wb35rx.c

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/*
 * ============================================================================
 *  Copyright (c) 1996-2002 Winbond Electronic Corporation
 *
 *  Module Name:
 *    Wb35Rx.c
 *
 *  Abstract:
 *    Processing the Rx message from down layer
 *
 * ============================================================================
 */
#include <linux/usb.h>
#include <linux/slab.h>

#include "core.h"
#include "wb35rx_f.h"

static void packet_came(struct ieee80211_hw *hw, char *pRxBufferAddress, int PacketSize)
{
    struct wbsoft_priv *priv = hw->priv;
    struct sk_buff *skb;
    struct ieee80211_rx_status rx_status = {0};

    if (!priv->enabled)
        return;

    skb = dev_alloc_skb(PacketSize);
    if (!skb) {
        printk("Not enough memory for packet, FIXME\n");
        return;
    }

    memcpy(skb_put(skb, PacketSize), pRxBufferAddress, PacketSize);

    memcpy(IEEE80211_SKB_RXCB(skb), &rx_status, sizeof(rx_status));
    ieee80211_rx_irqsafe(hw, skb);
}

static void Wb35Rx_adjust(struct wb35_descriptor *pRxDes)
{
    u32 *pRxBufferAddress;
    u32 DecryptionMethod;
    u32 i;
    u16 BufferSize;

    DecryptionMethod = pRxDes->R01.R01_decryption_method;
    pRxBufferAddress = pRxDes->buffer_address[0];
    BufferSize = pRxDes->buffer_size[0];

    /* Adjust the last part of data. Only data left */
    BufferSize -= 4; /* For CRC-32 */
    if (DecryptionMethod)
        BufferSize -= 4;
    if (DecryptionMethod == 3) /* For CCMP */
        BufferSize -= 4;

    /* Adjust the IV field which after 802.11 header and ICV field. */
    if (DecryptionMethod == 1) { /* For WEP */
        for (i = 6; i > 0; i--)
            pRxBufferAddress[i] = pRxBufferAddress[i - 1];
        pRxDes->buffer_address[0] = pRxBufferAddress + 1;
        BufferSize -= 4; /* 4 byte for IV */
    } else if (DecryptionMethod) { /* For TKIP and CCMP */
        for (i = 7; i > 1; i--)
            pRxBufferAddress[i] = pRxBufferAddress[i - 2];
        pRxDes->buffer_address[0] = pRxBufferAddress + 2; /* Update the descriptor, shift 8 byte */
        BufferSize -= 8; /* 8 byte for IV + ICV */
    }
    pRxDes->buffer_size[0] = BufferSize;
}

static u16 Wb35Rx_indicate(struct ieee80211_hw *hw)
{
    struct wbsoft_priv  *priv = hw->priv;
    struct hw_data      *pHwData = &priv->sHwData;
    struct wb35_descriptor  RxDes;
    struct wb35_rx      *pWb35Rx = &pHwData->Wb35Rx;
    u8          *pRxBufferAddress;
    u16         PacketSize;
    u16         stmp, BufferSize, stmp2 = 0;
    u32         RxBufferId;

    /* Only one thread be allowed to run into the following */
    do {
        RxBufferId = pWb35Rx->RxProcessIndex;
        if (pWb35Rx->RxOwner[RxBufferId]) /* Owner by VM */
            break;

        pWb35Rx->RxProcessIndex++;
        pWb35Rx->RxProcessIndex %= MAX_USB_RX_BUFFER_NUMBER;

        pRxBufferAddress = pWb35Rx->pDRx;
        BufferSize = pWb35Rx->RxBufferSize[RxBufferId];

        /* Parse the bulkin buffer */
        while (BufferSize >= 4) {
            if ((cpu_to_le32(*(u32 *)pRxBufferAddress) & 0x0fffffff) == RX_END_TAG) /* Is ending? */
                break;

            /* Get the R00 R01 first */
            RxDes.R00.value = le32_to_cpu(*(u32 *)pRxBufferAddress);
            PacketSize = (u16)RxDes.R00.R00_receive_byte_count;
            RxDes.R01.value = le32_to_cpu(*((u32 *)(pRxBufferAddress + 4)));
            /* For new DMA 4k */
            if ((PacketSize & 0x03) > 0)
                PacketSize -= 4;

            /* Basic check for Rx length. Is length valid? */
            if (PacketSize > MAX_PACKET_SIZE) {
                pr_debug("Serious ERROR : Rx data size too long, size =%d\n", PacketSize);
                pWb35Rx->EP3vm_state = VM_STOP;
                pWb35Rx->Ep3ErrorCount2++;
                break;
            }

