aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/net/pasemi_mac.c
blob: 76fe9dd8e841581cd70dcbd09746bd7a84705ea0 (plain) (tree)
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731















































































































































































































































































































































                                                                                    










































































































































































































































































































































































































                                                                                    

                                                                  
                                                

                                                     
                                                                                  
                                                                


                                                     
                                                                                  
                                                                



















































































































































































































































































                                                                                   
/*
 * Copyright (C) 2006-2007 PA Semi, Inc
 *
 * Driver for the PA Semi PWRficient onchip 1G/10G Ethernet MACs
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/dmaengine.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <asm/dma-mapping.h>
#include <linux/in.h>
#include <linux/skbuff.h>

#include <linux/ip.h>
#include <linux/tcp.h>
#include <net/checksum.h>

#include "pasemi_mac.h"


/* TODO list
 *
 * - Get rid of pci_{read,write}_config(), map registers with ioremap
 *   for performance
 * - PHY support
 * - Multicast support
 * - Large MTU support
 * - Other performance improvements
 */


/* Must be a power of two */
#define RX_RING_SIZE 512
#define TX_RING_SIZE 512

#define TX_DESC(mac, num)	((mac)->tx->desc[(num) & (TX_RING_SIZE-1)])
#define TX_DESC_INFO(mac, num)	((mac)->tx->desc_info[(num) & (TX_RING_SIZE-1)])
#define RX_DESC(mac, num)	((mac)->rx->desc[(num) & (RX_RING_SIZE-1)])
#define RX_DESC_INFO(mac, num)	((mac)->rx->desc_info[(num) & (RX_RING_SIZE-1)])
#define RX_BUFF(mac, num)	((mac)->rx->buffers[(num) & (RX_RING_SIZE-1)])

#define BUF_SIZE 1646 /* 1500 MTU + ETH_HLEN + VLAN_HLEN + 2 64B cachelines */

/* XXXOJN these should come out of the device tree some day */
#define PAS_DMA_CAP_BASE   0xe00d0040
#define PAS_DMA_CAP_SIZE   0x100
#define PAS_DMA_COM_BASE   0xe00d0100
#define PAS_DMA_COM_SIZE   0x100

static struct pasdma_status *dma_status;

static int pasemi_get_mac_addr(struct pasemi_mac *mac)
{
	struct pci_dev *pdev = mac->pdev;
	struct device_node *dn = pci_device_to_OF_node(pdev);
	const u8 *maddr;
	u8 addr[6];

	if (!dn) {
		dev_dbg(&pdev->dev,
			  "No device node for mac, not configuring\n");
		return -ENOENT;
	}

	maddr = get_property(dn, "mac-address", NULL);
	if (maddr == NULL) {
		dev_warn(&pdev->dev,
			 "no mac address in device tree, not configuring\n");
		return -ENOENT;
	}

	if (sscanf(maddr, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &addr[0],
		   &addr[1], &addr[2], &addr[3], &addr[4], &addr[5]) != 6) {
		dev_warn(&pdev->dev,
			 "can't parse mac address, not configuring\n");
		return -EINVAL;
	}

	memcpy(mac->mac_addr, addr, sizeof(addr));
	return 0;
}

static int pasemi_mac_setup_rx_resources(struct net_device *dev)
{
	struct pasemi_mac_rxring *ring;
	struct pasemi_mac *mac = netdev_priv(dev);
	int chan_id = mac->dma_rxch;

	ring = kzalloc(sizeof(*ring), GFP_KERNEL);

	if (!ring)
		goto out_ring;

	spin_lock_init(&ring->lock);

	ring->desc_info = kzalloc(sizeof(struct pasemi_mac_buffer) *
				  RX_RING_SIZE, GFP_KERNEL);

	if (!ring->desc_info)
		goto out_desc_info;

	/* Allocate descriptors */
	ring->desc = dma_alloc_coherent(&mac->dma_pdev->dev,
					RX_RING_SIZE *
					sizeof(struct pas_dma_xct_descr),
					&ring->dma, GFP_KERNEL);

	if (!ring->desc)
		goto out_desc;

	memset(ring->desc, 0, RX_RING_SIZE * sizeof(struct pas_dma_xct_descr));

	ring->buffers = dma_alloc_coherent(&mac->dma_pdev->dev,
					   RX_RING_SIZE * sizeof(u64),
					   &ring->buf_dma, GFP_KERNEL);
	if (!ring->buffers)
		goto out_buffers;

	memset(ring->buffers, 0, RX_RING_SIZE * sizeof(u64));

