1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Driver for SGI's IOC3 based Ethernet cards as found in the PCI card.
7  *
8  * Copyright (C) 1999, 2000, 01, 03, 06 Ralf Baechle
9  * Copyright (C) 1995, 1999, 2000, 2001 by Silicon Graphics, Inc.
10  *
11  * References:
12  *  o IOC3 ASIC specification 4.51, 1996-04-18
13  *  o IEEE 802.3 specification, 2000 edition
14  *  o DP38840A Specification, National Semiconductor, March 1997
15  *
16  * To do:
17  *
18  *  o Handle allocation failures in ioc3_alloc_skb() more gracefully.
19  *  o Handle allocation failures in ioc3_init_rings().
20  *  o Use prefetching for large packets.  What is a good lower limit for
21  *    prefetching?
22  *  o We're probably allocating a bit too much memory.
23  *  o Use hardware checksums.
24  *  o Convert to using a IOC3 meta driver.
25  *  o Which PHYs might possibly be attached to the IOC3 in real live,
26  *    which workarounds are required for them?  Do we ever have Lucent's?
27  *  o For the 2.5 branch kill the mii-tool ioctls.
28  */
29 
30 #define IOC3_NAME	"ioc3-eth"
31 #define IOC3_VERSION	"2.6.3-4"
32 
33 #include <linux/delay.h>
34 #include <linux/kernel.h>
35 #include <linux/mm.h>
36 #include <linux/errno.h>
37 #include <linux/module.h>
38 #include <linux/pci.h>
39 #include <linux/crc32.h>
40 #include <linux/mii.h>
41 #include <linux/in.h>
42 #include <linux/ip.h>
43 #include <linux/tcp.h>
44 #include <linux/udp.h>
45 #include <linux/dma-mapping.h>
46 #include <linux/gfp.h>
47 
48 #ifdef CONFIG_SERIAL_8250
49 #include <linux/serial_core.h>
50 #include <linux/serial_8250.h>
51 #include <linux/serial_reg.h>
52 #endif
53 
54 #include <linux/netdevice.h>
55 #include <linux/etherdevice.h>
56 #include <linux/ethtool.h>
57 #include <linux/skbuff.h>
58 #include <net/ip.h>
59 
60 #include <asm/byteorder.h>
61 #include <asm/io.h>
62 #include <asm/pgtable.h>
63 #include <linux/uaccess.h>
64 #include <asm/sn/types.h>
65 #include <asm/sn/ioc3.h>
66 #include <asm/pci/bridge.h>
67 
68 /*
69  * 64 RX buffers.  This is tunable in the range of 16 <= x < 512.  The
70  * value must be a power of two.
71  */
72 #define RX_BUFFS 64
73 
74 #define ETCSR_FD	((17<<ETCSR_IPGR2_SHIFT) | (11<<ETCSR_IPGR1_SHIFT) | 21)
75 #define ETCSR_HD	((21<<ETCSR_IPGR2_SHIFT) | (21<<ETCSR_IPGR1_SHIFT) | 21)
76 
77 /* Private per NIC data of the driver.  */
78 struct ioc3_private {
79 	struct ioc3 *regs;
80 	unsigned long *rxr;		/* pointer to receiver ring */
81 	struct ioc3_etxd *txr;
82 	struct sk_buff *rx_skbs[512];
83 	struct sk_buff *tx_skbs[128];
84 	int rx_ci;			/* RX consumer index */
85 	int rx_pi;			/* RX producer index */
86 	int tx_ci;			/* TX consumer index */
87 	int tx_pi;			/* TX producer index */
88 	int txqlen;
89 	u32 emcr, ehar_h, ehar_l;
90 	spinlock_t ioc3_lock;
91 	struct mii_if_info mii;
92 
93 	struct net_device *dev;
94 	struct pci_dev *pdev;
95 
96 	/* Members used by autonegotiation  */
97 	struct timer_list ioc3_timer;
98 };
99 
100 static int ioc3_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
101 static void ioc3_set_multicast_list(struct net_device *dev);
102 static netdev_tx_t ioc3_start_xmit(struct sk_buff *skb, struct net_device *dev);
103 static void ioc3_timeout(struct net_device *dev);
104 static inline unsigned int ioc3_hash(const unsigned char *addr);
105 static inline void ioc3_stop(struct ioc3_private *ip);
106 static void ioc3_init(struct net_device *dev);
107 
108 static const char ioc3_str[] = "IOC3 Ethernet";
109 static const struct ethtool_ops ioc3_ethtool_ops;
110 
111 /* We use this to acquire receive skb's that we can DMA directly into. */
112 
113 #define IOC3_CACHELINE	128UL
114 
115 static inline unsigned long aligned_rx_skb_addr(unsigned long addr)
116 {
117 	return (~addr + 1) & (IOC3_CACHELINE - 1UL);
118 }
119 
120 static inline struct sk_buff * ioc3_alloc_skb(unsigned long length,
121 	unsigned int gfp_mask)
122 {
123 	struct sk_buff *skb;
124 
125 	skb = alloc_skb(length + IOC3_CACHELINE - 1, gfp_mask);
126 	if (likely(skb)) {
127 		int offset = aligned_rx_skb_addr((unsigned long) skb->data);
128 		if (offset)
129 			skb_reserve(skb, offset);
130 	}
131 
132 	return skb;
133 }
134 
135 static inline unsigned long ioc3_map(void *ptr, unsigned long vdev)
136 {
137 #ifdef CONFIG_SGI_IP27
138 	vdev <<= 57;   /* Shift to PCI64_ATTR_VIRTUAL */
139 
140 	return vdev | (0xaUL << PCI64_ATTR_TARG_SHFT) | PCI64_ATTR_PREF |
141 	       ((unsigned long)ptr & TO_PHYS_MASK);
142 #else
143 	return virt_to_bus(ptr);
144 #endif
145 }
146 
147 /* BEWARE: The IOC3 documentation documents the size of rx buffers as
148    1644 while it's actually 1664.  This one was nasty to track down ...  */
149 #define RX_OFFSET		10
150 #define RX_BUF_ALLOC_SIZE	(1664 + RX_OFFSET + IOC3_CACHELINE)
151 
152 /* DMA barrier to separate cached and uncached accesses.  */
153 #define BARRIER()							\
154 	__asm__("sync" ::: "memory")
155 
156 
157 #define IOC3_SIZE 0x100000
158 
159 /*
160  * IOC3 is a big endian device
161  *
162  * Unorthodox but makes the users of these macros more readable - the pointer
163  * to the IOC3's memory mapped registers is expected as struct ioc3 * ioc3
164  * in the environment.
