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
30static 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 */
64static int rx_copybreak = 100;
65
66#define PAD_SIZE    (128 - sizeof(struct hpc_dma_desc) - sizeof(void *))
67
68struct sgiseeq_rx_desc {
69	volatile struct hpc_dma_desc rdma;
70	u8 padding[PAD_SIZE];
71	struct sk_buff *skb;
72};
73
74struct 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 */
85struct 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
90struct 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
113static inline void dma_sync_desc_cpu(struct net_device *dev, void *addr)
114{
115	struct sgiseeq_private *sp = netdev_priv(dev);
116
117	dma_sync_single_for_cpu(dev->dev.parent, VIRT_TO_DMA(sp, addr),
118			sizeof(struct sgiseeq_rx_desc), DMA_BIDIRECTIONAL);
119}
120
121static inline void dma_sync_desc_dev(struct net_device *dev, void *addr)
122{
123	struct sgiseeq_private *sp = netdev_priv(dev);
124
125	dma_sync_single_for_device(dev->dev.parent, VIRT_TO_DMA(sp, addr),
126			sizeof(struct sgiseeq_rx_desc), DMA_BIDIRECTIONAL);
127}
128
129static inline void hpc3_eth_reset(struct hpc3_ethregs *hregs)
130{
131	hregs->reset = HPC3_ERST_CRESET | HPC3_ERST_CLRIRQ;
132	udelay(20);
133	hregs->reset = 0;
134}
135
136static inline void reset_hpc3_and_seeq(struct hpc3_ethregs *hregs,
137				       struct sgiseeq_regs *sregs)
138{
139	hregs->rx_ctrl = hregs->tx_ctrl = 0;
140	hpc3_eth_reset(hregs);
141}
142
143#define RSTAT_GO_BITS (SEEQ_RCMD_IGOOD | SEEQ_RCMD_IEOF | SEEQ_RCMD_ISHORT | \
144		       SEEQ_RCMD_IDRIB | SEEQ_RCMD_ICRC)
145
146static inline void seeq_go(struct sgiseeq_private *sp,
147			   struct hpc3_ethregs *hregs,
148			   struct sgiseeq_regs *sregs)
149{
150	sregs->rstat = sp->mode | RSTAT_GO_BITS;
151	hregs->rx_ctrl = HPC3_ERXCTRL_ACTIVE;
152}
153
154static inline void __sgiseeq_set_mac_address(struct net_device *dev)
155{
156	struct sgiseeq_private *sp = netdev_priv(dev);
157	struct sgiseeq_regs *sregs = sp->sregs;
158	int i;
159
160	sregs->tstat = SEEQ_TCMD_RB0;
161	for (i = 0; i < 6; i++)
162		sregs->rw.eth_addr[i] = dev->dev_addr[i];
163}
164
165static int sgiseeq_set_mac_address(struct net_device *dev, void *addr)
166{
167	struct sgiseeq_private *sp = netdev_priv(dev);
168	struct sockaddr *sa = addr;
169
170	eth_hw_addr_set(dev, sa->sa_data);
171
172	spin_lock_irq(&sp->tx_lock);
173	__sgiseeq_set_mac_address(dev);
174	spin_unlock_irq(&sp->tx_lock);
175
176	return 0;
177}
178
179#define TCNTINFO_INIT (HPCDMA_EOX | HPCDMA_ETXD)
180#define RCNTCFG_INIT  (HPCDMA_OWN | HPCDMA_EORP | HPCDMA_XIE)
181#define RCNTINFO_INIT (RCNTCFG_INIT | (PKT_BUF_SZ & HPCDMA_BCNT))
182
