xref: /linux/drivers/net/ethernet/seeq/sgiseeq.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * sgiseeq.c: Seeq8003 ethernet driver for SGI machines.
3  *
4  * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
5  */
6 
7 #undef DEBUG
8 
9 #include <linux/dma-mapping.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/errno.h>
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/interrupt.h>
17 #include <linux/string.h>
18 #include <linux/delay.h>
19 #include <linux/netdevice.h>
20 #include <linux/platform_device.h>
21 #include <linux/etherdevice.h>
22 #include <linux/skbuff.h>
23 
24 #include <asm/sgi/hpc3.h>
25 #include <asm/sgi/ip22.h>
26 #include <asm/sgi/seeq.h>
27 
28 #include "sgiseeq.h"
29 
30 static char *sgiseeqstr = "SGI Seeq8003";
31 
32 /*
33  * If you want speed, you do something silly, it always has worked for me.  So,
34  * with that in mind, I've decided to make this driver look completely like a
35  * stupid Lance from a driver architecture perspective.  Only difference is that
36  * here our "ring buffer" looks and acts like a real Lance one does but is
37  * laid out like how the HPC DMA and the Seeq want it to.  You'd be surprised
38  * how a stupid idea like this can pay off in performance, not to mention
39  * making this driver 2,000 times easier to write. ;-)
40  */
41 
42 /* Tune these if we tend to run out often etc. */
43 #define SEEQ_RX_BUFFERS  16
44 #define SEEQ_TX_BUFFERS  16
45 
46 #define PKT_BUF_SZ       1584
47 
48 #define NEXT_RX(i)  (((i) + 1) & (SEEQ_RX_BUFFERS - 1))
49 #define NEXT_TX(i)  (((i) + 1) & (SEEQ_TX_BUFFERS - 1))
50 #define PREV_RX(i)  (((i) - 1) & (SEEQ_RX_BUFFERS - 1))
51 #define PREV_TX(i)  (((i) - 1) & (SEEQ_TX_BUFFERS - 1))
52 
53 #define TX_BUFFS_AVAIL(sp) ((sp->tx_old <= sp->tx_new) ? \
54 			    sp->tx_old + (SEEQ_TX_BUFFERS - 1) - sp->tx_new : \
55 			    sp->tx_old - sp->tx_new - 1)
56 
57 #define VIRT_TO_DMA(sp, v) ((sp)->srings_dma +                                 \
58 				  (dma_addr_t)((unsigned long)(v) -            \
59 					       (unsigned long)((sp)->rx_desc)))
60 
61 /* Copy frames shorter than rx_copybreak, otherwise pass on up in
62  * a full sized sk_buff.  Value of 100 stolen from tulip.c (!alpha).
63  */
64 static int rx_copybreak = 100;
65 
66 #define PAD_SIZE    (128 - sizeof(struct hpc_dma_desc) - sizeof(void *))
67 
68 struct sgiseeq_rx_desc {
69 	volatile struct hpc_dma_desc rdma;
70 	u8 padding[PAD_SIZE];
71 	struct sk_buff *skb;
72 };
73 
74 struct sgiseeq_tx_desc {
75 	volatile struct hpc_dma_desc tdma;
76 	u8 padding[PAD_SIZE];
77 	struct sk_buff *skb;
78 };
79 
80 /*
81  * Warning: This structure is laid out in a certain way because HPC dma
82  *          descriptors must be 8-byte aligned.  So don't touch this without
83  *          some care.