	pci_write_config_dword(mac->dma_pdev, PAS_DMA_RXCHAN_BASEL(chan_id),
			       PAS_DMA_RXCHAN_BASEL_BRBL(ring->dma));

	pci_write_config_dword(mac->dma_pdev, PAS_DMA_RXCHAN_BASEU(chan_id),
			       PAS_DMA_RXCHAN_BASEU_BRBH(ring->dma >> 32) |
			       PAS_DMA_RXCHAN_BASEU_SIZ(RX_RING_SIZE >> 2));

	pci_write_config_dword(mac->dma_pdev, PAS_DMA_RXCHAN_CFG(chan_id),
			       PAS_DMA_RXCHAN_CFG_HBU(1));

	pci_write_config_dword(mac->dma_pdev, PAS_DMA_RXINT_BASEL(mac->dma_if),
			       PAS_DMA_RXINT_BASEL_BRBL(__pa(ring->buffers)));

	pci_write_config_dword(mac->dma_pdev, PAS_DMA_RXINT_BASEU(mac->dma_if),
			       PAS_DMA_RXINT_BASEU_BRBH(__pa(ring->buffers) >> 32) |
			       PAS_DMA_RXINT_BASEU_SIZ(RX_RING_SIZE >> 3));

	ring->next_to_fill = 0;
	ring->next_to_clean = 0;

	snprintf(ring->irq_name, sizeof(ring->irq_name),
		 "%s rx", dev->name);
	mac->rx = ring;

	return 0;

out_buffers:
	dma_free_coherent(&mac->dma_pdev->dev,
			  RX_RING_SIZE * sizeof(struct pas_dma_xct_descr),
			  mac->rx->desc, mac->rx->dma);
out_desc:
	kfree(ring->desc_info);
out_desc_info:
	kfree(ring);
out_ring:
	return -ENOMEM;
}


static int pasemi_mac_setup_tx_resources(struct net_device *dev)
{
	struct pasemi_mac *mac = netdev_priv(dev);
	u32 val;
	int chan_id = mac->dma_txch;
	struct pasemi_mac_txring *ring;

	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
	if (!ring)
		goto out_ring;

	spin_lock_init(&ring->lock);

	ring->desc_info = kzalloc(sizeof(struct pasemi_mac_buffer) *
				  TX_RING_SIZE, GFP_KERNEL);
	if (!ring->desc_info)
		goto out_desc_info;

	/* Allocate descriptors */
	ring->desc = dma_alloc_coherent(&mac->dma_pdev->dev,
					TX_RING_SIZE *
					sizeof(struct pas_dma_xct_descr),
					&ring->dma, GFP_KERNEL);
	if (!ring->desc)
		goto out_desc;

	memset(ring->desc, 0, TX_RING_SIZE * sizeof(struct pas_dma_xct_descr));

	pci_write_config_dword(mac->dma_pdev, PAS_DMA_TXCHAN_BASEL(chan_id),
			       PAS_DMA_TXCHAN_BASEL_BRBL(ring->dma));
	val = PAS_DMA_TXCHAN_BASEU_BRBH(ring->dma >> 32);
	val |= PAS_DMA_TXCHAN_BASEU_SIZ(TX_RING_SIZE >> 2);

	pci_write_config_dword(mac->dma_pdev, PAS_DMA_TXCHAN_BASEU(chan_id), val);

	pci_write_config_dword(mac->dma_pdev, PAS_DMA_TXCHAN_CFG(chan_id),
			       PAS_DMA_TXCHAN_CFG_TY_IFACE |
			       PAS_DMA_TXCHAN_CFG_TATTR(mac->dma_if) |
			       PAS_DMA_TXCHAN_CFG_UP |
			       PAS_DMA_TXCHAN_CFG_WT(2));

	ring->next_to_use = 0;
	ring->next_to_clean = 0;

	snprintf(ring->irq_name, sizeof(ring->irq_name),
		 "%s tx", dev->name);
	mac->tx = ring;

	return 0;

out_desc:
	kfree(ring->desc_info);
out_desc_info:
	kfree(ring);
out_ring:
	return -ENOMEM;
}

static void pasemi_mac_free_tx_resources(struct net_device *dev)
{
	struct pasemi_mac *mac = netdev_priv(dev);
	unsigned int i;
	struct pasemi_mac_buffer *info;
	struct pas_dma_xct_descr *dp;