183static int seeq_init_ring(struct net_device *dev)
184{
185	struct sgiseeq_private *sp = netdev_priv(dev);
186	int i;
187
188	netif_stop_queue(dev);
189	sp->rx_new = sp->tx_new = 0;
190	sp->rx_old = sp->tx_old = 0;
191
192	__sgiseeq_set_mac_address(dev);
193
194	/* Setup tx ring. */
195	for(i = 0; i < SEEQ_TX_BUFFERS; i++) {
196		sp->tx_desc[i].tdma.cntinfo = TCNTINFO_INIT;
197		dma_sync_desc_dev(dev, &sp->tx_desc[i]);
198	}
199
200	/* And now the rx ring. */
201	for (i = 0; i < SEEQ_RX_BUFFERS; i++) {
202		if (!sp->rx_desc[i].skb) {
203			dma_addr_t dma_addr;
204			struct sk_buff *skb = netdev_alloc_skb(dev, PKT_BUF_SZ);
205
206			if (skb == NULL)
207				return -ENOMEM;
208			skb_reserve(skb, 2);
209			dma_addr = dma_map_single(dev->dev.parent,
210						  skb->data - 2,
211						  PKT_BUF_SZ, DMA_FROM_DEVICE);
212			sp->rx_desc[i].skb = skb;
213			sp->rx_desc[i].rdma.pbuf = dma_addr;
214		}
215		sp->rx_desc[i].rdma.cntinfo = RCNTINFO_INIT;
216		dma_sync_desc_dev(dev, &sp->rx_desc[i]);
217	}
218	sp->rx_desc[i - 1].rdma.cntinfo |= HPCDMA_EOR;
219	dma_sync_desc_dev(dev, &sp->rx_desc[i - 1]);
220	return 0;
221}
222
223static void seeq_purge_ring(struct net_device *dev)
224{
225	struct sgiseeq_private *sp = netdev_priv(dev);
226	int i;
227
228	/* clear tx ring. */
229	for (i = 0; i < SEEQ_TX_BUFFERS; i++) {
230		if (sp->tx_desc[i].skb) {
231			dev_kfree_skb(sp->tx_desc[i].skb);
232			sp->tx_desc[i].skb = NULL;
233		}
234	}
235
236	/* And now the rx ring. */
237	for (i = 0; i < SEEQ_RX_BUFFERS; i++) {
238		if (sp->rx_desc[i].skb) {
239			dev_kfree_skb(sp->rx_desc[i].skb);
240			sp->rx_desc[i].skb = NULL;
241		}
242	}
243}
244
245#ifdef DEBUG
246static struct sgiseeq_private *gpriv;
247static struct net_device *gdev;
248
249static void sgiseeq_dump_rings(void)
250{
251	static int once;
252	struct sgiseeq_rx_desc *r = gpriv->rx_desc;
253	struct sgiseeq_tx_desc *t = gpriv->tx_desc;
254	struct hpc3_ethregs *hregs = gpriv->hregs;
255	int i;
256
257	if (once)
258		return;
259	once++;
260	printk("RING DUMP:\n");
261	for (i = 0; i < SEEQ_RX_BUFFERS; i++) {
262		printk("RX [%d]: @(%p) [%08x,%08x,%08x] ",
263		       i, (&r[i]), r[i].rdma.pbuf, r[i].rdma.cntinfo,
264		       r[i].rdma.pnext);
265		i += 1;
266		printk("-- [%d]: @(%p) [%08x,%08x,%08x]\n",
267		       i, (&r[i]), r[i].rdma.pbuf, r[i].rdma.cntinfo,
268		       r[i].rdma.pnext);
269	}
270	for (i = 0; i < SEEQ_TX_BUFFERS; i++) {
271		printk("TX [%d]: @(%p) [%08x,%08x,%08x] ",
272		       i, (&t[i]), t[i].tdma.pbuf, t[i].tdma.cntinfo,
273		       t[i].tdma.pnext);
274		i += 1;
275		printk("-- [%d]: @(%p) [%08x,%08x,%08x]\n",
276		       i, (&t[i]), t[i].tdma.pbuf, t[i].tdma.cntinfo,
