1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * sgiseeq.c: Seeq8003 ethernet driver for SGI machines.
4  *
5  * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
6  */
7 
8 #undef DEBUG
9 
10 #include <linux/dma-mapping.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/errno.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 (!ether_addr_equal(rd->skb->data + 6, dev->dev_addr)) {
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 					dev->stats.rx_dropped++;
385 				}
386 			} else {
387 				/* Silently drop my own packets */
388 				newskb = rd->skb;
389 			}
390 		} else {
391 			record_rx_errors(dev, pkt_status);
392 			newskb = rd->skb;
393 		}
394 		rd->skb = newskb;
395 		rd->rdma.pbuf = dma_map_single(dev->dev.parent,
396 					       newskb->data - 2,
397 					       PKT_BUF_SZ, DMA_FROM_DEVICE);
398 
399 		/* Return the entry to the ring pool. */
400 		rd->rdma.cntinfo = RCNTINFO_INIT;
401 		sp->rx_new = NEXT_RX(sp->rx_new);
402 		dma_sync_desc_dev(dev, rd);
403 		rd = &sp->rx_desc[sp->rx_new];
404 		dma_sync_desc_cpu(dev, rd);
405 	}
406 	dma_sync_desc_cpu(dev, &sp->rx_desc[orig_end]);
407 	sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR);
408 	dma_sync_desc_dev(dev, &sp->rx_desc[orig_end]);
409 	dma_sync_desc_cpu(dev, &sp->rx_desc[PREV_RX(sp->rx_new)]);
410 	sp->rx_desc[PREV_RX(sp->rx_new)].rdma.cntinfo |= HPCDMA_EOR;
411 	dma_sync_desc_dev(dev, &sp->rx_desc[PREV_RX(sp->rx_new)]);
412 	rx_maybe_restart(sp, hregs, sregs);
413 }
414 
415 static inline void tx_maybe_reset_collisions(struct sgiseeq_private *sp,
416 					     struct sgiseeq_regs *sregs)
417 {
418 	if (sp->is_edlc) {
419 		sregs->rw.wregs.control = sp->control & ~(SEEQ_CTRL_XCNT);
420 		sregs->rw.wregs.control = sp->control;
421 	}
422 }
423 
424 static inline void kick_tx(struct net_device *dev,
425 			   struct sgiseeq_private *sp,
426 			   struct hpc3_ethregs *hregs)
427 {
428 	struct sgiseeq_tx_desc *td;
429 	int i = sp->tx_old;
430 
431 	/* If the HPC aint doin nothin, and there are more packets
432 	 * with ETXD cleared and XIU set we must make very certain
433 	 * that we restart the HPC else we risk locking up the
434 	 * adapter.  The following code is only safe iff the HPCDMA
435 	 * is not active!
436 	 */
437 	td = &sp->tx_desc[i];
438 	dma_sync_desc_cpu(dev, td);
439 	while ((td->tdma.cntinfo & (HPCDMA_XIU | HPCDMA_ETXD)) ==
440 	      (HPCDMA_XIU | HPCDMA_ETXD)) {
441 		i = NEXT_TX(i);
442 		td = &sp->tx_desc[i];
443 		dma_sync_desc_cpu(dev, td);
444 	}
445 	if (td->tdma.cntinfo & HPCDMA_XIU) {
446 		hregs->tx_ndptr = VIRT_TO_DMA(sp, td);
447 		hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
448 	}
449 }
450 
451 static inline void sgiseeq_tx(struct net_device *dev, struct sgiseeq_private *sp,
452 			      struct hpc3_ethregs *hregs,
453 			      struct sgiseeq_regs *sregs)
454 {
455 	struct sgiseeq_tx_desc *td;
456 	unsigned long status = hregs->tx_ctrl;
457 	int j;
458 
459 	tx_maybe_reset_collisions(sp, sregs);
460 
461 	if (!(status & (HPC3_ETXCTRL_ACTIVE | SEEQ_TSTAT_PTRANS))) {
462 		/* Oops, HPC detected some sort of error. */