	for (i = 0; i < TX_RING_SIZE; i++) {
		info = &TX_DESC_INFO(mac, i);
		dp = &TX_DESC(mac, i);
		if (info->dma) {
			if (info->skb) {
				pci_unmap_single(mac->dma_pdev,
						 info->dma,
						 info->skb->len,
						 PCI_DMA_TODEVICE);
				dev_kfree_skb_any(info->skb);
			}
			info->dma = 0;
			info->skb = NULL;
			dp->mactx = 0;
			dp->ptr = 0;
		}
	}

	dma_free_coherent(&mac->dma_pdev->dev,
			  TX_RING_SIZE * sizeof(struct pas_dma_xct_descr),
			  mac->tx->desc, mac->tx->dma);

	kfree(mac->tx->desc_info);
	kfree(mac->tx);
	mac->tx = NULL;
}

static void pasemi_mac_free_rx_resources(struct net_device *dev)
{
	struct pasemi_mac *mac = netdev_priv(dev);
	unsigned int i;
	struct pasemi_mac_buffer *info;
	struct pas_dma_xct_descr *dp;

	for (i = 0; i < RX_RING_SIZE; i++) {
		info = &RX_DESC_INFO(mac, i);
		dp = &RX_DESC(mac, i);
		if (info->dma) {
			if (info->skb) {
				pci_unmap_single(mac->dma_pdev,
						 info->dma,
						 info->skb->len,
						 PCI_DMA_FROMDEVICE);
				dev_kfree_skb_any(info->skb);
			}
			info->dma = 0;
			info->skb = NULL;
			dp->macrx = 0;
			dp->ptr = 0;
		}
	}

	dma_free_coherent(&mac->dma_pdev->dev,
			  RX_RING_SIZE * sizeof(struct pas_dma_xct_descr),
			  mac->rx->desc, mac->rx->dma);

	dma_free_coherent(&mac->dma_pdev->dev, RX_RING_SIZE * sizeof(u64),
			  mac->rx->buffers, mac->rx->buf_dma);

	kfree(mac->rx->desc_info);
	kfree(mac->rx);
	mac->rx = NULL;
}

static void pasemi_mac_replenish_rx_ring(struct net_device *dev)
{
	struct pasemi_mac *mac = netdev_priv(dev);
	unsigned int i;
	int start = mac->rx->next_to_fill;
	unsigned int count;

	count = (mac->rx->next_to_clean + RX_RING_SIZE -
		 mac->rx->next_to_fill) & (RX_RING_SIZE - 1);

	/* Check to see if we're doing first-time setup */
	if (unlikely(mac->rx->next_to_clean == 0 && mac->rx->next_to_fill == 0))
		count = RX_RING_SIZE;

	if (count <= 0)
		return;

	for (i = start; i < start + count; i++) {
		struct pasemi_mac_buffer *info = &RX_DESC_INFO(mac, i);
		u64 *buff = &RX_BUFF(mac, i);
		struct sk_buff *skb;
		dma_addr_t dma;

		skb = dev_alloc_skb(BUF_SIZE);

		if (!skb) {
			count = i - start;
			break;
		}

		dma = pci_map_single(mac->dma_pdev, skb->data, skb->len,
				     PCI_DMA_FROMDEVICE);

		if (dma_mapping_error(dma)) {
			dev_kfree_skb_irq(info->skb);
			count = i - start;
			break;
		}

		info->skb = skb;
		info->dma = dma;
		*buff = XCT_RXB_LEN(BUF_SIZE) | XCT_RXB_ADDR(dma);
	}

	wmb();

	pci_write_config_dword(mac->dma_pdev,
			       PAS_DMA_RXCHAN_INCR(mac->dma_rxch),
			       count);
	pci_write_config_dword(mac->dma_pdev,
			       PAS_DMA_RXINT_INCR(mac->dma_if),
			       count);

	mac->rx->next_to_fill += count;
}

static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit)
{
	unsigned int i;
	int start, count;

	spin_lock(&mac->rx->lock);

	start = mac->rx->next_to_clean;
	count = 0;

	for (i = start; i < (start + RX_RING_SIZE) && count < limit; i++) {
		struct pas_dma_xct_descr *dp;
		struct pasemi_mac_buffer *info;
		struct sk_buff *skb;
		unsigned int j, len;
		dma_addr_t dma;

		rmb();

		dp = &RX_DESC(mac, i);

		if (!(dp->macrx & XCT_MACRX_O))
			break;

		count++;

		info = NULL;

		/* We have to scan for our skb since there's no way
		 * to back-map them from the descriptor, and if we
		 * have several receive channels then they might not
		 * show up in the same order as they were put on the
		 * interface ring.
		 */

		dma = (dp->ptr & XCT_PTR_ADDR_M);
		for (j = start; j < (start + RX_RING_SIZE); j++) {
			info = &RX_DESC_INFO(mac, j);
			if (info->dma == dma)
				break;
		}