84  */
85 struct sgiseeq_init_block { /* Note the name ;-) */
86 	struct sgiseeq_rx_desc rxvector[SEEQ_RX_BUFFERS];
87 	struct sgiseeq_tx_desc txvector[SEEQ_TX_BUFFERS];
88 };
89 
90 struct sgiseeq_private {
91 	struct sgiseeq_init_block *srings;
92 	dma_addr_t srings_dma;
93 
94 	/* Ptrs to the descriptors in uncached space. */
95 	struct sgiseeq_rx_desc *rx_desc;
96 	struct sgiseeq_tx_desc *tx_desc;
97 
98 	char *name;
99 	struct hpc3_ethregs *hregs;
100 	struct sgiseeq_regs *sregs;
101 
102 	/* Ring entry counters. */
103 	unsigned int rx_new, tx_new;
104 	unsigned int rx_old, tx_old;
105 
106 	int is_edlc;
107 	unsigned char control;
108 	unsigned char mode;
109 
110 	spinlock_t tx_lock;
111 };
112 
113 static inline void dma_sync_desc_cpu(struct net_device *dev, void *addr)
114 {
115 	dma_cache_sync(dev->dev.parent, addr, sizeof(struct sgiseeq_rx_desc),
116 		       DMA_FROM_DEVICE);
117 }
118 
119 static inline void dma_sync_desc_dev(struct net_device *dev, void *addr)
120 {
121 	dma_cache_sync(dev->dev.parent, addr, sizeof(struct sgiseeq_rx_desc),
122 		       DMA_TO_DEVICE);
123 }
124 
125 static inline void hpc3_eth_reset(struct hpc3_ethregs *hregs)
126 {
127 	hregs->reset = HPC3_ERST_CRESET | HPC3_ERST_CLRIRQ;
128 	udelay(20);
129 	hregs->reset = 0;
130 }
131 
132 static inline void reset_hpc3_and_seeq(struct hpc3_ethregs *hregs,
133 				       struct sgiseeq_regs *sregs)
134 {
135 	hregs->rx_ctrl = hregs->tx_ctrl = 0;
136 	hpc3_eth_reset(hregs);
137 }
138 
139 #define RSTAT_GO_BITS (SEEQ_RCMD_IGOOD | SEEQ_RCMD_IEOF | SEEQ_RCMD_ISHORT | \
140 		       SEEQ_RCMD_IDRIB | SEEQ_RCMD_ICRC)
141 
142 static inline void seeq_go(struct sgiseeq_private *sp,
143 			   struct hpc3_ethregs *hregs,
144 			   struct sgiseeq_regs *sregs)
145 {
146 	sregs->rstat = sp->mode | RSTAT_GO_BITS;
147 	hregs->rx_ctrl = HPC3_ERXCTRL_ACTIVE;
148 }
149 
150 static inline void __sgiseeq_set_mac_address(struct net_device *dev)
151 {
152 	struct sgiseeq_private *sp = netdev_priv(dev);
153 	struct sgiseeq_regs *sregs = sp->sregs;
154 	int i;
155 
156 	sregs->tstat = SEEQ_TCMD_RB0;
157 	for (i = 0; i < 6; i++)
158 		sregs->rw.eth_addr[i] = dev->dev_addr[i];
159 }
160 
161 static int sgiseeq_set_mac_address(struct net_device *dev, void *addr)
162 {
163 	struct sgiseeq_private *sp = netdev_priv(dev);
164 	struct sockaddr *sa = addr;
165 
166 	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
167 
168 	spin_lock_irq(&sp->tx_lock);
169 	__sgiseeq_set_mac_address(dev);
170 	spin_unlock_irq(&sp->tx_lock);
171 
172 	return 0;
173 }
174 
175 #define TCNTINFO_INIT (HPCDMA_EOX | HPCDMA_ETXD)
176 #define RCNTCFG_INIT  (HPCDMA_OWN | HPCDMA_EORP | HPCDMA_XIE)
177 #define RCNTINFO_INIT (RCNTCFG_INIT | (PKT_BUF_SZ & HPCDMA_BCNT))
178 
179 static int seeq_init_ring(struct net_device *dev)
180 {
181 	struct sgiseeq_private *sp = netdev_priv(dev);
182 	int i;
183 
184 	netif_stop_queue(dev);
185 	sp->rx_new = sp->tx_new = 0;
186 	sp->rx_old = sp->tx_old = 0;
187 
188 	__sgiseeq_set_mac_address(dev);
189 
190 	/* Setup tx ring. */
191 	for(i = 0; i < SEEQ_TX_BUFFERS; i++) {
192 		sp->tx_desc[i].tdma.cntinfo = TCNTINFO_INIT;
193 		dma_sync_desc_dev(dev, &sp->tx_desc[i]);
194 	}
195 
196 	/* And now the rx ring. */
197 	for (i = 0; i < SEEQ_RX_BUFFERS; i++) {
198 		if (!sp->rx_desc[i].skb) {
199 			dma_addr_t dma_addr;
200 			struct sk_buff *skb = netdev_alloc_skb(dev, PKT_BUF_SZ);
201 
202 			if (skb == NULL)
203 				return -ENOMEM;
204 			skb_reserve(skb, 2);
205 			dma_addr = dma_map_single(dev->dev.parent,
206 						  skb->data - 2,
207 						  PKT_BUF_SZ, DMA_FROM_DEVICE);
208 			sp->rx_desc[i].skb = skb;
209 			sp->rx_desc[i].rdma.pbuf = dma_addr;
210 		}