277		       t[i].tdma.pnext);
278	}
279	printk("INFO: [rx_new = %d rx_old=%d] [tx_new = %d tx_old = %d]\n",
280	       gpriv->rx_new, gpriv->rx_old, gpriv->tx_new, gpriv->tx_old);
281	printk("RREGS: rx_cbptr[%08x] rx_ndptr[%08x] rx_ctrl[%08x]\n",
282	       hregs->rx_cbptr, hregs->rx_ndptr, hregs->rx_ctrl);
283	printk("TREGS: tx_cbptr[%08x] tx_ndptr[%08x] tx_ctrl[%08x]\n",
284	       hregs->tx_cbptr, hregs->tx_ndptr, hregs->tx_ctrl);
285}
286#endif
287
288#define TSTAT_INIT_SEEQ (SEEQ_TCMD_IPT|SEEQ_TCMD_I16|SEEQ_TCMD_IC|SEEQ_TCMD_IUF)
289#define TSTAT_INIT_EDLC ((TSTAT_INIT_SEEQ) | SEEQ_TCMD_RB2)
290
291static int init_seeq(struct net_device *dev, struct sgiseeq_private *sp,
292		     struct sgiseeq_regs *sregs)
293{
294	struct hpc3_ethregs *hregs = sp->hregs;
295	int err;
296
297	reset_hpc3_and_seeq(hregs, sregs);
298	err = seeq_init_ring(dev);
299	if (err)
300		return err;
301
302	/* Setup to field the proper interrupt types. */
303	if (sp->is_edlc) {
304		sregs->tstat = TSTAT_INIT_EDLC;
305		sregs->rw.wregs.control = sp->control;
306		sregs->rw.wregs.frame_gap = 0;
307	} else {
308		sregs->tstat = TSTAT_INIT_SEEQ;
309	}
310
311	hregs->rx_ndptr = VIRT_TO_DMA(sp, sp->rx_desc);
312	hregs->tx_ndptr = VIRT_TO_DMA(sp, sp->tx_desc);
313
314	seeq_go(sp, hregs, sregs);
315	return 0;
316}
317
318static void record_rx_errors(struct net_device *dev, unsigned char status)
319{
320	if (status & SEEQ_RSTAT_OVERF ||
321	    status & SEEQ_RSTAT_SFRAME)
322		dev->stats.rx_over_errors++;
323	if (status & SEEQ_RSTAT_CERROR)
324		dev->stats.rx_crc_errors++;
325	if (status & SEEQ_RSTAT_DERROR)
326		dev->stats.rx_frame_errors++;
327	if (status & SEEQ_RSTAT_REOF)
328		dev->stats.rx_errors++;
329}
330
331static inline void rx_maybe_restart(struct sgiseeq_private *sp,
332				    struct hpc3_ethregs *hregs,
333				    struct sgiseeq_regs *sregs)
334{
335	if (!(hregs->rx_ctrl & HPC3_ERXCTRL_ACTIVE)) {
336		hregs->rx_ndptr = VIRT_TO_DMA(sp, sp->rx_desc + sp->rx_new);
337		seeq_go(sp, hregs, sregs);
338	}
339}
340
341static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp,
342			      struct hpc3_ethregs *hregs,
343			      struct sgiseeq_regs *sregs)
344{
345	struct sgiseeq_rx_desc *rd;
346	struct sk_buff *skb = NULL;
347	struct sk_buff *newskb;
348	unsigned char pkt_status;
349	int len = 0;
350	unsigned int orig_end = PREV_RX(sp->rx_new);
351
352	/* Service every received packet. */
353	rd = &sp->rx_desc[sp->rx_new];
354	dma_sync_desc_cpu(dev, rd);
355	while (!(rd->rdma.cntinfo & HPCDMA_OWN)) {
356		len = PKT_BUF_SZ - (rd->rdma.cntinfo & HPCDMA_BCNT) - 3;
357		dma_unmap_single(dev->dev.parent, rd->rdma.pbuf,
358				 PKT_BUF_SZ, DMA_FROM_DEVICE);