		BUG_ON(!info);
		BUG_ON(info->dma != dma);

		pci_unmap_single(mac->dma_pdev, info->dma, info->skb->len,
				 PCI_DMA_FROMDEVICE);

		skb = info->skb;

		len = (dp->macrx & XCT_MACRX_LLEN_M) >> XCT_MACRX_LLEN_S;

		skb_put(skb, len);

		skb->protocol = eth_type_trans(skb, mac->netdev);

		if ((dp->macrx & XCT_MACRX_HTY_M) == XCT_MACRX_HTY_IPV4_OK) {
			skb->ip_summed = CHECKSUM_COMPLETE;
			skb->csum = (dp->macrx & XCT_MACRX_CSUM_M) >>
					   XCT_MACRX_CSUM_S;
		} else
			skb->ip_summed = CHECKSUM_NONE;

		mac->stats.rx_bytes += len;
		mac->stats.rx_packets++;

		netif_receive_skb(skb);

		info->dma = 0;
		info->skb = NULL;
		dp->ptr = 0;
		dp->macrx = 0;
	}

	mac->rx->next_to_clean += count;
	pasemi_mac_replenish_rx_ring(mac->netdev);

	spin_unlock(&mac->rx->lock);

	return count;
}

static int pasemi_mac_clean_tx(struct pasemi_mac *mac)
{
	int i;
	struct pasemi_mac_buffer *info;
	struct pas_dma_xct_descr *dp;
	int start, count;
	int flags;

	spin_lock_irqsave(&mac->tx->lock, flags);

	start = mac->tx->next_to_clean;
	count = 0;

	for (i = start; i < mac->tx->next_to_use; i++) {
		dp = &TX_DESC(mac, i);
		if (!dp || (dp->mactx & XCT_MACTX_O))
			break;

		count++;

		info = &TX_DESC_INFO(mac, i);

		pci_unmap_single(mac->dma_pdev, info->dma,
				 info->skb->len, PCI_DMA_TODEVICE);
		dev_kfree_skb_irq(info->skb);

		info->skb = NULL;
		info->dma = 0;
		dp->mactx = 0;
		dp->ptr = 0;
	}
	mac->tx->next_to_clean += count;
	spin_unlock_irqrestore(&mac->tx->lock, flags);

	return count;
}


static irqreturn_t pasemi_mac_rx_intr(int irq, void *data)
{
	struct net_device *dev = data;
	struct pasemi_mac *mac = netdev_priv(dev);
	unsigned int reg;

	if (!(*mac->rx_status & PAS_STATUS_INT))
		return IRQ_NONE;

	netif_rx_schedule(dev);
	pci_write_config_dword(mac->iob_pdev, PAS_IOB_DMA_COM_TIMEOUTCFG,
			       PAS_IOB_DMA_COM_TIMEOUTCFG_TCNT(0));

	reg = PAS_IOB_DMA_RXCH_RESET_PINTC | PAS_IOB_DMA_RXCH_RESET_SINTC |
	      PAS_IOB_DMA_RXCH_RESET_DINTC;
	if (*mac->rx_status & PAS_STATUS_TIMER)
		reg |= PAS_IOB_DMA_RXCH_RESET_TINTC;

	pci_write_config_dword(mac->iob_pdev,
			       PAS_IOB_DMA_RXCH_RESET(mac->dma_rxch), reg);


	return IRQ_HANDLED;
}

static irqreturn_t pasemi_mac_tx_intr(int irq, void *data)
{
	struct net_device *dev = data;
	struct pasemi_mac *mac = netdev_priv(dev);
	unsigned int reg;
	int was_full;

	was_full = mac->tx->next_to_clean - mac->tx->next_to_use == TX_RING_SIZE;

	if (!(*mac->tx_status & PAS_STATUS_INT))
		return IRQ_NONE;

	pasemi_mac_clean_tx(mac);

	reg = PAS_IOB_DMA_TXCH_RESET_PINTC | PAS_IOB_DMA_TXCH_RESET_SINTC;
	if (*mac->tx_status & PAS_STATUS_TIMER)
		reg |= PAS_IOB_DMA_TXCH_RESET_TINTC;

	pci_write_config_dword(mac->iob_pdev, PAS_IOB_DMA_TXCH_RESET(mac->dma_txch),
			       reg);

	if (was_full)
		netif_wake_queue(dev);

	return IRQ_HANDLED;
}

static int pasemi_mac_open(struct net_device *dev)
{
	struct pasemi_mac *mac = netdev_priv(dev);
	unsigned int flags;
	int ret;