165  */
166 #define ioc3_r_mcr()		be32_to_cpu(ioc3->mcr)
167 #define ioc3_w_mcr(v)		do { ioc3->mcr = cpu_to_be32(v); } while (0)
168 #define ioc3_w_gpcr_s(v)	do { ioc3->gpcr_s = cpu_to_be32(v); } while (0)
169 #define ioc3_r_emcr()		be32_to_cpu(ioc3->emcr)
170 #define ioc3_w_emcr(v)		do { ioc3->emcr = cpu_to_be32(v); } while (0)
171 #define ioc3_r_eisr()		be32_to_cpu(ioc3->eisr)
172 #define ioc3_w_eisr(v)		do { ioc3->eisr = cpu_to_be32(v); } while (0)
173 #define ioc3_r_eier()		be32_to_cpu(ioc3->eier)
174 #define ioc3_w_eier(v)		do { ioc3->eier = cpu_to_be32(v); } while (0)
175 #define ioc3_r_ercsr()		be32_to_cpu(ioc3->ercsr)
176 #define ioc3_w_ercsr(v)		do { ioc3->ercsr = cpu_to_be32(v); } while (0)
177 #define ioc3_r_erbr_h()		be32_to_cpu(ioc3->erbr_h)
178 #define ioc3_w_erbr_h(v)	do { ioc3->erbr_h = cpu_to_be32(v); } while (0)
179 #define ioc3_r_erbr_l()		be32_to_cpu(ioc3->erbr_l)
180 #define ioc3_w_erbr_l(v)	do { ioc3->erbr_l = cpu_to_be32(v); } while (0)
181 #define ioc3_r_erbar()		be32_to_cpu(ioc3->erbar)
182 #define ioc3_w_erbar(v)		do { ioc3->erbar = cpu_to_be32(v); } while (0)
183 #define ioc3_r_ercir()		be32_to_cpu(ioc3->ercir)
184 #define ioc3_w_ercir(v)		do { ioc3->ercir = cpu_to_be32(v); } while (0)
185 #define ioc3_r_erpir()		be32_to_cpu(ioc3->erpir)
186 #define ioc3_w_erpir(v)		do { ioc3->erpir = cpu_to_be32(v); } while (0)
187 #define ioc3_r_ertr()		be32_to_cpu(ioc3->ertr)
188 #define ioc3_w_ertr(v)		do { ioc3->ertr = cpu_to_be32(v); } while (0)
189 #define ioc3_r_etcsr()		be32_to_cpu(ioc3->etcsr)
190 #define ioc3_w_etcsr(v)		do { ioc3->etcsr = cpu_to_be32(v); } while (0)
191 #define ioc3_r_ersr()		be32_to_cpu(ioc3->ersr)
192 #define ioc3_w_ersr(v)		do { ioc3->ersr = cpu_to_be32(v); } while (0)
193 #define ioc3_r_etcdc()		be32_to_cpu(ioc3->etcdc)
194 #define ioc3_w_etcdc(v)		do { ioc3->etcdc = cpu_to_be32(v); } while (0)
195 #define ioc3_r_ebir()		be32_to_cpu(ioc3->ebir)
196 #define ioc3_w_ebir(v)		do { ioc3->ebir = cpu_to_be32(v); } while (0)
197 #define ioc3_r_etbr_h()		be32_to_cpu(ioc3->etbr_h)
198 #define ioc3_w_etbr_h(v)	do { ioc3->etbr_h = cpu_to_be32(v); } while (0)
199 #define ioc3_r_etbr_l()		be32_to_cpu(ioc3->etbr_l)
200 #define ioc3_w_etbr_l(v)	do { ioc3->etbr_l = cpu_to_be32(v); } while (0)
201 #define ioc3_r_etcir()		be32_to_cpu(ioc3->etcir)
202 #define ioc3_w_etcir(v)		do { ioc3->etcir = cpu_to_be32(v); } while (0)
203 #define ioc3_r_etpir()		be32_to_cpu(ioc3->etpir)
204 #define ioc3_w_etpir(v)		do { ioc3->etpir = cpu_to_be32(v); } while (0)
205 #define ioc3_r_emar_h()		be32_to_cpu(ioc3->emar_h)
206 #define ioc3_w_emar_h(v)	do { ioc3->emar_h = cpu_to_be32(v); } while (0)
207 #define ioc3_r_emar_l()		be32_to_cpu(ioc3->emar_l)
208 #define ioc3_w_emar_l(v)	do { ioc3->emar_l = cpu_to_be32(v); } while (0)
209 #define ioc3_r_ehar_h()		be32_to_cpu(ioc3->ehar_h)
210 #define ioc3_w_ehar_h(v)	do { ioc3->ehar_h = cpu_to_be32(v); } while (0)
211 #define ioc3_r_ehar_l()		be32_to_cpu(ioc3->ehar_l)
212 #define ioc3_w_ehar_l(v)	do { ioc3->ehar_l = cpu_to_be32(v); } while (0)
213 #define ioc3_r_micr()		be32_to_cpu(ioc3->micr)
214 #define ioc3_w_micr(v)		do { ioc3->micr = cpu_to_be32(v); } while (0)
215 #define ioc3_r_midr_r()		be32_to_cpu(ioc3->midr_r)
216 #define ioc3_w_midr_r(v)	do { ioc3->midr_r = cpu_to_be32(v); } while (0)
217 #define ioc3_r_midr_w()		be32_to_cpu(ioc3->midr_w)
218 #define ioc3_w_midr_w(v)	do { ioc3->midr_w = cpu_to_be32(v); } while (0)
219 
220 static inline u32 mcr_pack(u32 pulse, u32 sample)
221 {
222 	return (pulse << 10) | (sample << 2);
223 }
224 
225 static int nic_wait(struct ioc3 *ioc3)
226 {
227 	u32 mcr;
228 
229         do {
230                 mcr = ioc3_r_mcr();
231         } while (!(mcr & 2));
232 
233         return mcr & 1;
234 }
235 
236 static int nic_reset(struct ioc3 *ioc3)
237 {
238         int presence;
239 
240 	ioc3_w_mcr(mcr_pack(500, 65));
241 	presence = nic_wait(ioc3);
242 
243 	ioc3_w_mcr(mcr_pack(0, 500));
244 	nic_wait(ioc3);
245 
246         return presence;
247 }
248 
249 static inline int nic_read_bit(struct ioc3 *ioc3)
250 {
251 	int result;
252 
253 	ioc3_w_mcr(mcr_pack(6, 13));
254 	result = nic_wait(ioc3);
255 	ioc3_w_mcr(mcr_pack(0, 100));
256 	nic_wait(ioc3);
257 
258 	return result;
259 }
260 
261 static inline void nic_write_bit(struct ioc3 *ioc3, int bit)
262 {
263 	if (bit)
264 		ioc3_w_mcr(mcr_pack(6, 110));
265 	else
266 		ioc3_w_mcr(mcr_pack(80, 30));
267 
268 	nic_wait(ioc3);
269 }
270 
271 /*
272  * Read a byte from an iButton device
273  */
274 static u32 nic_read_byte(struct ioc3 *ioc3)
275 {
276 	u32 result = 0;
277 	int i;
278 
279 	for (i = 0; i < 8; i++)
280 		result = (result >> 1) | (nic_read_bit(ioc3) << 7);
281 
282 	return result;
283 }
284 
285 /*
286  * Write a byte to an iButton device
287  */
288 static void nic_write_byte(struct ioc3 *ioc3, int byte)
289 {
290 	int i, bit;
291 
292 	for (i = 8; i; i--) {
293 		bit = byte & 1;
294 		byte >>= 1;
295 
296 		nic_write_bit(ioc3, bit);
297 	}
298 }
299 
300 static u64 nic_find(struct ioc3 *ioc3, int *last)
301 {
302 	int a, b, index, disc;
303 	u64 address = 0;
304 
305 	nic_reset(ioc3);
306 	/* Search ROM.  */
307 	nic_write_byte(ioc3, 0xf0);
308 
309 	/* Algorithm from ``Book of iButton Standards''.  */
310 	for (index = 0, disc = 0; index < 64; index++) {
311 		a = nic_read_bit(ioc3);
312 		b = nic_read_bit(ioc3);
313 
314 		if (a && b) {
315 			printk("NIC search failed (not fatal).\n");
316 			*last = 0;
317 			return 0;
318 		}
319 
320 		if (!a && !b) {
321 			if (index == *last) {
322 				address |= 1UL << index;
323 			} else if (index > *last) {
324 				address &= ~(1UL << index);
325 				disc = index;
326 			} else if ((address & (1UL << index)) == 0)
327 				disc = index;
328 			nic_write_bit(ioc3, address & (1UL << index));
329 			continue;
330 		} else {
331 			if (a)
332 				address |= 1UL << index;
333 			else
334 				address &= ~(1UL << index);
335 			nic_write_bit(ioc3, a);
336 			continue;
337 		}
338 	}
339 
340 	*last = disc;
341 
342 	return address;
343 }
344 
345 static int nic_init(struct ioc3 *ioc3)
346 {
347 	const char *unknown = "unknown";
348 	const char *type = unknown;
349 	u8 crc;
350 	u8 serial[6];
351 	int save = 0, i;
352 
353 	while (1) {
354 		u64 reg;
355 		reg = nic_find(ioc3, &save);
356 
357 		switch (reg & 0xff) {
358 		case 0x91:
359 			type = "DS1981U";
360 			break;
361 		default:
362 			if (save == 0) {
363 				/* Let the caller try again.  */
364 				return -1;
365 			}
366 			continue;
367 		}
368 
369 		nic_reset(ioc3);
370 
371 		/* Match ROM.  */
372 		nic_write_byte(ioc3, 0x55);
373 		for (i = 0; i < 8; i++)
374 			nic_write_byte(ioc3, (reg >> (i << 3)) & 0xff);
375 
376 		reg >>= 8; /* Shift out type.  */
377 		for (i = 0; i < 6; i++) {
378 			serial[i] = reg & 0xff;
379 			reg >>= 8;
380 		}
381 		crc = reg & 0xff;
382 		break;
383 	}
384 
385 	printk("Found %s NIC", type);
386 	if (type != unknown)
387 		printk (" registration number %pM, CRC %02x", serial, crc);
388 	printk(".\n");
389 
390 	return 0;
391 }
392 
393 /*
394  * Read the NIC (Number-In-a-Can) device used to store the MAC address on
395  * SN0 / SN00 nodeboards and PCI cards.
396  */
397 static void ioc3_get_eaddr_nic(struct ioc3_private *ip)
398 {
399 	struct ioc3 *ioc3 = ip->regs;
400 	u8 nic[14];
401 	int tries = 2; /* There may be some problem with the battery?  */
402 	int i;
403 
404 	ioc3_w_gpcr_s(1 << 21);
405 
406 	while (tries--) {
407 		if (!nic_init(ioc3))
408 			break;
409 		udelay(500);
410 	}
411 
412 	if (tries < 0) {
413 		printk("Failed to read MAC address\n");
414 		return;
415 	}
416 
417 	/* Read Memory.  */
418 	nic_write_byte(ioc3, 0xf0);
419 	nic_write_byte(ioc3, 0x00);
420 	nic_write_byte(ioc3, 0x00);
421 
422 	for (i = 13; i >= 0; i--)
423 		nic[i] = nic_read_byte(ioc3);
424 
425 	for (i = 2; i < 8; i++)
426 		ip->dev->dev_addr[i - 2] = nic[i];
427 }
428 
429 /*
430  * Ok, this is hosed by design.  It's necessary to know what machine the
431  * NIC is in in order to know how to read the NIC address.  We also have
432  * to know if it's a PCI card or a NIC in on the node board ...
