[PATCH] net: add driver for the NIC on Cell Blades

This patch adds a driver for a new 1000 Mbit ethernet NIC.  It is
integrated on the south bridge that is used for our Cell Blades.

The code gets the MAC address from the Open Firmware device tree, so it
won't compile on platforms other than ppc64.

This is the first public release, so I don't expect the first version to
get merged, but I'd aim for integration within the 2.6.13 time frame.

Cc: Utz Bacher <utz.bacher@de.ibm.com>
Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

5 files changed, 2883 insertions, 0 deletions

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index ae9e7a579b94..6bb9232514b4 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -2058,6 +2058,13 @@ config BNX2
 	  To compile this driver as a module, choose M here: the module
 	  will be called bnx2.  This is recommended.
 
+config SPIDER_NET
+	tristate "Spider Gigabit Ethernet driver"
+	depends on PCI && PPC_BPA
+	help
+	  This driver supports the Gigabit Ethernet chips present on the
+	  Cell Processor-Based Blades from IBM.
+
 config GIANFAR
 	tristate "Gianfar Ethernet"
 	depends on 85xx || 83xx
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 5baafcd55610..8645c843cf4d 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -54,6 +54,8 @@ obj-$(CONFIG_STNIC) += stnic.o 8390.o
 obj-$(CONFIG_FEALNX) += fealnx.o
 obj-$(CONFIG_TIGON3) += tg3.o
 obj-$(CONFIG_BNX2) += bnx2.o
+spidernet-y += spider_net.o spider_net_ethtool.o sungem_phy.o
+obj-$(CONFIG_SPIDER_NET) += spidernet.o
 obj-$(CONFIG_TC35815) += tc35815.o
 obj-$(CONFIG_SKGE) += skge.o
 obj-$(CONFIG_SK98LIN) += sk98lin/
diff --git a/drivers/net/spider_net.c b/drivers/net/spider_net.c
new file mode 100644
index 000000000000..692a0437fef7
--- /dev/null
+++ b/drivers/net/spider_net.c
@@ -0,0 +1,2298 @@
+/*
+ * Network device driver for Cell Processor-Based Blade
+ *
+ * (C) Copyright IBM Corp. 2005
+ *
+ * Authors : Utz Bacher <utz.bacher@de.ibm.com>
+ *           Jens Osterkamp <Jens.Osterkamp@de.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/config.h>
+
+#include <linux/compiler.h>
+#include <linux/crc32.h>
+#include <linux/delay.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/firmware.h>
+#include <linux/if_vlan.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/ip.h>
+#include <linux/kernel.h>
+#include <linux/mii.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/device.h>
+#include <linux/pci.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/tcp.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+#include <asm/bitops.h>
+#include <asm/pci-bridge.h>
+#include <net/checksum.h>
+
+#include "spider_net.h"
+
+MODULE_AUTHOR("Utz Bacher <utz.bacher@de.ibm.com> and Jens Osterkamp " \
+	      "<Jens.Osterkamp@de.ibm.com>");
+MODULE_DESCRIPTION("Spider Southbridge Gigabit Ethernet driver");
+MODULE_LICENSE("GPL");
+
+static int rx_descriptors = SPIDER_NET_RX_DESCRIPTORS_DEFAULT;
+static int tx_descriptors = SPIDER_NET_TX_DESCRIPTORS_DEFAULT;
+
+module_param(rx_descriptors, int, 0644);
+module_param(tx_descriptors, int, 0644);
+
+MODULE_PARM_DESC(rx_descriptors, "number of descriptors used " \
+		 "in rx chains");
+MODULE_PARM_DESC(tx_descriptors, "number of descriptors used " \
+		 "in tx chain");
+
+char spider_net_driver_name[] = "spidernet";
+
+static struct pci_device_id spider_net_pci_tbl[] = {
+	{ PCI_VENDOR_ID_TOSHIBA_2, PCI_DEVICE_ID_TOSHIBA_SPIDER_NET,
+	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
+	{ 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, spider_net_pci_tbl);
+
+/**
+ * spider_net_read_reg - reads an SMMIO register of a card
+ * @card: device structure
+ * @reg: register to read from
+ *
+ * returns the content of the specified SMMIO register.
