597 				break;
598 			/* send it to meth_rx for handling */
599 			meth_rx(dev, status);
600 		}
601 		status = mace->eth.int_stat;
602 	}
603 
604 	return IRQ_HANDLED;
605 }
606 
607 /*
608  * Transmits packets that fit into TX descriptor (are <=120B)
609  */
meth_tx_short_prepare(struct meth_private * priv,struct sk_buff * skb)610 static void meth_tx_short_prepare(struct meth_private *priv,
611 				  struct sk_buff *skb)
612 {
613 	tx_packet *desc = &priv->tx_ring[priv->tx_write];
614 	int len = (skb->len < ETH_ZLEN) ? ETH_ZLEN : skb->len;
615 
616 	desc->header.raw = METH_TX_CMD_INT_EN | (len-1) | ((128-len) << 16);
617 	/* maybe I should set whole thing to 0 first... */
618 	skb_copy_from_linear_data(skb, desc->data.dt + (120 - len), skb->len);
619 	if (skb->len < len)
620 		memset(desc->data.dt + 120 - len + skb->len, 0, len-skb->len);
621 }
622 #define TX_CATBUF1 BIT(25)
meth_tx_1page_prepare(struct meth_private * priv,struct sk_buff * skb)623 static void meth_tx_1page_prepare(struct meth_private *priv,
624 				  struct sk_buff *skb)
625 {
626 	tx_packet *desc = &priv->tx_ring[priv->tx_write];
627 	void *buffer_data = (void *)(((unsigned long)skb->data + 7) & ~7);
628 	int unaligned_len = (int)((unsigned long)buffer_data - (unsigned long)skb->data);
629 	int buffer_len = skb->len - unaligned_len;
630 	dma_addr_t catbuf;
631 
632 	desc->header.raw = METH_TX_CMD_INT_EN | TX_CATBUF1 | (skb->len - 1);
633 
634 	/* unaligned part */
635 	if (unaligned_len) {
636 		skb_copy_from_linear_data(skb, desc->data.dt + (120 - unaligned_len),
637 			      unaligned_len);
638 		desc->header.raw |= (128 - unaligned_len) << 16;
639 	}
640 
641 	/* first page */
642 	catbuf = dma_map_single(NULL, buffer_data, buffer_len,
643 				DMA_TO_DEVICE);
644 	desc->data.cat_buf[0].form.start_addr = catbuf >> 3;
645 	desc->data.cat_buf[0].form.len = buffer_len - 1;
646 }
647 #define TX_CATBUF2 BIT(26)
meth_tx_2page_prepare(struct meth_private * priv,struct sk_buff * skb)648 static void meth_tx_2page_prepare(struct meth_private *priv,
649 				  struct sk_buff *skb)
650 {
651 	tx_packet *desc = &priv->tx_ring[priv->tx_write];
652 	void *buffer1_data = (void *)(((unsigned long)skb->data + 7) & ~7);
653 	void *buffer2_data = (void *)PAGE_ALIGN((unsigned long)skb->data);
654 	int unaligned_len = (int)((unsigned long)buffer1_data - (unsigned long)skb->data);
655 	int buffer1_len = (int)((unsigned long)buffer2_data - (unsigned long)buffer1_data);
656 	int buffer2_len = skb->len - buffer1_len - unaligned_len;
657 	dma_addr_t catbuf1, catbuf2;
658 
659 	desc->header.raw = METH_TX_CMD_INT_EN | TX_CATBUF1 | TX_CATBUF2| (skb->len - 1);
660 	/* unaligned part */
661 	if (unaligned_len){
662 		skb_copy_from_linear_data(skb, desc->data.dt + (120 - unaligned_len),
663 			      unaligned_len);
664 		desc->header.raw |= (128 - unaligned_len) << 16;
665 	}
666 
667 	/* first page */
668 	catbuf1 = dma_map_single(NULL, buffer1_data, buffer1_len,
669 				 DMA_TO_DEVICE);
670 	desc->data.cat_buf[0].form.start_addr = catbuf1 >> 3;
671 	desc->data.cat_buf[0].form.len = buffer1_len - 1;
672 	/* second page */
673 	catbuf2 = dma_map_single(NULL, buffer2_data, buffer2_len,
674 				 DMA_TO_DEVICE);