433  */
434 static void ioc3_get_eaddr(struct ioc3_private *ip)
435 {
436 	ioc3_get_eaddr_nic(ip);
437 
438 	printk("Ethernet address is %pM.\n", ip->dev->dev_addr);
439 }
440 
441 static void __ioc3_set_mac_address(struct net_device *dev)
442 {
443 	struct ioc3_private *ip = netdev_priv(dev);
444 	struct ioc3 *ioc3 = ip->regs;
445 
446 	ioc3_w_emar_h((dev->dev_addr[5] <<  8) | dev->dev_addr[4]);
447 	ioc3_w_emar_l((dev->dev_addr[3] << 24) | (dev->dev_addr[2] << 16) |
448 	              (dev->dev_addr[1] <<  8) | dev->dev_addr[0]);
449 }
450 
451 static int ioc3_set_mac_address(struct net_device *dev, void *addr)
452 {
453 	struct ioc3_private *ip = netdev_priv(dev);
454 	struct sockaddr *sa = addr;
455 
456 	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
457 
458 	spin_lock_irq(&ip->ioc3_lock);
459 	__ioc3_set_mac_address(dev);
460 	spin_unlock_irq(&ip->ioc3_lock);
461 
462 	return 0;
463 }
464 
465 /*
466  * Caller must hold the ioc3_lock ever for MII readers.  This is also
467  * used to protect the transmitter side but it's low contention.
468  */
469 static int ioc3_mdio_read(struct net_device *dev, int phy, int reg)
470 {
471 	struct ioc3_private *ip = netdev_priv(dev);
472 	struct ioc3 *ioc3 = ip->regs;
473 
474 	while (ioc3_r_micr() & MICR_BUSY);
475 	ioc3_w_micr((phy << MICR_PHYADDR_SHIFT) | reg | MICR_READTRIG);
476 	while (ioc3_r_micr() & MICR_BUSY);
477 
478 	return ioc3_r_midr_r() & MIDR_DATA_MASK;
479 }
480 
481 static void ioc3_mdio_write(struct net_device *dev, int phy, int reg, int data)
482 {
483 	struct ioc3_private *ip = netdev_priv(dev);
484 	struct ioc3 *ioc3 = ip->regs;
485 
486 	while (ioc3_r_micr() & MICR_BUSY);
487 	ioc3_w_midr_w(data);
488 	ioc3_w_micr((phy << MICR_PHYADDR_SHIFT) | reg);
489 	while (ioc3_r_micr() & MICR_BUSY);
490 }
491 
492 static int ioc3_mii_init(struct ioc3_private *ip);
493 
494 static struct net_device_stats *ioc3_get_stats(struct net_device *dev)
495 {
496 	struct ioc3_private *ip = netdev_priv(dev);
497 	struct ioc3 *ioc3 = ip->regs;
498 
499 	dev->stats.collisions += (ioc3_r_etcdc() & ETCDC_COLLCNT_MASK);
500 	return &dev->stats;
501 }
502 
503 static void ioc3_tcpudp_checksum(struct sk_buff *skb, uint32_t hwsum, int len)
504 {
505 	struct ethhdr *eh = eth_hdr(skb);
506 	uint32_t csum, ehsum;
507 	unsigned int proto;
508 	struct iphdr *ih;
509 	uint16_t *ew;
510 	unsigned char *cp;
511 
512 	/*
513 	 * Did hardware handle the checksum at all?  The cases we can handle
514 	 * are:
515 	 *
516 	 * - TCP and UDP checksums of IPv4 only.
517 	 * - IPv6 would be doable but we keep that for later ...
518 	 * - Only unfragmented packets.  Did somebody already tell you
519 	 *   fragmentation is evil?
520 	 * - don't care about packet size.  Worst case when processing a
521 	 *   malformed packet we'll try to access the packet at ip header +
522 	 *   64 bytes which is still inside the skb.  Even in the unlikely
523 	 *   case where the checksum is right the higher layers will still
524 	 *   drop the packet as appropriate.
525 	 */
526 	if (eh->h_proto != htons(ETH_P_IP))
527 		return;
528 
529 	ih = (struct iphdr *) ((char *)eh + ETH_HLEN);
530 	if (ip_is_fragment(ih))
531 		return;
532 
533 	proto = ih->protocol;
534 	if (proto != IPPROTO_TCP && proto != IPPROTO_UDP)
535 		return;
536 
537 	/* Same as tx - compute csum of pseudo header  */
538 	csum = hwsum +
539 	       (ih->tot_len - (ih->ihl << 2)) +
540 	       htons((uint16_t)ih->protocol) +
541 	       (ih->saddr >> 16) + (ih->saddr & 0xffff) +
542 	       (ih->daddr >> 16) + (ih->daddr & 0xffff);
543 
544 	/* Sum up ethernet dest addr, src addr and protocol  */
545 	ew = (uint16_t *) eh;
546 	ehsum = ew[0] + ew[1] + ew[2] + ew[3] + ew[4] + ew[5] + ew[6];
547 
548 	ehsum = (ehsum & 0xffff) + (ehsum >> 16);
549 	ehsum = (ehsum & 0xffff) + (ehsum >> 16);
550 
551 	csum += 0xffff ^ ehsum;
552 
553 	/* In the next step we also subtract the 1's complement
554 	   checksum of the trailing ethernet CRC.  */
555 	cp = (char *)eh + len;	/* points at trailing CRC */
556 	if (len & 1) {
557 		csum += 0xffff ^ (uint16_t) ((cp[1] << 8) | cp[0]);
558 		csum += 0xffff ^ (uint16_t) ((cp[3] << 8) | cp[2]);
559 	} else {
560 		csum += 0xffff ^ (uint16_t) ((cp[0] << 8) | cp[1]);
561 		csum += 0xffff ^ (uint16_t) ((cp[2] << 8) | cp[3]);
562 	}
563 
564 	csum = (csum & 0xffff) + (csum >> 16);
565 	csum = (csum & 0xffff) + (csum >> 16);
566 
567 	if (csum == 0xffff)
568 		skb->ip_summed = CHECKSUM_UNNECESSARY;
569 }
570 
571 static inline void ioc3_rx(struct net_device *dev)
572 {
573 	struct ioc3_private *ip = netdev_priv(dev);
574 	struct sk_buff *skb, *new_skb;
575 	struct ioc3 *ioc3 = ip->regs;
576 	int rx_entry, n_entry, len;
577 	struct ioc3_erxbuf *rxb;
578 	unsigned long *rxr;
579 	u32 w0, err;
580 
581 	rxr = ip->rxr;		/* Ring base */
582 	rx_entry = ip->rx_ci;				/* RX consume index */
583 	n_entry = ip->rx_pi;
584 
585 	skb = ip->rx_skbs[rx_entry];
586 	rxb = (struct ioc3_erxbuf *) (skb->data - RX_OFFSET);
587 	w0 = be32_to_cpu(rxb->w0);
588 
589 	while (w0 & ERXBUF_V) {
590 		err = be32_to_cpu(rxb->err);		/* It's valid ...  */
591 		if (err & ERXBUF_GOODPKT) {
592 			len = ((w0 >> ERXBUF_BYTECNT_SHIFT) & 0x7ff) - 4;
593 			skb_trim(skb, len);
594 			skb->protocol = eth_type_trans(skb, dev);
595 
596 			new_skb = ioc3_alloc_skb(RX_BUF_ALLOC_SIZE, GFP_ATOMIC);
597 			if (!new_skb) {
598 				/* Ouch, drop packet and just recycle packet
599 				   to keep the ring filled.  */
600 				dev->stats.rx_dropped++;
601 				new_skb = skb;
602 				goto next;
603 			}
604 
605 			if (likely(dev->features & NETIF_F_RXCSUM))
606 				ioc3_tcpudp_checksum(skb,
607 					w0 & ERXBUF_IPCKSUM_MASK, len);
608 
609 			netif_rx(skb);
610 
611 			ip->rx_skbs[rx_entry] = NULL;	/* Poison  */
612 
613 			/* Because we reserve afterwards. */
614 			skb_put(new_skb, (1664 + RX_OFFSET));
615 			rxb = (struct ioc3_erxbuf *) new_skb->data;
616 			skb_reserve(new_skb, RX_OFFSET);
617 
618 			dev->stats.rx_packets++;		/* Statistics */
619 			dev->stats.rx_bytes += len;
620 		} else {
621 			/* The frame is invalid and the skb never
622 			   reached the network layer so we can just
623 			   recycle it.  */
624 			new_skb = skb;
625 			dev->stats.rx_errors++;
626 		}
627 		if (err & ERXBUF_CRCERR)	/* Statistics */
628 			dev->stats.rx_crc_errors++;
629 		if (err & ERXBUF_FRAMERR)
630 			dev->stats.rx_frame_errors++;
631 next:
632 		ip->rx_skbs[n_entry] = new_skb;
633 		rxr[n_entry] = cpu_to_be64(ioc3_map(rxb, 1));
634 		rxb->w0 = 0;				/* Clear valid flag */
635 		n_entry = (n_entry + 1) & 511;		/* Update erpir */
636 
637 		/* Now go on to the next ring entry.  */
638 		rx_entry = (rx_entry + 1) & 511;
639 		skb = ip->rx_skbs[rx_entry];
640 		rxb = (struct ioc3_erxbuf *) (skb->data - RX_OFFSET);
641 		w0 = be32_to_cpu(rxb->w0);
642 	}
643 	ioc3_w_erpir((n_entry << 3) | ERPIR_ARM);
644 	ip->rx_pi = n_entry;
645 	ip->rx_ci = rx_entry;
646 }
647 
648 static inline void ioc3_tx(struct net_device *dev)
649 {
650 	struct ioc3_private *ip = netdev_priv(dev);
651 	unsigned long packets, bytes;
652 	struct ioc3 *ioc3 = ip->regs;
653 	int tx_entry, o_entry;
654 	struct sk_buff *skb;
655 	u32 etcir;
656 
657 	spin_lock(&ip->ioc3_lock);
658 	etcir = ioc3_r_etcir();
659 
660 	tx_entry = (etcir >> 7) & 127;
661 	o_entry = ip->tx_ci;
662 	packets = 0;
663 	bytes = 0;
664 
665 	while (o_entry != tx_entry) {
666 		packets++;
667 		skb = ip->tx_skbs[o_entry];
668 		bytes += skb->len;
669 		dev_consume_skb_irq(skb);
670 		ip->tx_skbs[o_entry] = NULL;
671 
672 		o_entry = (o_entry + 1) & 127;		/* Next */
673 
674 		etcir = ioc3_r_etcir();			/* More pkts sent?  */
675 		tx_entry = (etcir >> 7) & 127;
676 	}
677 
678 	dev->stats.tx_packets += packets;
679 	dev->stats.tx_bytes += bytes;
680 	ip->txqlen -= packets;
681 
682 	if (ip->txqlen < 128)
683 		netif_wake_queue(dev);
684 
685 	ip->tx_ci = o_entry;
686 	spin_unlock(&ip->ioc3_lock);
687 }
688 
689 /*
690  * Deal with fatal IOC3 errors.  This condition might be caused by a hard or
691  * software problems, so we should try to recover
692  * more gracefully if this ever happens.  In theory we might be flooded
693  * with such error interrupts if something really goes wrong, so we might
694  * also consider to take the interface down.