359		pkt_status = rd->skb->data[len];
360		if (pkt_status & SEEQ_RSTAT_FIG) {
361			/* Packet is OK. */
362			/* We don't want to receive our own packets */
363			if (!ether_addr_equal(rd->skb->data + 6, dev->dev_addr)) {
364				if (len > rx_copybreak) {
365					skb = rd->skb;
366					newskb = netdev_alloc_skb(dev, PKT_BUF_SZ);
367					if (!newskb) {
368						newskb = skb;
369						skb = NULL;
370						goto memory_squeeze;
371					}
372					skb_reserve(newskb, 2);
373				} else {
374					skb = netdev_alloc_skb_ip_align(dev, len);
375					if (skb)
376						skb_copy_to_linear_data(skb, rd->skb->data, len);
377
378					newskb = rd->skb;
379				}
380memory_squeeze:
381				if (skb) {
382					skb_put(skb, len);
383					skb->protocol = eth_type_trans(skb, dev);
384					netif_rx(skb);
385					dev->stats.rx_packets++;
386					dev->stats.rx_bytes += len;
387				} else {
388					dev->stats.rx_dropped++;
389				}
390			} else {
391				/* Silently drop my own packets */
392				newskb = rd->skb;
393			}
394		} else {
395			record_rx_errors(dev, pkt_status);
396			newskb = rd->skb;
397		}
398		rd->skb = newskb;
399		rd->rdma.pbuf = dma_map_single(dev->dev.parent,
400					       newskb->data - 2,
401					       PKT_BUF_SZ, DMA_FROM_DEVICE);
402
403		/* Return the entry to the ring pool. */
404		rd->rdma.cntinfo = RCNTINFO_INIT;
405		sp->rx_new = NEXT_RX(sp->rx_new);
406		dma_sync_desc_dev(dev, rd);
407		rd = &sp->rx_desc[sp->rx_new];
408		dma_sync_desc_cpu(dev, rd);
409	}
410	dma_sync_desc_dev(dev, rd);
411
412	dma_sync_desc_cpu(dev, &sp->rx_desc[orig_end]);
413	sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR);
414	dma_sync_desc_dev(dev, &sp->rx_desc[orig_end]);
415	dma_sync_desc_cpu(dev, &sp->rx_desc[PREV_RX(sp->rx_new)]);
416	sp->rx_desc[PREV_RX(sp->rx_new)].rdma.cntinfo |= HPCDMA_EOR;
417	dma_sync_desc_dev(dev, &sp->rx_desc[PREV_RX(sp->rx_new)]);
418	rx_maybe_restart(sp, hregs, sregs);
419}
420
421static inline void tx_maybe_reset_collisions(struct sgiseeq_private *sp,
422					     struct sgiseeq_regs *sregs)
423{
424	if (sp->is_edlc) {
425		sregs->rw.wregs.control = sp->control & ~(SEEQ_CTRL_XCNT);
426		sregs->rw.wregs.control = sp->control;
427	}
428}
429
430static inline void kick_tx(struct net_device *dev,
431			   struct sgiseeq_private *sp,
432			   struct hpc3_ethregs *hregs)
433{
434	struct sgiseeq_tx_desc *td;
435	int i = sp->tx_old;
436
437	/* If the HPC aint doin nothin, and there are more packets
438	 * with ETXD cleared and XIU set we must make very certain
439	 * that we restart the HPC else we risk locking up the
440	 * adapter.  The following code is only safe iff the HPCDMA
441	 * is not active!