+ */
+static u32
+spider_net_read_reg(struct spider_net_card *card, u32 reg)
+{
+	u32 value;
+
+	value = readl(card->regs + reg);
+	value = le32_to_cpu(value);
+
+	return value;
+}
+
+/**
+ * spider_net_write_reg - writes to an SMMIO register of a card
+ * @card: device structure
+ * @reg: register to write to
+ * @value: value to write into the specified SMMIO register
+ */
+static void
+spider_net_write_reg(struct spider_net_card *card, u32 reg, u32 value)
+{
+	value = cpu_to_le32(value);
+	writel(value, card->regs + reg);
+}
+
+/**
+ * spider_net_rx_irq_off - switch off rx irq on this spider card
+ * @card: device structure
+ *
+ * switches off rx irq by masking them out in the GHIINTnMSK register
+ */
+static void
+spider_net_rx_irq_off(struct spider_net_card *card)
+{
+	u32 regvalue;
+	unsigned long flags;
+
+	spin_lock_irqsave(&card->intmask_lock, flags);
+	regvalue = spider_net_read_reg(card, SPIDER_NET_GHIINT0MSK);
+	regvalue &= ~SPIDER_NET_RXINT;
+	spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, regvalue);
+	spin_unlock_irqrestore(&card->intmask_lock, flags);
+}
+
+/** spider_net_write_phy - write to phy register
+ * @netdev: adapter to be written to
+ * @mii_id: id of MII
+ * @reg: PHY register
+ * @val: value to be written to phy register
+ *
+ * spider_net_write_phy_register writes to an arbitrary PHY
+ * register via the spider GPCWOPCMD register. We assume the queue does
+ * not run full (not more than 15 commands outstanding).
+ **/
+static void
+spider_net_write_phy(struct net_device *netdev, int mii_id,
+		     int reg, int val)
+{
+	struct spider_net_card *card = netdev_priv(netdev);
+	u32 writevalue;
+
+	writevalue = ((u32)mii_id << 21) |
+		((u32)reg << 16) | ((u32)val);
+
+	spider_net_write_reg(card, SPIDER_NET_GPCWOPCMD, writevalue);
+}
+
+/** spider_net_read_phy - read from phy register
+ * @netdev: network device to be read from
+ * @mii_id: id of MII
+ * @reg: PHY register
+ *
+ * Returns value read from PHY register
+ *
+ * spider_net_write_phy reads from an arbitrary PHY
+ * register via the spider GPCROPCMD register
+ **/
+static int
+spider_net_read_phy(struct net_device *netdev, int mii_id, int reg)
+{
+	struct spider_net_card *card = netdev_priv(netdev);
+	u32 readvalue;
+
+	readvalue = ((u32)mii_id << 21) | ((u32)reg << 16);
+	spider_net_write_reg(card, SPIDER_NET_GPCROPCMD, readvalue);
+
+	/* we don't use semaphores to wait for an SPIDER_NET_GPROPCMPINT
+	 * interrupt, as we poll for the completion of the read operation
+	 * in spider_net_read_phy. Should take about 50 us */
+	do {
+		readvalue = spider_net_read_reg(card, SPIDER_NET_GPCROPCMD);
+	} while (readvalue & SPIDER_NET_GPREXEC);
+
+	readvalue &= SPIDER_NET_GPRDAT_MASK;
+
+	return readvalue;
+}
+
+/**
+ * spider_net_rx_irq_on - switch on rx irq on this spider card
+ * @card: device structure
+ *
+ * switches on rx irq by enabling them in the GHIINTnMSK register
+ */
+static void
+spider_net_rx_irq_on(struct spider_net_card *card)
+{
+	u32 regvalue;
+	unsigned long flags;
+
+	spin_lock_irqsave(&card->intmask_lock, flags);
+	regvalue = spider_net_read_reg(card, SPIDER_NET_GHIINT0MSK);
+	regvalue |= SPIDER_NET_RXINT;
+	spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, regvalue);
+	spin_unlock_irqrestore(&card->intmask_lock, flags);
+}
+
+/**
+ * spider_net_tx_irq_off - switch off tx irq on this spider card
+ * @card: device structure
+ *
+ * switches off tx irq by masking them out in the GHIINTnMSK register
+ */
+static void
+spider_net_tx_irq_off(struct spider_net_card *card)
+{
+	u32 regvalue;
+	unsigned long flags;
+
+	spin_lock_irqsave(&card->intmask_lock, flags);
+	regvalue = spider_net_read_reg(card, SPIDER_NET_GHIINT0MSK);
+	regvalue &= ~SPIDER_NET_TXINT;
+	spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, regvalue);
+	spin_unlock_irqrestore(&card->intmask_lock, flags);
+}
+
+/**
+ * spider_net_tx_irq_on - switch on tx irq on this spider card
+ * @card: device structure
+ *
+ * switches on tx irq by enabling them in the GHIINTnMSK register
+ */
+static void
+spider_net_tx_irq_on(struct spider_net_card *card)
+{
+	u32 regvalue;
+	unsigned long flags;
+
+	spin_lock_irqsave(&card->intmask_lock, flags);