695  */
696 static void ioc3_error(struct net_device *dev, u32 eisr)
697 {
698 	struct ioc3_private *ip = netdev_priv(dev);
699 	unsigned char *iface = dev->name;
700 
701 	spin_lock(&ip->ioc3_lock);
702 
703 	if (eisr & EISR_RXOFLO)
704 		printk(KERN_ERR "%s: RX overflow.\n", iface);
705 	if (eisr & EISR_RXBUFOFLO)
706 		printk(KERN_ERR "%s: RX buffer overflow.\n", iface);
707 	if (eisr & EISR_RXMEMERR)
708 		printk(KERN_ERR "%s: RX PCI error.\n", iface);
709 	if (eisr & EISR_RXPARERR)
710 		printk(KERN_ERR "%s: RX SSRAM parity error.\n", iface);
711 	if (eisr & EISR_TXBUFUFLO)
712 		printk(KERN_ERR "%s: TX buffer underflow.\n", iface);
713 	if (eisr & EISR_TXMEMERR)
714 		printk(KERN_ERR "%s: TX PCI error.\n", iface);
715 
716 	ioc3_stop(ip);
717 	ioc3_init(dev);
718 	ioc3_mii_init(ip);
719 
720 	netif_wake_queue(dev);
721 
722 	spin_unlock(&ip->ioc3_lock);
723 }
724 
725 /* The interrupt handler does all of the Rx thread work and cleans up
726    after the Tx thread.  */
727 static irqreturn_t ioc3_interrupt(int irq, void *_dev)
728 {
729 	struct net_device *dev = (struct net_device *)_dev;
730 	struct ioc3_private *ip = netdev_priv(dev);
731 	struct ioc3 *ioc3 = ip->regs;
732 	const u32 enabled = EISR_RXTIMERINT | EISR_RXOFLO | EISR_RXBUFOFLO |
733 	                    EISR_RXMEMERR | EISR_RXPARERR | EISR_TXBUFUFLO |
734 	                    EISR_TXEXPLICIT | EISR_TXMEMERR;
735 	u32 eisr;
736 
737 	eisr = ioc3_r_eisr() & enabled;
738 
739 	ioc3_w_eisr(eisr);
740 	(void) ioc3_r_eisr();				/* Flush */
741 
742 	if (eisr & (EISR_RXOFLO | EISR_RXBUFOFLO | EISR_RXMEMERR |
743 	            EISR_RXPARERR | EISR_TXBUFUFLO | EISR_TXMEMERR))
744 		ioc3_error(dev, eisr);
745 	if (eisr & EISR_RXTIMERINT)
746 		ioc3_rx(dev);
747 	if (eisr & EISR_TXEXPLICIT)
748 		ioc3_tx(dev);
749 
750 	return IRQ_HANDLED;
751 }
752 
753 static inline void ioc3_setup_duplex(struct ioc3_private *ip)
754 {
755 	struct ioc3 *ioc3 = ip->regs;
756 
757 	if (ip->mii.full_duplex) {
758 		ioc3_w_etcsr(ETCSR_FD);
759 		ip->emcr |= EMCR_DUPLEX;
760 	} else {
761 		ioc3_w_etcsr(ETCSR_HD);
762 		ip->emcr &= ~EMCR_DUPLEX;
763 	}
764 	ioc3_w_emcr(ip->emcr);
765 }
766 
767 static void ioc3_timer(struct timer_list *t)
768 {
769 	struct ioc3_private *ip = from_timer(ip, t, ioc3_timer);
770 
771 	/* Print the link status if it has changed */
772 	mii_check_media(&ip->mii, 1, 0);
773 	ioc3_setup_duplex(ip);
774 
775 	ip->ioc3_timer.expires = jiffies + ((12 * HZ)/10); /* 1.2s */
776 	add_timer(&ip->ioc3_timer);
777 }
778 
779 /*
780  * Try to find a PHY.  There is no apparent relation between the MII addresses
781  * in the SGI documentation and what we find in reality, so we simply probe
782  * for the PHY.  It seems IOC3 PHYs usually live on address 31.  One of my
783  * onboard IOC3s has the special oddity that probing doesn't seem to find it
784  * yet the interface seems to work fine, so if probing fails we for now will
785  * simply default to PHY 31 instead of bailing out.