442	 */
443	td = &sp->tx_desc[i];
444	dma_sync_desc_cpu(dev, td);
445	while ((td->tdma.cntinfo & (HPCDMA_XIU | HPCDMA_ETXD)) ==
446	      (HPCDMA_XIU | HPCDMA_ETXD)) {
447		i = NEXT_TX(i);
448		td = &sp->tx_desc[i];
449		dma_sync_desc_cpu(dev, td);
450	}
451	if (td->tdma.cntinfo & HPCDMA_XIU) {
452		dma_sync_desc_dev(dev, td);
453		hregs->tx_ndptr = VIRT_TO_DMA(sp, td);
454		hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
455	}
456}
457
458static inline void sgiseeq_tx(struct net_device *dev, struct sgiseeq_private *sp,
459			      struct hpc3_ethregs *hregs,
460			      struct sgiseeq_regs *sregs)
461{
462	struct sgiseeq_tx_desc *td;
463	unsigned long status = hregs->tx_ctrl;
464	int j;
465
466	tx_maybe_reset_collisions(sp, sregs);
467
468	if (!(status & (HPC3_ETXCTRL_ACTIVE | SEEQ_TSTAT_PTRANS))) {
469		/* Oops, HPC detected some sort of error. */
470		if (status & SEEQ_TSTAT_R16)
471			dev->stats.tx_aborted_errors++;
472		if (status & SEEQ_TSTAT_UFLOW)
473			dev->stats.tx_fifo_errors++;
474		if (status & SEEQ_TSTAT_LCLS)
475			dev->stats.collisions++;
476	}
477
478	/* Ack 'em... */
479	for (j = sp->tx_old; j != sp->tx_new; j = NEXT_TX(j)) {
480		td = &sp->tx_desc[j];
481
482		dma_sync_desc_cpu(dev, td);
483		if (!(td->tdma.cntinfo & (HPCDMA_XIU)))
484			break;
485		if (!(td->tdma.cntinfo & (HPCDMA_ETXD))) {
486			dma_sync_desc_dev(dev, td);
487			if (!(status & HPC3_ETXCTRL_ACTIVE)) {
488				hregs->tx_ndptr = VIRT_TO_DMA(sp, td);
489				hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
490			}
491			break;
492		}
493		dev->stats.tx_packets++;
494		sp->tx_old = NEXT_TX(sp->tx_old);
495		td->tdma.cntinfo &= ~(HPCDMA_XIU | HPCDMA_XIE);
496		td->tdma.cntinfo |= HPCDMA_EOX;
497		if (td->skb) {
498			dev_kfree_skb_any(td->skb);
499			td->skb = NULL;
500		}
501		dma_sync_desc_dev(dev, td);
502	}
503}
504
505static irqreturn_t sgiseeq_interrupt(int irq, void *dev_id)
506{
507	struct net_device *dev = (struct net_device *) dev_id;
508	struct sgiseeq_private *sp = netdev_priv(dev);
509	struct hpc3_ethregs *hregs = sp->hregs;
510	struct sgiseeq_regs *sregs = sp->sregs;
511
512	spin_lock(&sp->tx_lock);
513
514	/* Ack the IRQ and set software state. */
515	hregs->reset = HPC3_ERST_CLRIRQ;
516
517	/* Always check for received packets. */
518	sgiseeq_rx(dev, sp, hregs, sregs);
519
520	/* Only check for tx acks if we have something queued. */
521	if (sp->tx_old != sp->tx_new)
522		sgiseeq_tx(dev, sp, hregs, sregs);
523
524	if ((TX_BUFFS_AVAIL(sp) > 0) && netif_queue_stopped(dev)) {
525		netif_wake_queue(dev);
526	}
527	spin_unlock(&sp->tx_lock);
528
529	return IRQ_HANDLED;
530}
531
532static int sgiseeq_open(struct net_device *dev)
533{
534	struct sgiseeq_private *sp = netdev_priv(dev);
535	struct sgiseeq_regs *sregs = sp->sregs;
536	unsigned int irq = dev->irq;
537	int err;
538
539	if (request_irq(irq, sgiseeq_interrupt, 0, sgiseeqstr, dev)) {
540		printk(KERN_ERR "Seeq8003: Can't get irq %d\n", dev->irq);
541		return -EAGAIN;
542	}
543
544	err = init_seeq(dev, sp, sregs);
545	if (err)
546		goto out_free_irq;
547
548	netif_start_queue(dev);
549
550	return 0;
551
552out_free_irq:
553	free_irq(irq, dev);
554
555	return err;
556}
557
558static int sgiseeq_close(struct net_device *dev)
559{
560	struct sgiseeq_private *sp = netdev_priv(dev);
561	struct sgiseeq_regs *sregs = sp->sregs;
562	unsigned int irq = dev->irq;
563
564	netif_stop_queue(dev);
565
566	/* Shutdown the Seeq. */