	/* enable rx section */
	pci_write_config_dword(mac->dma_pdev, PAS_DMA_COM_RXCMD,
			       PAS_DMA_COM_RXCMD_EN);

	/* enable tx section */
	pci_write_config_dword(mac->dma_pdev, PAS_DMA_COM_TXCMD,
			       PAS_DMA_COM_TXCMD_EN);

	flags = PAS_MAC_CFG_TXP_FCE | PAS_MAC_CFG_TXP_FPC(3) |
		PAS_MAC_CFG_TXP_SL(3) | PAS_MAC_CFG_TXP_COB(0xf) |
		PAS_MAC_CFG_TXP_TIFT(8) | PAS_MAC_CFG_TXP_TIFG(12);

	pci_write_config_dword(mac->pdev, PAS_MAC_CFG_TXP, flags);

	flags = PAS_MAC_CFG_PCFG_S1 | PAS_MAC_CFG_PCFG_PE |
		PAS_MAC_CFG_PCFG_PR | PAS_MAC_CFG_PCFG_CE;

	flags |= PAS_MAC_CFG_PCFG_TSR_1G | PAS_MAC_CFG_PCFG_SPD_1G;

	pci_write_config_dword(mac->iob_pdev, PAS_IOB_DMA_RXCH_CFG(mac->dma_rxch),
			       PAS_IOB_DMA_RXCH_CFG_CNTTH(30));

	pci_write_config_dword(mac->iob_pdev, PAS_IOB_DMA_COM_TIMEOUTCFG,
			       PAS_IOB_DMA_COM_TIMEOUTCFG_TCNT(1000000));

	pci_write_config_dword(mac->pdev, PAS_MAC_CFG_PCFG, flags);

	ret = pasemi_mac_setup_rx_resources(dev);
	if (ret)
		goto out_rx_resources;

	ret = pasemi_mac_setup_tx_resources(dev);
	if (ret)
		goto out_tx_resources;

	pci_write_config_dword(mac->pdev, PAS_MAC_IPC_CHNL,
			       PAS_MAC_IPC_CHNL_DCHNO(mac->dma_rxch) |
			       PAS_MAC_IPC_CHNL_BCH(mac->dma_rxch));

	/* enable rx if */
	pci_write_config_dword(mac->dma_pdev,
			       PAS_DMA_RXINT_RCMDSTA(mac->dma_if),
			       PAS_DMA_RXINT_RCMDSTA_EN);

	/* enable rx channel */
	pci_write_config_dword(mac->dma_pdev,
			       PAS_DMA_RXCHAN_CCMDSTA(mac->dma_rxch),
			       PAS_DMA_RXCHAN_CCMDSTA_EN |
			       PAS_DMA_RXCHAN_CCMDSTA_DU);

	/* enable tx channel */
	pci_write_config_dword(mac->dma_pdev,
			       PAS_DMA_TXCHAN_TCMDSTA(mac->dma_txch),
			       PAS_DMA_TXCHAN_TCMDSTA_EN);

	pasemi_mac_replenish_rx_ring(dev);

	netif_start_queue(dev);
	netif_poll_enable(dev);

	ret = request_irq(mac->dma_pdev->irq + mac->dma_txch,
			  &pasemi_mac_tx_intr, IRQF_DISABLED,
			  mac->tx->irq_name, dev);
	if (ret) {
		dev_err(&mac->pdev->dev, "request_irq of irq %d failed: %d\n",
		       mac->dma_pdev->irq + mac->dma_txch, ret);
		goto out_tx_int;
	}

	ret = request_irq(mac->dma_pdev->irq + 20 + mac->dma_rxch,
			  &pasemi_mac_rx_intr, IRQF_DISABLED,
			  mac->rx->irq_name, dev);
	if (ret) {
		dev_err(&mac->pdev->dev, "request_irq of irq %d failed: %d\n",
		       mac->dma_pdev->irq + 20 + mac->dma_rxch, ret);
		goto out_rx_int;
	}

	return 0;

out_rx_int:
	free_irq(mac->dma_pdev->irq + mac->dma_txch, dev);
out_tx_int:
	netif_poll_disable(dev);
	netif_stop_queue(dev);
	pasemi_mac_free_tx_resources(dev);
out_tx_resources:
	pasemi_mac_free_rx_resources(dev);
out_rx_resources:

	return ret;
}

#define MAX_RETRIES 5000

static int pasemi_mac_close(struct net_device *dev)
{
	struct pasemi_mac *mac = netdev_priv(dev);
	unsigned int stat;
	int retries;

	netif_stop_queue(dev);

