c2.c

linux内核源码

/*
 * Copyright (c) 2005 Ammasso, Inc. All rights reserved.
 * Copyright (c) 2005 Open Grid Computing, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/inetdevice.h>
#include <linux/delay.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/if_vlan.h>
#include <linux/crc32.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/byteorder.h>

#include <rdma/ib_smi.h>
#include "c2.h"
#include "c2_provider.h"

MODULE_AUTHOR("Tom Tucker <[e-mail]>");
MODULE_DESCRIPTION("Ammasso AMSO1100 Low-level iWARP Driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_VERSION(DRV_VERSION);

static const u32 default_msg = NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK
    | NETIF_MSG_IFUP | NETIF_MSG_IFDOWN;

static int debug = -1;		/* defaults above */
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");

static int c2_up(struct net_device *netdev);
static int c2_down(struct net_device *netdev);
static int c2_xmit_frame(struct sk_buff *skb, struct net_device *netdev);
static void c2_tx_interrupt(struct net_device *netdev);
static void c2_rx_interrupt(struct net_device *netdev);
static irqreturn_t c2_interrupt(int irq, void *dev_id);
static void c2_tx_timeout(struct net_device *netdev);
static int c2_change_mtu(struct net_device *netdev, int new_mtu);
static void c2_reset(struct c2_port *c2_port);
static struct net_device_stats *c2_get_stats(struct net_device *netdev);

static struct pci_device_id c2_pci_table[] = {
	{ PCI_DEVICE(0x18b8, 0xb001) },
	{ 0 }
};

MODULE_DEVICE_TABLE(pci, c2_pci_table);

static void c2_print_macaddr(struct net_device *netdev)
{
	pr_debug("%s: MAC %02X:%02X:%02X:%02X:%02X:%02X, "
		"IRQ %u\n", netdev->name,
		netdev->dev_addr[0], netdev->dev_addr[1], netdev->dev_addr[2],
		netdev->dev_addr[3], netdev->dev_addr[4], netdev->dev_addr[5],
		netdev->irq);
}

static void c2_set_rxbufsize(struct c2_port *c2_port)
{
	struct net_device *netdev = c2_port->netdev;

	if (netdev->mtu > RX_BUF_SIZE)
		c2_port->rx_buf_size =
		    netdev->mtu + ETH_HLEN + sizeof(struct c2_rxp_hdr) +
		    NET_IP_ALIGN;
	else
		c2_port->rx_buf_size = sizeof(struct c2_rxp_hdr) + RX_BUF_SIZE;
}

/*
 * Allocate TX ring elements and chain them together.
 * One-to-one association of adapter descriptors with ring elements.
 */
static int c2_tx_ring_alloc(struct c2_ring *tx_ring, void *vaddr,
			    dma_addr_t base, void __iomem * mmio_txp_ring)
{
	struct c2_tx_desc *tx_desc;
	struct c2_txp_desc __iomem *txp_desc;
	struct c2_element *elem;
	int i;

	tx_ring->start = kmalloc(sizeof(*elem) * tx_ring->count, GFP_KERNEL);
	if (!tx_ring->start)
		return -ENOMEM;

	elem = tx_ring->start;
	tx_desc = vaddr;
	txp_desc = mmio_txp_ring;
	for (i = 0; i < tx_ring->count; i++, elem++, tx_desc++, txp_desc++) {
		tx_desc->len = 0;
		tx_desc->status = 0;

		/* Set TXP_HTXD_UNINIT */
		__raw_writeq(cpu_to_be64(0x1122334455667788ULL),
			     (void __iomem *) txp_desc + C2_TXP_ADDR);
		__raw_writew(0, (void __iomem *) txp_desc + C2_TXP_LEN);
		__raw_writew(cpu_to_be16(TXP_HTXD_UNINIT),
			     (void __iomem *) txp_desc + C2_TXP_FLAGS);

		elem->skb = NULL;
		elem->ht_desc = tx_desc;
		elem->hw_desc = txp_desc;

		if (i == tx_ring->count - 1) {
			elem->next = tx_ring->start;
			tx_desc->next_offset = base;
		} else {
			elem->next = elem + 1;
			tx_desc->next_offset =
			    base + (i + 1) * sizeof(*tx_desc);
		}
	}

	tx_ring->to_use = tx_ring->to_clean = tx_ring->start;

	return 0;
}

/*
 * Allocate RX ring elements and chain them together.
 * One-to-one association of adapter descriptors with ring elements.
 */
static int c2_rx_ring_alloc(struct c2_ring *rx_ring, void *vaddr,
			    dma_addr_t base, void __iomem * mmio_rxp_ring)
{
	struct c2_rx_desc *rx_desc;
	struct c2_rxp_desc __iomem *rxp_desc;
	struct c2_element *elem;
	int i;

	rx_ring->start = kmalloc(sizeof(*elem) * rx_ring->count, GFP_KERNEL);
	if (!rx_ring->start)
		return -ENOMEM;

	elem = rx_ring->start;
	rx_desc = vaddr;
	rxp_desc = mmio_rxp_ring;
	for (i = 0; i < rx_ring->count; i++, elem++, rx_desc++, rxp_desc++) {
		rx_desc->len = 0;
		rx_desc->status = 0;

