[TG3]: Set minimal hw interrupt mitigation.

[linux-2.6/verdex.git] / drivers / net / wireless / prism54 / islpci_dev.c

/*
 *  
 *  Copyright (C) 2002 Intersil Americas Inc.
 *  Copyright (C) 2003 Herbert Valerio Riedel <hvr@gnu.org>
 *  Copyright (C) 2003 Luis R. Rodriguez <mcgrof@ruslug.rutgers.edu>
 *
 *  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/version.h>
#include <linux/module.h>

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

#include <asm/io.h>

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

#define ISL3877_IMAGE_FILE      "isl3877"
#define ISL3886_IMAGE_FILE      "isl3886"
#define ISL3890_IMAGE_FILE      "isl3890"

static int prism54_bring_down(islpci_private *);
static int islpci_alloc_memory(islpci_private *);
static struct net_device_stats *islpci_statistics(struct net_device *);

/* Temporary dummy MAC address to use until firmware is loaded.
 * The idea there is that some tools (such as nameif) may query
 * the MAC address before the netdev is 'open'. By using a valid
 * OUI prefix, they can process the netdev properly.
 * Of course, this is not the final/real MAC address. It doesn't
 * matter, as you are suppose to be able to change it anytime via
 * ndev->set_mac_address. Jean II */
static const unsigned char      dummy_mac[6] = { 0x00, 0x30, 0xB4, 0x00, 0x00, 0x00 };

static int
isl_upload_firmware(islpci_private *priv)
{
        u32 reg, rc;
        void __iomem *device_base = priv->device_base;

        /* clear the RAMBoot and the Reset bit */
        reg = readl(device_base + ISL38XX_CTRL_STAT_REG);
        reg &= ~ISL38XX_CTRL_STAT_RESET;
        reg &= ~ISL38XX_CTRL_STAT_RAMBOOT;
        writel(reg, device_base + ISL38XX_CTRL_STAT_REG);
        wmb();
        udelay(ISL38XX_WRITEIO_DELAY);

        /* set the Reset bit without reading the register ! */
        reg |= ISL38XX_CTRL_STAT_RESET;
        writel(reg, device_base + ISL38XX_CTRL_STAT_REG);
        wmb();
        udelay(ISL38XX_WRITEIO_DELAY);

        /* clear the Reset bit */
        reg &= ~ISL38XX_CTRL_STAT_RESET;
        writel(reg, device_base + ISL38XX_CTRL_STAT_REG);
        wmb();

        /* wait a while for the device to reboot */
        mdelay(50);

        {
                const struct firmware *fw_entry = NULL;
                long fw_len;
                const u32 *fw_ptr;

                rc = request_firmware(&fw_entry, priv->firmware, PRISM_FW_PDEV);
                if (rc) {
                        printk(KERN_ERR
                               "%s: request_firmware() failed for '%s'\n",
                               "prism54", priv->firmware);
                        return rc;
                }
                /* prepare the Direct Memory Base register */
                reg = ISL38XX_DEV_FIRMWARE_ADDRES;

                fw_ptr = (u32 *) fw_entry->data;
                fw_len = fw_entry->size;

                if (fw_len % 4) {
                        printk(KERN_ERR
                               "%s: firmware '%s' size is not multiple of 32bit, aborting!\n",
                               "prism54", priv->firmware);
                        release_firmware(fw_entry);
                        return -EILSEQ; /* Illegal byte sequence  */;
                }

                while (fw_len > 0) {
                        long _fw_len =
                            (fw_len >
                             ISL38XX_MEMORY_WINDOW_SIZE) ?
                            ISL38XX_MEMORY_WINDOW_SIZE : fw_len;
                        u32 __iomem *dev_fw_ptr = device_base + ISL38XX_DIRECT_MEM_WIN;

                        /* set the cards base address for writting the data */
                        isl38xx_w32_flush(device_base, reg,
                                          ISL38XX_DIR_MEM_BASE_REG);
                        wmb();  /* be paranoid */

                        /* increment the write address for next iteration */
                        reg += _fw_len;
                        fw_len -= _fw_len;