211 		sp->rx_desc[i].rdma.cntinfo = RCNTINFO_INIT;
212 		dma_sync_desc_dev(dev, &sp->rx_desc[i]);
213 	}
214 	sp->rx_desc[i - 1].rdma.cntinfo |= HPCDMA_EOR;
215 	dma_sync_desc_dev(dev, &sp->rx_desc[i - 1]);
216 	return 0;
217 }
218 
219 static void seeq_purge_ring(struct net_device *dev)
220 {
221 	struct sgiseeq_private *sp = netdev_priv(dev);
222 	int i;
223 
224 	/* clear tx ring. */
225 	for (i = 0; i < SEEQ_TX_BUFFERS; i++) {
226 		if (sp->tx_desc[i].skb) {
227 			dev_kfree_skb(sp->tx_desc[i].skb);
228 			sp->tx_desc[i].skb = NULL;
229 		}
230 	}
231 
232 	/* And now the rx ring. */
233 	for (i = 0; i < SEEQ_RX_BUFFERS; i++) {
234 		if (sp->rx_desc[i].skb) {
235 			dev_kfree_skb(sp->rx_desc[i].skb);
236 			sp->rx_desc[i].skb = NULL;
237 		}
238 	}
239 }
240 
241 #ifdef DEBUG
242 static struct sgiseeq_private *gpriv;
243 static struct net_device *gdev;
244 
245 static void sgiseeq_dump_rings(void)
246 {
247 	static int once;
248 	struct sgiseeq_rx_desc *r = gpriv->rx_desc;
249 	struct sgiseeq_tx_desc *t = gpriv->tx_desc;
250 	struct hpc3_ethregs *hregs = gpriv->hregs;
251 	int i;
252 
253 	if (once)
254 		return;
255 	once++;
256 	printk("RING DUMP:\n");
257 	for (i = 0; i < SEEQ_RX_BUFFERS; i++) {
258 		printk("RX [%d]: @(%p) [%08x,%08x,%08x] ",
259 		       i, (&r[i]), r[i].rdma.pbuf, r[i].rdma.cntinfo,
260 		       r[i].rdma.pnext);
261 		i += 1;
262 		printk("-- [%d]: @(%p) [%08x,%08x,%08x]\n",
263 		       i, (&r[i]), r[i].rdma.pbuf, r[i].rdma.cntinfo,
264 		       r[i].rdma.pnext);
265 	}
266 	for (i = 0; i < SEEQ_TX_BUFFERS; i++) {
267 		printk("TX [%d]: @(%p) [%08x,%08x,%08x] ",
268 		       i, (&t[i]), t[i].tdma.pbuf, t[i].tdma.cntinfo,
269 		       t[i].tdma.pnext);
270 		i += 1;
271 		printk("-- [%d]: @(%p) [%08x,%08x,%08x]\n",
272 		       i, (&t[i]), t[i].tdma.pbuf, t[i].tdma.cntinfo,
273 		       t[i].tdma.pnext);
274 	}
275 	printk("INFO: [rx_new = %d rx_old=%d] [tx_new = %d tx_old = %d]\n",
276 	       gpriv->rx_new, gpriv->rx_old, gpriv->tx_new, gpriv->tx_old);
277 	printk("RREGS: rx_cbptr[%08x] rx_ndptr[%08x] rx_ctrl[%08x]\n",
278 	       hregs->rx_cbptr, hregs->rx_ndptr, hregs->rx_ctrl);
279 	printk("TREGS: tx_cbptr[%08x] tx_ndptr[%08x] tx_ctrl[%08x]\n",
280 	       hregs->tx_cbptr, hregs->tx_ndptr, hregs->tx_ctrl);
281 }
282 #endif
283 
284 #define TSTAT_INIT_SEEQ (SEEQ_TCMD_IPT|SEEQ_TCMD_I16|SEEQ_TCMD_IC|SEEQ_TCMD_IUF)
285 #define TSTAT_INIT_EDLC ((TSTAT_INIT_SEEQ) | SEEQ_TCMD_RB2)
286 
287 static int init_seeq(struct net_device *dev, struct sgiseeq_private *sp,
288 		     struct sgiseeq_regs *sregs)
289 {
290 	struct hpc3_ethregs *hregs = sp->hregs;
291 	int err;
292 
293 	reset_hpc3_and_seeq(hregs, sregs);
294 	err = seeq_init_ring(dev);
295 	if (err)
296 		return err;
297 
298 	/* Setup to field the proper interrupt types. */
299 	if (sp->is_edlc) {
300 		sregs->tstat = TSTAT_INIT_EDLC;
301 		sregs->rw.wregs.control = sp->control;
302 		sregs->rw.wregs.frame_gap = 0;
303 	} else {
304 		sregs->tstat = TSTAT_INIT_SEEQ;
305 	}
306 
307 	hregs->rx_ndptr = VIRT_TO_DMA(sp, sp->rx_desc);
308 	hregs->tx_ndptr = VIRT_TO_DMA(sp, sp->tx_desc);
309 
310 	seeq_go(sp, hregs, sregs);
311 	return 0;
312 }
313 
314 static void record_rx_errors(struct net_device *dev, unsigned char status)
315 {
316 	if (status & SEEQ_RSTAT_OVERF ||
317 	    status & SEEQ_RSTAT_SFRAME)
318 		dev->stats.rx_over_errors++;
319 	if (status & SEEQ_RSTAT_CERROR)
320 		dev->stats.rx_crc_errors++;
321 	if (status & SEEQ_RSTAT_DERROR)
322 		dev->stats.rx_frame_errors++;
323 	if (status & SEEQ_RSTAT_REOF)
324 		dev->stats.rx_errors++;
325 }
326 
327 static inline void rx_maybe_restart(struct sgiseeq_private *sp,
328 				    struct hpc3_ethregs *hregs,