786  */
787 static int ioc3_mii_init(struct ioc3_private *ip)
788 {
789 	int i, found = 0, res = 0;
790 	int ioc3_phy_workaround = 1;
791 	u16 word;
792 
793 	for (i = 0; i < 32; i++) {
794 		word = ioc3_mdio_read(ip->dev, i, MII_PHYSID1);
795 
796 		if (word != 0xffff && word != 0x0000) {
797 			found = 1;
798 			break;			/* Found a PHY		*/
799 		}
800 	}
801 
802 	if (!found) {
803 		if (ioc3_phy_workaround)
804 			i = 31;
805 		else {
806 			ip->mii.phy_id = -1;
807 			res = -ENODEV;
808 			goto out;
809 		}
810 	}
811 
812 	ip->mii.phy_id = i;
813 
814 out:
815 	return res;
816 }
817 
818 static void ioc3_mii_start(struct ioc3_private *ip)
819 {
820 	ip->ioc3_timer.expires = jiffies + (12 * HZ)/10;  /* 1.2 sec. */
821 	add_timer(&ip->ioc3_timer);
822 }
823 
824 static inline void ioc3_clean_rx_ring(struct ioc3_private *ip)
825 {
826 	struct sk_buff *skb;
827 	int i;
828 
829 	for (i = ip->rx_ci; i & 15; i++) {
830 		ip->rx_skbs[ip->rx_pi] = ip->rx_skbs[ip->rx_ci];
831 		ip->rxr[ip->rx_pi++] = ip->rxr[ip->rx_ci++];
832 	}
833 	ip->rx_pi &= 511;
834 	ip->rx_ci &= 511;
835 
836 	for (i = ip->rx_ci; i != ip->rx_pi; i = (i+1) & 511) {
837 		struct ioc3_erxbuf *rxb;
838 		skb = ip->rx_skbs[i];
839 		rxb = (struct ioc3_erxbuf *) (skb->data - RX_OFFSET);
840 		rxb->w0 = 0;
841 	}
842 }
843 
844 static inline void ioc3_clean_tx_ring(struct ioc3_private *ip)
845 {
846 	struct sk_buff *skb;
847 	int i;
848 
849 	for (i=0; i < 128; i++) {
850 		skb = ip->tx_skbs[i];
851 		if (skb) {
852 			ip->tx_skbs[i] = NULL;
853 			dev_kfree_skb_any(skb);
854 		}
855 		ip->txr[i].cmd = 0;
856 	}
857 	ip->tx_pi = 0;
858 	ip->tx_ci = 0;
859 }
860 
861 static void ioc3_free_rings(struct ioc3_private *ip)
862 {
863 	struct sk_buff *skb;
864 	int rx_entry, n_entry;
865 
866 	if (ip->txr) {
867 		ioc3_clean_tx_ring(ip);
868 		free_pages((unsigned long)ip->txr, 2);
869 		ip->txr = NULL;
870 	}
871 
872 	if (ip->rxr) {
873 		n_entry = ip->rx_ci;
874 		rx_entry = ip->rx_pi;
875 
876 		while (n_entry != rx_entry) {
877 			skb = ip->rx_skbs[n_entry];
878 			if (skb)
879 				dev_kfree_skb_any(skb);
880 
881 			n_entry = (n_entry + 1) & 511;
882 		}
883 		free_page((unsigned long)ip->rxr);
884 		ip->rxr = NULL;
885 	}
886 }
887 
888 static void ioc3_alloc_rings(struct net_device *dev)
889 {
890 	struct ioc3_private *ip = netdev_priv(dev);
891 	struct ioc3_erxbuf *rxb;
892 	unsigned long *rxr;
893 	int i;
894 
895 	if (ip->rxr == NULL) {
896 		/* Allocate and initialize rx ring.  4kb = 512 entries  */
897 		ip->rxr = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
898 		rxr = ip->rxr;
899 		if (!rxr)
900 			printk("ioc3_alloc_rings(): get_zeroed_page() failed!\n");
901 
902 		/* Now the rx buffers.  The RX ring may be larger but
903 		   we only allocate 16 buffers for now.  Need to tune
904 		   this for performance and memory later.  */
905 		for (i = 0; i < RX_BUFFS; i++) {
906 			struct sk_buff *skb;
907 
908 			skb = ioc3_alloc_skb(RX_BUF_ALLOC_SIZE, GFP_ATOMIC);
909 			if (!skb) {
910 				show_free_areas(0, NULL);
911 				continue;
912 			}
913 
914 			ip->rx_skbs[i] = skb;
915 
916 			/* Because we reserve afterwards. */
917 			skb_put(skb, (1664 + RX_OFFSET));
918 			rxb = (struct ioc3_erxbuf *) skb->data;
919 			rxr[i] = cpu_to_be64(ioc3_map(rxb, 1));
920 			skb_reserve(skb, RX_OFFSET);
921 		}
922 		ip->rx_ci = 0;
923 		ip->rx_pi = RX_BUFFS;
924 	}
925 
926 	if (ip->txr == NULL) {
927 		/* Allocate and initialize tx rings.  16kb = 128 bufs.  */
928 		ip->txr = (struct ioc3_etxd *)__get_free_pages(GFP_KERNEL, 2);
929 		if (!ip->txr)
930 			printk("ioc3_alloc_rings(): __get_free_pages() failed!\n");
931 		ip->tx_pi = 0;
932 		ip->tx_ci = 0;
933 	}
934 }
935 
936 static void ioc3_init_rings(struct net_device *dev)
937 {
938 	struct ioc3_private *ip = netdev_priv(dev);
939 	struct ioc3 *ioc3 = ip->regs;
940 	unsigned long ring;
941 
942 	ioc3_free_rings(ip);
943 	ioc3_alloc_rings(dev);
944 
945 	ioc3_clean_rx_ring(ip);
946 	ioc3_clean_tx_ring(ip);
947 
948 	/* Now the rx ring base, consume & produce registers.  */
949 	ring = ioc3_map(ip->rxr, 0);
950 	ioc3_w_erbr_h(ring >> 32);
951 	ioc3_w_erbr_l(ring & 0xffffffff);
952 	ioc3_w_ercir(ip->rx_ci << 3);
953 	ioc3_w_erpir((ip->rx_pi << 3) | ERPIR_ARM);
954 
955 	ring = ioc3_map(ip->txr, 0);
956 
957 	ip->txqlen = 0;					/* nothing queued  */
958 
959 	/* Now the tx ring base, consume & produce registers.  */
960 	ioc3_w_etbr_h(ring >> 32);
961 	ioc3_w_etbr_l(ring & 0xffffffff);
962 	ioc3_w_etpir(ip->tx_pi << 7);
963 	ioc3_w_etcir(ip->tx_ci << 7);
964 	(void) ioc3_r_etcir();				/* Flush */
965 }
966 
967 static inline void ioc3_ssram_disc(struct ioc3_private *ip)
968 {
969 	struct ioc3 *ioc3 = ip->regs;
970 	volatile u32 *ssram0 = &ioc3->ssram[0x0000];
971 	volatile u32 *ssram1 = &ioc3->ssram[0x4000];
972 	unsigned int pattern = 0x5555;
973 
974 	/* Assume the larger size SSRAM and enable parity checking */
975 	ioc3_w_emcr(ioc3_r_emcr() | (EMCR_BUFSIZ | EMCR_RAMPAR));
976 
977 	*ssram0 = pattern;
978 	*ssram1 = ~pattern & IOC3_SSRAM_DM;
979 
980 	if ((*ssram0 & IOC3_SSRAM_DM) != pattern ||
981 	    (*ssram1 & IOC3_SSRAM_DM) != (~pattern & IOC3_SSRAM_DM)) {
982 		/* set ssram size to 64 KB */
983 		ip->emcr = EMCR_RAMPAR;
984 		ioc3_w_emcr(ioc3_r_emcr() & ~EMCR_BUFSIZ);
985 	} else
986 		ip->emcr = EMCR_BUFSIZ | EMCR_RAMPAR;
987 }
988 
989 static void ioc3_init(struct net_device *dev)
990 {
991 	struct ioc3_private *ip = netdev_priv(dev);
992 	struct ioc3 *ioc3 = ip->regs;
993 
994 	del_timer_sync(&ip->ioc3_timer);	/* Kill if running	*/
995 
996 	ioc3_w_emcr(EMCR_RST);			/* Reset		*/
997 	(void) ioc3_r_emcr();			/* Flush WB		*/
998 	udelay(4);				/* Give it time ...	*/
999 	ioc3_w_emcr(0);
1000 	(void) ioc3_r_emcr();
1001 
1002 	/* Misc registers  */
1003 #ifdef CONFIG_SGI_IP27
1004 	ioc3_w_erbar(PCI64_ATTR_BAR >> 32);	/* Barrier on last store */
1005 #else
1006 	ioc3_w_erbar(0);			/* Let PCI API get it right */
1007 #endif
1008 	(void) ioc3_r_etcdc();			/* Clear on read */
1009 	ioc3_w_ercsr(15);			/* RX low watermark  */
1010 	ioc3_w_ertr(0);				/* Interrupt immediately */
1011 	__ioc3_set_mac_address(dev);
1012 	ioc3_w_ehar_h(ip->ehar_h);
1013 	ioc3_w_ehar_l(ip->ehar_l);
1014 	ioc3_w_ersr(42);			/* XXX should be random */
1015 
1016 	ioc3_init_rings(dev);
1017 
1018 	ip->emcr |= ((RX_OFFSET / 2) << EMCR_RXOFF_SHIFT) | EMCR_TXDMAEN |
1019 	             EMCR_TXEN | EMCR_RXDMAEN | EMCR_RXEN | EMCR_PADEN;
1020 	ioc3_w_emcr(ip->emcr);
1021 	ioc3_w_eier(EISR_RXTIMERINT | EISR_RXOFLO | EISR_RXBUFOFLO |
1022 	            EISR_RXMEMERR | EISR_RXPARERR | EISR_TXBUFUFLO |
1023 	            EISR_TXEXPLICIT | EISR_TXMEMERR);
1024 	(void) ioc3_r_eier();
1025 }
1026 
1027 static inline void ioc3_stop(struct ioc3_private *ip)
1028 {
1029 	struct ioc3 *ioc3 = ip->regs;
1030 
1031 	ioc3_w_emcr(0);				/* Shutup */
1032 	ioc3_w_eier(0);				/* Disable interrupts */
1033 	(void) ioc3_r_eier();			/* Flush */
1034 }
1035 
1036 static int ioc3_open(struct net_device *dev)
1037 {
1038 	struct ioc3_private *ip = netdev_priv(dev);
1039 
1040 	if (request_irq(dev->irq, ioc3_interrupt, IRQF_SHARED, ioc3_str, dev)) {
1041 		printk(KERN_ERR "%s: Can't get irq %d\n", dev->name, dev->irq);
1042 
1043 		return -EAGAIN;
1044 	}
1045 
1046 	ip->ehar_h = 0;
1047 	ip->ehar_l = 0;
1048 	ioc3_init(dev);
1049 	ioc3_mii_start(ip);
1050 
1051 	netif_start_queue(dev);
1052 	return 0;
1053 }
1054 
1055 static int ioc3_close(struct net_device *dev)
1056 {
1057 	struct ioc3_private *ip = netdev_priv(dev);
1058 
1059 	del_timer_sync(&ip->ioc3_timer);
1060 
1061 	netif_stop_queue(dev);
1062 
1063 	ioc3_stop(ip);
1064 	free_irq(dev->irq, dev);
1065 
1066 	ioc3_free_rings(ip);
1067 	return 0;
1068 }
1069 
1070 /*
1071  * MENET cards have four IOC3 chips, which are attached to two sets of
1072  * PCI slot resources each: the primary connections are on slots
1073  * 0..3 and the secondaries are on 4..7
1074  *
1075  * All four ethernets are brought out to connectors; six serial ports
1076  * (a pair from each of the first three IOC3s) are brought out to
1077  * MiniDINs; all other subdevices are left swinging in the wind, leave
1078  * them disabled.