                        /* write the data to the Direct Memory Window 32bit-wise */
                        /* memcpy_toio() doesn't guarantee 32bit writes :-| */
                        while (_fw_len > 0) {
                                /* use non-swapping writel() */
                                __raw_writel(*fw_ptr, dev_fw_ptr);
                                fw_ptr++, dev_fw_ptr++;
                                _fw_len -= 4;
                        }

                        /* flush PCI posting */
                        (void) readl(device_base + ISL38XX_PCI_POSTING_FLUSH);
                        wmb();  /* be paranoid again */

                        BUG_ON(_fw_len != 0);
                }

                BUG_ON(fw_len != 0);

                /* Firmware version is at offset 40 (also for "newmac") */
                printk(KERN_DEBUG "%s: firmware version: %.8s\n",
                       priv->ndev->name, fw_entry->data + 40);

                release_firmware(fw_entry);
        }

        /* now reset the device
         * clear the Reset & ClkRun bit, set the RAMBoot bit */
        reg = readl(device_base + ISL38XX_CTRL_STAT_REG);
        reg &= ~ISL38XX_CTRL_STAT_CLKRUN;
        reg &= ~ISL38XX_CTRL_STAT_RESET;
        reg |= ISL38XX_CTRL_STAT_RAMBOOT;
        isl38xx_w32_flush(device_base, reg, ISL38XX_CTRL_STAT_REG);
        wmb();
        udelay(ISL38XX_WRITEIO_DELAY);

        /* set the reset bit latches the host override and RAMBoot bits
         * into the device for operation when the reset bit is reset */
        reg |= ISL38XX_CTRL_STAT_RESET;
        writel(reg, device_base + ISL38XX_CTRL_STAT_REG);
        /* don't do flush PCI posting here! */
        wmb();
        udelay(ISL38XX_WRITEIO_DELAY);

        /* clear the reset bit should start the whole circus */
        reg &= ~ISL38XX_CTRL_STAT_RESET;
        writel(reg, device_base + ISL38XX_CTRL_STAT_REG);
        /* don't do flush PCI posting here! */
        wmb();
        udelay(ISL38XX_WRITEIO_DELAY);

        return 0;
}

/******************************************************************************
    Device Interrupt Handler
******************************************************************************/

irqreturn_t
islpci_interrupt(int irq, void *config, struct pt_regs *regs)
{
        u32 reg;
        islpci_private *priv = config;
        struct net_device *ndev = priv->ndev;
        void __iomem *device = priv->device_base;
        int powerstate = ISL38XX_PSM_POWERSAVE_STATE;

        /* lock the interrupt handler */
        spin_lock(&priv->slock);

        /* received an interrupt request on a shared IRQ line
         * first check whether the device is in sleep mode */
        reg = readl(device + ISL38XX_CTRL_STAT_REG);
        if (reg & ISL38XX_CTRL_STAT_SLEEPMODE)
                /* device is in sleep mode, IRQ was generated by someone else */
        {
#if VERBOSE > SHOW_ERROR_MESSAGES
                DEBUG(SHOW_TRACING, "Assuming someone else called the IRQ\n");
#endif
                spin_unlock(&priv->slock);
                return IRQ_NONE;
        }


        /* check whether there is any source of interrupt on the device */
        reg = readl(device + ISL38XX_INT_IDENT_REG);

        /* also check the contents of the Interrupt Enable Register, because this
         * will filter out interrupt sources from other devices on the same irq ! */
        reg &= readl(device + ISL38XX_INT_EN_REG);
        reg &= ISL38XX_INT_SOURCES;

        if (reg != 0) {
                if (islpci_get_state(priv) != PRV_STATE_SLEEP)
                        powerstate = ISL38XX_PSM_ACTIVE_STATE;

                /* reset the request bits in the Identification register */
                isl38xx_w32_flush(device, reg, ISL38XX_INT_ACK_REG);

#if VERBOSE > SHOW_ERROR_MESSAGES
                DEBUG(SHOW_FUNCTION_CALLS,
                      "IRQ: Identification register 0x%p 0x%x \n", device, reg);
#endif

                /* check for each bit in the register separately */
                if (reg & ISL38XX_INT_IDENT_UPDATE) {
#if VERBOSE > SHOW_ERROR_MESSAGES
                        /* Queue has been updated */
                        DEBUG(SHOW_TRACING, "IRQ: Update flag \n");