567	reset_hpc3_and_seeq(sp->hregs, sregs);
568	free_irq(irq, dev);
569	seeq_purge_ring(dev);
570
571	return 0;
572}
573
574static inline int sgiseeq_reset(struct net_device *dev)
575{
576	struct sgiseeq_private *sp = netdev_priv(dev);
577	struct sgiseeq_regs *sregs = sp->sregs;
578	int err;
579
580	err = init_seeq(dev, sp, sregs);
581	if (err)
582		return err;
583
584	netif_trans_update(dev); /* prevent tx timeout */
585	netif_wake_queue(dev);
586
587	return 0;
588}
589
590static netdev_tx_t
591sgiseeq_start_xmit(struct sk_buff *skb, struct net_device *dev)
592{
593	struct sgiseeq_private *sp = netdev_priv(dev);
594	struct hpc3_ethregs *hregs = sp->hregs;
595	unsigned long flags;
596	struct sgiseeq_tx_desc *td;
597	int len, entry;
598
599	spin_lock_irqsave(&sp->tx_lock, flags);
600
601	/* Setup... */
602	len = skb->len;
603	if (len < ETH_ZLEN) {
604		if (skb_padto(skb, ETH_ZLEN)) {
605			spin_unlock_irqrestore(&sp->tx_lock, flags);
606			return NETDEV_TX_OK;
607		}
608		len = ETH_ZLEN;
609	}
610
611	dev->stats.tx_bytes += len;
612	entry = sp->tx_new;
613	td = &sp->tx_desc[entry];
614	dma_sync_desc_cpu(dev, td);
615
616	/* Create entry.  There are so many races with adding a new
617	 * descriptor to the chain:
618	 * 1) Assume that the HPC is off processing a DMA chain while
619	 *    we are changing all of the following.
620	 * 2) Do no allow the HPC to look at a new descriptor until
621	 *    we have completely set up it's state.  This means, do
622	 *    not clear HPCDMA_EOX in the current last descritptor
623	 *    until the one we are adding looks consistent and could
624	 *    be processes right now.
625	 * 3) The tx interrupt code must notice when we've added a new
626	 *    entry and the HPC got to the end of the chain before we
627	 *    added this new entry and restarted it.
628	 */
629	td->skb = skb;
630	td->tdma.pbuf = dma_map_single(dev->dev.parent, skb->data,
631				       len, DMA_TO_DEVICE);
632	td->tdma.cntinfo = (len & HPCDMA_BCNT) |
633	                   HPCDMA_XIU | HPCDMA_EOXP | HPCDMA_XIE | HPCDMA_EOX;
634	dma_sync_desc_dev(dev, td);
635	if (sp->tx_old != sp->tx_new) {
636		struct sgiseeq_tx_desc *backend;
637
638		backend = &sp->tx_desc[PREV_TX(sp->tx_new)];
639		dma_sync_desc_cpu(dev, backend);
640		backend->tdma.cntinfo &= ~HPCDMA_EOX;
641		dma_sync_desc_dev(dev, backend);
642	}
643	sp->tx_new = NEXT_TX(sp->tx_new); /* Advance. */
644
645	/* Maybe kick the HPC back into motion. */
646	if (!(hregs->tx_ctrl & HPC3_ETXCTRL_ACTIVE))
647		kick_tx(dev, sp, hregs);
648
649	if (!TX_BUFFS_AVAIL(sp))
650		netif_stop_queue(dev);
651	spin_unlock_irqrestore(&sp->tx_lock, flags);
652
653	return NETDEV_TX_OK;
654}
655
656static void timeout(struct net_device *dev, unsigned int txqueue)
657{
658	printk(KERN_NOTICE "%s: transmit timed out, resetting\n", dev->name);
659	sgiseeq_reset(dev);
660
661	netif_trans_update(dev); /* prevent tx timeout */
662	netif_wake_queue(dev);
663}
664
665static void sgiseeq_set_multicast(struct net_device *dev)
666{
667	struct sgiseeq_private *sp = netdev_priv(dev);
668	unsigned char oldmode = sp->mode;
669
670	if(dev->flags & IFF_PROMISC)
671		sp->mode = SEEQ_RCMD_RANY;
672	else if ((dev->flags & IFF_ALLMULTI) || !netdev_mc_empty(dev))
673		sp->mode = SEEQ_RCMD_RBMCAST;
674	else
675		sp->mode = SEEQ_RCMD_RBCAST;
676
677	/* XXX I know this sucks, but is there a better way to reprogram
678	 * XXX the receiver? At least, this shouldn't happen too often.