1079  */
1080 
1081 static int ioc3_adjacent_is_ioc3(struct pci_dev *pdev, int slot)
1082 {
1083 	struct pci_dev *dev = pci_get_slot(pdev->bus, PCI_DEVFN(slot, 0));
1084 	int ret = 0;
1085 
1086 	if (dev) {
1087 		if (dev->vendor == PCI_VENDOR_ID_SGI &&
1088 			dev->device == PCI_DEVICE_ID_SGI_IOC3)
1089 			ret = 1;
1090 		pci_dev_put(dev);
1091 	}
1092 
1093 	return ret;
1094 }
1095 
1096 static int ioc3_is_menet(struct pci_dev *pdev)
1097 {
1098 	return pdev->bus->parent == NULL &&
1099 	       ioc3_adjacent_is_ioc3(pdev, 0) &&
1100 	       ioc3_adjacent_is_ioc3(pdev, 1) &&
1101 	       ioc3_adjacent_is_ioc3(pdev, 2);
1102 }
1103 
1104 #ifdef CONFIG_SERIAL_8250
1105 /*
1106  * Note about serial ports and consoles:
1107  * For console output, everyone uses the IOC3 UARTA (offset 0x178)
1108  * connected to the master node (look in ip27_setup_console() and
1109  * ip27prom_console_write()).
1110  *
1111  * For serial (/dev/ttyS0 etc), we can not have hardcoded serial port
1112  * addresses on a partitioned machine. Since we currently use the ioc3
1113  * serial ports, we use dynamic serial port discovery that the serial.c
1114  * driver uses for pci/pnp ports (there is an entry for the SGI ioc3
1115  * boards in pci_boards[]). Unfortunately, UARTA's pio address is greater
1116  * than UARTB's, although UARTA on o200s has traditionally been known as
1117  * port 0. So, we just use one serial port from each ioc3 (since the
1118  * serial driver adds addresses to get to higher ports).
1119  *
1120  * The first one to do a register_console becomes the preferred console
1121  * (if there is no kernel command line console= directive). /dev/console
1122  * (ie 5, 1) is then "aliased" into the device number returned by the
1123  * "device" routine referred to in this console structure
1124  * (ip27prom_console_dev).
1125  *
1126  * Also look in ip27-pci.c:pci_fixup_ioc3() for some comments on working
1127  * around ioc3 oddities in this respect.
1128  *
1129  * The IOC3 serials use a 22MHz clock rate with an additional divider which
1130  * can be programmed in the SCR register if the DLAB bit is set.
1131  *
1132  * Register to interrupt zero because we share the interrupt with
1133  * the serial driver which we don't properly support yet.
1134  *
1135  * Can't use UPF_IOREMAP as the whole of IOC3 resources have already been
1136  * registered.
1137  */
1138 static void ioc3_8250_register(struct ioc3_uartregs __iomem *uart)
1139 {
1140 #define COSMISC_CONSTANT 6
1141 
1142 	struct uart_8250_port port = {
1143 	        .port = {
1144 			.irq		= 0,
1145 			.flags		= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF,
1146 			.iotype		= UPIO_MEM,
1147 			.regshift	= 0,
1148 			.uartclk	= (22000000 << 1) / COSMISC_CONSTANT,
1149 
1150 			.membase	= (unsigned char __iomem *) uart,
1151 			.mapbase	= (unsigned long) uart,
1152                 }
1153 	};
1154 	unsigned char lcr;
1155 
1156 	lcr = uart->iu_lcr;
1157 	uart->iu_lcr = lcr | UART_LCR_DLAB;
1158 	uart->iu_scr = COSMISC_CONSTANT,
1159 	uart->iu_lcr = lcr;
1160 	uart->iu_lcr;
1161 	serial8250_register_8250_port(&port);
1162 }
1163 
1164 static void ioc3_serial_probe(struct pci_dev *pdev, struct ioc3 *ioc3)
1165 {
1166 	/*
1167 	 * We need to recognice and treat the fourth MENET serial as it
1168 	 * does not have an SuperIO chip attached to it, therefore attempting
1169 	 * to access it will result in bus errors.  We call something an
1170 	 * MENET if PCI slot 0, 1, 2 and 3 of a master PCI bus all have an IOC3
1171 	 * in it.  This is paranoid but we want to avoid blowing up on a
1172 	 * showhorn PCI box that happens to have 4 IOC3 cards in it so it's
1173 	 * not paranoid enough ...
1174 	 */
1175 	if (ioc3_is_menet(pdev) && PCI_SLOT(pdev->devfn) == 3)
1176 		return;
1177 
1178 	/*
1179 	 * Switch IOC3 to PIO mode.  It probably already was but let's be
1180 	 * paranoid
1181 	 */
1182 	ioc3->gpcr_s = GPCR_UARTA_MODESEL | GPCR_UARTB_MODESEL;
1183 	ioc3->gpcr_s;
1184 	ioc3->gppr_6 = 0;
1185 	ioc3->gppr_6;
1186 	ioc3->gppr_7 = 0;
1187 	ioc3->gppr_7;
1188 	ioc3->sscr_a = ioc3->sscr_a & ~SSCR_DMA_EN;
1189 	ioc3->sscr_a;
1190 	ioc3->sscr_b = ioc3->sscr_b & ~SSCR_DMA_EN;
1191 	ioc3->sscr_b;
1192 	/* Disable all SA/B interrupts except for SA/B_INT in SIO_IEC. */
1193 	ioc3->sio_iec &= ~ (SIO_IR_SA_TX_MT | SIO_IR_SA_RX_FULL |
1194 			    SIO_IR_SA_RX_HIGH | SIO_IR_SA_RX_TIMER |
1195 			    SIO_IR_SA_DELTA_DCD | SIO_IR_SA_DELTA_CTS |
1196 			    SIO_IR_SA_TX_EXPLICIT | SIO_IR_SA_MEMERR);
1197 	ioc3->sio_iec |= SIO_IR_SA_INT;
1198 	ioc3->sscr_a = 0;
1199 	ioc3->sio_iec &= ~ (SIO_IR_SB_TX_MT | SIO_IR_SB_RX_FULL |
1200 			    SIO_IR_SB_RX_HIGH | SIO_IR_SB_RX_TIMER |
1201 			    SIO_IR_SB_DELTA_DCD | SIO_IR_SB_DELTA_CTS |
1202 			    SIO_IR_SB_TX_EXPLICIT | SIO_IR_SB_MEMERR);
1203 	ioc3->sio_iec |= SIO_IR_SB_INT;
1204 	ioc3->sscr_b = 0;
1205 
1206 	ioc3_8250_register(&ioc3->sregs.uarta);
1207 	ioc3_8250_register(&ioc3->sregs.uartb);
1208 }
1209 #endif
1210 
1211 static const struct net_device_ops ioc3_netdev_ops = {
1212 	.ndo_open		= ioc3_open,
1213 	.ndo_stop		= ioc3_close,
1214 	.ndo_start_xmit		= ioc3_start_xmit,
1215 	.ndo_tx_timeout		= ioc3_timeout,
1216 	.ndo_get_stats		= ioc3_get_stats,
1217 	.ndo_set_rx_mode	= ioc3_set_multicast_list,
1218 	.ndo_do_ioctl		= ioc3_ioctl,
1219 	.ndo_validate_addr	= eth_validate_addr,
1220 	.ndo_set_mac_address	= ioc3_set_mac_address,
1221 };
1222 
1223 static int ioc3_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