463 		if (status & SEEQ_TSTAT_R16)
464 			dev->stats.tx_aborted_errors++;
465 		if (status & SEEQ_TSTAT_UFLOW)
466 			dev->stats.tx_fifo_errors++;
467 		if (status & SEEQ_TSTAT_LCLS)
468 			dev->stats.collisions++;
469 	}
470 
471 	/* Ack 'em... */
472 	for (j = sp->tx_old; j != sp->tx_new; j = NEXT_TX(j)) {
473 		td = &sp->tx_desc[j];
474 
475 		dma_sync_desc_cpu(dev, td);
476 		if (!(td->tdma.cntinfo & (HPCDMA_XIU)))
477 			break;
478 		if (!(td->tdma.cntinfo & (HPCDMA_ETXD))) {
479 			if (!(status & HPC3_ETXCTRL_ACTIVE)) {
480 				hregs->tx_ndptr = VIRT_TO_DMA(sp, td);
481 				hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
482 			}
483 			break;
484 		}
485 		dev->stats.tx_packets++;
486 		sp->tx_old = NEXT_TX(sp->tx_old);
487 		td->tdma.cntinfo &= ~(HPCDMA_XIU | HPCDMA_XIE);
488 		td->tdma.cntinfo |= HPCDMA_EOX;
489 		if (td->skb) {
490 			dev_kfree_skb_any(td->skb);
491 			td->skb = NULL;
492 		}
493 		dma_sync_desc_dev(dev, td);
494 	}
495 }
496 
497 static irqreturn_t sgiseeq_interrupt(int irq, void *dev_id)
498 {
499 	struct net_device *dev = (struct net_device *) dev_id;
500 	struct sgiseeq_private *sp = netdev_priv(dev);
501 	struct hpc3_ethregs *hregs = sp->hregs;
502 	struct sgiseeq_regs *sregs = sp->sregs;
503 
504 	spin_lock(&sp->tx_lock);
505 
506 	/* Ack the IRQ and set software state. */
507 	hregs->reset = HPC3_ERST_CLRIRQ;
508 
509 	/* Always check for received packets. */
510 	sgiseeq_rx(dev, sp, hregs, sregs);
511 
512 	/* Only check for tx acks if we have something queued. */
513 	if (sp->tx_old != sp->tx_new)
514 		sgiseeq_tx(dev, sp, hregs, sregs);
515 
516 	if ((TX_BUFFS_AVAIL(sp) > 0) && netif_queue_stopped(dev)) {
517 		netif_wake_queue(dev);
518 	}
519 	spin_unlock(&sp->tx_lock);
520 
521 	return IRQ_HANDLED;
522 }
523 
524 static int sgiseeq_open(struct net_device *dev)
525 {
526 	struct sgiseeq_private *sp = netdev_priv(dev);
527 	struct sgiseeq_regs *sregs = sp->sregs;
528 	unsigned int irq = dev->irq;
529 	int err;
530 
531 	if (request_irq(irq, sgiseeq_interrupt, 0, sgiseeqstr, dev)) {
532 		printk(KERN_ERR "Seeq8003: Can't get irq %d\n", dev->irq);
533 		return -EAGAIN;
534 	}
535 
536 	err = init_seeq(dev, sp, sregs);
537 	if (err)
538 		goto out_free_irq;
539 
540 	netif_start_queue(dev);
541 
542 	return 0;
543 
544 out_free_irq:
545 	free_irq(irq, dev);
546 
547 	return err;
548 }
549 
550 static int sgiseeq_close(struct net_device *dev)
551 {
552 	struct sgiseeq_private *sp = netdev_priv(dev);
553 	struct sgiseeq_regs *sregs = sp->sregs;
554 	unsigned int irq = dev->irq;
555 
556 	netif_stop_queue(dev);
557 
558 	/* Shutdown the Seeq. */
559 	reset_hpc3_and_seeq(sp->hregs, sregs);
560 	free_irq(irq, dev);
561 	seeq_purge_ring(dev);
562 
563 	return 0;
564 }
565 
566 static inline int sgiseeq_reset(struct net_device *dev)
567 {
568 	struct sgiseeq_private *sp = netdev_priv(dev);
569 	struct sgiseeq_regs *sregs = sp->sregs;
570 	int err;
571 
572 	err = init_seeq(dev, sp, sregs);
573 	if (err)
574 		return err;
575 
576 	netif_trans_update(dev); /* prevent tx timeout */
577 	netif_wake_queue(dev);
