islpci_eth.c

Go to the documentation of this file.

/*
 *  Copyright (C) 2002 Intersil Americas Inc.
 *  Copyright (C) 2004 Aurelien Alleaume <[email protected]>
 *  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 of the License
 *
 *  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/module.h>
#include <linux/gfp.h>

#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <asm/byteorder.h>

#include "prismcompat.h"
#include "isl_38xx.h"
#include "islpci_eth.h"
#include "islpci_mgt.h"
#include "oid_mgt.h"

/******************************************************************************
    Network Interface functions
******************************************************************************/
void
islpci_eth_cleanup_transmit(islpci_private *priv,
                isl38xx_control_block *control_block)
{
    struct sk_buff *skb;
    u32 index;

    /* compare the control block read pointer with the free pointer */
    while (priv->free_data_tx !=
           le32_to_cpu(control_block->
               device_curr_frag[ISL38XX_CB_TX_DATA_LQ])) {
        /* read the index of the first fragment to be freed */
        index = priv->free_data_tx % ISL38XX_CB_TX_QSIZE;

        /* check for holes in the arrays caused by multi fragment frames
         * searching for the last fragment of a frame */
        if (priv->pci_map_tx_address[index]) {
            /* entry is the last fragment of a frame
             * free the skb structure and unmap pci memory */
            skb = priv->data_low_tx[index];

#if VERBOSE > SHOW_ERROR_MESSAGES
            DEBUG(SHOW_TRACING,
                  "cleanup skb %p skb->data %p skb->len %u truesize %u\n ",
                  skb, skb->data, skb->len, skb->truesize);
#endif

            pci_unmap_single(priv->pdev,
                     priv->pci_map_tx_address[index],
                     skb->len, PCI_DMA_TODEVICE);
            dev_kfree_skb_irq(skb);
            skb = NULL;
        }
        /* increment the free data low queue pointer */
        priv->free_data_tx++;
    }
}

netdev_tx_t
islpci_eth_transmit(struct sk_buff *skb, struct net_device *ndev)
{
    islpci_private *priv = netdev_priv(ndev);
    isl38xx_control_block *cb = priv->control_block;
    u32 index;
    dma_addr_t pci_map_address;
    int frame_size;
    isl38xx_fragment *fragment;
    int offset;
    struct sk_buff *newskb;
    int newskb_offset;
    unsigned long flags;
    unsigned char wds_mac[6];
    u32 curr_frag;

#if VERBOSE > SHOW_ERROR_MESSAGES
    DEBUG(SHOW_FUNCTION_CALLS, "islpci_eth_transmit\n");
#endif

    /* lock the driver code */
    spin_lock_irqsave(&priv->slock, flags);

    /* check whether the destination queue has enough fragments for the frame */
    curr_frag = le32_to_cpu(cb->driver_curr_frag[ISL38XX_CB_TX_DATA_LQ]);
    if (unlikely(curr_frag - priv->free_data_tx >= ISL38XX_CB_TX_QSIZE)) {
        printk(KERN_ERR "%s: transmit device queue full when awake\n",
               ndev->name);
        netif_stop_queue(ndev);

        /* trigger the device */
        isl38xx_w32_flush(priv->device_base, ISL38XX_DEV_INT_UPDATE,
                  ISL38XX_DEV_INT_REG);
        udelay(ISL38XX_WRITEIO_DELAY);
        goto drop_free;
    }
    /* Check alignment and WDS frame formatting. The start of the packet should
     * be aligned on a 4-byte boundary. If WDS is enabled add another 6 bytes
     * and add WDS address information */
    if (likely(((long) skb->data & 0x03) | init_wds)) {
        /* get the number of bytes to add and re-align */
        offset = (4 - (long) skb->data) & 0x03;
        offset += init_wds ? 6 : 0;

        /* check whether the current skb can be used  */
        if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
            unsigned char *src = skb->data;

#if VERBOSE > SHOW_ERROR_MESSAGES
            DEBUG(SHOW_TRACING, "skb offset %i wds %i\n", offset,
                  init_wds);
#endif

            /* align the buffer on 4-byte boundary */
            skb_reserve(skb, (4 - (long) skb->data) & 0x03);
            if (init_wds) {
                /* wds requires an additional address field of 6 bytes */
                skb_put(skb, 6);
#ifdef ISLPCI_ETH_DEBUG
                printk("islpci_eth_transmit:wds_mac\n");
#endif
                memmove(skb->data + 6, src, skb->len);
                skb_copy_to_linear_data(skb, wds_mac, 6);
            } else {
                memmove(skb->data, src, skb->len);
            }