            /*
             * Wb35Rx_indicate() is called synchronously so it isn't
             * necessary to set "RxDes.Desctriptor_ID = RxBufferID;"
             */
            BufferSize -= 8; /* subtract 8 byte for 35's USB header length */
            pRxBufferAddress += 8;

            RxDes.buffer_address[0] = pRxBufferAddress;
            RxDes.buffer_size[0] = PacketSize;
            RxDes.buffer_number = 1;
            RxDes.buffer_start_index = 0;
            RxDes.buffer_total_size = RxDes.buffer_size[0];
            Wb35Rx_adjust(&RxDes);

            packet_came(hw, pRxBufferAddress, PacketSize);

            /* Move RxBuffer point to the next */
            stmp = PacketSize + 3;
            stmp &= ~0x03; /* 4n alignment */
            pRxBufferAddress += stmp;
            BufferSize -= stmp;
            stmp2 += stmp;
        }

        /* Reclaim resource */
        pWb35Rx->RxOwner[RxBufferId] = 1;
    } while (true);
    return stmp2;
}

static void Wb35Rx(struct ieee80211_hw *hw);

static void Wb35Rx_Complete(struct urb *urb)
{
    struct ieee80211_hw *hw = urb->context;
    struct wbsoft_priv  *priv = hw->priv;
    struct hw_data      *pHwData = &priv->sHwData;
    struct wb35_rx      *pWb35Rx = &pHwData->Wb35Rx;
    u8          *pRxBufferAddress;
    u32         SizeCheck;
    u16         BulkLength;
    u32         RxBufferId;
    struct R00_descriptor       R00;

    /* Variable setting */
    pWb35Rx->EP3vm_state = VM_COMPLETED;
    pWb35Rx->EP3VM_status = urb->status; /* Store the last result of Irp */

    RxBufferId = pWb35Rx->CurrentRxBufferId;

    pRxBufferAddress = pWb35Rx->pDRx;
    BulkLength = (u16)urb->actual_length;

    /* The IRP is completed */
    pWb35Rx->EP3vm_state = VM_COMPLETED;

    if (pHwData->SurpriseRemove) /* Must be here, or RxBufferId is invalid */
        goto error;

    if (pWb35Rx->rx_halt)
        goto error;

    /* Start to process the data only in successful condition */
    pWb35Rx->RxOwner[RxBufferId] = 0; /* Set the owner to driver */
    R00.value = le32_to_cpu(*(u32 *)pRxBufferAddress);

    /* The URB is completed, check the result */
    if (pWb35Rx->EP3VM_status != 0) {
        pr_debug("EP3 IoCompleteRoutine return error\n");
        pWb35Rx->EP3vm_state = VM_STOP;
        goto error;
    }

    /* For recovering. check if operating in single USB mode */
    if (!HAL_USB_MODE_BURST(pHwData)) {
        SizeCheck = R00.R00_receive_byte_count;
        if ((SizeCheck & 0x03) > 0)
            SizeCheck -= 4;
        SizeCheck = (SizeCheck + 3) & ~0x03;
        SizeCheck += 12; /* 8 + 4 badbeef */
        if ((BulkLength > 1600) ||
            (SizeCheck > 1600) ||
            (BulkLength != SizeCheck) ||
            (BulkLength == 0)) { /* Add for fail Urb */
            pWb35Rx->EP3vm_state = VM_STOP;
            pWb35Rx->Ep3ErrorCount2++;
        }
    }

    /* Indicating the receiving data */
    pWb35Rx->ByteReceived += BulkLength;
    pWb35Rx->RxBufferSize[RxBufferId] = BulkLength;

    if (!pWb35Rx->RxOwner[RxBufferId])
        Wb35Rx_indicate(hw);

    kfree(pWb35Rx->pDRx);
    /* Do the next receive */
    Wb35Rx(hw);
    return;

error:
    pWb35Rx->RxOwner[RxBufferId] = 1; /* Set the owner to hardware */
    atomic_dec(&pWb35Rx->RxFireCounter);
    pWb35Rx->EP3vm_state = VM_STOP;
}

/* This function cannot reentrain */
static void Wb35Rx(struct ieee80211_hw *hw)
{
    struct wbsoft_priv  *priv = hw->priv;
    struct hw_data      *pHwData = &priv->sHwData;
    struct wb35_rx      *pWb35Rx = &pHwData->Wb35Rx;
    u8          *pRxBufferAddress;
    struct urb      *urb = pWb35Rx->RxUrb;
    int         retv;
    u32         RxBufferId;