		/* Set RXP_HRXD_UNINIT */
		__raw_writew(cpu_to_be16(RXP_HRXD_OK),
		       (void __iomem *) rxp_desc + C2_RXP_STATUS);
		__raw_writew(0, (void __iomem *) rxp_desc + C2_RXP_COUNT);
		__raw_writew(0, (void __iomem *) rxp_desc + C2_RXP_LEN);
		__raw_writeq(cpu_to_be64(0x99aabbccddeeffULL),
			     (void __iomem *) rxp_desc + C2_RXP_ADDR);
		__raw_writew(cpu_to_be16(RXP_HRXD_UNINIT),
			     (void __iomem *) rxp_desc + C2_RXP_FLAGS);

		elem->skb = NULL;
		elem->ht_desc = rx_desc;
		elem->hw_desc = rxp_desc;

		if (i == rx_ring->count - 1) {
			elem->next = rx_ring->start;
			rx_desc->next_offset = base;
		} else {
			elem->next = elem + 1;
			rx_desc->next_offset =
			    base + (i + 1) * sizeof(*rx_desc);
		}
	}

	rx_ring->to_use = rx_ring->to_clean = rx_ring->start;

	return 0;
}

/* Setup buffer for receiving */
static inline int c2_rx_alloc(struct c2_port *c2_port, struct c2_element *elem)
{
	struct c2_dev *c2dev = c2_port->c2dev;
	struct c2_rx_desc *rx_desc = elem->ht_desc;
	struct sk_buff *skb;
	dma_addr_t mapaddr;
	u32 maplen;
	struct c2_rxp_hdr *rxp_hdr;

	skb = dev_alloc_skb(c2_port->rx_buf_size);
	if (unlikely(!skb)) {
		pr_debug("%s: out of memory for receive\n",
			c2_port->netdev->name);
		return -ENOMEM;
	}

	/* Zero out the rxp hdr in the sk_buff */
	memset(skb->data, 0, sizeof(*rxp_hdr));

	skb->dev = c2_port->netdev;

	maplen = c2_port->rx_buf_size;
	mapaddr =
	    pci_map_single(c2dev->pcidev, skb->data, maplen,
			   PCI_DMA_FROMDEVICE);

	/* Set the sk_buff RXP_header to RXP_HRXD_READY */
	rxp_hdr = (struct c2_rxp_hdr *) skb->data;
	rxp_hdr->flags = RXP_HRXD_READY;

	__raw_writew(0, elem->hw_desc + C2_RXP_STATUS);
	__raw_writew(cpu_to_be16((u16) maplen - sizeof(*rxp_hdr)),
		     elem->hw_desc + C2_RXP_LEN);
	__raw_writeq(cpu_to_be64(mapaddr), elem->hw_desc + C2_RXP_ADDR);
	__raw_writew(cpu_to_be16(RXP_HRXD_READY), elem->hw_desc + C2_RXP_FLAGS);

	elem->skb = skb;
	elem->mapaddr = mapaddr;
	elem->maplen = maplen;
	rx_desc->len = maplen;

	return 0;
}

/*
 * Allocate buffers for the Rx ring
 * For receive:  rx_ring.to_clean is next received frame
 */
static int c2_rx_fill(struct c2_port *c2_port)
{
	struct c2_ring *rx_ring = &c2_port->rx_ring;
	struct c2_element *elem;
	int ret = 0;

	elem = rx_ring->start;
	do {
		if (c2_rx_alloc(c2_port, elem)) {
			ret = 1;
			break;
		}
	} while ((elem = elem->next) != rx_ring->start);

	rx_ring->to_clean = rx_ring->start;
	return ret;
}

/* Free all buffers in RX ring, assumes receiver stopped */
static void c2_rx_clean(struct c2_port *c2_port)
{
	struct c2_dev *c2dev = c2_port->c2dev;
	struct c2_ring *rx_ring = &c2_port->rx_ring;
	struct c2_element *elem;
	struct c2_rx_desc *rx_desc;

	elem = rx_ring->start;
	do {
		rx_desc = elem->ht_desc;
		rx_desc->len = 0;