1224 {
1225 	unsigned int sw_physid1, sw_physid2;
1226 	struct net_device *dev = NULL;
1227 	struct ioc3_private *ip;
1228 	struct ioc3 *ioc3;
1229 	unsigned long ioc3_base, ioc3_size;
1230 	u32 vendor, model, rev;
1231 	int err, pci_using_dac;
1232 
1233 	/* Configure DMA attributes. */
1234 	err = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
1235 	if (!err) {
1236 		pci_using_dac = 1;
1237 		err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
1238 		if (err < 0) {
1239 			printk(KERN_ERR "%s: Unable to obtain 64 bit DMA "
1240 			       "for consistent allocations\n", pci_name(pdev));
1241 			goto out;
1242 		}
1243 	} else {
1244 		err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
1245 		if (err) {
1246 			printk(KERN_ERR "%s: No usable DMA configuration, "
1247 			       "aborting.\n", pci_name(pdev));
1248 			goto out;
1249 		}
1250 		pci_using_dac = 0;
1251 	}
1252 
1253 	if (pci_enable_device(pdev))
1254 		return -ENODEV;
1255 
1256 	dev = alloc_etherdev(sizeof(struct ioc3_private));
1257 	if (!dev) {
1258 		err = -ENOMEM;
1259 		goto out_disable;
1260 	}
1261 
1262 	if (pci_using_dac)
1263 		dev->features |= NETIF_F_HIGHDMA;
1264 
1265 	err = pci_request_regions(pdev, "ioc3");
1266 	if (err)
1267 		goto out_free;
1268 
1269 	SET_NETDEV_DEV(dev, &pdev->dev);
1270 
1271 	ip = netdev_priv(dev);
1272 	ip->dev = dev;
1273 
1274 	dev->irq = pdev->irq;
1275 
1276 	ioc3_base = pci_resource_start(pdev, 0);
1277 	ioc3_size = pci_resource_len(pdev, 0);
1278 	ioc3 = (struct ioc3 *) ioremap(ioc3_base, ioc3_size);
1279 	if (!ioc3) {
1280 		printk(KERN_CRIT "ioc3eth(%s): ioremap failed, goodbye.\n",
1281 		       pci_name(pdev));
1282 		err = -ENOMEM;
1283 		goto out_res;
1284 	}
1285 	ip->regs = ioc3;
1286 
1287 #ifdef CONFIG_SERIAL_8250
1288 	ioc3_serial_probe(pdev, ioc3);
1289 #endif
1290 
1291 	spin_lock_init(&ip->ioc3_lock);
1292 	timer_setup(&ip->ioc3_timer, ioc3_timer, 0);
1293 
1294 	ioc3_stop(ip);
1295 	ioc3_init(dev);
1296 
1297 	ip->pdev = pdev;
1298 
1299 	ip->mii.phy_id_mask = 0x1f;
1300 	ip->mii.reg_num_mask = 0x1f;
1301 	ip->mii.dev = dev;
1302 	ip->mii.mdio_read = ioc3_mdio_read;
1303 	ip->mii.mdio_write = ioc3_mdio_write;
1304 
1305 	ioc3_mii_init(ip);
1306 
1307 	if (ip->mii.phy_id == -1) {
1308 		printk(KERN_CRIT "ioc3-eth(%s): Didn't find a PHY, goodbye.\n",
1309 		       pci_name(pdev));
1310 		err = -ENODEV;
1311 		goto out_stop;
1312 	}
1313 
1314 	ioc3_mii_start(ip);
1315 	ioc3_ssram_disc(ip);
1316 	ioc3_get_eaddr(ip);
1317 
1318 	/* The IOC3-specific entries in the device structure. */
1319 	dev->watchdog_timeo	= 5 * HZ;
1320 	dev->netdev_ops		= &ioc3_netdev_ops;
1321 	dev->ethtool_ops	= &ioc3_ethtool_ops;
1322 	dev->hw_features	= NETIF_F_IP_CSUM | NETIF_F_RXCSUM;
1323 	dev->features		= NETIF_F_IP_CSUM;
1324 
1325 	sw_physid1 = ioc3_mdio_read(dev, ip->mii.phy_id, MII_PHYSID1);
1326 	sw_physid2 = ioc3_mdio_read(dev, ip->mii.phy_id, MII_PHYSID2);
1327 
1328 	err = register_netdev(dev);
1329 	if (err)
1330 		goto out_stop;
1331 
1332 	mii_check_media(&ip->mii, 1, 1);
1333 	ioc3_setup_duplex(ip);
1334 
1335 	vendor = (sw_physid1 << 12) | (sw_physid2 >> 4);
1336 	model  = (sw_physid2 >> 4) & 0x3f;
1337 	rev    = sw_physid2 & 0xf;
1338 	printk(KERN_INFO "%s: Using PHY %d, vendor 0x%x, model %d, "
1339 	       "rev %d.\n", dev->name, ip->mii.phy_id, vendor, model, rev);
1340 	printk(KERN_INFO "%s: IOC3 SSRAM has %d kbyte.\n", dev->name,
1341 	       ip->emcr & EMCR_BUFSIZ ? 128 : 64);
1342 
1343 	return 0;
1344 
1345 out_stop:
1346 	ioc3_stop(ip);
1347 	del_timer_sync(&ip->ioc3_timer);
1348 	ioc3_free_rings(ip);
1349 out_res:
1350 	pci_release_regions(pdev);
1351 out_free:
1352 	free_netdev(dev);
1353 out_disable:
1354 	/*
1355 	 * We should call pci_disable_device(pdev); here if the IOC3 wasn't
1356 	 * such a weird device ...
1357 	 */
1358 out:
1359 	return err;
1360 }
1361 
1362 static void ioc3_remove_one(struct pci_dev *pdev)
1363 {
1364 	struct net_device *dev = pci_get_drvdata(pdev);
1365 	struct ioc3_private *ip = netdev_priv(dev);
1366 	struct ioc3 *ioc3 = ip->regs;
1367 
1368 	unregister_netdev(dev);
1369 	del_timer_sync(&ip->ioc3_timer);
1370 
1371 	iounmap(ioc3);
1372 	pci_release_regions(pdev);
1373 	free_netdev(dev);
1374 	/*
1375 	 * We should call pci_disable_device(pdev); here if the IOC3 wasn't
1376 	 * such a weird device ...
1377 	 */
1378 }
1379 
1380 static const struct pci_device_id ioc3_pci_tbl[] = {
1381 	{ PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC3, PCI_ANY_ID, PCI_ANY_ID },
1382 	{ 0 }
1383 };
1384 MODULE_DEVICE_TABLE(pci, ioc3_pci_tbl);
1385 
1386 static struct pci_driver ioc3_driver = {
1387 	.name		= "ioc3-eth",
1388 	.id_table	= ioc3_pci_tbl,
1389 	.probe		= ioc3_probe,
1390 	.remove		= ioc3_remove_one,
1391 };
1392 
1393 static netdev_tx_t ioc3_start_xmit(struct sk_buff *skb, struct net_device *dev)
1394 {
1395 	unsigned long data;
1396 	struct ioc3_private *ip = netdev_priv(dev);
1397 	struct ioc3 *ioc3 = ip->regs;
1398 	unsigned int len;
1399 	struct ioc3_etxd *desc;
1400 	uint32_t w0 = 0;
1401 	int produce;
1402 
1403 	/*
1404 	 * IOC3 has a fairly simple minded checksumming hardware which simply
1405 	 * adds up the 1's complement checksum for the entire packet and
1406 	 * inserts it at an offset which can be specified in the descriptor
1407 	 * into the transmit packet.  This means we have to compensate for the
1408 	 * MAC header which should not be summed and the TCP/UDP pseudo headers
1409 	 * manually.