675 	desc->data.cat_buf[1].form.start_addr = catbuf2 >> 3;
676 	desc->data.cat_buf[1].form.len = buffer2_len - 1;
677 }
678 
meth_add_to_tx_ring(struct meth_private * priv,struct sk_buff * skb)679 static void meth_add_to_tx_ring(struct meth_private *priv, struct sk_buff *skb)
680 {
681 	/* Remember the skb, so we can free it at interrupt time */
682 	priv->tx_skbs[priv->tx_write] = skb;
683 	if (skb->len <= 120) {
684 		/* Whole packet fits into descriptor */
685 		meth_tx_short_prepare(priv, skb);
686 	} else if (PAGE_ALIGN((unsigned long)skb->data) !=
687 		   PAGE_ALIGN((unsigned long)skb->data + skb->len - 1)) {
688 		/* Packet crosses page boundary */
689 		meth_tx_2page_prepare(priv, skb);
690 	} else {
691 		/* Packet is in one page */
692 		meth_tx_1page_prepare(priv, skb);
693 	}
694 	priv->tx_write = (priv->tx_write + 1) & (TX_RING_ENTRIES - 1);
695 	mace->eth.tx_info = priv->tx_write;
696 	priv->tx_count++;
697 }
698 
699 /*
700  * Transmit a packet (called by the kernel)
701  */
meth_tx(struct sk_buff * skb,struct net_device * dev)702 static int meth_tx(struct sk_buff *skb, struct net_device *dev)
703 {
704 	struct meth_private *priv = netdev_priv(dev);
705 	unsigned long flags;
706 
707 	spin_lock_irqsave(&priv->meth_lock, flags);
708 	/* Stop DMA notification */
709 	priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
710 	mace->eth.dma_ctrl = priv->dma_ctrl;
711 
712 	meth_add_to_tx_ring(priv, skb);
713 	dev->trans_start = jiffies; /* save the timestamp */
714 
715 	/* If TX ring is full, tell the upper layer to stop sending packets */
716 	if (meth_tx_full(dev)) {
717 	        printk(KERN_DEBUG "TX full: stopping\n");
718 		netif_stop_queue(dev);
719 	}
720 
721 	/* Restart DMA notification */
722 	priv->dma_ctrl |= METH_DMA_TX_INT_EN;
723 	mace->eth.dma_ctrl = priv->dma_ctrl;
724 
725 	spin_unlock_irqrestore(&priv->meth_lock, flags);
726 
727 	return NETDEV_TX_OK;
728 }
729 
730 /*
731  * Deal with a transmit timeout.
732  */
meth_tx_timeout(struct net_device * dev)733 static void meth_tx_timeout(struct net_device *dev)
734 {
735 	struct meth_private *priv = netdev_priv(dev);
736 	unsigned long flags;
737 
738 	printk(KERN_WARNING "%s: transmit timed out\n", dev->name);
739 
740 	/* Protect against concurrent rx interrupts */
741 	spin_lock_irqsave(&priv->meth_lock,flags);
742 
743 	/* Try to reset the interface. */
744 	meth_reset(dev);
745 
746 	dev->stats.tx_errors++;
747 
748 	/* Clear all rings */
749 	meth_free_tx_ring(priv);
750 	meth_free_rx_ring(priv);
751 	meth_init_tx_ring(priv);
752 	meth_init_rx_ring(priv);
753 
754 	/* Restart dma */
755 	priv->dma_ctrl |= METH_DMA_TX_EN | METH_DMA_RX_EN | METH_DMA_RX_INT_EN;
756 	mace->eth.dma_ctrl = priv->dma_ctrl;
757 
758 	/* Enable interrupt */
759 	spin_unlock_irqrestore(&priv->meth_lock, flags);
760 
761 	dev->trans_start = jiffies; /* prevent tx timeout */
762 	netif_wake_queue(dev);
763 }
764 
765 /*
766  * Ioctl commands
767  */
meth_ioctl(struct net_device * dev,struct ifreq * rq,int cmd)768 static int meth_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
769 {
770 	/* XXX Not yet implemented */
771 	switch(cmd) {
772 	case SIOCGMIIPHY:
773 	case SIOCGMIIREG:
774 	case SIOCSMIIREG:
775 	default:
