Subversion Repositories pcie_ds_dma

#include <linux/kernel.h>

#define __NO_VERSION__

#include <linux/module.h>

#include <linux/types.h>

#include <linux/ioport.h>

#include <linux/pci.h>

#include <linux/interrupt.h>

#include <linux/pagemap.h>

#include <linux/interrupt.h>

#include <linux/proc_fs.h>

#include <asm/io.h>

#ifndef _EVENT_H_

#include "event.h"

#endif

#ifndef  _DMA_CHAN_H_

#include "dmachan.h"

#endif

#ifndef  _HARDWARE_H_

#include "hardware.h"

#endif

//-----------------------------------------------------------------------------

struct CDmaChannel* CDmaChannelCreate(  u32 NumberOfChannel,

        void *brd,

        struct device   *dev,

        u32 cbMaxTransferLength,

        u16 idBlockFifo,

        int bScatterGather )

{

    struct CDmaChannel *dma = NULL;

    dma = kzalloc(sizeof(struct CDmaChannel), GFP_KERNEL);

    if(!dma) {

        printk("<0>%s(): Error allocate memory for CDmaChannel object\n", __FUNCTION__);

        return NULL;

    }

    dma->m_NumberOfChannel = NumberOfChannel;

    dma->m_Board = brd;

    dma->m_dev = dev;

    dma->m_UseCount = 0;

    dma->m_DpcForIsr = DmaDpcForIsr;

    dma->m_idBlockFifo = idBlockFifo;

    spin_lock_init( &dma->m_DmaLock );

    init_waitqueue_head( &dma->m_DmaWq );

    tasklet_init( &dma->m_Dpc, dma->m_DpcForIsr, (unsigned long)dma );

    InitKevent( &dma->m_BlockEndEvent );

    InitKevent( &dma->m_BufferEndEvent );

    //printk("<0>%s(%d): COMPLETE.\n", __FUNCTION__, dma->m_NumberOfChannel);

    return dma;

}

//-----------------------------------------------------------------------------

void CDmaChannelDelete(struct CDmaChannel *dma)

{

    //printk("<0>%s()\n", __FUNCTION__);

    if (dma) {

        tasklet_kill( &dma->m_Dpc );

        kfree(dma);

    }

}

//-----------------------------------------------------------------------------

int RequestMemory(struct CDmaChannel *dma, void** ppVirtAddr, u32 size, u32 *pCount, void** pStub, u32 bMemType)

{

    int Status = -ENOMEM;

    //printk("<0>%s(): Channel = %d\n", __FUNCTION__, dma->m_NumberOfChannel);

    // при первом обращении действительно выделяем память,

    // а при повторных только отображаем выделенную память на пользовательское пространство

    if(!dma->m_UseCount)

    {

        dma->m_MemType = bMemType;

        dma->m_BlockCount = *pCount;

        dma->m_BlockSize = size;

        // выделяем память под описатели блоков (системный, и логический адрес для каждого блока)

        dma->m_pBufDscr.SystemAddress = (void*)dma_alloc_coherent( dma->m_dev,

                                                                   dma->m_BlockCount * sizeof(SHARED_MEMORY_DESCRIPTION),

                                                                   &dma->m_pBufDscr.LogicalAddress, GFP_KERNEL);

        if(!dma->m_pBufDscr.SystemAddress)

        {

            printk("<0>%s(): Not memory for buffer descriptions\n", __FUNCTION__);

            return -ENOMEM;

        }

        dma->m_ScatterGatherTableEntryCnt = 0;

    }

    Status = RequestStub(dma, pStub);

    if(Status == 0)

    {

        if(dma->m_MemType == SYSTEM_MEMORY_TYPE) {

            Status = RequestSysBuf(dma, ppVirtAddr);

        } else {

            ReleaseStub(dma);

            dma_free_coherent(dma->m_dev,

                              dma->m_BlockCount * sizeof(SHARED_MEMORY_DESCRIPTION),

                              dma->m_pBufDscr.SystemAddress,

                              dma->m_pBufDscr.LogicalAddress);

            dma->m_pBufDscr.SystemAddress = NULL;

            dma->m_pBufDscr.LogicalAddress = 0;

            printk("<0>%s(): Invalid memory type for DMA data blocks\n", __FUNCTION__);

            return -EINVAL;