679	 */
680
681	if (oldmode != sp->mode)
682		sgiseeq_reset(dev);
683}
684
685static inline void setup_tx_ring(struct net_device *dev,
686				 struct sgiseeq_tx_desc *buf,
687				 int nbufs)
688{
689	struct sgiseeq_private *sp = netdev_priv(dev);
690	int i = 0;
691
692	while (i < (nbufs - 1)) {
693		buf[i].tdma.pnext = VIRT_TO_DMA(sp, buf + i + 1);
694		buf[i].tdma.pbuf = 0;
695		dma_sync_desc_dev(dev, &buf[i]);
696		i++;
697	}
698	buf[i].tdma.pnext = VIRT_TO_DMA(sp, buf);
699	dma_sync_desc_dev(dev, &buf[i]);
700}
701
702static inline void setup_rx_ring(struct net_device *dev,
703				 struct sgiseeq_rx_desc *buf,
704				 int nbufs)
705{
706	struct sgiseeq_private *sp = netdev_priv(dev);
707	int i = 0;
708
709	while (i < (nbufs - 1)) {
710		buf[i].rdma.pnext = VIRT_TO_DMA(sp, buf + i + 1);
711		buf[i].rdma.pbuf = 0;
712		dma_sync_desc_dev(dev, &buf[i]);
713		i++;
714	}
715	buf[i].rdma.pbuf = 0;
716	buf[i].rdma.pnext = VIRT_TO_DMA(sp, buf);
717	dma_sync_desc_dev(dev, &buf[i]);
718}
719
720static const struct net_device_ops sgiseeq_netdev_ops = {
721	.ndo_open		= sgiseeq_open,
722	.ndo_stop		= sgiseeq_close,
723	.ndo_start_xmit		= sgiseeq_start_xmit,
724	.ndo_tx_timeout		= timeout,
725	.ndo_set_rx_mode	= sgiseeq_set_multicast,
726	.ndo_set_mac_address	= sgiseeq_set_mac_address,
727	.ndo_validate_addr	= eth_validate_addr,
728};
729
730static int sgiseeq_probe(struct platform_device *pdev)
731{
732	struct sgiseeq_platform_data *pd = dev_get_platdata(&pdev->dev);
733	struct hpc3_regs *hpcregs = pd->hpc;
734	struct sgiseeq_init_block *sr;
735	unsigned int irq = pd->irq;
736	struct sgiseeq_private *sp;
737	struct net_device *dev;
738	int err;
739
740	dev = alloc_etherdev(sizeof (struct sgiseeq_private));
741	if (!dev) {
742		err = -ENOMEM;
743		goto err_out;
744	}
745
746	platform_set_drvdata(pdev, dev);
747	SET_NETDEV_DEV(dev, &pdev->dev);
748	sp = netdev_priv(dev);
749
750	/* Make private data page aligned */
751	sr = dma_alloc_noncoherent(&pdev->dev, sizeof(*sp->srings),
752			&sp->srings_dma, DMA_BIDIRECTIONAL, GFP_KERNEL);
753	if (!sr) {
754		printk(KERN_ERR "Sgiseeq: Page alloc failed, aborting.\n");
755		err = -ENOMEM;
756		goto err_out_free_dev;
757	}
758	sp->srings = sr;
759	sp->rx_desc = sp->srings->rxvector;
760	sp->tx_desc = sp->srings->txvector;
761	spin_lock_init(&sp->tx_lock);
762
763	/* A couple calculations now, saves many cycles later. */