                        DEBUG(SHOW_QUEUE_INDEXES,
                              "CB drv Qs: [%i][%i][%i][%i][%i][%i]\n",
                              le32_to_cpu(priv->control_block->
                                          driver_curr_frag[0]),
                              le32_to_cpu(priv->control_block->
                                          driver_curr_frag[1]),
                              le32_to_cpu(priv->control_block->
                                          driver_curr_frag[2]),
                              le32_to_cpu(priv->control_block->
                                          driver_curr_frag[3]),
                              le32_to_cpu(priv->control_block->
                                          driver_curr_frag[4]),
                              le32_to_cpu(priv->control_block->
                                          driver_curr_frag[5])
                            );

                        DEBUG(SHOW_QUEUE_INDEXES,
                              "CB dev Qs: [%i][%i][%i][%i][%i][%i]\n",
                              le32_to_cpu(priv->control_block->
                                          device_curr_frag[0]),
                              le32_to_cpu(priv->control_block->
                                          device_curr_frag[1]),
                              le32_to_cpu(priv->control_block->
                                          device_curr_frag[2]),
                              le32_to_cpu(priv->control_block->
                                          device_curr_frag[3]),
                              le32_to_cpu(priv->control_block->
                                          device_curr_frag[4]),
                              le32_to_cpu(priv->control_block->
                                          device_curr_frag[5])
                            );
#endif

                        /* cleanup the data low transmit queue */
                        islpci_eth_cleanup_transmit(priv, priv->control_block);

                        /* device is in active state, update the
                         * powerstate flag if necessary */
                        powerstate = ISL38XX_PSM_ACTIVE_STATE;

                        /* check all three queues in priority order
                         * call the PIMFOR receive function until the
                         * queue is empty */
                        if (isl38xx_in_queue(priv->control_block,
                                                ISL38XX_CB_RX_MGMTQ) != 0) {
#if VERBOSE > SHOW_ERROR_MESSAGES
                                DEBUG(SHOW_TRACING,
                                      "Received frame in Management Queue\n");
#endif
                                islpci_mgt_receive(ndev);

                                islpci_mgt_cleanup_transmit(ndev);

                                /* Refill slots in receive queue */
                                islpci_mgmt_rx_fill(ndev);

                                /* no need to trigger the device, next
                                   islpci_mgt_transaction does it */
                        }

                        while (isl38xx_in_queue(priv->control_block,
                                                ISL38XX_CB_RX_DATA_LQ) != 0) {
#if VERBOSE > SHOW_ERROR_MESSAGES
                                DEBUG(SHOW_TRACING,
                                      "Received frame in Data Low Queue \n");
#endif
                                islpci_eth_receive(priv);
                        }

                        /* check whether the data transmit queues were full */
                        if (priv->data_low_tx_full) {
                                /* check whether the transmit is not full anymore */
                                if (ISL38XX_CB_TX_QSIZE -
                                    isl38xx_in_queue(priv->control_block,
                                                     ISL38XX_CB_TX_DATA_LQ) >=
                                    ISL38XX_MIN_QTHRESHOLD) {
                                        /* nope, the driver is ready for more network frames */
                                        netif_wake_queue(priv->ndev);

                                        /* reset the full flag */
                                        priv->data_low_tx_full = 0;
                                }
                        }
                }

                if (reg & ISL38XX_INT_IDENT_INIT) {
                        /* Device has been initialized */
#if VERBOSE > SHOW_ERROR_MESSAGES
                        DEBUG(SHOW_TRACING,
                              "IRQ: Init flag, device initialized \n");
#endif
                        wake_up(&priv->reset_done);
                }

                if (reg & ISL38XX_INT_IDENT_SLEEP) {
                        /* Device intends to move to powersave state */
#if VERBOSE > SHOW_ERROR_MESSAGES
                        DEBUG(SHOW_TRACING, "IRQ: Sleep flag \n");
#endif
                        isl38xx_handle_sleep_request(priv->control_block,
                                                     &powerstate,
                                                     priv->device_base);
                }

                if (reg & ISL38XX_INT_IDENT_WAKEUP) {
                        /* Device has been woken up to active state */
#if VERBOSE > SHOW_ERROR_MESSAGES
                        DEBUG(SHOW_TRACING, "IRQ: Wakeup flag \n");
#endif