	/* Clean out any pending buffers */
	pasemi_mac_clean_tx(mac);
	pasemi_mac_clean_rx(mac, RX_RING_SIZE);

	/* Disable interface */
	pci_write_config_dword(mac->dma_pdev,
			       PAS_DMA_TXCHAN_TCMDSTA(mac->dma_txch),
			       PAS_DMA_TXCHAN_TCMDSTA_ST);
	pci_write_config_dword(mac->dma_pdev,
		      PAS_DMA_RXINT_RCMDSTA(mac->dma_if),
		      PAS_DMA_RXINT_RCMDSTA_ST);
	pci_write_config_dword(mac->dma_pdev,
		      PAS_DMA_RXCHAN_CCMDSTA(mac->dma_rxch),
		      PAS_DMA_RXCHAN_CCMDSTA_ST);

	for (retries = 0; retries < MAX_RETRIES; retries++) {
		pci_read_config_dword(mac->dma_pdev,
				      PAS_DMA_TXCHAN_TCMDSTA(mac->dma_txch),
				      &stat);
		if (stat & PAS_DMA_TXCHAN_TCMDSTA_ACT)
			break;
		cond_resched();
	}

	if (!(stat & PAS_DMA_TXCHAN_TCMDSTA_ACT)) {
		dev_err(&mac->dma_pdev->dev, "Failed to stop tx channel\n");
	}

	for (retries = 0; retries < MAX_RETRIES; retries++) {
		pci_read_config_dword(mac->dma_pdev,
				      PAS_DMA_RXCHAN_CCMDSTA(mac->dma_rxch),
				      &stat);
		if (stat & PAS_DMA_RXCHAN_CCMDSTA_ACT)
			break;
		cond_resched();
	}

	if (!(stat & PAS_DMA_RXCHAN_CCMDSTA_ACT)) {
		dev_err(&mac->dma_pdev->dev, "Failed to stop rx channel\n");
	}

	for (retries = 0; retries < MAX_RETRIES; retries++) {
		pci_read_config_dword(mac->dma_pdev,
				      PAS_DMA_RXINT_RCMDSTA(mac->dma_if),
				      &stat);
		if (stat & PAS_DMA_RXINT_RCMDSTA_ACT)
			break;
		cond_resched();
	}

	if (!(stat & PAS_DMA_RXINT_RCMDSTA_ACT)) {
		dev_err(&mac->dma_pdev->dev, "Failed to stop rx interface\n");
	}

	/* Then, disable the channel. This must be done separately from
	 * stopping, since you can't disable when active.
	 */

	pci_write_config_dword(mac->dma_pdev,
			       PAS_DMA_TXCHAN_TCMDSTA(mac->dma_txch), 0);
	pci_write_config_dword(mac->dma_pdev,
			       PAS_DMA_RXCHAN_CCMDSTA(mac->dma_rxch), 0);
	pci_write_config_dword(mac->dma_pdev,
			       PAS_DMA_RXINT_RCMDSTA(mac->dma_if), 0);

	free_irq(mac->dma_pdev->irq + mac->dma_txch, dev);
	free_irq(mac->dma_pdev->irq + 20 + mac->dma_rxch, dev);

	/* Free resources */
	pasemi_mac_free_rx_resources(dev);
	pasemi_mac_free_tx_resources(dev);

	return 0;
}

static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev)
{
	struct pasemi_mac *mac = netdev_priv(dev);
	struct pasemi_mac_txring *txring;
	struct pasemi_mac_buffer *info;
	struct pas_dma_xct_descr *dp;
	u64 dflags;
	dma_addr_t map;
	int flags;

	dflags = XCT_MACTX_O | XCT_MACTX_ST | XCT_MACTX_SS | XCT_MACTX_CRC_PAD;

	if (skb->ip_summed == CHECKSUM_PARTIAL) {
		const unsigned char *nh = skb_network_header(skb);

		switch (ip_hdr(skb)->protocol) {
		case IPPROTO_TCP:
			dflags |= XCT_MACTX_CSUM_TCP;
			dflags |= XCT_MACTX_IPH(skb_network_header_len(skb) >> 2);
			dflags |= XCT_MACTX_IPO(nh - skb->data);
			break;
		case IPPROTO_UDP:
			dflags |= XCT_MACTX_CSUM_UDP;
			dflags |= XCT_MACTX_IPH(skb_network_header_len(skb) >> 2);
			dflags |= XCT_MACTX_IPO(nh - skb->data);
			break;
		}
	}

