pasemi_mac.c

linux 内核源代码

/*
 * 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 <asm/irq.h>
#include <asm/firmware.h>

#include "pasemi_mac.h"

/* We have our own align, since ppc64 in general has it at 0 because
 * of design flaws in some of the server bridge chips. However, for
 * PWRficient doing the unaligned copies is more expensive than doing
 * unaligned DMA, so make sure the data is aligned instead.
 */
#define LOCAL_SKB_ALIGN	2

/* TODO list
 *
 * - Multicast support
 * - Large MTU support
 * - SW LRO
 * - Multiqueue RX/TX
 */


/* Must be a power of two */
#define RX_RING_SIZE 4096
#define TX_RING_SIZE 4096

#define DEFAULT_MSG_ENABLE	  \
	(NETIF_MSG_DRV		| \
	 NETIF_MSG_PROBE	| \
	 NETIF_MSG_LINK		| \
	 NETIF_MSG_TIMER	| \
	 NETIF_MSG_IFDOWN	| \
	 NETIF_MSG_IFUP		| \
	 NETIF_MSG_RX_ERR	| \
	 NETIF_MSG_TX_ERR)

#define TX_RING(mac, num)	((mac)->tx->ring[(num) & (TX_RING_SIZE-1)])
#define TX_RING_INFO(mac, num)	((mac)->tx->ring_info[(num) & (TX_RING_SIZE-1)])
#define RX_RING(mac, num)	((mac)->rx->ring[(num) & (RX_RING_SIZE-1)])
#define RX_RING_INFO(mac, num)	((mac)->rx->ring_info[(num) & (RX_RING_SIZE-1)])
#define RX_BUFF(mac, num)	((mac)->rx->buffers[(num) & (RX_RING_SIZE-1)])

#define RING_USED(ring)		(((ring)->next_to_fill - (ring)->next_to_clean) \
				 & ((ring)->size - 1))
#define RING_AVAIL(ring)	((ring->size) - RING_USED(ring))

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

MODULE_LICENSE("GPL");
MODULE_AUTHOR ("Olof Johansson <[e-mail]>");
MODULE_DESCRIPTION("PA Semi PWRficient Ethernet driver");

static int debug = -1;	/* -1 == use DEFAULT_MSG_ENABLE as value */
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "PA Semi MAC bitmapped debugging message enable value");

static struct pasdma_status *dma_status;

static int translation_enabled(void)
{
#if defined(CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE)
	return 1;
#else
	return firmware_has_feature(FW_FEATURE_LPAR);
#endif
}

static void write_iob_reg(struct pasemi_mac *mac, unsigned int reg,
			  unsigned int val)
{
	out_le32(mac->iob_regs+reg, val);
}

static unsigned int read_mac_reg(struct pasemi_mac *mac, unsigned int reg)
{
	return in_le32(mac->regs+reg);
}

static void write_mac_reg(struct pasemi_mac *mac, unsigned int reg,
			  unsigned int val)
{
	out_le32(mac->regs+reg, val);
}

static unsigned int read_dma_reg(struct pasemi_mac *mac, unsigned int reg)
{
	return in_le32(mac->dma_regs+reg);
}

static void write_dma_reg(struct pasemi_mac *mac, unsigned int reg,
			  unsigned int val)
{
	out_le32(mac->dma_regs+reg, val);
}

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);
	int len;
	const u8 *maddr;
	u8 addr[6];

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

	maddr = of_get_property(dn, "local-mac-address", &len);

	if (maddr && len == 6) {
		memcpy(mac->mac_addr, maddr, 6);
		return 0;
	}

	/* Some old versions of firmware mistakenly uses mac-address
	 * (and as a string) instead of a byte array in local-mac-address.
	 */

	if (maddr == NULL)
		maddr = of_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, 6);

	return 0;
}

static int pasemi_mac_unmap_tx_skb(struct pasemi_mac *mac,
				    struct sk_buff *skb,
				    dma_addr_t *dmas)
{
	int f;
	int nfrags = skb_shinfo(skb)->nr_frags;

	pci_unmap_single(mac->dma_pdev, dmas[0], skb_headlen(skb),
			 PCI_DMA_TODEVICE);

	for (f = 0; f < nfrags; f++) {
		skb_frag_t *frag = &skb_shinfo(skb)->frags[f];

		pci_unmap_page(mac->dma_pdev, dmas[f+1], frag->size,
			       PCI_DMA_TODEVICE);
	}
	dev_kfree_skb_irq(skb);