                        isl38xx_handle_wakeup(priv->control_block,
                                              &powerstate, priv->device_base);
                }
        } else {
#if VERBOSE > SHOW_ERROR_MESSAGES
                DEBUG(SHOW_TRACING, "Assuming someone else called the IRQ\n");
#endif
                spin_unlock(&priv->slock);
                return IRQ_NONE;
        }

        /* sleep -> ready */
        if (islpci_get_state(priv) == PRV_STATE_SLEEP
            && powerstate == ISL38XX_PSM_ACTIVE_STATE)
                islpci_set_state(priv, PRV_STATE_READY);

        /* !sleep -> sleep */
        if (islpci_get_state(priv) != PRV_STATE_SLEEP
            && powerstate == ISL38XX_PSM_POWERSAVE_STATE)
                islpci_set_state(priv, PRV_STATE_SLEEP);

        /* unlock the interrupt handler */
        spin_unlock(&priv->slock);

        return IRQ_HANDLED;
}

/******************************************************************************
    Network Interface Control & Statistical functions
******************************************************************************/
static int
islpci_open(struct net_device *ndev)
{
        u32 rc;
        islpci_private *priv = netdev_priv(ndev);

        /* reset data structures, upload firmware and reset device */
        rc = islpci_reset(priv,1);
        if (rc) {
                prism54_bring_down(priv);
                return rc; /* Returns informative message */
        }

        netif_start_queue(ndev);
/*      netif_mark_up( ndev ); */

        return 0;
}

static int
islpci_close(struct net_device *ndev)
{
        islpci_private *priv = netdev_priv(ndev);

        printk(KERN_DEBUG "%s: islpci_close ()\n", ndev->name);

        netif_stop_queue(ndev);

        return prism54_bring_down(priv);
}

static int
prism54_bring_down(islpci_private *priv)
{
        void __iomem *device_base = priv->device_base;
        u32 reg;
        /* we are going to shutdown the device */
        islpci_set_state(priv, PRV_STATE_PREBOOT);

        /* disable all device interrupts in case they weren't */
        isl38xx_disable_interrupts(priv->device_base);  

        /* For safety reasons, we may want to ensure that no DMA transfer is
         * currently in progress by emptying the TX and RX queues. */

        /* wait until interrupts have finished executing on other CPUs */
        synchronize_irq(priv->pdev->irq);

        reg = readl(device_base + ISL38XX_CTRL_STAT_REG);
        reg &= ~(ISL38XX_CTRL_STAT_RESET | ISL38XX_CTRL_STAT_RAMBOOT);
        writel(reg, device_base + ISL38XX_CTRL_STAT_REG);
        wmb();
        udelay(ISL38XX_WRITEIO_DELAY);

        reg |= ISL38XX_CTRL_STAT_RESET;
        writel(reg, device_base + ISL38XX_CTRL_STAT_REG);
        wmb();
        udelay(ISL38XX_WRITEIO_DELAY);

        /* clear the Reset bit */
        reg &= ~ISL38XX_CTRL_STAT_RESET;
        writel(reg, device_base + ISL38XX_CTRL_STAT_REG);
        wmb();

        /* wait a while for the device to reset */
        set_current_state(TASK_UNINTERRUPTIBLE);
        schedule_timeout(50*HZ/1000);

        return 0;
}

static int
islpci_upload_fw(islpci_private *priv)
{
        islpci_state_t old_state;
        u32 rc;

        old_state = islpci_set_state(priv, PRV_STATE_BOOT);

        printk(KERN_DEBUG "%s: uploading firmware...\n", priv->ndev->name);

        rc = isl_upload_firmware(priv);
        if (rc) {
                /* error uploading the firmware */
                printk(KERN_ERR "%s: could not upload firmware ('%s')\n",
                       priv->ndev->name, priv->firmware);

                islpci_set_state(priv, old_state);
                return rc;
        }

        printk(KERN_DEBUG "%s: firmware upload complete\n",
               priv->ndev->name);

        islpci_set_state(priv, PRV_STATE_POSTBOOT);

        return 0;
}

static int
islpci_reset_if(islpci_private *priv)
{
        long remaining;
        int result = -ETIME;
        int count;