578 
579 	return 0;
580 }
581 
582 static netdev_tx_t
583 sgiseeq_start_xmit(struct sk_buff *skb, struct net_device *dev)
584 {
585 	struct sgiseeq_private *sp = netdev_priv(dev);
586 	struct hpc3_ethregs *hregs = sp->hregs;
587 	unsigned long flags;
588 	struct sgiseeq_tx_desc *td;
589 	int len, entry;
590 
591 	spin_lock_irqsave(&sp->tx_lock, flags);
592 
593 	/* Setup... */
594 	len = skb->len;
595 	if (len < ETH_ZLEN) {
596 		if (skb_padto(skb, ETH_ZLEN)) {
597 			spin_unlock_irqrestore(&sp->tx_lock, flags);
598 			return NETDEV_TX_OK;
599 		}
600 		len = ETH_ZLEN;
601 	}
602 
603 	dev->stats.tx_bytes += len;
604 	entry = sp->tx_new;
605 	td = &sp->tx_desc[entry];
606 	dma_sync_desc_cpu(dev, td);
607 
608 	/* Create entry.  There are so many races with adding a new
609 	 * descriptor to the chain:
610 	 * 1) Assume that the HPC is off processing a DMA chain while
611 	 *    we are changing all of the following.
612 	 * 2) Do no allow the HPC to look at a new descriptor until
613 	 *    we have completely set up it's state.  This means, do
614 	 *    not clear HPCDMA_EOX in the current last descritptor
615 	 *    until the one we are adding looks consistent and could
616 	 *    be processes right now.
617 	 * 3) The tx interrupt code must notice when we've added a new
618 	 *    entry and the HPC got to the end of the chain before we
619 	 *    added this new entry and restarted it.
620 	 */
621 	td->skb = skb;
622 	td->tdma.pbuf = dma_map_single(dev->dev.parent, skb->data,
623 				       len, DMA_TO_DEVICE);
624 	td->tdma.cntinfo = (len & HPCDMA_BCNT) |
625 	                   HPCDMA_XIU | HPCDMA_EOXP | HPCDMA_XIE | HPCDMA_EOX;
626 	dma_sync_desc_dev(dev, td);
627 	if (sp->tx_old != sp->tx_new) {
628 		struct sgiseeq_tx_desc *backend;
629 
630 		backend = &sp->tx_desc[PREV_TX(sp->tx_new)];
631 		dma_sync_desc_cpu(dev, backend);
632 		backend->tdma.cntinfo &= ~HPCDMA_EOX;
633 		dma_sync_desc_dev(dev, backend);
634 	}
635 	sp->tx_new = NEXT_TX(sp->tx_new); /* Advance. */
636 
637 	/* Maybe kick the HPC back into motion. */
638 	if (!(hregs->tx_ctrl & HPC3_ETXCTRL_ACTIVE))
639 		kick_tx(dev, sp, hregs);
640 
641 	if (!TX_BUFFS_AVAIL(sp))
642 		netif_stop_queue(dev);
643 	spin_unlock_irqrestore(&sp->tx_lock, flags);
644 
645 	return NETDEV_TX_OK;
646 }
647 
648 static void timeout(struct net_device *dev, unsigned int txqueue)
649 {
650 	printk(KERN_NOTICE "%s: transmit timed out, resetting\n", dev->name);
651 	sgiseeq_reset(dev);
652 
653 	netif_trans_update(dev); /* prevent tx timeout */
654 	netif_wake_queue(dev);
655 }
656 
657 static void sgiseeq_set_multicast(struct net_device *dev)
658 {
659 	struct sgiseeq_private *sp = netdev_priv(dev);
660 	unsigned char oldmode = sp->mode;
661 
662 	if(dev->flags & IFF_PROMISC)
663 		sp->mode = SEEQ_RCMD_RANY;
664 	else if ((dev->flags & IFF_ALLMULTI) || !netdev_mc_empty(dev))
665 		sp->mode = SEEQ_RCMD_RBMCAST;
666 	else
667 		sp->mode = SEEQ_RCMD_RBCAST;
668 
669 	/* XXX I know this sucks, but is there a better way to reprogram
670 	 * XXX the receiver? At least, this shouldn't happen too often.