	/* Freed descriptor slot + main SKB ptr + nfrags additional ptrs,
	 * aligned up to a power of 2
	 */
	return (nfrags + 3) & ~1;
}

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;
	unsigned int cfg;

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

	if (!ring)
		goto out_ring;

	spin_lock_init(&ring->lock);

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

	if (!ring->ring_info)
		goto out_ring_info;

	/* Allocate descriptors */
	ring->ring = dma_alloc_coherent(&mac->dma_pdev->dev,
					RX_RING_SIZE * sizeof(u64),
					&ring->dma, GFP_KERNEL);

	if (!ring->ring)
		goto out_ring_desc;

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

	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));

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

	write_dma_reg(mac, PAS_DMA_RXCHAN_BASEU(chan_id),
			   PAS_DMA_RXCHAN_BASEU_BRBH(ring->dma >> 32) |
			   PAS_DMA_RXCHAN_BASEU_SIZ(RX_RING_SIZE >> 3));

	cfg = PAS_DMA_RXCHAN_CFG_HBU(2);

	if (translation_enabled())
		cfg |= PAS_DMA_RXCHAN_CFG_CTR;

	write_dma_reg(mac, PAS_DMA_RXCHAN_CFG(chan_id), cfg);

	write_dma_reg(mac, PAS_DMA_RXINT_BASEL(mac->dma_if),
			   PAS_DMA_RXINT_BASEL_BRBL(ring->buf_dma));

	write_dma_reg(mac, PAS_DMA_RXINT_BASEU(mac->dma_if),
			   PAS_DMA_RXINT_BASEU_BRBH(ring->buf_dma >> 32) |
			   PAS_DMA_RXINT_BASEU_SIZ(RX_RING_SIZE >> 3));

	cfg = PAS_DMA_RXINT_CFG_DHL(3) | PAS_DMA_RXINT_CFG_L2 |
	      PAS_DMA_RXINT_CFG_LW | PAS_DMA_RXINT_CFG_RBP |
	      PAS_DMA_RXINT_CFG_HEN;

	if (translation_enabled())
		cfg |= PAS_DMA_RXINT_CFG_ITRR | PAS_DMA_RXINT_CFG_ITR;

	write_dma_reg(mac, PAS_DMA_RXINT_CFG(mac->dma_if), cfg);

	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(u64),
			  mac->rx->ring, mac->rx->dma);
out_ring_desc:
	kfree(ring->ring_info);
out_ring_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;
	unsigned int cfg;

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

	spin_lock_init(&ring->lock);

	ring->size = TX_RING_SIZE;
	ring->ring_info = kzalloc(sizeof(struct pasemi_mac_buffer) *
				  TX_RING_SIZE, GFP_KERNEL);
	if (!ring->ring_info)
		goto out_ring_info;

	/* Allocate descriptors */
	ring->ring = dma_alloc_coherent(&mac->dma_pdev->dev,
					TX_RING_SIZE * sizeof(u64),
					&ring->dma, GFP_KERNEL);
	if (!ring->ring)
		goto out_ring_desc;

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

	write_dma_reg(mac, 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 >> 3);

	write_dma_reg(mac, PAS_DMA_TXCHAN_BASEU(chan_id), val);

	cfg = 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);

	if (translation_enabled())
		cfg |= PAS_DMA_TXCHAN_CFG_TRD | PAS_DMA_TXCHAN_CFG_TRR;

	write_dma_reg(mac, PAS_DMA_TXCHAN_CFG(chan_id), cfg);