#if VERBOSE > SHOW_ERROR_MESSAGES
            DEBUG(SHOW_TRACING, "memmove %p %p %i\n", skb->data,
                  src, skb->len);
#endif
        } else {
            newskb =
                dev_alloc_skb(init_wds ? skb->len + 6 : skb->len);
            if (unlikely(newskb == NULL)) {
                printk(KERN_ERR "%s: Cannot allocate skb\n",
                       ndev->name);
                goto drop_free;
            }
            newskb_offset = (4 - (long) newskb->data) & 0x03;

            /* Check if newskb->data is aligned */
            if (newskb_offset)
                skb_reserve(newskb, newskb_offset);

            skb_put(newskb, init_wds ? skb->len + 6 : skb->len);
            if (init_wds) {
                skb_copy_from_linear_data(skb,
                              newskb->data + 6,
                              skb->len);
                skb_copy_to_linear_data(newskb, wds_mac, 6);
#ifdef ISLPCI_ETH_DEBUG
                printk("islpci_eth_transmit:wds_mac\n");
#endif
            } else
                skb_copy_from_linear_data(skb, newskb->data,
                              skb->len);

#if VERBOSE > SHOW_ERROR_MESSAGES
            DEBUG(SHOW_TRACING, "memcpy %p %p %i wds %i\n",
                  newskb->data, skb->data, skb->len, init_wds);
#endif

            newskb->dev = skb->dev;
            dev_kfree_skb_irq(skb);
            skb = newskb;
        }
    }
    /* display the buffer contents for debugging */
#if VERBOSE > SHOW_ERROR_MESSAGES
    DEBUG(SHOW_BUFFER_CONTENTS, "\ntx %p ", skb->data);
    display_buffer((char *) skb->data, skb->len);
#endif

    /* map the skb buffer to pci memory for DMA operation */
    pci_map_address = pci_map_single(priv->pdev,
                     (void *) skb->data, skb->len,
                     PCI_DMA_TODEVICE);
    if (unlikely(pci_map_address == 0)) {
        printk(KERN_WARNING "%s: cannot map buffer to PCI\n",
               ndev->name);
        goto drop_free;
    }
    /* Place the fragment in the control block structure. */
    index = curr_frag % ISL38XX_CB_TX_QSIZE;
    fragment = &cb->tx_data_low[index];

    priv->pci_map_tx_address[index] = pci_map_address;
    /* store the skb address for future freeing  */
    priv->data_low_tx[index] = skb;
    /* set the proper fragment start address and size information */
    frame_size = skb->len;
    fragment->size = cpu_to_le16(frame_size);
    fragment->flags = cpu_to_le16(0);   /* set to 1 if more fragments */
    fragment->address = cpu_to_le32(pci_map_address);
    curr_frag++;

    /* The fragment address in the control block must have been
     * written before announcing the frame buffer to device. */
    wmb();
    cb->driver_curr_frag[ISL38XX_CB_TX_DATA_LQ] = cpu_to_le32(curr_frag);

    if (curr_frag - priv->free_data_tx + ISL38XX_MIN_QTHRESHOLD
        > ISL38XX_CB_TX_QSIZE) {
        /* stop sends from upper layers */
        netif_stop_queue(ndev);

        /* set the full flag for the transmission queue */
        priv->data_low_tx_full = 1;
    }

    ndev->stats.tx_packets++;
    ndev->stats.tx_bytes += skb->len;

    /* trigger the device */
    islpci_trigger(priv);

    /* unlock the driver code */
    spin_unlock_irqrestore(&priv->slock, flags);

    return NETDEV_TX_OK;

      drop_free:
    ndev->stats.tx_dropped++;
    spin_unlock_irqrestore(&priv->slock, flags);
    dev_kfree_skb(skb);
    return NETDEV_TX_OK;
}

static inline int
islpci_monitor_rx(islpci_private *priv, struct sk_buff **skb)
{
    /* The card reports full 802.11 packets but with a 20 bytes
     * header and without the FCS. But there a is a bit that
     * indicates if the packet is corrupted :-) */
    struct rfmon_header *hdr = (struct rfmon_header *) (*skb)->data;

    if (hdr->flags & 0x01)
        /* This one is bad. Drop it ! */
        return -1;
    if (priv->ndev->type == ARPHRD_IEEE80211_PRISM) {
        struct avs_80211_1_header *avs;
        /* extract the relevant data from the header */
        u32 clock = le32_to_cpu(hdr->clock);
        u8 rate = hdr->rate;
        u16 freq = le16_to_cpu(hdr->freq);
        u8 rssi = hdr->rssi;

        skb_pull(*skb, sizeof (struct rfmon_header));

        if (skb_headroom(*skb) < sizeof (struct avs_80211_1_header)) {
            struct sk_buff *newskb = skb_copy_expand(*skb,
                                 sizeof (struct
                                     avs_80211_1_header),
                                 0, GFP_ATOMIC);
            if (newskb) {
                dev_kfree_skb_irq(*skb);
                *skb = newskb;
            } else
                return -1;
            /* This behavior is not very subtile... */
        }