	map = pci_map_single(mac->dma_pdev, skb->data, skb->len, PCI_DMA_TODEVICE);

	if (dma_mapping_error(map))
		return NETDEV_TX_BUSY;

	txring = mac->tx;

	spin_lock_irqsave(&txring->lock, flags);

	if (txring->next_to_clean - txring->next_to_use == TX_RING_SIZE) {
		spin_unlock_irqrestore(&txring->lock, flags);
		pasemi_mac_clean_tx(mac);
		spin_lock_irqsave(&txring->lock, flags);

		if (txring->next_to_clean - txring->next_to_use ==
		    TX_RING_SIZE) {
			/* Still no room -- stop the queue and wait for tx
			 * intr when there's room.
			 */
			netif_stop_queue(dev);
			goto out_err;
		}
	}


	dp = &TX_DESC(mac, txring->next_to_use);
	info = &TX_DESC_INFO(mac, txring->next_to_use);

	dp->mactx = dflags | XCT_MACTX_LLEN(skb->len);
	dp->ptr   = XCT_PTR_LEN(skb->len) | XCT_PTR_ADDR(map);
	info->dma = map;
	info->skb = skb;

	txring->next_to_use++;
	mac->stats.tx_packets++;
	mac->stats.tx_bytes += skb->len;

	spin_unlock_irqrestore(&txring->lock, flags);

	pci_write_config_dword(mac->dma_pdev,
			       PAS_DMA_TXCHAN_INCR(mac->dma_txch), 1);

	return NETDEV_TX_OK;

out_err:
	spin_unlock_irqrestore(&txring->lock, flags);
	pci_unmap_single(mac->dma_pdev, map, skb->len, PCI_DMA_TODEVICE);
	return NETDEV_TX_BUSY;
}

static struct net_device_stats *pasemi_mac_get_stats(struct net_device *dev)
{
	struct pasemi_mac *mac = netdev_priv(dev);

	return &mac->stats;
}

static void pasemi_mac_set_rx_mode(struct net_device *dev)
{
	struct pasemi_mac *mac = netdev_priv(dev);
	unsigned int flags;

	pci_read_config_dword(mac->pdev, PAS_MAC_CFG_PCFG, &flags);

	/* Set promiscuous */
	if (dev->flags & IFF_PROMISC)
		flags |= PAS_MAC_CFG_PCFG_PR;
	else
		flags &= ~PAS_MAC_CFG_PCFG_PR;

	pci_write_config_dword(mac->pdev, PAS_MAC_CFG_PCFG, flags);
}


static int pasemi_mac_poll(struct net_device *dev, int *budget)
{
	int pkts, limit = min(*budget, dev->quota);
	struct pasemi_mac *mac = netdev_priv(dev);

	pkts = pasemi_mac_clean_rx(mac, limit);

	if (pkts < limit) {
		/* all done, no more packets present */
		netif_rx_complete(dev);

		/* re-enable receive interrupts */
		pci_write_config_dword(mac->iob_pdev, PAS_IOB_DMA_COM_TIMEOUTCFG,
				       PAS_IOB_DMA_COM_TIMEOUTCFG_TCNT(1000000));
		return 0;
	} else {
		/* used up our quantum, so reschedule */
		dev->quota -= pkts;
		*budget -= pkts;
		return 1;
	}
}

static int __devinit
pasemi_mac_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
	static int index = 0;
	struct net_device *dev;
	struct pasemi_mac *mac;
	int err;

	err = pci_enable_device(pdev);
	if (err)
		return err;

	dev = alloc_etherdev(sizeof(struct pasemi_mac));
	if (dev == NULL) {
		dev_err(&pdev->dev,
			"pasemi_mac: Could not allocate ethernet device.\n");
		err = -ENOMEM;
		goto out_disable_device;
	}

	SET_MODULE_OWNER(dev);
	pci_set_drvdata(pdev, dev);
	SET_NETDEV_DEV(dev, &pdev->dev);

	mac = netdev_priv(dev);

	mac->pdev = pdev;
	mac->netdev = dev;
	mac->dma_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa007, NULL);

	if (!mac->dma_pdev) {
		dev_err(&pdev->dev, "Can't find DMA Controller\n");
		err = -ENODEV;
		goto out_free_netdev;
	}

	mac->iob_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa001, NULL);

	if (!mac->iob_pdev) {
		dev_err(&pdev->dev, "Can't find I/O Bridge\n");
		err = -ENODEV;
		goto out_put_dma_pdev;
	}