329 				    struct sgiseeq_regs *sregs)
330 {
331 	if (!(hregs->rx_ctrl & HPC3_ERXCTRL_ACTIVE)) {
332 		hregs->rx_ndptr = VIRT_TO_DMA(sp, sp->rx_desc + sp->rx_new);
333 		seeq_go(sp, hregs, sregs);
334 	}
335 }
336 
337 static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp,
338 			      struct hpc3_ethregs *hregs,
339 			      struct sgiseeq_regs *sregs)
340 {
341 	struct sgiseeq_rx_desc *rd;
342 	struct sk_buff *skb = NULL;
343 	struct sk_buff *newskb;
344 	unsigned char pkt_status;
345 	int len = 0;
346 	unsigned int orig_end = PREV_RX(sp->rx_new);
347 
348 	/* Service every received packet. */
349 	rd = &sp->rx_desc[sp->rx_new];
350 	dma_sync_desc_cpu(dev, rd);
351 	while (!(rd->rdma.cntinfo & HPCDMA_OWN)) {
352 		len = PKT_BUF_SZ - (rd->rdma.cntinfo & HPCDMA_BCNT) - 3;
353 		dma_unmap_single(dev->dev.parent, rd->rdma.pbuf,
354 				 PKT_BUF_SZ, DMA_FROM_DEVICE);
355 		pkt_status = rd->skb->data[len];
356 		if (pkt_status & SEEQ_RSTAT_FIG) {
357 			/* Packet is OK. */
358 			/* We don't want to receive our own packets */
359 			if (memcmp(rd->skb->data + 6, dev->dev_addr, ETH_ALEN)) {
360 				if (len > rx_copybreak) {
361 					skb = rd->skb;
362 					newskb = netdev_alloc_skb(dev, PKT_BUF_SZ);
363 					if (!newskb) {
364 						newskb = skb;
365 						skb = NULL;
366 						goto memory_squeeze;
367 					}
368 					skb_reserve(newskb, 2);
369 				} else {
370 					skb = netdev_alloc_skb_ip_align(dev, len);
371 					if (skb)
372 						skb_copy_to_linear_data(skb, rd->skb->data, len);
373 
374 					newskb = rd->skb;
375 				}
376 memory_squeeze:
377 				if (skb) {
378 					skb_put(skb, len);
379 					skb->protocol = eth_type_trans(skb, dev);
380 					netif_rx(skb);
381 					dev->stats.rx_packets++;
382 					dev->stats.rx_bytes += len;
383 				} else {
384 					printk(KERN_NOTICE "%s: Memory squeeze, deferring packet.\n",
385 						dev->name);
386 					dev->stats.rx_dropped++;
387 				}
388 			} else {
389 				/* Silently drop my own packets */
390 				newskb = rd->skb;
391 			}
392 		} else {
393 			record_rx_errors(dev, pkt_status);
394 			newskb = rd->skb;
395 		}
396 		rd->skb = newskb;
397 		rd->rdma.pbuf = dma_map_single(dev->dev.parent,
398 					       newskb->data - 2,
399 					       PKT_BUF_SZ, DMA_FROM_DEVICE);
400 
401 		/* Return the entry to the ring pool. */
402 		rd->rdma.cntinfo = RCNTINFO_INIT;
403 		sp->rx_new = NEXT_RX(sp->rx_new);
404 		dma_sync_desc_dev(dev, rd);
405 		rd = &sp->rx_desc[sp->rx_new];
406 		dma_sync_desc_cpu(dev, rd);
407 	}
408 	dma_sync_desc_cpu(dev, &sp->rx_desc[orig_end]);
409 	sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR);
410 	dma_sync_desc_dev(dev, &sp->rx_desc[orig_end]);
411 	dma_sync_desc_cpu(dev, &sp->rx_desc[PREV_RX(sp->rx_new)]);
412 	sp->rx_desc[PREV_RX(sp->rx_new)].rdma.cntinfo |= HPCDMA_EOR;
413 	dma_sync_desc_dev(dev, &sp->rx_desc[PREV_RX(sp->rx_new)]);
414 	rx_maybe_restart(sp, hregs, sregs);
415 }
416 
417 static inline void tx_maybe_reset_collisions(struct sgiseeq_private *sp,
418 					     struct sgiseeq_regs *sregs)
419 {
420 	if (sp->is_edlc) {
421 		sregs->rw.wregs.control = sp->control & ~(SEEQ_CTRL_XCNT);
422 		sregs->rw.wregs.control = sp->control;
423 	}
424 }
425 
426 static inline void kick_tx(struct net_device *dev,
427 			   struct sgiseeq_private *sp,
428 			   struct hpc3_ethregs *hregs)
429 {
430 	struct sgiseeq_tx_desc *td;
431 	int i = sp->tx_old;
432 
433 	/* If the HPC aint doin nothin, and there are more packets
434 	 * with ETXD cleared and XIU set we must make very certain
435 	 * that we restart the HPC else we risk locking up the
436 	 * adapter.  The following code is only safe iff the HPCDMA
437 	 * is not active!