+	regvalue = spider_net_read_reg(card, SPIDER_NET_GHIINT0MSK);
+	regvalue |= SPIDER_NET_TXINT;
+	spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, regvalue);
+	spin_unlock_irqrestore(&card->intmask_lock, flags);
+}
+
+/**
+ * spider_net_set_promisc - sets the unicast address or the promiscuous mode
+ * @card: card structure
+ *
+ * spider_net_set_promisc sets the unicast destination address filter and
+ * thus either allows for non-promisc mode or promisc mode
+ */
+static void
+spider_net_set_promisc(struct spider_net_card *card)
+{
+	u32 macu, macl;
+	struct net_device *netdev = card->netdev;
+
+	if (netdev->flags & IFF_PROMISC) {
+		/* clear destination entry 0 */
+		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR, 0);
+		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR + 0x04, 0);
+		spider_net_write_reg(card, SPIDER_NET_GMRUA0FIL15R,
+				     SPIDER_NET_PROMISC_VALUE);
+	} else {
+		macu = netdev->dev_addr[0];
+		macu <<= 8;
+		macu |= netdev->dev_addr[1];
+		memcpy(&macl, &netdev->dev_addr[2], sizeof(macl));
+
+		macu |= SPIDER_NET_UA_DESCR_VALUE;
+		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR, macu);
+		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR + 0x04, macl);
+		spider_net_write_reg(card, SPIDER_NET_GMRUA0FIL15R,
+				     SPIDER_NET_NONPROMISC_VALUE);
+	}
+}
+
+/**
+ * spider_net_get_mac_address - read mac address from spider card
+ * @card: device structure
+ *
+ * reads MAC address from GMACUNIMACU and GMACUNIMACL registers
+ */
+static int
+spider_net_get_mac_address(struct net_device *netdev)
+{
+	struct spider_net_card *card = netdev_priv(netdev);
+	u32 macl, macu;
+
+	macl = spider_net_read_reg(card, SPIDER_NET_GMACUNIMACL);
+	macu = spider_net_read_reg(card, SPIDER_NET_GMACUNIMACU);
+
+	netdev->dev_addr[0] = (macu >> 24) & 0xff;
+	netdev->dev_addr[1] = (macu >> 16) & 0xff;
+	netdev->dev_addr[2] = (macu >> 8) & 0xff;
+	netdev->dev_addr[3] = macu & 0xff;
+	netdev->dev_addr[4] = (macl >> 8) & 0xff;
+	netdev->dev_addr[5] = macl & 0xff;
+
+	if (!is_valid_ether_addr(&netdev->dev_addr[0]))
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
+ * spider_net_get_descr_status -- returns the status of a descriptor
+ * @descr: descriptor to look at
+ *
+ * returns the status as in the dmac_cmd_status field of the descriptor
+ */
+static enum spider_net_descr_status
+spider_net_get_descr_status(struct spider_net_descr *descr)
+{
+	u32 cmd_status;
+	rmb();
+	cmd_status = descr->dmac_cmd_status;
+	rmb();
+	cmd_status >>= SPIDER_NET_DESCR_IND_PROC_SHIFT;
+	/* no need to mask out any bits, as cmd_status is 32 bits wide only
+	 * (and unsigned) */
+	return cmd_status;
+}
+
+/**
+ * spider_net_set_descr_status -- sets the status of a descriptor
+ * @descr: descriptor to change
+ * @status: status to set in the descriptor
+ *
+ * changes the status to the specified value. Doesn't change other bits
+ * in the status
+ */
+static void
+spider_net_set_descr_status(struct spider_net_descr *descr,
+			    enum spider_net_descr_status status)
+{
+	u32 cmd_status;
+	/* read the status */
+	mb();
+	cmd_status = descr->dmac_cmd_status;
+	/* clean the upper 4 bits */
+	cmd_status &= SPIDER_NET_DESCR_IND_PROC_MASKO;
+	/* add the status to it */
+	cmd_status |= ((u32)status)<<SPIDER_NET_DESCR_IND_PROC_SHIFT;
+	/* and write it back */
+	descr->dmac_cmd_status = cmd_status;
+	wmb();
+}
+
+/**
+ * spider_net_free_chain - free descriptor chain
+ * @card: card structure
+ * @chain: address of chain
+ *
+ */
+static void
+spider_net_free_chain(struct spider_net_card *card,
+		      struct spider_net_descr_chain *chain)
+{
+	struct spider_net_descr *descr;
+
+	for (descr = chain->tail; !descr->bus_addr; descr = descr->next) {
+		pci_unmap_single(card->pdev, descr->bus_addr,
+				 SPIDER_NET_DESCR_SIZE, PCI_DMA_BIDIRECTIONAL);
+		descr->bus_addr = 0;
+	}
+}
+
+/**
+ * spider_net_init_chain - links descriptor chain
+ * @card: card structure
+ * @chain: address of chain
+ * @start_descr: address of descriptor array
+ * @no: number of descriptors
+ *
+ * we manage a circular list that mirrors the hardware structure,
+ * except that the hardware uses bus addresses.
