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