438 	 */
439 	td = &sp->tx_desc[i];
440 	dma_sync_desc_cpu(dev, td);
441 	while ((td->tdma.cntinfo & (HPCDMA_XIU | HPCDMA_ETXD)) ==
442 	      (HPCDMA_XIU | HPCDMA_ETXD)) {
443 		i = NEXT_TX(i);
444 		td = &sp->tx_desc[i];
445 		dma_sync_desc_cpu(dev, td);
446 	}
447 	if (td->tdma.cntinfo & HPCDMA_XIU) {
448 		hregs->tx_ndptr = VIRT_TO_DMA(sp, td);
449 		hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
450 	}
451 }
452 
453 static inline void sgiseeq_tx(struct net_device *dev, struct sgiseeq_private *sp,
454 			      struct hpc3_ethregs *hregs,
455 			      struct sgiseeq_regs *sregs)
456 {
457 	struct sgiseeq_tx_desc *td;
458 	unsigned long status = hregs->tx_ctrl;
459 	int j;
460 
461 	tx_maybe_reset_collisions(sp, sregs);
462 
463 	if (!(status & (HPC3_ETXCTRL_ACTIVE | SEEQ_TSTAT_PTRANS))) {
464 		/* Oops, HPC detected some sort of error. */
465 		if (status & SEEQ_TSTAT_R16)
466 			dev->stats.tx_aborted_errors++;
467 		if (status & SEEQ_TSTAT_UFLOW)
468 			dev->stats.tx_fifo_errors++;
469 		if (status & SEEQ_TSTAT_LCLS)
470 			dev->stats.collisions++;
471 	}
472 
473 	/* Ack 'em... */
474 	for (j = sp->tx_old; j != sp->tx_new; j = NEXT_TX(j)) {
475 		td = &sp->tx_desc[j];
476 
477 		dma_sync_desc_cpu(dev, td);
478 		if (!(td->tdma.cntinfo & (HPCDMA_XIU)))
479 			break;
480 		if (!(td->tdma.cntinfo & (HPCDMA_ETXD))) {
481 			if (!(status & HPC3_ETXCTRL_ACTIVE)) {
482 				hregs->tx_ndptr = VIRT_TO_DMA(sp, td);
483 				hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
484 			}
485 			break;
486 		}
487 		dev->stats.tx_packets++;
488 		sp->tx_old = NEXT_TX(sp->tx_old);
489 		td->tdma.cntinfo &= ~(HPCDMA_XIU | HPCDMA_XIE);
490 		td->tdma.cntinfo |= HPCDMA_EOX;
491 		if (td->skb) {
492 			dev_kfree_skb_any(td->skb);
493 			td->skb = NULL;
494 		}
495 		dma_sync_desc_dev(dev, td);
496 	}
497 }
498 
499 static irqreturn_t sgiseeq_interrupt(int irq, void *dev_id)
500 {
501 	struct net_device *dev = (struct net_device *) dev_id;
502 	struct sgiseeq_private *sp = netdev_priv(dev);
503 	struct hpc3_ethregs *hregs = sp->hregs;
504 	struct sgiseeq_regs *sregs = sp->sregs;
505 
506 	spin_lock(&sp->tx_lock);
507 
508 	/* Ack the IRQ and set software state. */
509 	hregs->reset = HPC3_ERST_CLRIRQ;
510 
511 	/* Always check for received packets. */
512 	sgiseeq_rx(dev, sp, hregs, sregs);
513 
514 	/* Only check for tx acks if we have something queued. */
515 	if (sp->tx_old != sp->tx_new)
516 		sgiseeq_tx(dev, sp, hregs, sregs);
517 
518 	if ((TX_BUFFS_AVAIL(sp) > 0) && netif_queue_stopped(dev)) {
519 		netif_wake_queue(dev);
520 	}
521 	spin_unlock(&sp->tx_lock);
522 
523 	return IRQ_HANDLED;
524 }
525 
526 static int sgiseeq_open(struct net_device *dev)