    /* Issuing URB */
    if (pHwData->SurpriseRemove)
        goto error;

    if (pWb35Rx->rx_halt)
        goto error;

    /* Get RxBuffer's ID */
    RxBufferId = pWb35Rx->RxBufferId;
    if (!pWb35Rx->RxOwner[RxBufferId]) {
        /* It's impossible to run here. */
        pr_debug("Rx driver fifo unavailable\n");
        goto error;
    }

    /* Update buffer point, then start to bulkin the data from USB */
    pWb35Rx->RxBufferId++;
    pWb35Rx->RxBufferId %= MAX_USB_RX_BUFFER_NUMBER;

    pWb35Rx->CurrentRxBufferId = RxBufferId;

    pWb35Rx->pDRx = kzalloc(MAX_USB_RX_BUFFER, GFP_ATOMIC);
    if (!pWb35Rx->pDRx) {
        printk("w35und: Rx memory alloc failed\n");
        goto error;
    }
    pRxBufferAddress = pWb35Rx->pDRx;

    usb_fill_bulk_urb(urb, pHwData->udev,
              usb_rcvbulkpipe(pHwData->udev, 3),
              pRxBufferAddress, MAX_USB_RX_BUFFER,
              Wb35Rx_Complete, hw);

    pWb35Rx->EP3vm_state = VM_RUNNING;

    retv = usb_submit_urb(urb, GFP_ATOMIC);

    if (retv != 0) {
        printk("Rx URB sending error\n");
        goto error;
    }
    return;

error:
    /* VM stop */
    pWb35Rx->EP3vm_state = VM_STOP;
    atomic_dec(&pWb35Rx->RxFireCounter);
}

void Wb35Rx_start(struct ieee80211_hw *hw)
{
    struct wbsoft_priv  *priv = hw->priv;
    struct hw_data      *pHwData = &priv->sHwData;
    struct wb35_rx      *pWb35Rx = &pHwData->Wb35Rx;

    /* Allow only one thread to run into the Wb35Rx() function */
    if (atomic_inc_return(&pWb35Rx->RxFireCounter) == 1) {
        pWb35Rx->EP3vm_state = VM_RUNNING;
        Wb35Rx(hw);
    } else
        atomic_dec(&pWb35Rx->RxFireCounter);
}

static void Wb35Rx_reset_descriptor(struct hw_data *pHwData)
{
    struct wb35_rx  *pWb35Rx = &pHwData->Wb35Rx;
    u32     i;

    pWb35Rx->ByteReceived = 0;
    pWb35Rx->RxProcessIndex = 0;
    pWb35Rx->RxBufferId = 0;
    pWb35Rx->EP3vm_state = VM_STOP;
    pWb35Rx->rx_halt = 0;

    /* Initial the Queue. The last buffer is reserved for used if the Rx resource is unavailable. */
    for (i = 0; i < MAX_USB_RX_BUFFER_NUMBER; i++)
        pWb35Rx->RxOwner[i] = 1;
}

unsigned char Wb35Rx_initial(struct hw_data *pHwData)
{
    struct wb35_rx *pWb35Rx = &pHwData->Wb35Rx;

    /* Initial the Buffer Queue */
    Wb35Rx_reset_descriptor(pHwData);

    pWb35Rx->RxUrb = usb_alloc_urb(0, GFP_ATOMIC);
    return !!pWb35Rx->RxUrb;
}

void Wb35Rx_stop(struct hw_data *pHwData)
{
    struct wb35_rx *pWb35Rx = &pHwData->Wb35Rx;

    /* Canceling the Irp if already sends it out. */
    if (pWb35Rx->EP3vm_state == VM_RUNNING) {
        usb_unlink_urb(pWb35Rx->RxUrb); /* Only use unlink, let Wb35Rx_destroy to free them */
        pr_debug("EP3 Rx stop\n");
    }
}

/* Needs process context */
void Wb35Rx_destroy(struct hw_data *pHwData)
{
    struct wb35_rx *pWb35Rx = &pHwData->Wb35Rx;

    do {
        msleep(10); /* Delay for waiting function enter */
    } while (pWb35Rx->EP3vm_state != VM_STOP);
    msleep(10); /* Delay for waiting function exit */

    if (pWb35Rx->RxUrb)
        usb_free_urb(pWb35Rx->RxUrb);
    pr_debug("Wb35Rx_destroy OK\n");
}