        /* make room for the new header and fill it. */
        avs =
            (struct avs_80211_1_header *) skb_push(*skb,
                               sizeof (struct
                                   avs_80211_1_header));

        avs->version = cpu_to_be32(P80211CAPTURE_VERSION);
        avs->length = cpu_to_be32(sizeof (struct avs_80211_1_header));
        avs->mactime = cpu_to_be64(clock);
        avs->hosttime = cpu_to_be64(jiffies);
        avs->phytype = cpu_to_be32(6);  /*OFDM: 6 for (g), 8 for (a) */
        avs->channel = cpu_to_be32(channel_of_freq(freq));
        avs->datarate = cpu_to_be32(rate * 5);
        avs->antenna = cpu_to_be32(0);  /*unknown */
        avs->priority = cpu_to_be32(0); /*unknown */
        avs->ssi_type = cpu_to_be32(3); /*2: dBm, 3: raw RSSI */
        avs->ssi_signal = cpu_to_be32(rssi & 0x7f);
        avs->ssi_noise = cpu_to_be32(priv->local_iwstatistics.qual.noise);  /*better than 'undefined', I assume */
        avs->preamble = cpu_to_be32(0); /*unknown */
        avs->encoding = cpu_to_be32(0); /*unknown */
    } else
        skb_pull(*skb, sizeof (struct rfmon_header));

    (*skb)->protocol = htons(ETH_P_802_2);
    skb_reset_mac_header(*skb);
    (*skb)->pkt_type = PACKET_OTHERHOST;

    return 0;
}

int
islpci_eth_receive(islpci_private *priv)
{
    struct net_device *ndev = priv->ndev;
    isl38xx_control_block *control_block = priv->control_block;
    struct sk_buff *skb;
    u16 size;
    u32 index, offset;
    unsigned char *src;
    int discard = 0;

#if VERBOSE > SHOW_ERROR_MESSAGES
    DEBUG(SHOW_FUNCTION_CALLS, "islpci_eth_receive\n");
#endif

    /* the device has written an Ethernet frame in the data area
     * of the sk_buff without updating the structure, do it now */
    index = priv->free_data_rx % ISL38XX_CB_RX_QSIZE;
    size = le16_to_cpu(control_block->rx_data_low[index].size);
    skb = priv->data_low_rx[index];
    offset = ((unsigned long)
          le32_to_cpu(control_block->rx_data_low[index].address) -
          (unsigned long) skb->data) & 3;

#if VERBOSE > SHOW_ERROR_MESSAGES
    DEBUG(SHOW_TRACING,
          "frq->addr %x skb->data %p skb->len %u offset %u truesize %u\n ",
          control_block->rx_data_low[priv->free_data_rx].address, skb->data,
          skb->len, offset, skb->truesize);
#endif

    /* delete the streaming DMA mapping before processing the skb */
    pci_unmap_single(priv->pdev,
             priv->pci_map_rx_address[index],
             MAX_FRAGMENT_SIZE_RX + 2, PCI_DMA_FROMDEVICE);

    /* update the skb structure and align the buffer */
    skb_put(skb, size);
    if (offset) {
        /* shift the buffer allocation offset bytes to get the right frame */
        skb_pull(skb, 2);
        skb_put(skb, 2);
    }
#if VERBOSE > SHOW_ERROR_MESSAGES
    /* display the buffer contents for debugging */
    DEBUG(SHOW_BUFFER_CONTENTS, "\nrx %p ", skb->data);
    display_buffer((char *) skb->data, skb->len);
#endif

    /* check whether WDS is enabled and whether the data frame is a WDS frame */

    if (init_wds) {
        /* WDS enabled, check for the wds address on the first 6 bytes of the buffer */
        src = skb->data + 6;
        memmove(skb->data, src, skb->len - 6);
        skb_trim(skb, skb->len - 6);
    }
#if VERBOSE > SHOW_ERROR_MESSAGES
    DEBUG(SHOW_TRACING, "Fragment size %i in skb at %p\n", size, skb);
    DEBUG(SHOW_TRACING, "Skb data at %p, length %i\n", skb->data, skb->len);