527 {
528 	struct sgiseeq_private *sp = netdev_priv(dev);
529 	struct sgiseeq_regs *sregs = sp->sregs;
530 	unsigned int irq = dev->irq;
531 	int err;
532 
533 	if (request_irq(irq, sgiseeq_interrupt, 0, sgiseeqstr, dev)) {
534 		printk(KERN_ERR "Seeq8003: Can't get irq %d\n", dev->irq);
535 		return -EAGAIN;
536 	}
537 
538 	err = init_seeq(dev, sp, sregs);
539 	if (err)
540 		goto out_free_irq;
541 
542 	netif_start_queue(dev);
543 
544 	return 0;
545 
546 out_free_irq:
547 	free_irq(irq, dev);
548 
549 	return err;
550 }
551 
552 static int sgiseeq_close(struct net_device *dev)
553 {
554 	struct sgiseeq_private *sp = netdev_priv(dev);
555 	struct sgiseeq_regs *sregs = sp->sregs;
556 	unsigned int irq = dev->irq;
557 
558 	netif_stop_queue(dev);
559 
560 	/* Shutdown the Seeq. */
561 	reset_hpc3_and_seeq(sp->hregs, sregs);
562 	free_irq(irq, dev);
563 	seeq_purge_ring(dev);
564 
565 	return 0;
566 }
567 
568 static inline int sgiseeq_reset(struct net_device *dev)
569 {
570 	struct sgiseeq_private *sp = netdev_priv(dev);
571 	struct sgiseeq_regs *sregs = sp->sregs;
572 	int err;
573 
574 	err = init_seeq(dev, sp, sregs);
575 	if (err)
576 		return err;
577 
578 	dev->trans_start = jiffies; /* prevent tx timeout */
579 	netif_wake_queue(dev);
580 
581 	return 0;
582 }
583 
584 static int sgiseeq_start_xmit(struct sk_buff *skb, struct net_device *dev)
585 {
586 	struct sgiseeq_private *sp = netdev_priv(dev);
587 	struct hpc3_ethregs *hregs = sp->hregs;
588 	unsigned long flags;
589 	struct sgiseeq_tx_desc *td;
590 	int len, entry;
591 
592 	spin_lock_irqsave(&sp->tx_lock, flags);
593 
594 	/* Setup... */
595 	len = skb->len;
596 	if (len < ETH_ZLEN) {
597 		if (skb_padto(skb, ETH_ZLEN)) {
598 			spin_unlock_irqrestore(&sp->tx_lock, flags);
599 			return NETDEV_TX_OK;
600 		}
601 		len = ETH_ZLEN;
602 	}
603 
604 	dev->stats.tx_bytes += len;
605 	entry = sp->tx_new;
606 	td = &sp->tx_desc[entry];
607 	dma_sync_desc_cpu(dev, td);
608 
609 	/* Create entry.  There are so many races with adding a new
610 	 * descriptor to the chain:
611 	 * 1) Assume that the HPC is off processing a DMA chain while
612 	 *    we are changing all of the following.
613 	 * 2) Do no allow the HPC to look at a new descriptor until
614 	 *    we have completely set up it's state.  This means, do
615 	 *    not clear HPCDMA_EOX in the current last descritptor
616 	 *    until the one we are adding looks consistent and could
617 	 *    be processes right now.
618 	 * 3) The tx interrupt code must notice when we've added a new
619 	 *    entry and the HPC got to the end of the chain before we
620 	 *    added this new entry and restarted it.