+ *
+ * returns 0 on success, <0 on failure
+ */
+static int
+spider_net_init_chain(struct spider_net_card *card,
+		       struct spider_net_descr_chain *chain,
+		       struct spider_net_descr *start_descr, int no)
+{
+	int i;
+	struct spider_net_descr *descr;
+
+	spin_lock_init(&card->chain_lock);
+
+	descr = start_descr;
+	memset(descr, 0, sizeof(*descr) * no);
+
+	/* set up the hardware pointers in each descriptor */
+	for (i=0; i<no; i++, descr++) {
+		spider_net_set_descr_status(descr, SPIDER_NET_DESCR_NOT_IN_USE);
+
+		descr->bus_addr =
+			pci_map_single(card->pdev, descr,
+				       SPIDER_NET_DESCR_SIZE,
+				       PCI_DMA_BIDIRECTIONAL);
+
+		if (descr->bus_addr == DMA_ERROR_CODE)
+			goto iommu_error;
+
+		descr->next = descr + 1;
+		descr->prev = descr - 1;
+
+	}
+	/* do actual circular list */
+	(descr-1)->next = start_descr;
+	start_descr->prev = descr-1;
+
+	descr = start_descr;
+	for (i=0; i < no; i++, descr++) {
+		descr->next_descr_addr = descr->next->bus_addr;
+	}
+
+	chain->head = start_descr;
+	chain->tail = start_descr;
+
+	return 0;
+
+iommu_error:
+	descr = start_descr;
+	for (i=0; i < no; i++, descr++)
+		if (descr->bus_addr)
+			pci_unmap_single(card->pdev, descr->bus_addr,
+					 SPIDER_NET_DESCR_SIZE, PCI_DMA_BIDIRECTIONAL);
+	return -ENOMEM;
+}
+
+/**
+ * spider_net_free_rx_chain_contents - frees descr contents in rx chain
+ * @card: card structure
+ *
+ * returns 0 on success, <0 on failure
+ */
+static void
+spider_net_free_rx_chain_contents(struct spider_net_card *card)
+{
+	struct spider_net_descr *descr;
+
+	descr = card->rx_chain.head;
+	while (descr->next != card->rx_chain.head) {
+		if (descr->skb) {
+			dev_kfree_skb(descr->skb);
+			pci_unmap_single(card->pdev, descr->buf_addr,
+					 SPIDER_NET_MAX_MTU,
+					 PCI_DMA_BIDIRECTIONAL);
+		}
+		descr = descr->next;
+	}
+}
+
+/**
+ * spider_net_prepare_rx_descr - reinitializes a rx descriptor
+ * @card: card structure
+ * @descr: descriptor to re-init
+ *
+ * return 0 on succes, <0 on failure
+ *
+ * allocates a new rx skb, iommu-maps it and attaches it to the descriptor.
+ * Activate the descriptor state-wise
+ */
+static int
+spider_net_prepare_rx_descr(struct spider_net_card *card,
+			    struct spider_net_descr *descr)
+{
+	int error = 0;
+	int offset;
+	int bufsize;
+
+	/* we need to round up the buffer size to a multiple of 128 */
+	bufsize = (SPIDER_NET_MAX_MTU + SPIDER_NET_RXBUF_ALIGN - 1) &
+		(~(SPIDER_NET_RXBUF_ALIGN - 1));
+
+	/* and we need to have it 128 byte aligned, therefore we allocate a
+	 * bit more */
+	/* allocate an skb */
+	descr->skb = dev_alloc_skb(bufsize + SPIDER_NET_RXBUF_ALIGN - 1);
+	if (!descr->skb) {
+		if (net_ratelimit())
+			if (netif_msg_rx_err(card))
+				pr_err("Not enough memory to allocate "
+					"rx buffer\n");
+		return -ENOMEM;
+	}
+	descr->buf_size = bufsize;
+	descr->result_size = 0;
+	descr->valid_size = 0;
+	descr->data_status = 0;
+	descr->data_error = 0;
+
+	offset = ((unsigned long)descr->skb->data) &
+		(SPIDER_NET_RXBUF_ALIGN - 1);
+	if (offset)
+		skb_reserve(descr->skb, SPIDER_NET_RXBUF_ALIGN - offset);
+	/* io-mmu-map the skb */
+	descr->buf_addr = pci_map_single(card->pdev, descr->skb->data,
+					 SPIDER_NET_MAX_MTU,
+					 PCI_DMA_BIDIRECTIONAL);
+	if (descr->buf_addr == DMA_ERROR_CODE) {
+		dev_kfree_skb_any(descr->skb);
+		if (netif_msg_rx_err(card))
+			pr_err("Could not iommu-map rx buffer\n");
+		spider_net_set_descr_status(descr, SPIDER_NET_DESCR_NOT_IN_USE);
+	} else {
+		descr->dmac_cmd_status = SPIDER_NET_DMAC_RX_CARDOWNED;
+	}
+
+	return error;
+}
+
+/**
+ * spider_net_enable_rxctails - sets RX dmac chain tail addresses
+ * @card: card structure
+ *
+ * spider_net_enable_rxctails sets the RX DMAC chain tail adresses in the
+ * chip by writing to the appropriate register. DMA is enabled in
+ * spider_net_enable_rxdmac.