		__raw_writew(0, elem->hw_desc + C2_RXP_STATUS);
		__raw_writew(0, elem->hw_desc + C2_RXP_COUNT);
		__raw_writew(0, elem->hw_desc + C2_RXP_LEN);
		__raw_writeq(cpu_to_be64(0x99aabbccddeeffULL),
			     elem->hw_desc + C2_RXP_ADDR);
		__raw_writew(cpu_to_be16(RXP_HRXD_UNINIT),
			     elem->hw_desc + C2_RXP_FLAGS);

		if (elem->skb) {
			pci_unmap_single(c2dev->pcidev, elem->mapaddr,
					 elem->maplen, PCI_DMA_FROMDEVICE);
			dev_kfree_skb(elem->skb);
			elem->skb = NULL;
		}
	} while ((elem = elem->next) != rx_ring->start);
}

static inline int c2_tx_free(struct c2_dev *c2dev, struct c2_element *elem)
{
	struct c2_tx_desc *tx_desc = elem->ht_desc;

	tx_desc->len = 0;

	pci_unmap_single(c2dev->pcidev, elem->mapaddr, elem->maplen,
			 PCI_DMA_TODEVICE);

	if (elem->skb) {
		dev_kfree_skb_any(elem->skb);
		elem->skb = NULL;
	}

	return 0;
}

/* Free all buffers in TX ring, assumes transmitter stopped */
static void c2_tx_clean(struct c2_port *c2_port)
{
	struct c2_ring *tx_ring = &c2_port->tx_ring;
	struct c2_element *elem;
	struct c2_txp_desc txp_htxd;
	int retry;
	unsigned long flags;

	spin_lock_irqsave(&c2_port->tx_lock, flags);

	elem = tx_ring->start;

	do {
		retry = 0;
		do {
			txp_htxd.flags =
			    readw(elem->hw_desc + C2_TXP_FLAGS);

			if (txp_htxd.flags == TXP_HTXD_READY) {
				retry = 1;
				__raw_writew(0,
					     elem->hw_desc + C2_TXP_LEN);
				__raw_writeq(0,
					     elem->hw_desc + C2_TXP_ADDR);
				__raw_writew(cpu_to_be16(TXP_HTXD_DONE),
					     elem->hw_desc + C2_TXP_FLAGS);
				c2_port->netstats.tx_dropped++;
				break;
			} else {
				__raw_writew(0,
					     elem->hw_desc + C2_TXP_LEN);
				__raw_writeq(cpu_to_be64(0x1122334455667788ULL),
					     elem->hw_desc + C2_TXP_ADDR);
				__raw_writew(cpu_to_be16(TXP_HTXD_UNINIT),
					     elem->hw_desc + C2_TXP_FLAGS);
			}

			c2_tx_free(c2_port->c2dev, elem);

		} while ((elem = elem->next) != tx_ring->start);
	} while (retry);

	c2_port->tx_avail = c2_port->tx_ring.count - 1;
	c2_port->c2dev->cur_tx = tx_ring->to_use - tx_ring->start;

	if (c2_port->tx_avail > MAX_SKB_FRAGS + 1)
		netif_wake_queue(c2_port->netdev);

	spin_unlock_irqrestore(&c2_port->tx_lock, flags);
}

/*
 * Process transmit descriptors marked 'DONE' by the firmware,
 * freeing up their unneeded sk_buffs.
 */
static void c2_tx_interrupt(struct net_device *netdev)
{
	struct c2_port *c2_port = netdev_priv(netdev);
	struct c2_dev *c2dev = c2_port->c2dev;
	struct c2_ring *tx_ring = &c2_port->tx_ring;
	struct c2_element *elem;
	struct c2_txp_desc txp_htxd;

	spin_lock(&c2_port->tx_lock);

	for (elem = tx_ring->to_clean; elem != tx_ring->to_use;
	     elem = elem->next) {
		txp_htxd.flags =
		    be16_to_cpu(readw(elem->hw_desc + C2_TXP_FLAGS));

		if (txp_htxd.flags != TXP_HTXD_DONE)
			break;

		if (netif_msg_tx_done(c2_port)) {
			/* PCI reads are expensive in fast path */
			txp_htxd.len =
			    be16_to_cpu(readw(elem->hw_desc + C2_TXP_LEN));
			pr_debug("%s: tx done slot %3Zu status 0x%x len "
				"%5u bytes\n",
				netdev->name, elem - tx_ring->start,
				txp_htxd.flags, txp_htxd.len);
		}

		c2_tx_free(c2dev, elem);
		++(c2_port->tx_avail);
	}

	tx_ring->to_clean = elem;

	if (netif_queue_stopped(netdev)
	    && c2_port->tx_avail > MAX_SKB_FRAGS + 1)
		netif_wake_queue(netdev);

	spin_unlock(&c2_port->tx_lock);
}