621 	 */
622 	td->skb = skb;
623 	td->tdma.pbuf = dma_map_single(dev->dev.parent, skb->data,
624 				       len, DMA_TO_DEVICE);
625 	td->tdma.cntinfo = (len & HPCDMA_BCNT) |
626 	                   HPCDMA_XIU | HPCDMA_EOXP | HPCDMA_XIE | HPCDMA_EOX;
627 	dma_sync_desc_dev(dev, td);
628 	if (sp->tx_old != sp->tx_new) {
629 		struct sgiseeq_tx_desc *backend;
630 
631 		backend = &sp->tx_desc[PREV_TX(sp->tx_new)];
632 		dma_sync_desc_cpu(dev, backend);
633 		backend->tdma.cntinfo &= ~HPCDMA_EOX;
634 		dma_sync_desc_dev(dev, backend);
635 	}
636 	sp->tx_new = NEXT_TX(sp->tx_new); /* Advance. */
637 
638 	/* Maybe kick the HPC back into motion. */
639 	if (!(hregs->tx_ctrl & HPC3_ETXCTRL_ACTIVE))
640 		kick_tx(dev, sp, hregs);
641 
642 	if (!TX_BUFFS_AVAIL(sp))
643 		netif_stop_queue(dev);
644 	spin_unlock_irqrestore(&sp->tx_lock, flags);
645 
646 	return NETDEV_TX_OK;
647 }
648 
649 static void timeout(struct net_device *dev)
650 {
651 	printk(KERN_NOTICE "%s: transmit timed out, resetting\n", dev->name);
652 	sgiseeq_reset(dev);
653 
654 	dev->trans_start = jiffies; /* prevent tx timeout */
655 	netif_wake_queue(dev);
656 }
657 
658 static void sgiseeq_set_multicast(struct net_device *dev)
659 {
660 	struct sgiseeq_private *sp = netdev_priv(dev);
661 	unsigned char oldmode = sp->mode;
662 
663 	if(dev->flags & IFF_PROMISC)
664 		sp->mode = SEEQ_RCMD_RANY;
665 	else if ((dev->flags & IFF_ALLMULTI) || !netdev_mc_empty(dev))
666 		sp->mode = SEEQ_RCMD_RBMCAST;
667 	else
668 		sp->mode = SEEQ_RCMD_RBCAST;
669 
670 	/* XXX I know this sucks, but is there a better way to reprogram
671 	 * XXX the receiver? At least, this shouldn't happen too often.
672 	 */
673 
674 	if (oldmode != sp->mode)
675 		sgiseeq_reset(dev);
676 }
677 
678 static inline void setup_tx_ring(struct net_device *dev,
679 				 struct sgiseeq_tx_desc *buf,
680 				 int nbufs)
681 {
682 	struct sgiseeq_private *sp = netdev_priv(dev);
683 	int i = 0;
684 
685 	while (i < (nbufs - 1)) {
686 		buf[i].tdma.pnext = VIRT_TO_DMA(sp, buf + i + 1);
687 		buf[i].tdma.pbuf = 0;
688 		dma_sync_desc_dev(dev, &buf[i]);
689 		i++;
690 	}
691 	buf[i].tdma.pnext = VIRT_TO_DMA(sp, buf);
692 	dma_sync_desc_dev(dev, &buf[i]);
693 }
694 
695 static inline void setup_rx_ring(struct net_device *dev,
696 				 struct sgiseeq_rx_desc *buf,
697 				 int nbufs)
698 {
699 	struct sgiseeq_private *sp = netdev_priv(dev);
700 	int i = 0;
701 
702 	while (i < (nbufs - 1)) {
703 		buf[i].rdma.pnext = VIRT_TO_DMA(sp, buf + i + 1);
704 		buf[i].rdma.pbuf = 0;
705 		dma_sync_desc_dev(dev, &buf[i]);
706 		i++;
707 	}
708 	buf[i].rdma.pbuf = 0;
709 	buf[i].rdma.pnext = VIRT_TO_DMA(sp, buf);
710 	dma_sync_desc_dev(dev, &buf[i]);
711 }
712 
713 static const struct net_device_ops sgiseeq_netdev_ops = {
714 	.ndo_open		= sgiseeq_open,
715 	.ndo_stop		= sgiseeq_close,
716 	.ndo_start_xmit		= sgiseeq_start_xmit,
717 	.ndo_tx_timeout		= timeout,
718 	.ndo_set_rx_mode	= sgiseeq_set_multicast,
719 	.ndo_set_mac_address	= sgiseeq_set_mac_address,
720 	.ndo_change_mtu		= eth_change_mtu,
721 	.ndo_validate_addr	= eth_validate_addr,
722 };
723 
724 static int sgiseeq_probe(struct platform_device *pdev)
725 {
726 	struct sgiseeq_platform_data *pd = pdev->dev.platform_data;
727 	struct hpc3_regs *hpcregs = pd->hpc;
728 	struct sgiseeq_init_block *sr;