        DEFINE_WAIT(wait);
        prepare_to_wait(&priv->reset_done, &wait, TASK_UNINTERRUPTIBLE);
        
        /* now the last step is to reset the interface */
        isl38xx_interface_reset(priv->device_base, priv->device_host_address);
        islpci_set_state(priv, PRV_STATE_PREINIT);

        for(count = 0; count < 2 && result; count++) {
                /* The software reset acknowledge needs about 220 msec here.
                 * Be conservative and wait for up to one second. */
        
                set_current_state(TASK_UNINTERRUPTIBLE);
                remaining = schedule_timeout(HZ);

                if(remaining > 0) {
                        result = 0;
                        break;
                }

                /* If we're here it's because our IRQ hasn't yet gone through. 
                 * Retry a bit more...
                 */
                printk(KERN_ERR "%s: no 'reset complete' IRQ seen - retrying\n",
                        priv->ndev->name);
        }

        finish_wait(&priv->reset_done, &wait);

        if (result) {
                printk(KERN_ERR "%s: interface reset failure\n", priv->ndev->name);
                return result;
        }

        islpci_set_state(priv, PRV_STATE_INIT);

        /* Now that the device is 100% up, let's allow
         * for the other interrupts --
         * NOTE: this is not *yet* true since we've only allowed the 
         * INIT interrupt on the IRQ line. We can perhaps poll
         * the IRQ line until we know for sure the reset went through */
        isl38xx_enable_common_interrupts(priv->device_base);

        down_write(&priv->mib_sem);
        result = mgt_commit(priv);
        if (result) {
                printk(KERN_ERR "%s: interface reset failure\n", priv->ndev->name);
                up_write(&priv->mib_sem);
                return result;
        }
        up_write(&priv->mib_sem);

        islpci_set_state(priv, PRV_STATE_READY);

        printk(KERN_DEBUG "%s: interface reset complete\n", priv->ndev->name);
        return 0;
}

int
islpci_reset(islpci_private *priv, int reload_firmware)
{
        isl38xx_control_block *cb =    /* volatile not needed */
                (isl38xx_control_block *) priv->control_block;
        unsigned counter;
        int rc;

        if (reload_firmware)
                islpci_set_state(priv, PRV_STATE_PREBOOT);
        else
                islpci_set_state(priv, PRV_STATE_POSTBOOT);

        printk(KERN_DEBUG "%s: resetting device...\n", priv->ndev->name);

        /* disable all device interrupts in case they weren't */
        isl38xx_disable_interrupts(priv->device_base);

        /* flush all management queues */
        priv->index_mgmt_tx = 0;
        priv->index_mgmt_rx = 0;

        /* clear the indexes in the frame pointer */
        for (counter = 0; counter < ISL38XX_CB_QCOUNT; counter++) {
                cb->driver_curr_frag[counter] = cpu_to_le32(0);
                cb->device_curr_frag[counter] = cpu_to_le32(0);
        }

        /* reset the mgmt receive queue */
        for (counter = 0; counter < ISL38XX_CB_MGMT_QSIZE; counter++) {
                isl38xx_fragment *frag = &cb->rx_data_mgmt[counter];
                frag->size = cpu_to_le16(MGMT_FRAME_SIZE);
                frag->flags = 0;
                frag->address = cpu_to_le32(priv->mgmt_rx[counter].pci_addr);
        }

        for (counter = 0; counter < ISL38XX_CB_RX_QSIZE; counter++) {
                cb->rx_data_low[counter].address =
                    cpu_to_le32((u32) priv->pci_map_rx_address[counter]);
        }

        /* since the receive queues are filled with empty fragments, now we can
         * set the corresponding indexes in the Control Block */
        priv->control_block->driver_curr_frag[ISL38XX_CB_RX_DATA_LQ] =
            cpu_to_le32(ISL38XX_CB_RX_QSIZE);
        priv->control_block->driver_curr_frag[ISL38XX_CB_RX_MGMTQ] =
            cpu_to_le32(ISL38XX_CB_MGMT_QSIZE);