671 	 */
672 
673 	if (oldmode != sp->mode)
674 		sgiseeq_reset(dev);
675 }
676 
677 static inline void setup_tx_ring(struct net_device *dev,
678 				 struct sgiseeq_tx_desc *buf,
679 				 int nbufs)
680 {
681 	struct sgiseeq_private *sp = netdev_priv(dev);
682 	int i = 0;
683 
684 	while (i < (nbufs - 1)) {
685 		buf[i].tdma.pnext = VIRT_TO_DMA(sp, buf + i + 1);
686 		buf[i].tdma.pbuf = 0;
687 		dma_sync_desc_dev(dev, &buf[i]);
688 		i++;
689 	}
690 	buf[i].tdma.pnext = VIRT_TO_DMA(sp, buf);
691 	dma_sync_desc_dev(dev, &buf[i]);
692 }
693 
694 static inline void setup_rx_ring(struct net_device *dev,
695 				 struct sgiseeq_rx_desc *buf,
696 				 int nbufs)
697 {
698 	struct sgiseeq_private *sp = netdev_priv(dev);
699 	int i = 0;
700 
701 	while (i < (nbufs - 1)) {
702 		buf[i].rdma.pnext = VIRT_TO_DMA(sp, buf + i + 1);
703 		buf[i].rdma.pbuf = 0;
704 		dma_sync_desc_dev(dev, &buf[i]);
705 		i++;
706 	}
707 	buf[i].rdma.pbuf = 0;
708 	buf[i].rdma.pnext = VIRT_TO_DMA(sp, buf);
709 	dma_sync_desc_dev(dev, &buf[i]);
710 }
711 
712 static const struct net_device_ops sgiseeq_netdev_ops = {
713 	.ndo_open		= sgiseeq_open,
714 	.ndo_stop		= sgiseeq_close,
715 	.ndo_start_xmit		= sgiseeq_start_xmit,
716 	.ndo_tx_timeout		= timeout,
717 	.ndo_set_rx_mode	= sgiseeq_set_multicast,
718 	.ndo_set_mac_address	= sgiseeq_set_mac_address,
719 	.ndo_validate_addr	= eth_validate_addr,
720 };
721 
722 static int sgiseeq_probe(struct platform_device *pdev)
723 {
724 	struct sgiseeq_platform_data *pd = dev_get_platdata(&pdev->dev);
725 	struct hpc3_regs *hpcregs = pd->hpc;
726 	struct sgiseeq_init_block *sr;
727 	unsigned int irq = pd->irq;
728 	struct sgiseeq_private *sp;
729 	struct net_device *dev;
730 	int err;
731 
732 	dev = alloc_etherdev(sizeof (struct sgiseeq_private));
733 	if (!dev) {
734 		err = -ENOMEM;
735 		goto err_out;
736 	}
737 
738 	platform_set_drvdata(pdev, dev);
739 	SET_NETDEV_DEV(dev, &pdev->dev);
740 	sp = netdev_priv(dev);
741 
742 	/* Make private data page aligned */
743 	sr = dma_alloc_attrs(&pdev->dev, sizeof(*sp->srings), &sp->srings_dma,
744 			     GFP_KERNEL, DMA_ATTR_NON_CONSISTENT);
745 	if (!sr) {
746 		printk(KERN_ERR "Sgiseeq: Page alloc failed, aborting.\n");
747 		err = -ENOMEM;
748 		goto err_out_free_dev;
749 	}
750 	sp->srings = sr;
751 	sp->rx_desc = sp->srings->rxvector;
752 	sp->tx_desc = sp->srings->txvector;
753 	spin_lock_init(&sp->tx_lock);
754 