729 	unsigned int irq = pd->irq;
730 	struct sgiseeq_private *sp;
731 	struct net_device *dev;
732 	int err;
733 
734 	dev = alloc_etherdev(sizeof (struct sgiseeq_private));
735 	if (!dev) {
736 		err = -ENOMEM;
737 		goto err_out;
738 	}
739 
740 	platform_set_drvdata(pdev, dev);
741 	sp = netdev_priv(dev);
742 
743 	/* Make private data page aligned */
744 	sr = dma_alloc_noncoherent(&pdev->dev, sizeof(*sp->srings),
745 				&sp->srings_dma, GFP_KERNEL);
746 	if (!sr) {
747 		printk(KERN_ERR "Sgiseeq: Page alloc failed, aborting.\n");
748 		err = -ENOMEM;
749 		goto err_out_free_dev;
750 	}
751 	sp->srings = sr;
752 	sp->rx_desc = sp->srings->rxvector;
753 	sp->tx_desc = sp->srings->txvector;
754 	spin_lock_init(&sp->tx_lock);
755 
756 	/* A couple calculations now, saves many cycles later. */
757 	setup_rx_ring(dev, sp->rx_desc, SEEQ_RX_BUFFERS);
758 	setup_tx_ring(dev, sp->tx_desc, SEEQ_TX_BUFFERS);
759 
760 	memcpy(dev->dev_addr, pd->mac, ETH_ALEN);
761 
762 #ifdef DEBUG
763 	gpriv = sp;
764 	gdev = dev;
765 #endif
766 	sp->sregs = (struct sgiseeq_regs *) &hpcregs->eth_ext[0];
767 	sp->hregs = &hpcregs->ethregs;
768 	sp->name = sgiseeqstr;
769 	sp->mode = SEEQ_RCMD_RBCAST;
770 
771 	/* Setup PIO and DMA transfer timing */
772 	sp->hregs->pconfig = 0x161;
773 	sp->hregs->dconfig = HPC3_EDCFG_FIRQ | HPC3_EDCFG_FEOP |
774 			     HPC3_EDCFG_FRXDC | HPC3_EDCFG_PTO | 0x026;
775 
776 	/* Setup PIO and DMA transfer timing */
777 	sp->hregs->pconfig = 0x161;
778 	sp->hregs->dconfig = HPC3_EDCFG_FIRQ | HPC3_EDCFG_FEOP |
779 			     HPC3_EDCFG_FRXDC | HPC3_EDCFG_PTO | 0x026;
780 
781 	/* Reset the chip. */
782 	hpc3_eth_reset(sp->hregs);
783 
784 	sp->is_edlc = !(sp->sregs->rw.rregs.collision_tx[0] & 0xff);
785 	if (sp->is_edlc)
786 		sp->control = SEEQ_CTRL_XCNT | SEEQ_CTRL_ACCNT |
787 			      SEEQ_CTRL_SFLAG | SEEQ_CTRL_ESHORT |
788 			      SEEQ_CTRL_ENCARR;
789 
790 	dev->netdev_ops		= &sgiseeq_netdev_ops;
791 	dev->watchdog_timeo	= (200 * HZ) / 1000;
792 	dev->irq		= irq;
793 
794 	if (register_netdev(dev)) {
795 		printk(KERN_ERR "Sgiseeq: Cannot register net device, "
796 		       "aborting.\n");
797 		err = -ENODEV;
798 		goto err_out_free_page;
799 	}
800 
801 	printk(KERN_INFO "%s: %s %pM\n", dev->name, sgiseeqstr, dev->dev_addr);
802 
803 	return 0;
804 
805 err_out_free_page:
806 	free_page((unsigned long) sp->srings);
807 err_out_free_dev:
808 	free_netdev(dev);
809 
810 err_out:
811 	return err;
812 }
813 
814 static int __exit sgiseeq_remove(struct platform_device *pdev)
815 {
816 	struct net_device *dev = platform_get_drvdata(pdev);
817 	struct sgiseeq_private *sp = netdev_priv(dev);
818 
819 	unregister_netdev(dev);
820 	dma_free_noncoherent(&pdev->dev, sizeof(*sp->srings), sp->srings,
821 			     sp->srings_dma);
822 	free_netdev(dev);
823 	platform_set_drvdata(pdev, NULL);
824 
825 	return 0;
826 }
827 
828 static struct platform_driver sgiseeq_driver = {
829 	.probe	= sgiseeq_probe,
830 	.remove	= __exit_p(sgiseeq_remove),
831 	.driver = {
832 		.name	= "sgiseeq",
833 		.owner	= THIS_MODULE,
834 	}
835 };
836 
837 module_platform_driver(sgiseeq_driver);
838 
839 MODULE_DESCRIPTION("SGI Seeq 8003 driver");
840 MODULE_AUTHOR("Linux/MIPS Mailing List <linux-mips@linux-mips.org>");
841 MODULE_LICENSE("GPL");
842 MODULE_ALIAS("platform:sgiseeq");
843