+ */
+static void
+spider_net_enable_rxchtails(struct spider_net_card *card)
+{
+	/* assume chain is aligned correctly */
+	spider_net_write_reg(card, SPIDER_NET_GDADCHA ,
+			     card->rx_chain.tail->bus_addr);
+}
+
+/**
+ * spider_net_enable_rxdmac - enables a receive DMA controller
+ * @card: card structure
+ *
+ * spider_net_enable_rxdmac enables the DMA controller by setting RX_DMA_EN
+ * in the GDADMACCNTR register
+ */
+static void
+spider_net_enable_rxdmac(struct spider_net_card *card)
+{
+	spider_net_write_reg(card, SPIDER_NET_GDADMACCNTR,
+			     SPIDER_NET_DMA_RX_VALUE);
+}
+
+/**
+ * spider_net_refill_rx_chain - refills descriptors/skbs in the rx chains
+ * @card: card structure
+ *
+ * refills descriptors in all chains (last used chain first): allocates skbs
+ * and iommu-maps them.
+ */
+static void
+spider_net_refill_rx_chain(struct spider_net_card *card)
+{
+	struct spider_net_descr_chain *chain;
+	int count = 0;
+	unsigned long flags;
+
+	chain = &card->rx_chain;
+
+	spin_lock_irqsave(&card->chain_lock, flags);
+	while (spider_net_get_descr_status(chain->head) ==
+				SPIDER_NET_DESCR_NOT_IN_USE) {
+		if (spider_net_prepare_rx_descr(card, chain->head))
+			break;
+		count++;
+		chain->head = chain->head->next;
+	}
+	spin_unlock_irqrestore(&card->chain_lock, flags);
+
+	/* could be optimized, only do that, if we know the DMA processing
+	 * has terminated */
+	if (count)
+		spider_net_enable_rxdmac(card);
+}
+
+/**
+ * spider_net_alloc_rx_skbs - allocates rx skbs in rx descriptor chains
+ * @card: card structure
+ *
+ * returns 0 on success, <0 on failure
+ */
+static int
+spider_net_alloc_rx_skbs(struct spider_net_card *card)
+{
+	int result;
+	struct spider_net_descr_chain *chain;
+
+	result = -ENOMEM;
+
+	chain = &card->rx_chain;
+	/* put at least one buffer into the chain. if this fails,
+	 * we've got a problem. if not, spider_net_refill_rx_chain
+	 * will do the rest at the end of this function */
+	if (spider_net_prepare_rx_descr(card, chain->head))
+		goto error;
+	else
+		chain->head = chain->head->next;
+
+	/* this will allocate the rest of the rx buffers; if not, it's
+	 * business as usual later on */
+	spider_net_refill_rx_chain(card);
+	return 0;
+
+error:
+	spider_net_free_rx_chain_contents(card);
+	return result;
+}
+
+/**
+ * spider_net_release_tx_descr - processes a used tx descriptor
+ * @card: card structure
+ * @descr: descriptor to release
+ *
+ * releases a used tx descriptor (unmapping, freeing of skb)
+ */
+static void
+spider_net_release_tx_descr(struct spider_net_card *card,
+			    struct spider_net_descr *descr)
+{
+	struct sk_buff *skb;
+
+	/* unmap the skb */
+	skb = descr->skb;
+	pci_unmap_single(card->pdev, descr->buf_addr, skb->len,
+			 PCI_DMA_BIDIRECTIONAL);
+
+	dev_kfree_skb_any(skb);
+
+	/* set status to not used */
+	spider_net_set_descr_status(descr, SPIDER_NET_DESCR_NOT_IN_USE);
+}
+
+/**
+ * spider_net_release_tx_chain - processes sent tx descriptors
+ * @card: adapter structure
+ * @brutal: if set, don't care about whether descriptor seems to be in use
+ *
+ * releases the tx descriptors that spider has finished with (if non-brutal)
+ * or simply release tx descriptors (if brutal)
+ */
+static void
+spider_net_release_tx_chain(struct spider_net_card *card, int brutal)
+{
+	struct spider_net_descr_chain *tx_chain = &card->tx_chain;
+	enum spider_net_descr_status status;
+
+	spider_net_tx_irq_off(card);
+
+	/* no lock for chain needed, if this is only executed once at a time */
+again:
+	for (;;) {
+		status = spider_net_get_descr_status(tx_chain->tail);
+		switch (status) {
+		case SPIDER_NET_DESCR_CARDOWNED:
+			if (!brutal) goto out;
+			/* fallthrough, if we release the descriptors
+			 * brutally (then we don't care about
+			 * SPIDER_NET_DESCR_CARDOWNED) */
+		case SPIDER_NET_DESCR_RESPONSE_ERROR:
+		case SPIDER_NET_DESCR_PROTECTION_ERROR:
+		case SPIDER_NET_DESCR_FORCE_END:
+			if (netif_msg_tx_err(card))
+				pr_err("%s: forcing end of tx descriptor "
+				       "with status x%02x\n",
+				       card->netdev->name, status);
+			card->netdev_stats.tx_dropped++;
+			break;
+
+		case SPIDER_NET_DESCR_COMPLETE:
+			card->netdev_stats.tx_packets++;
+			card->netdev_stats.tx_bytes +=
+				tx_chain->tail->skb->len;
+			break;
+
+		default: /* any other value (== SPIDER_NET_DESCR_NOT_IN_USE) */
+			goto out;
+		}
+		spider_net_release_tx_descr(card, tx_chain->tail);
+		tx_chain->tail = tx_chain->tail->next;
+	}
+out:
+	netif_wake_queue(card->netdev);
+
+	if (!brutal) {
+		/* switch on tx irqs (while we are still in the interrupt
+		 * handler, so we don't get an interrupt), check again
+		 * for done descriptors. This results in fewer interrupts */
+		spider_net_tx_irq_on(card);
+		status = spider_net_get_descr_status(tx_chain->tail);
+		switch (status) {
+			case SPIDER_NET_DESCR_RESPONSE_ERROR:
+			case SPIDER_NET_DESCR_PROTECTION_ERROR:
+			case SPIDER_NET_DESCR_FORCE_END:
+			case SPIDER_NET_DESCR_COMPLETE:
+				goto again;
+			default:
+				break;
+		}
+	}
+
+}
+
+/**
+ * spider_net_get_multicast_hash - generates hash for multicast filter table
+ * @addr: multicast address
+ *
+ * returns the hash value.
+ *
+ * spider_net_get_multicast_hash calculates a hash value for a given multicast
+ * address, that is used to set the multicast filter tables
+ */
+static u8
+spider_net_get_multicast_hash(struct net_device *netdev, __u8 *addr)
+{
+	/* FIXME: an addr of 01:00:5e:00:00:01 must result in 0xa9,
+	 * ff:ff:ff:ff:ff:ff must result in 0xfd */
+	u32 crc;
+	u8 hash;
+
+	crc = crc32_be(~0, addr, netdev->addr_len);
+
+	hash = (crc >> 27);
+	hash <<= 3;
+	hash |= crc & 7;
+
+	return hash;
+}
+
+/**
+ * spider_net_set_multi - sets multicast addresses and promisc flags
+ * @netdev: interface device structure
+ *
+ * spider_net_set_multi configures multicast addresses as needed for the
+ * netdev interface. It also sets up multicast, allmulti and promisc
+ * flags appropriately
+ */
+static void
+spider_net_set_multi(struct net_device *netdev)
+{
+	struct dev_mc_list *mc;
+	u8 hash;
+	int i;
+	u32 reg;
+	struct spider_net_card *card = netdev_priv(netdev);
+	unsigned long bitmask[SPIDER_NET_MULTICAST_HASHES / BITS_PER_LONG] =
+		{0, };
+
+	spider_net_set_promisc(card);
+
+	if (netdev->flags & IFF_ALLMULTI) {
+		for (i = 0; i < SPIDER_NET_MULTICAST_HASHES; i++) {
+			set_bit(i, bitmask);
+		}
+		goto write_hash;
+	}
+
+	/* well, we know, what the broadcast hash value is: it's xfd
+	hash = spider_net_get_multicast_hash(netdev, netdev->broadcast); */
+	set_bit(0xfd, bitmask);
+
+	for (mc = netdev->mc_list; mc; mc = mc->next) {
+		hash = spider_net_get_multicast_hash(netdev, mc->dmi_addr);
+		set_bit(hash, bitmask);
+	}
+
+write_hash:
+	for (i = 0; i < SPIDER_NET_MULTICAST_HASHES / 4; i++) {
+		reg = 0;
+		if (test_bit(i * 4, bitmask))
+			reg += 0x08;
+		reg <<= 8;
+		if (test_bit(i * 4 + 1, bitmask))
+			reg += 0x08;
+		reg <<= 8;
+		if (test_bit(i * 4 + 2, bitmask))
+			reg += 0x08;
+		reg <<= 8;
+		if (test_bit(i * 4 + 3, bitmask))
+			reg += 0x08;
+
+		spider_net_write_reg(card, SPIDER_NET_GMRMHFILnR + i * 4, reg);
+	}
+}
+
+/**
+ * spider_net_disable_rxdmac - disables the receive DMA controller
+ * @card: card structure
+ *
+ * spider_net_disable_rxdmac terminates processing on the DMA controller by
+ * turing off DMA and issueing a force end
+ */
+static void
+spider_net_disable_rxdmac(struct spider_net_card *card)
+{
+	spider_net_write_reg(card, SPIDER_NET_GDADMACCNTR,
+			     SPIDER_NET_DMA_RX_FEND_VALUE);
+}
+
+/**
+ * spider_net_stop - called upon ifconfig down
+ * @netdev: interface device structure
+ *
+ * always returns 0
+ */
+int
+spider_net_stop(struct net_device *netdev)
+{