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

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

	return 0;

out_ring_desc:
	kfree(ring->ring_info);
out_ring_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, j;
	struct pasemi_mac_buffer *info;
	dma_addr_t dmas[MAX_SKB_FRAGS+1];
	int freed;
	int start, limit;

	start = mac->tx->next_to_clean;
	limit = mac->tx->next_to_fill;

	/* Compensate for when fill has wrapped and clean has not */
	if (start > limit)
		limit += TX_RING_SIZE;

	for (i = start; i < limit; i += freed) {
		info = &TX_RING_INFO(mac, i+1);
		if (info->dma && info->skb) {
			for (j = 0; j <= skb_shinfo(info->skb)->nr_frags; j++)
				dmas[j] = TX_RING_INFO(mac, i+1+j).dma;
			freed = pasemi_mac_unmap_tx_skb(mac, info->skb, dmas);
		} else
			freed = 2;
	}

	for (i = 0; i < TX_RING_SIZE; i++)
		TX_RING(mac, i) = 0;

	dma_free_coherent(&mac->dma_pdev->dev,
			  TX_RING_SIZE * sizeof(u64),
			  mac->tx->ring, mac->tx->dma);

	kfree(mac->tx->ring_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;

	for (i = 0; i < RX_RING_SIZE; i++) {
		info = &RX_RING_INFO(mac, i);
		if (info->skb && info->dma) {
			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;
	}

	for (i = 0; i < RX_RING_SIZE; i++)
		RX_RING(mac, i) = 0;

	dma_free_coherent(&mac->dma_pdev->dev,
			  RX_RING_SIZE * sizeof(u64),
			  mac->rx->ring, 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->ring_info);
	kfree(mac->rx);
	mac->rx = NULL;
}

static void pasemi_mac_replenish_rx_ring(struct net_device *dev, int limit)
{
	struct pasemi_mac *mac = netdev_priv(dev);
	int fill, count;

	if (limit <= 0)
		return;

	fill = mac->rx->next_to_fill;
	for (count = 0; count < limit; count++) {
		struct pasemi_mac_buffer *info = &RX_RING_INFO(mac, fill);
		u64 *buff = &RX_BUFF(mac, fill);
		struct sk_buff *skb;
		dma_addr_t dma;

		/* Entry in use? */
		WARN_ON(*buff);

		/* skb might still be in there for recycle on short receives */
		if (info->skb)
			skb = info->skb;
		else {
			skb = dev_alloc_skb(BUF_SIZE);
			skb_reserve(skb, LOCAL_SKB_ALIGN);
		}

		if (unlikely(!skb))
			break;

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

		if (unlikely(dma_mapping_error(dma))) {
			dev_kfree_skb_irq(info->skb);
			break;
		}

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

	wmb();

	write_dma_reg(mac, PAS_DMA_RXINT_INCR(mac->dma_if), count);

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

static void pasemi_mac_restart_rx_intr(struct pasemi_mac *mac)
{
	unsigned int reg, pcnt;
	/* Re-enable packet count interrupts: finally
	 * ack the packet count interrupt we got in rx_intr.
	 */

	pcnt = *mac->rx_status & PAS_STATUS_PCNT_M;

	reg = PAS_IOB_DMA_RXCH_RESET_PCNT(pcnt) | PAS_IOB_DMA_RXCH_RESET_PINTC;

	write_iob_reg(mac, PAS_IOB_DMA_RXCH_RESET(mac->dma_rxch), reg);
}

static void pasemi_mac_restart_tx_intr(struct pasemi_mac *mac)
{
	unsigned int reg, pcnt;

	/* Re-enable packet count interrupts */
	pcnt = *mac->tx_status & PAS_STATUS_PCNT_M;

	reg = PAS_IOB_DMA_TXCH_RESET_PCNT(pcnt) | PAS_IOB_DMA_TXCH_RESET_PINTC;

	write_iob_reg(mac, PAS_IOB_DMA_TXCH_RESET(mac->dma_txch), reg);