	/* These should come out of the device tree eventually */
	mac->dma_txch = index;
	mac->dma_rxch = index;

	/* We probe GMAC before XAUI, but the DMA interfaces are
	 * in XAUI, GMAC order.
	 */
	if (index < 4)
		mac->dma_if = index + 2;
	else
		mac->dma_if = index - 4;
	index++;

	switch (pdev->device) {
	case 0xa005:
		mac->type = MAC_TYPE_GMAC;
		break;
	case 0xa006:
		mac->type = MAC_TYPE_XAUI;
		break;
	default:
		err = -ENODEV;
		goto out;
	}

	/* get mac addr from device tree */
	if (pasemi_get_mac_addr(mac) || !is_valid_ether_addr(mac->mac_addr)) {
		err = -ENODEV;
		goto out;
	}
	memcpy(dev->dev_addr, mac->mac_addr, sizeof(mac->mac_addr));

	dev->open = pasemi_mac_open;
	dev->stop = pasemi_mac_close;
	dev->hard_start_xmit = pasemi_mac_start_tx;
	dev->get_stats = pasemi_mac_get_stats;
	dev->set_multicast_list = pasemi_mac_set_rx_mode;
	dev->weight = 64;
	dev->poll = pasemi_mac_poll;
	dev->features = NETIF_F_HW_CSUM;

	/* The dma status structure is located in the I/O bridge, and
	 * is cache coherent.
	 */
	if (!dma_status)
		/* XXXOJN This should come from the device tree */
		dma_status = __ioremap(0xfd800000, 0x1000, 0);

	mac->rx_status = &dma_status->rx_sta[mac->dma_rxch];
	mac->tx_status = &dma_status->tx_sta[mac->dma_txch];

	err = register_netdev(dev);

	if (err) {
		dev_err(&mac->pdev->dev, "register_netdev failed with error %d\n",
			err);
		goto out;
	} else
		printk(KERN_INFO "%s: PA Semi %s: intf %d, txch %d, rxch %d, "
		       "hw addr %02x:%02x:%02x:%02x:%02x:%02x\n",
		       dev->name, mac->type == MAC_TYPE_GMAC ? "GMAC" : "XAUI",
		       mac->dma_if, mac->dma_txch, mac->dma_rxch,
		       dev->dev_addr[0], dev->dev_addr[1], dev->dev_addr[2],
		       dev->dev_addr[3], dev->dev_addr[4], dev->dev_addr[5]);

	return err;

out:
	pci_dev_put(mac->iob_pdev);
out_put_dma_pdev:
	pci_dev_put(mac->dma_pdev);
out_free_netdev:
	free_netdev(dev);
out_disable_device:
	pci_disable_device(pdev);
	return err;

}

static void __devexit pasemi_mac_remove(struct pci_dev *pdev)
{
	struct net_device *netdev = pci_get_drvdata(pdev);
	struct pasemi_mac *mac;

	if (!netdev)
		return;

	mac = netdev_priv(netdev);

	unregister_netdev(netdev);

	pci_disable_device(pdev);
	pci_dev_put(mac->dma_pdev);
	pci_dev_put(mac->iob_pdev);

	pci_set_drvdata(pdev, NULL);
	free_netdev(netdev);
}

static struct pci_device_id pasemi_mac_pci_tbl[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_PASEMI, 0xa005) },
	{ PCI_DEVICE(PCI_VENDOR_ID_PASEMI, 0xa006) },
};

MODULE_DEVICE_TABLE(pci, pasemi_mac_pci_tbl);

static struct pci_driver pasemi_mac_driver = {
	.name		= "pasemi_mac",
	.id_table	= pasemi_mac_pci_tbl,
	.probe		= pasemi_mac_probe,
	.remove		= __devexit_p(pasemi_mac_remove),
};

static void __exit pasemi_mac_cleanup_module(void)
{
	pci_unregister_driver(&pasemi_mac_driver);
	__iounmap(dma_status);
	dma_status = NULL;
}

int pasemi_mac_init_module(void)
{
	return pci_register_driver(&pasemi_mac_driver);
}

MODULE_LICENSE("GPL");
MODULE_AUTHOR ("Olof Johansson <olof@lixom.net>");
MODULE_DESCRIPTION("PA Semi PWRficient Ethernet driver");

module_init(pasemi_mac_init_module);
module_exit(pasemi_mac_cleanup_module);