1410 	 */
1411 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
1412 		const struct iphdr *ih = ip_hdr(skb);
1413 		const int proto = ntohs(ih->protocol);
1414 		unsigned int csoff;
1415 		uint32_t csum, ehsum;
1416 		uint16_t *eh;
1417 
1418 		/* The MAC header.  skb->mac seem the logic approach
1419 		   to find the MAC header - except it's a NULL pointer ...  */
1420 		eh = (uint16_t *) skb->data;
1421 
1422 		/* Sum up dest addr, src addr and protocol  */
1423 		ehsum = eh[0] + eh[1] + eh[2] + eh[3] + eh[4] + eh[5] + eh[6];
1424 
1425 		/* Fold ehsum.  can't use csum_fold which negates also ...  */
1426 		ehsum = (ehsum & 0xffff) + (ehsum >> 16);
1427 		ehsum = (ehsum & 0xffff) + (ehsum >> 16);
1428 
1429 		/* Skip IP header; it's sum is always zero and was
1430 		   already filled in by ip_output.c */
1431 		csum = csum_tcpudp_nofold(ih->saddr, ih->daddr,
1432 		                          ih->tot_len - (ih->ihl << 2),
1433 		                          proto, 0xffff ^ ehsum);
1434 
1435 		csum = (csum & 0xffff) + (csum >> 16);	/* Fold again */
1436 		csum = (csum & 0xffff) + (csum >> 16);
1437 
1438 		csoff = ETH_HLEN + (ih->ihl << 2);
1439 		if (proto == IPPROTO_UDP) {
1440 			csoff += offsetof(struct udphdr, check);
1441 			udp_hdr(skb)->check = csum;
1442 		}
1443 		if (proto == IPPROTO_TCP) {
1444 			csoff += offsetof(struct tcphdr, check);
1445 			tcp_hdr(skb)->check = csum;
1446 		}
1447 
1448 		w0 = ETXD_DOCHECKSUM | (csoff << ETXD_CHKOFF_SHIFT);
1449 	}
1450 
1451 	spin_lock_irq(&ip->ioc3_lock);
1452 
1453 	data = (unsigned long) skb->data;
1454 	len = skb->len;
1455 
1456 	produce = ip->tx_pi;
1457 	desc = &ip->txr[produce];
1458 
1459 	if (len <= 104) {
1460 		/* Short packet, let's copy it directly into the ring.  */
1461 		skb_copy_from_linear_data(skb, desc->data, skb->len);
1462 		if (len < ETH_ZLEN) {
1463 			/* Very short packet, pad with zeros at the end. */
1464 			memset(desc->data + len, 0, ETH_ZLEN - len);
1465 			len = ETH_ZLEN;
1466 		}
1467 		desc->cmd = cpu_to_be32(len | ETXD_INTWHENDONE | ETXD_D0V | w0);
1468 		desc->bufcnt = cpu_to_be32(len);
1469 	} else if ((data ^ (data + len - 1)) & 0x4000) {
1470 		unsigned long b2 = (data | 0x3fffUL) + 1UL;
1471 		unsigned long s1 = b2 - data;
1472 		unsigned long s2 = data + len - b2;
1473 
1474 		desc->cmd    = cpu_to_be32(len | ETXD_INTWHENDONE |
1475 		                           ETXD_B1V | ETXD_B2V | w0);
1476 		desc->bufcnt = cpu_to_be32((s1 << ETXD_B1CNT_SHIFT) |
1477 		                           (s2 << ETXD_B2CNT_SHIFT));
1478 		desc->p1     = cpu_to_be64(ioc3_map(skb->data, 1));
1479 		desc->p2     = cpu_to_be64(ioc3_map((void *) b2, 1));
1480 	} else {
1481 		/* Normal sized packet that doesn't cross a page boundary. */
1482 		desc->cmd = cpu_to_be32(len | ETXD_INTWHENDONE | ETXD_B1V | w0);
1483 		desc->bufcnt = cpu_to_be32(len << ETXD_B1CNT_SHIFT);
1484 		desc->p1     = cpu_to_be64(ioc3_map(skb->data, 1));
1485 	}
1486 
1487 	BARRIER();
1488 
1489 	ip->tx_skbs[produce] = skb;			/* Remember skb */
1490 	produce = (produce + 1) & 127;
1491 	ip->tx_pi = produce;
1492 	ioc3_w_etpir(produce << 7);			/* Fire ... */
1493 
1494 	ip->txqlen++;
1495 
1496 	if (ip->txqlen >= 127)
1497 		netif_stop_queue(dev);
1498 
1499 	spin_unlock_irq(&ip->ioc3_lock);
1500 
1501 	return NETDEV_TX_OK;
1502 }
1503 
1504 static void ioc3_timeout(struct net_device *dev)
1505 {
1506 	struct ioc3_private *ip = netdev_priv(dev);
1507 
1508 	printk(KERN_ERR "%s: transmit timed out, resetting\n", dev->name);
1509 
1510 	spin_lock_irq(&ip->ioc3_lock);
1511 
1512 	ioc3_stop(ip);
1513 	ioc3_init(dev);
1514 	ioc3_mii_init(ip);
1515 	ioc3_mii_start(ip);
1516 
1517 	spin_unlock_irq(&ip->ioc3_lock);
1518 
1519 	netif_wake_queue(dev);
1520 }
1521 
1522 /*
1523  * Given a multicast ethernet address, this routine calculates the
1524  * address's bit index in the logical address filter mask
1525  */
1526 
1527 static inline unsigned int ioc3_hash(const unsigned char *addr)
1528 {
1529 	unsigned int temp = 0;
1530 	u32 crc;
1531 	int bits;
1532 
1533 	crc = ether_crc_le(ETH_ALEN, addr);
1534 
1535 	crc &= 0x3f;    /* bit reverse lowest 6 bits for hash index */
1536 	for (bits = 6; --bits >= 0; ) {
1537 		temp <<= 1;
1538 		temp |= (crc & 0x1);
1539 		crc >>= 1;
1540 	}
1541 
1542 	return temp;
1543 }
1544 
1545 static void ioc3_get_drvinfo (struct net_device *dev,
1546 	struct ethtool_drvinfo *info)
1547 {
1548 	struct ioc3_private *ip = netdev_priv(dev);
1549 
1550 	strlcpy(info->driver, IOC3_NAME, sizeof(info->driver));
1551 	strlcpy(info->version, IOC3_VERSION, sizeof(info->version));
1552 	strlcpy(info->bus_info, pci_name(ip->pdev), sizeof(info->bus_info));
1553 }
1554 
1555 static int ioc3_get_link_ksettings(struct net_device *dev,
1556 				   struct ethtool_link_ksettings *cmd)
1557 {
1558 	struct ioc3_private *ip = netdev_priv(dev);
1559 
1560 	spin_lock_irq(&ip->ioc3_lock);
1561 	mii_ethtool_get_link_ksettings(&ip->mii, cmd);
1562 	spin_unlock_irq(&ip->ioc3_lock);
1563 
1564 	return 0;
1565 }
1566 
1567 static int ioc3_set_link_ksettings(struct net_device *dev,
1568 				   const struct ethtool_link_ksettings *cmd)
1569 {
1570 	struct ioc3_private *ip = netdev_priv(dev);
1571 	int rc;
1572 
1573 	spin_lock_irq(&ip->ioc3_lock);
1574 	rc = mii_ethtool_set_link_ksettings(&ip->mii, cmd);
1575 	spin_unlock_irq(&ip->ioc3_lock);
1576 
1577 	return rc;
1578 }
1579 
1580 static int ioc3_nway_reset(struct net_device *dev)
1581 {
1582 	struct ioc3_private *ip = netdev_priv(dev);
1583 	int rc;
1584 
1585 	spin_lock_irq(&ip->ioc3_lock);
1586 	rc = mii_nway_restart(&ip->mii);
1587 	spin_unlock_irq(&ip->ioc3_lock);
1588 
1589 	return rc;
1590 }
1591 
1592 static u32 ioc3_get_link(struct net_device *dev)
1593 {
1594 	struct ioc3_private *ip = netdev_priv(dev);
1595 	int rc;
1596 
1597 	spin_lock_irq(&ip->ioc3_lock);
1598 	rc = mii_link_ok(&ip->mii);
1599 	spin_unlock_irq(&ip->ioc3_lock);
1600 
1601 	return rc;
1602 }
1603 
1604 static const struct ethtool_ops ioc3_ethtool_ops = {
1605 	.get_drvinfo		= ioc3_get_drvinfo,
1606 	.nway_reset		= ioc3_nway_reset,
1607 	.get_link		= ioc3_get_link,
1608 	.get_link_ksettings	= ioc3_get_link_ksettings,
1609 	.set_link_ksettings	= ioc3_set_link_ksettings,
1610 };
1611 
1612 static int ioc3_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
1613 {
1614 	struct ioc3_private *ip = netdev_priv(dev);
1615 	int rc;
1616 
1617 	spin_lock_irq(&ip->ioc3_lock);
1618 	rc = generic_mii_ioctl(&ip->mii, if_mii(rq), cmd, NULL);
1619 	spin_unlock_irq(&ip->ioc3_lock);
1620 
1621 	return rc;
1622 }
1623 
1624 static void ioc3_set_multicast_list(struct net_device *dev)
1625 {
1626 	struct netdev_hw_addr *ha;
1627 	struct ioc3_private *ip = netdev_priv(dev);
1628 	struct ioc3 *ioc3 = ip->regs;
1629 	u64 ehar = 0;
1630 
1631 	netif_stop_queue(dev);				/* Lock out others. */
1632 
1633 	if (dev->flags & IFF_PROMISC) {			/* Set promiscuous.  */
1634 		ip->emcr |= EMCR_PROMISC;
1635 		ioc3_w_emcr(ip->emcr);
1636 		(void) ioc3_r_emcr();
1637 	} else {
1638 		ip->emcr &= ~EMCR_PROMISC;
1639 		ioc3_w_emcr(ip->emcr);			/* Clear promiscuous. */
1640 		(void) ioc3_r_emcr();
1641 
1642 		if ((dev->flags & IFF_ALLMULTI) ||
1643 		    (netdev_mc_count(dev) > 64)) {
1644 			/* Too many for hashing to make sense or we want all
1645 			   multicast packets anyway,  so skip computing all the
1646 			   hashes and just accept all packets.  */
1647 			ip->ehar_h = 0xffffffff;
1648 			ip->ehar_l = 0xffffffff;
1649 		} else {
1650 			netdev_for_each_mc_addr(ha, dev) {
1651 				ehar |= (1UL << ioc3_hash(ha->addr));
1652 			}
1653 			ip->ehar_h = ehar >> 32;
1654 			ip->ehar_l = ehar & 0xffffffff;
1655 		}
1656 		ioc3_w_ehar_h(ip->ehar_h);
1657 		ioc3_w_ehar_l(ip->ehar_l);
1658 	}
1659 
1660 	netif_wake_queue(dev);			/* Let us get going again. */
1661 }
1662 
1663 module_pci_driver(ioc3_driver);
1664 MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
1665 MODULE_DESCRIPTION("SGI IOC3 Ethernet driver");
1666 MODULE_LICENSE("GPL");
1667