    /* display the buffer contents for debugging */
    DEBUG(SHOW_BUFFER_CONTENTS, "\nrx %p ", skb->data);
    display_buffer((char *) skb->data, skb->len);
#endif
    /* take care of monitor mode and spy monitoring. */
    if (unlikely(priv->iw_mode == IW_MODE_MONITOR)) {
        skb->dev = ndev;
        discard = islpci_monitor_rx(priv, &skb);
    } else {
        if (unlikely(skb->data[2 * ETH_ALEN] == 0)) {
            /* The packet has a rx_annex. Read it for spy monitoring, Then
             * remove it, while keeping the 2 leading MAC addr.
             */
            struct iw_quality wstats;
            struct rx_annex_header *annex =
                (struct rx_annex_header *) skb->data;
            wstats.level = annex->rfmon.rssi;
            /* The noise value can be a bit outdated if nobody's
             * reading wireless stats... */
            wstats.noise = priv->local_iwstatistics.qual.noise;
            wstats.qual = wstats.level - wstats.noise;
            wstats.updated = 0x07;
            /* Update spy records */
            wireless_spy_update(ndev, annex->addr2, &wstats);

            skb_copy_from_linear_data(skb,
                          (skb->data +
                           sizeof(struct rfmon_header)),
                          2 * ETH_ALEN);
            skb_pull(skb, sizeof (struct rfmon_header));
        }
        skb->protocol = eth_type_trans(skb, ndev);
    }
    skb->ip_summed = CHECKSUM_NONE;
    ndev->stats.rx_packets++;
    ndev->stats.rx_bytes += size;

    /* deliver the skb to the network layer */
#ifdef ISLPCI_ETH_DEBUG
    printk
        ("islpci_eth_receive:netif_rx %2.2X %2.2X %2.2X %2.2X %2.2X %2.2X\n",
         skb->data[0], skb->data[1], skb->data[2], skb->data[3],
         skb->data[4], skb->data[5]);
#endif
    if (unlikely(discard)) {
        dev_kfree_skb_irq(skb);
        skb = NULL;
    } else
        netif_rx(skb);

    /* increment the read index for the rx data low queue */
    priv->free_data_rx++;

    /* add one or more sk_buff structures */
    while (index =
           le32_to_cpu(control_block->
               driver_curr_frag[ISL38XX_CB_RX_DATA_LQ]),
           index - priv->free_data_rx < ISL38XX_CB_RX_QSIZE) {
        /* allocate an sk_buff for received data frames storage
         * include any required allignment operations */
        skb = dev_alloc_skb(MAX_FRAGMENT_SIZE_RX + 2);
        if (unlikely(skb == NULL)) {
            /* error allocating an sk_buff structure elements */
            DEBUG(SHOW_ERROR_MESSAGES, "Error allocating skb\n");
            break;
        }
        skb_reserve(skb, (4 - (long) skb->data) & 0x03);
        /* store the new skb structure pointer */
        index = index % ISL38XX_CB_RX_QSIZE;
        priv->data_low_rx[index] = skb;

#if VERBOSE > SHOW_ERROR_MESSAGES
        DEBUG(SHOW_TRACING,
              "new alloc skb %p skb->data %p skb->len %u index %u truesize %u\n ",
              skb, skb->data, skb->len, index, skb->truesize);
#endif

        /* set the streaming DMA mapping for proper PCI bus operation */
        priv->pci_map_rx_address[index] =
            pci_map_single(priv->pdev, (void *) skb->data,
                   MAX_FRAGMENT_SIZE_RX + 2,
                   PCI_DMA_FROMDEVICE);
        if (unlikely(!priv->pci_map_rx_address[index])) {
            /* error mapping the buffer to device accessible memory address */
            DEBUG(SHOW_ERROR_MESSAGES,
                  "Error mapping DMA address\n");

            /* free the skbuf structure before aborting */
            dev_kfree_skb_irq(skb);
            skb = NULL;
            break;
        }
        /* update the fragment address */
        control_block->rx_data_low[index].address =
            cpu_to_le32((u32)priv->pci_map_rx_address[index]);
        wmb();

        /* increment the driver read pointer */
        le32_add_cpu(&control_block->
                 driver_curr_frag[ISL38XX_CB_RX_DATA_LQ], 1);
    }

    /* trigger the device */
    islpci_trigger(priv);

    return 0;
}

void
islpci_do_reset_and_wake(struct work_struct *work)
{
    islpci_private *priv = container_of(work, islpci_private, reset_task);

    islpci_reset(priv, 1);
    priv->reset_task_pending = 0;
    smp_wmb();
    netif_wake_queue(priv->ndev);
}

void
islpci_eth_tx_timeout(struct net_device *ndev)
{
    islpci_private *priv = netdev_priv(ndev);

    /* increment the transmit error counter */
    ndev->stats.tx_errors++;

    if (!priv->reset_task_pending) {
        printk(KERN_WARNING
            "%s: tx_timeout, scheduling reset", ndev->name);
        netif_stop_queue(ndev);
        priv->reset_task_pending = 1;
        schedule_work(&priv->reset_task);
    } else {
        printk(KERN_WARNING
            "%s: tx_timeout, waiting for reset", ndev->name);
    }
}