+	struct spider_net_card *card = netdev_priv(netdev);
+
+	netif_poll_disable(netdev);
+	netif_carrier_off(netdev);
+	netif_stop_queue(netdev);
+
+	/* disable/mask all interrupts */
+	spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, 0);
+	spider_net_write_reg(card, SPIDER_NET_GHIINT1MSK, 0);
+	spider_net_write_reg(card, SPIDER_NET_GHIINT2MSK, 0);
+
+	spider_net_write_reg(card, SPIDER_NET_GDTDMACCNTR,
+			     SPIDER_NET_DMA_TX_FEND_VALUE);
+
+	/* turn off DMA, force end */
+	spider_net_disable_rxdmac(card);
+
+	/* release chains */
+	spider_net_release_tx_chain(card, 1);
+
+	/* switch off card */
+	spider_net_write_reg(card, SPIDER_NET_CKRCTRL,
+			     SPIDER_NET_CKRCTRL_STOP_VALUE);
+
+	spider_net_free_chain(card, &card->tx_chain);
+	spider_net_free_chain(card, &card->rx_chain);
+
+	return 0;
+}
+
+/**
+ * spider_net_get_next_tx_descr - returns the next available tx descriptor
+ * @card: device structure to get descriptor from
+ *
+ * returns the address of the next descriptor, or NULL if not available.
+ */
+static struct spider_net_descr *
+spider_net_get_next_tx_descr(struct spider_net_card *card)
+{
+	/* check, if head points to not-in-use descr */
+	if ( spider_net_get_descr_status(card->tx_chain.head) ==
+	     SPIDER_NET_DESCR_NOT_IN_USE ) {
+		return card->tx_chain.head;
+	} else {
+		return NULL;
+	}
+}
+
+/**
+ * spider_net_set_txdescr_cmdstat - sets the tx descriptor command field
+ * @descr: descriptor structure to fill out
+ * @skb: packet to consider
+ *
+ * fills out the command and status field of the descriptor structure,
+ * depending on hardware checksum settings. This function assumes a wmb()
+ * has executed before.
+ */
+static void
+spider_net_set_txdescr_cmdstat(struct spider_net_descr *descr,
+			       struct sk_buff *skb)
+{
+	if (skb->ip_summed != CHECKSUM_HW) {
+		descr->dmac_cmd_status = SPIDER_NET_DMAC_CMDSTAT_NOCS;
+		return;
+	}
+
+	/* is packet ip?
+	 * if yes: tcp? udp? */
+	if (skb->protocol == htons(ETH_P_IP)) {
+		if (skb->nh.iph->protocol == IPPROTO_TCP) {
+			descr->dmac_cmd_status = SPIDER_NET_DMAC_CMDSTAT_TCPCS;
+		} else if (skb->nh.iph->protocol == IPPROTO_UDP) {
+			descr->dmac_cmd_status = SPIDER_NET_DMAC_CMDSTAT_UDPCS;
+		} else { /* the stack should checksum non-tcp and non-udp
+			    packets on his own: NETIF_F_IP_CSUM */
+			descr->dmac_cmd_status = SPIDER_NET_DMAC_CMDSTAT_NOCS;
+		}
+	}
+}
+
+/**
+ * spider_net_prepare_tx_descr - fill tx descriptor with skb data
+ * @card: card structure
+ * @descr: descriptor structure to fill out
+ * @skb: packet to use
+ *
+ * returns 0 on success, <0 on failure.
+ *
+ * fills out the descriptor structure with skb data and len. Copies data,
+ * if needed (32bit DMA!)
+ */
+static int
+spider_net_prepare_tx_descr(struct spider_net_card *card,
+			    struct spider_net_descr *descr,
+			    struct sk_buff *skb)
+{
+	descr->buf_addr = pci_map_single(card->pdev, skb->data,
+					 skb->len, PCI_DMA_BIDIRECTIONAL);
+	if (descr->buf_addr == DMA_ERROR_CODE) {
+		if (netif_msg_tx_err(card))
+			pr_err("could not iommu-map packet (%p, %i). "
+				  "Dropping packet\n", skb->data, skb->len);
+		return -ENOMEM;
+	}
+
+	descr->buf_size = skb->len;
+	descr->skb = skb;
+	descr->data_status = 0;
+
+	/* make sure the above values are in memory before we change the
+	 * status */
+	wmb();
+
+	spider_net_set_txdescr_cmdstat(descr,skb);
+
+	return 0;
+}
+
+/**
+ * spider_net_kick_tx_dma - enables TX DMA processing
+ * @card: card structure
+ * @descr: descriptor address to enable TX processing at
+ *
+ * spider_net_kick_tx_dma writes the current tx chain head as start address
+ * of the tx descriptor chain and enables the transmission DMA engine
+ */
+static void
+spider_net_kick_tx_dma(struct spider_net_card *card,
+		       struct spider_net_descr *descr)
+{
+	/* this is the only descriptor in the output chain.