755 	/* A couple calculations now, saves many cycles later. */
756 	setup_rx_ring(dev, sp->rx_desc, SEEQ_RX_BUFFERS);
757 	setup_tx_ring(dev, sp->tx_desc, SEEQ_TX_BUFFERS);
758 
759 	memcpy(dev->dev_addr, pd->mac, ETH_ALEN);
760 
761 #ifdef DEBUG
762 	gpriv = sp;
763 	gdev = dev;
764 #endif
765 	sp->sregs = (struct sgiseeq_regs *) &hpcregs->eth_ext[0];
766 	sp->hregs = &hpcregs->ethregs;
767 	sp->name = sgiseeqstr;
768 	sp->mode = SEEQ_RCMD_RBCAST;
769 
770 	/* Setup PIO and DMA transfer timing */
771 	sp->hregs->pconfig = 0x161;
772 	sp->hregs->dconfig = HPC3_EDCFG_FIRQ | HPC3_EDCFG_FEOP |
773 			     HPC3_EDCFG_FRXDC | HPC3_EDCFG_PTO | 0x026;
774 
775 	/* Setup PIO and DMA transfer timing */
776 	sp->hregs->pconfig = 0x161;
777 	sp->hregs->dconfig = HPC3_EDCFG_FIRQ | HPC3_EDCFG_FEOP |
778 			     HPC3_EDCFG_FRXDC | HPC3_EDCFG_PTO | 0x026;
779 
780 	/* Reset the chip. */
781 	hpc3_eth_reset(sp->hregs);
782 
783 	sp->is_edlc = !(sp->sregs->rw.rregs.collision_tx[0] & 0xff);
784 	if (sp->is_edlc)
785 		sp->control = SEEQ_CTRL_XCNT | SEEQ_CTRL_ACCNT |
786 			      SEEQ_CTRL_SFLAG | SEEQ_CTRL_ESHORT |
787 			      SEEQ_CTRL_ENCARR;
788 
789 	dev->netdev_ops		= &sgiseeq_netdev_ops;
790 	dev->watchdog_timeo	= (200 * HZ) / 1000;
791 	dev->irq		= irq;
792 
793 	if (register_netdev(dev)) {
794 		printk(KERN_ERR "Sgiseeq: Cannot register net device, "
795 		       "aborting.\n");
796 		err = -ENODEV;
797 		goto err_out_free_attrs;
798 	}
799 
800 	printk(KERN_INFO "%s: %s %pM\n", dev->name, sgiseeqstr, dev->dev_addr);
801 
802 	return 0;
803 
804 err_out_free_attrs:
805 	dma_free_attrs(&pdev->dev, sizeof(*sp->srings), sp->srings,
806 		       sp->srings_dma, DMA_ATTR_NON_CONSISTENT);
807 err_out_free_dev:
808 	free_netdev(dev);
809 
810 err_out:
811 	return err;
812 }
813 
814 static int 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_attrs(&pdev->dev, sizeof(*sp->srings), sp->srings,
821 		       sp->srings_dma, DMA_ATTR_NON_CONSISTENT);
822 	free_netdev(dev);
823 
824 	return 0;
825 }
826 
827 static struct platform_driver sgiseeq_driver = {
828 	.probe	= sgiseeq_probe,
829 	.remove	= sgiseeq_remove,
830 	.driver = {
831 		.name	= "sgiseeq",
832 	}
833 };
834 
835 module_platform_driver(sgiseeq_driver);
836 
837 MODULE_DESCRIPTION("SGI Seeq 8003 driver");
838 MODULE_AUTHOR("Linux/MIPS Mailing List <linux-mips@linux-mips.org>");
839 MODULE_LICENSE("GPL");
840 MODULE_ALIAS("platform:sgiseeq");
841