764	setup_rx_ring(dev, sp->rx_desc, SEEQ_RX_BUFFERS);
765	setup_tx_ring(dev, sp->tx_desc, SEEQ_TX_BUFFERS);
766
767	eth_hw_addr_set(dev, pd->mac);
768
769#ifdef DEBUG
770	gpriv = sp;
771	gdev = dev;
772#endif
773	sp->sregs = (struct sgiseeq_regs *) &hpcregs->eth_ext[0];
774	sp->hregs = &hpcregs->ethregs;
775	sp->name = sgiseeqstr;
776	sp->mode = SEEQ_RCMD_RBCAST;
777
778	/* Setup PIO and DMA transfer timing */
779	sp->hregs->pconfig = 0x161;
780	sp->hregs->dconfig = HPC3_EDCFG_FIRQ | HPC3_EDCFG_FEOP |
781			     HPC3_EDCFG_FRXDC | HPC3_EDCFG_PTO | 0x026;
782
783	/* Setup PIO and DMA transfer timing */
784	sp->hregs->pconfig = 0x161;
785	sp->hregs->dconfig = HPC3_EDCFG_FIRQ | HPC3_EDCFG_FEOP |
786			     HPC3_EDCFG_FRXDC | HPC3_EDCFG_PTO | 0x026;
787
788	/* Reset the chip. */
789	hpc3_eth_reset(sp->hregs);
790
791	sp->is_edlc = !(sp->sregs->rw.rregs.collision_tx[0] & 0xff);
792	if (sp->is_edlc)
793		sp->control = SEEQ_CTRL_XCNT | SEEQ_CTRL_ACCNT |
794			      SEEQ_CTRL_SFLAG | SEEQ_CTRL_ESHORT |
795			      SEEQ_CTRL_ENCARR;
796
797	dev->netdev_ops		= &sgiseeq_netdev_ops;
798	dev->watchdog_timeo	= (200 * HZ) / 1000;
799	dev->irq		= irq;
800
801	if (register_netdev(dev)) {
802		printk(KERN_ERR "Sgiseeq: Cannot register net device, "
803		       "aborting.\n");
804		err = -ENODEV;
805		goto err_out_free_attrs;
806	}
807
808	printk(KERN_INFO "%s: %s %pM\n", dev->name, sgiseeqstr, dev->dev_addr);
809
810	return 0;
811
812err_out_free_attrs:
813	dma_free_noncoherent(&pdev->dev, sizeof(*sp->srings), sp->srings,
814		       sp->srings_dma, DMA_BIDIRECTIONAL);
815err_out_free_dev:
816	free_netdev(dev);
817
818err_out:
819	return err;
820}
821
822static void sgiseeq_remove(struct platform_device *pdev)
823{
824	struct net_device *dev = platform_get_drvdata(pdev);
825	struct sgiseeq_private *sp = netdev_priv(dev);
826
827	unregister_netdev(dev);
828	dma_free_noncoherent(&pdev->dev, sizeof(*sp->srings), sp->srings,
829		       sp->srings_dma, DMA_BIDIRECTIONAL);
830	free_netdev(dev);
831}
832
833static struct platform_driver sgiseeq_driver = {
834	.probe	= sgiseeq_probe,
835	.remove_new = sgiseeq_remove,
836	.driver = {
837		.name	= "sgiseeq",
838	}
839};
840
841module_platform_driver(sgiseeq_driver);
842
843MODULE_DESCRIPTION("SGI Seeq 8003 driver");
844MODULE_AUTHOR("Linux/MIPS Mailing List <linux-mips@linux-mips.org>");
845MODULE_LICENSE("GPL");
846MODULE_ALIAS("platform:sgiseeq");
847