+	 * Enable TX DMA */
+
+	spider_net_write_reg(card, SPIDER_NET_GDTDCHA,
+			     descr->bus_addr);
+
+	spider_net_write_reg(card, SPIDER_NET_GDTDMACCNTR,
+			     SPIDER_NET_DMA_TX_VALUE);
+}
+
+/**
+ * spider_net_xmit - transmits a frame over the device
+ * @skb: packet to send out
+ * @netdev: interface device structure
+ *
+ * returns 0 on success, <0 on failure
+ */
+static int
+spider_net_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+	struct spider_net_card *card = netdev_priv(netdev);
+	struct spider_net_descr *descr;
+	int result;
+
+	descr = spider_net_get_next_tx_descr(card);
+
+	if (!descr) {
+		netif_stop_queue(netdev);
+
+		descr = spider_net_get_next_tx_descr(card);
+		if (!descr)
+			goto error;
+		else
+			netif_start_queue(netdev);
+	}
+
+	result = spider_net_prepare_tx_descr(card, descr, skb);
+	if (result)
+		goto error;
+
+	card->tx_chain.head = card->tx_chain.head->next;
+
+	/* make sure the status from spider_net_prepare_tx_descr is in
+	 * memory before we check out the previous descriptor */
+	wmb();
+
+	if (spider_net_get_descr_status(descr->prev) !=
+	    SPIDER_NET_DESCR_CARDOWNED)
+		spider_net_kick_tx_dma(card, descr);
+
+	return NETDEV_TX_OK;
+
+error:
+	card->netdev_stats.tx_dropped++;
+	return NETDEV_TX_LOCKED;
+}
+
+/**
+ * spider_net_do_ioctl - called for device ioctls
+ * @netdev: interface device structure
+ * @ifr: request parameter structure for ioctl
+ * @cmd: command code for ioctl
+ *
+ * returns 0 on success, <0 on failure. Currently, we have no special ioctls.
+ * -EOPNOTSUPP is returned, if an unknown ioctl was requested
+ */
+static int
+spider_net_do_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
+{
+	switch (cmd) {
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+/**
+ * spider_net_pass_skb_up - takes an skb from a descriptor and passes it on
+ * @descr: descriptor to process
+ * @card: card structure
+ *
+ * returns 1 on success, 0 if no packet was passed to the stack
+ *
+ * iommu-unmaps the skb, fills out skb structure and passes the data to the
+ * stack. The descriptor state is not changed.
+ */
+static int
+spider_net_pass_skb_up(struct spider_net_descr *descr,
+		       struct spider_net_card *card)
+{
+	struct sk_buff *skb;
+	struct net_device *netdev;
+	u32 data_status, data_error;
+
+	data_status = descr->data_status;
+	data_error = descr->data_error;
+
+	netdev = card->netdev;
+
+	/* check for errors in the data_error flag */
+	if ((data_error & SPIDER_NET_DATA_ERROR_MASK) &&
+	    netif_msg_rx_err(card))
+		pr_err("error in received descriptor found, "
+		       "data_status=x%08x, data_error=x%08x\n",
+		       data_status, data_error);
+
+	/* prepare skb, unmap descriptor */
+	skb = descr->skb;
+	pci_unmap_single(card->pdev, descr->buf_addr, SPIDER_NET_MAX_MTU,
+			 PCI_DMA_BIDIRECTIONAL);
+
+	/* the cases we'll throw away the packet immediately */
+	if (data_error & SPIDER_NET_DESTROY_RX_FLAGS)
+		return 0;
+
+	skb->dev = netdev;
+	skb_put(skb, descr->valid_size);
+
+	/* the card seems to add 2 bytes of junk in front
+	 * of the ethernet frame */
+#define SPIDER_MISALIGN		2
+	skb_pull(skb, SPIDER_MISALIGN);
+	skb->protocol = eth_type_trans(skb, netdev);
+
+	/* checksum offload */
+	if (card->options.rx_csum) {
+		if ( (data_status & SPIDER_NET_DATA_STATUS_CHK_MASK) &&
+		     (!(data_error & SPIDER_NET_DATA_ERROR_CHK_MASK)) )
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+		else
+			skb->ip_summed = CHECKSUM_NONE;
+	} else {
+		skb->ip_summed = CHECKSUM_NONE;
+	}
+
+	if (data_status & SPIDER_NET_VLAN_PACKET) {
+		/* further enhancements: HW-accel VLAN
+		 * vlan_hwaccel_receive_skb
+		 */
+	}
+
+	/* pass skb up to stack */