        /* reset the remaining real index registers and full flags */
        priv->free_data_rx = 0;
        priv->free_data_tx = 0;
        priv->data_low_tx_full = 0;

        if (reload_firmware) { /* Should we load the firmware ? */
        /* now that the data structures are cleaned up, upload
         * firmware and reset interface */
                rc = islpci_upload_fw(priv);
                if (rc) {
                        printk(KERN_ERR "%s: islpci_reset: failure\n",
                                priv->ndev->name);
                        return rc;
                }
        }

        /* finally reset interface */
        rc = islpci_reset_if(priv);
        if (rc)
                printk(KERN_ERR "prism54: Your card/socket may be faulty, or IRQ line too busy :(\n");
        return rc;
}

static struct net_device_stats *
islpci_statistics(struct net_device *ndev)
{
        islpci_private *priv = netdev_priv(ndev);

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

        return &priv->statistics;
}

/******************************************************************************
    Network device configuration functions
******************************************************************************/
static int
islpci_alloc_memory(islpci_private *priv)
{
        int counter;

#if VERBOSE > SHOW_ERROR_MESSAGES
        printk(KERN_DEBUG "islpci_alloc_memory\n");
#endif

        /* remap the PCI device base address to accessable */
        if (!(priv->device_base =
              ioremap(pci_resource_start(priv->pdev, 0),
                      ISL38XX_PCI_MEM_SIZE))) {
                /* error in remapping the PCI device memory address range */
                printk(KERN_ERR "PCI memory remapping failed \n");
                return -1;
        }

        /* memory layout for consistent DMA region:
         *
         * Area 1: Control Block for the device interface
         * Area 2: Power Save Mode Buffer for temporary frame storage. Be aware that
         *         the number of supported stations in the AP determines the minimal
         *         size of the buffer !
         */

        /* perform the allocation */
        priv->driver_mem_address = pci_alloc_consistent(priv->pdev,
                                                        HOST_MEM_BLOCK,
                                                        &priv->
                                                        device_host_address);

        if (!priv->driver_mem_address) {
                /* error allocating the block of PCI memory */
                printk(KERN_ERR "%s: could not allocate DMA memory, aborting!",
                       "prism54");
                return -1;
        }

        /* assign the Control Block to the first address of the allocated area */
        priv->control_block =
            (isl38xx_control_block *) priv->driver_mem_address;

        /* set the Power Save Buffer pointer directly behind the CB */
        priv->device_psm_buffer =
                priv->device_host_address + CONTROL_BLOCK_SIZE;

        /* make sure all buffer pointers are initialized */
        for (counter = 0; counter < ISL38XX_CB_QCOUNT; counter++) {
                priv->control_block->driver_curr_frag[counter] = cpu_to_le32(0);
                priv->control_block->device_curr_frag[counter] = cpu_to_le32(0);
        }

        priv->index_mgmt_rx = 0;
        memset(priv->mgmt_rx, 0, sizeof(priv->mgmt_rx));
        memset(priv->mgmt_tx, 0, sizeof(priv->mgmt_tx));

        /* allocate rx queue for management frames */
        if (islpci_mgmt_rx_fill(priv->ndev) < 0)
                goto out_free;

        /* now get the data rx skb's */
        memset(priv->data_low_rx, 0, sizeof (priv->data_low_rx));
        memset(priv->pci_map_rx_address, 0, sizeof (priv->pci_map_rx_address));

        for (counter = 0; counter < ISL38XX_CB_RX_QSIZE; counter++) {
                struct sk_buff *skb;

                /* allocate an sk_buff for received data frames storage
                 * each frame on receive size consists of 1 fragment
                 * include any required allignment operations */
                if (!(skb = dev_alloc_skb(MAX_FRAGMENT_SIZE_RX + 2))) {
                        /* error allocating an sk_buff structure elements */
                        printk(KERN_ERR "Error allocating skb.\n");
                        skb = NULL;
                        goto out_free;
                }
                skb_reserve(skb, (4 - (long) skb->data) & 0x03);
                /* add the new allocated sk_buff to the buffer array */
                priv->data_low_rx[counter] = skb;