776 		return -EOPNOTSUPP;
777 	}
778 }
779 
meth_set_rx_mode(struct net_device * dev)780 static void meth_set_rx_mode(struct net_device *dev)
781 {
782 	struct meth_private *priv = netdev_priv(dev);
783 	unsigned long flags;
784 
785 	netif_stop_queue(dev);
786 	spin_lock_irqsave(&priv->meth_lock, flags);
787 	priv->mac_ctrl &= ~METH_PROMISC;
788 
789 	if (dev->flags & IFF_PROMISC) {
790 		priv->mac_ctrl |= METH_PROMISC;
791 		priv->mcast_filter = 0xffffffffffffffffUL;
792 	} else if ((netdev_mc_count(dev) > METH_MCF_LIMIT) ||
793 		   (dev->flags & IFF_ALLMULTI)) {
794 		priv->mac_ctrl |= METH_ACCEPT_AMCAST;
795 		priv->mcast_filter = 0xffffffffffffffffUL;
796 	} else {
797 		struct netdev_hw_addr *ha;
798 		priv->mac_ctrl |= METH_ACCEPT_MCAST;
799 
800 		netdev_for_each_mc_addr(ha, dev)
801 			set_bit((ether_crc(ETH_ALEN, ha->addr) >> 26),
802 			        (volatile unsigned long *)&priv->mcast_filter);
803 	}
804 
805 	/* Write the changes to the chip registers. */
806 	mace->eth.mac_ctrl = priv->mac_ctrl;
807 	mace->eth.mcast_filter = priv->mcast_filter;
808 
809 	/* Done! */
810 	spin_unlock_irqrestore(&priv->meth_lock, flags);
811 	netif_wake_queue(dev);
812 }
813 
814 static const struct net_device_ops meth_netdev_ops = {
815 	.ndo_open		= meth_open,
816 	.ndo_stop		= meth_release,
817 	.ndo_start_xmit		= meth_tx,
818 	.ndo_do_ioctl		= meth_ioctl,
819 	.ndo_tx_timeout		= meth_tx_timeout,
820 	.ndo_change_mtu		= eth_change_mtu,
821 	.ndo_validate_addr	= eth_validate_addr,
822 	.ndo_set_mac_address	= eth_mac_addr,
823 	.ndo_set_rx_mode    	= meth_set_rx_mode,
824 };
825 
826 /*
827  * The init function.
828  */
meth_probe(struct platform_device * pdev)829 static int meth_probe(struct platform_device *pdev)
830 {
831 	struct net_device *dev;
832 	struct meth_private *priv;
833 	int err;
834 
835 	dev = alloc_etherdev(sizeof(struct meth_private));
836 	if (!dev)
837 		return -ENOMEM;
838 
839 	dev->netdev_ops		= &meth_netdev_ops;
840 	dev->watchdog_timeo	= timeout;
841 	dev->irq		= MACE_ETHERNET_IRQ;
842 	dev->base_addr		= (unsigned long)&mace->eth;
843 	memcpy(dev->dev_addr, o2meth_eaddr, 6);
844 
845 	priv = netdev_priv(dev);
846 	spin_lock_init(&priv->meth_lock);
847 	SET_NETDEV_DEV(dev, &pdev->dev);
848 
849 	err = register_netdev(dev);
850 	if (err) {
851 		free_netdev(dev);
852 		return err;
853 	}
854 
855 	printk(KERN_INFO "%s: SGI MACE Ethernet rev. %d\n",
856 	       dev->name, (unsigned int)(mace->eth.mac_ctrl >> 29));
857 	return 0;
858 }
859 
meth_remove(struct platform_device * pdev)860 static int __exit meth_remove(struct platform_device *pdev)
861 {
862 	struct net_device *dev = platform_get_drvdata(pdev);
863 
864 	unregister_netdev(dev);
865 	free_netdev(dev);
866 	platform_set_drvdata(pdev, NULL);
867 
868 	return 0;
869 }
870 
871 static struct platform_driver meth_driver = {
872 	.probe	= meth_probe,
873 	.remove	= __exit_p(meth_remove),
874 	.driver = {
875 		.name	= "meth",
876 		.owner	= THIS_MODULE,
877 	}
878 };
879 
880 module_platform_driver(meth_driver);
881 
882 MODULE_AUTHOR("Ilya Volynets <ilya@theIlya.com>");
883 MODULE_DESCRIPTION("SGI O2 Builtin Fast Ethernet driver");
884 MODULE_LICENSE("GPL");
885 MODULE_ALIAS("platform:meth");
886