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/drivers/net/sgiseeq.c

https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t
C | 858 lines | 653 code | 135 blank | 70 comment | 71 complexity | 38e7374b2c5521888b0e93d7dc312a21 MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
  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
 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	dma_cache_sync(dev->dev.parent, addr, sizeof(struct sgiseeq_rx_desc),
116		       DMA_FROM_DEVICE);
117}
118
119static 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
125static 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
132static 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
142static 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
150static 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
161static 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
179static 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
219static 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
242static struct sgiseeq_private *gpriv;
243static struct net_device *gdev;
244
245static 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
287static 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
314static 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
327static 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
337static 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				}
376memory_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
417static 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
426static 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
453static 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
499static 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
526static 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
546out_free_irq:
547	free_irq(irq, dev);
548
549	return err;
550}
551
552static 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
568static 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
584static 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
649static 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
658static 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
678static 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
695static 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
713static 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_multicast_list	= 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
724static int __devinit 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		printk(KERN_ERR "Sgiseeq: Etherdev alloc failed, aborting.\n");
737		err = -ENOMEM;
738		goto err_out;
739	}
740
741	platform_set_drvdata(pdev, dev);
742	sp = netdev_priv(dev);
743
744	/* Make private data page aligned */
745	sr = dma_alloc_noncoherent(&pdev->dev, sizeof(*sp->srings),
746				&sp->srings_dma, GFP_KERNEL);
747	if (!sr) {
748		printk(KERN_ERR "Sgiseeq: Page alloc failed, aborting.\n");
749		err = -ENOMEM;
750		goto err_out_free_dev;
751	}
752	sp->srings = sr;
753	sp->rx_desc = sp->srings->rxvector;
754	sp->tx_desc = sp->srings->txvector;
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
805err_out_free_page:
806	free_page((unsigned long) sp->srings);
807err_out_free_dev:
808	free_netdev(dev);
809
810err_out:
811	return err;
812}
813
814static 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
828static 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
837static int __init sgiseeq_module_init(void)
838{
839	if (platform_driver_register(&sgiseeq_driver)) {
840		printk(KERN_ERR "Driver registration failed\n");
841		return -ENODEV;
842	}
843
844	return 0;
845}
846
847static void __exit sgiseeq_module_exit(void)
848{
849	platform_driver_unregister(&sgiseeq_driver);
850}
851
852module_init(sgiseeq_module_init);
853module_exit(sgiseeq_module_exit);
854
855MODULE_DESCRIPTION("SGI Seeq 8003 driver");
856MODULE_AUTHOR("Linux/MIPS Mailing List <linux-mips@linux-mips.org>");
857MODULE_LICENSE("GPL");
858MODULE_ALIAS("platform:sgiseeq");