                /* map the allocated skb data area to pci */
                priv->pci_map_rx_address[counter] =
                    pci_map_single(priv->pdev, (void *) skb->data,
                                   MAX_FRAGMENT_SIZE_RX + 2,
                                   PCI_DMA_FROMDEVICE);
                if (!priv->pci_map_rx_address[counter]) {
                        /* error mapping the buffer to device
                           accessable memory address */
                        printk(KERN_ERR "failed to map skb DMA'able\n");
                        goto out_free;
                }
        }

        prism54_acl_init(&priv->acl);
        prism54_wpa_ie_init(priv);
        if (mgt_init(priv)) 
                goto out_free;

        return 0;
 out_free:
        islpci_free_memory(priv);
        return -1;
}

int
islpci_free_memory(islpci_private *priv)
{
        int counter;

        if (priv->device_base)
                iounmap(priv->device_base);
        priv->device_base = NULL;

        /* free consistent DMA area... */
        if (priv->driver_mem_address)
                pci_free_consistent(priv->pdev, HOST_MEM_BLOCK,
                                    priv->driver_mem_address,
                                    priv->device_host_address);

        /* clear some dangling pointers */
        priv->driver_mem_address = NULL;
        priv->device_host_address = 0;
        priv->device_psm_buffer = 0;
        priv->control_block = NULL;

        /* clean up mgmt rx buffers */
        for (counter = 0; counter < ISL38XX_CB_MGMT_QSIZE; counter++) {
                struct islpci_membuf *buf = &priv->mgmt_rx[counter];
                if (buf->pci_addr)
                        pci_unmap_single(priv->pdev, buf->pci_addr,
                                         buf->size, PCI_DMA_FROMDEVICE);
                buf->pci_addr = 0;
                if (buf->mem)
                        kfree(buf->mem);
                buf->size = 0;
                buf->mem = NULL;
        }

        /* clean up data rx buffers */
        for (counter = 0; counter < ISL38XX_CB_RX_QSIZE; counter++) {
                if (priv->pci_map_rx_address[counter])
                        pci_unmap_single(priv->pdev,
                                         priv->pci_map_rx_address[counter],
                                         MAX_FRAGMENT_SIZE_RX + 2,
                                         PCI_DMA_FROMDEVICE);
                priv->pci_map_rx_address[counter] = 0;

                if (priv->data_low_rx[counter])
                        dev_kfree_skb(priv->data_low_rx[counter]);
                priv->data_low_rx[counter] = NULL;
        }

        /* Free the acces control list and the WPA list */
        prism54_acl_clean(&priv->acl);
        prism54_wpa_ie_clean(priv);
        mgt_clean(priv);

        return 0;
}

#if 0
static void
islpci_set_multicast_list(struct net_device *dev)
{
        /* put device into promisc mode and let network layer handle it */
}
#endif

struct net_device *
islpci_setup(struct pci_dev *pdev)
{
        islpci_private *priv;
        struct net_device *ndev = alloc_etherdev(sizeof (islpci_private));

        if (!ndev)
                return ndev;

        SET_MODULE_OWNER(ndev);
        pci_set_drvdata(pdev, ndev);
#if defined(SET_NETDEV_DEV)
        SET_NETDEV_DEV(ndev, &pdev->dev);
#endif

        /* setup the structure members */
        ndev->base_addr = pci_resource_start(pdev, 0);
        ndev->irq = pdev->irq;

        /* initialize the function pointers */
        ndev->open = &islpci_open;
        ndev->stop = &islpci_close;
        ndev->get_stats = &islpci_statistics;
        ndev->get_wireless_stats = &prism54_get_wireless_stats;
        ndev->do_ioctl = &prism54_ioctl;
        ndev->wireless_handlers =
            (struct iw_handler_def *) &prism54_handler_def;

        ndev->hard_start_xmit = &islpci_eth_transmit;
        /* ndev->set_multicast_list = &islpci_set_multicast_list; */
        ndev->addr_len = ETH_ALEN;
        ndev->set_mac_address = &prism54_set_mac_address;
        /* Get a non-zero dummy MAC address for nameif. Jean II */
        memcpy(ndev->dev_addr, dummy_mac, 6);

#ifdef HAVE_TX_TIMEOUT
        ndev->watchdog_timeo = ISLPCI_TX_TIMEOUT;
        ndev->tx_timeout = &islpci_eth_tx_timeout;
#endif

        /* allocate a private device structure to the network device  */
        priv = netdev_priv(ndev);
        priv->ndev = ndev;
        priv->pdev = pdev;
        priv->monitor_type = ARPHRD_IEEE80211;
        priv->ndev->type = (priv->iw_mode == IW_MODE_MONITOR) ?
                priv->monitor_type : ARPHRD_ETHER;

#if WIRELESS_EXT > 16
        /* Add pointers to enable iwspy support. */
        priv->wireless_data.spy_data = &priv->spy_data;
        ndev->wireless_data = &priv->wireless_data;
#endif /* WIRELESS_EXT > 16 */

        /* save the start and end address of the PCI memory area */
        ndev->mem_start = (unsigned long) priv->device_base;
        ndev->mem_end = ndev->mem_start + ISL38XX_PCI_MEM_SIZE;

#if VERBOSE > SHOW_ERROR_MESSAGES
        DEBUG(SHOW_TRACING, "PCI Memory remapped to 0x%p\n", priv->device_base);
#endif

        init_waitqueue_head(&priv->reset_done);

        /* init the queue read locks, process wait counter */
        sema_init(&priv->mgmt_sem, 1);
        priv->mgmt_received = NULL;
        init_waitqueue_head(&priv->mgmt_wqueue);
        sema_init(&priv->stats_sem, 1);
        spin_lock_init(&priv->slock);

        /* init state machine with off#1 state */
        priv->state = PRV_STATE_OFF;
        priv->state_off = 1;

        /* initialize workqueue's */
        INIT_WORK(&priv->stats_work,
                  (void (*)(void *)) prism54_update_stats, priv);
        priv->stats_timestamp = 0;

        INIT_WORK(&priv->reset_task, islpci_do_reset_and_wake, priv);
        priv->reset_task_pending = 0;

        /* allocate various memory areas */
        if (islpci_alloc_memory(priv))
                goto do_free_netdev;

        /* select the firmware file depending on the device id */
        switch (pdev->device) {
        case 0x3877:
                strcpy(priv->firmware, ISL3877_IMAGE_FILE);
                break;

        case 0x3886:
                strcpy(priv->firmware, ISL3886_IMAGE_FILE);
                break;

        default:
                strcpy(priv->firmware, ISL3890_IMAGE_FILE);
                break;
        }

        if (register_netdev(ndev)) {
                DEBUG(SHOW_ERROR_MESSAGES,
                      "ERROR: register_netdev() failed \n");
                goto do_islpci_free_memory;
        }

        return ndev;

      do_islpci_free_memory:
        islpci_free_memory(priv);
      do_free_netdev:
        pci_set_drvdata(pdev, NULL);
        free_netdev(ndev);
        priv = NULL;
        return NULL;
}

islpci_state_t
islpci_set_state(islpci_private *priv, islpci_state_t new_state)
{
        islpci_state_t old_state;

        /* lock */
        old_state = priv->state;

        /* this means either a race condition or some serious error in
         * the driver code */
        switch (new_state) {
        case PRV_STATE_OFF:
                priv->state_off++;
        default:
                priv->state = new_state;
                break;

        case PRV_STATE_PREBOOT:
                /* there are actually many off-states, enumerated by
                 * state_off */
                if (old_state == PRV_STATE_OFF)
                        priv->state_off--;

                /* only if hw_unavailable is zero now it means we either
                 * were in off#1 state, or came here from
                 * somewhere else */
                if (!priv->state_off)
                        priv->state = new_state;
                break;
        };
#if 0
        printk(KERN_DEBUG "%s: state transition %d -> %d (off#%d)\n",
               priv->ndev->name, old_state, new_state, priv->state_off);
#endif

        /* invariants */
        BUG_ON(priv->state_off < 0);
        BUG_ON(priv->state_off && (priv->state != PRV_STATE_OFF));
        BUG_ON(!priv->state_off && (priv->state == PRV_STATE_OFF));

        /* unlock */
        return old_state;
}