        }

        if(Status == 0)

        {

            if(!dma->m_UseCount)

            {

                //printk("<0>%s(): Scatter/Gather Table Entry is %d\n", __FUNCTION__, dma->m_ScatterGatherTableEntryCnt);

                if(dma->m_idBlockFifo == PE_EXT_FIFO_ID)

                    SetScatterGatherListExt(dma);

                else {

                    printk("<0>%s(): Scatter/Gather Table Entry not created\n", __FUNCTION__);

                    //SetScatterGatherList(dma);

                }

                *pCount = dma->m_BlockCount;

                dma->m_pStub = (PAMB_STUB)dma->m_StubDscr.SystemAddress;

                dma->m_pStub->lastBlock = -1;

                dma->m_pStub->totalCounter = 0;

                dma->m_pStub->offset = 0;

                dma->m_pStub->state = STATE_STOP;

            }

            dma->m_UseCount++;

        }

        else

        {

            ReleaseStub(dma);

            dma_free_coherent(dma->m_dev, dma->m_BlockCount * sizeof(SHARED_MEMORY_DESCRIPTION),

                              dma->m_pBufDscr.SystemAddress, dma->m_pBufDscr.LogicalAddress);

            dma->m_pBufDscr.SystemAddress = NULL;

            dma->m_pBufDscr.LogicalAddress = 0;

            printk("<0>%s(): Error allocate memory\n", __FUNCTION__);

            return -EINVAL;

        }

    }

    else

{

    if(!dma->m_UseCount)        {

        dma_free_coherent(dma->m_dev,

                          dma->m_BlockCount * sizeof(SHARED_MEMORY_DESCRIPTION),

                          dma->m_pBufDscr.SystemAddress, dma->m_pBufDscr.LogicalAddress);

        dma->m_pBufDscr.SystemAddress = NULL;

        dma->m_pBufDscr.LogicalAddress = 0;

    }

}

return Status;

}

//-----------------------------------------------------------------------------

void ReleaseMemory(struct CDmaChannel *dma)

{

    //printk("<0>%s(): Entered. Channel = %d\n", __FUNCTION__, dma->m_NumberOfChannel);

    if(!dma->m_UseCount) {

        printk("<0> %s: Memory not allocated.\n", __FUNCTION__);

        return;

    }

    ReleaseStub( dma );

    ReleaseSGList( dma );

    ReleaseSysBuf( dma );

    dma_free_coherent(dma->m_dev,

                      dma->m_BlockCount * sizeof(SHARED_MEMORY_DESCRIPTION),

                      dma->m_pBufDscr.SystemAddress, dma->m_pBufDscr.LogicalAddress);

    dma->m_pBufDscr.SystemAddress = NULL;

    dma->m_pBufDscr.LogicalAddress = 0;

    dma->m_UseCount--;

}

//-----------------------------------------------------------------------------

int SetScatterGatherListExt(struct CDmaChannel *dma)

{

    int Status = 0;

    u32 iBlock = 0;

    //u32 ii = 0;

    u32 iEntry = 0;

    u32 iBlkEntry = 0;

    u64 *pDscrBuf = NULL;

    u16* pNextDscr = NULL;

    u32 DscrSize = 0;

    SHARED_MEMORY_DESCRIPTION *pMemDscr = (SHARED_MEMORY_DESCRIPTION*)dma->m_pBufDscr.SystemAddress;

    DMA_CHAINING_DESCR_EXT      *pSGTEx = NULL;

    //printk("<0>%s()\n", __FUNCTION__);

    Status = RequestSGList(dma);

    if(Status < 0)

        return Status;

    //получим адрес таблицы для хранения цепочек DMA

    dma->m_pScatterGatherTableExt = (DMA_CHAINING_DESCR_EXT*)dma->m_SGTableDscr.SystemAddress;

    pSGTEx = dma->m_pScatterGatherTableExt;

    DscrSize = DSCR_BLOCK_SIZE*sizeof(DMA_CHAINING_DESCR_EXT);

    //обнулим таблицу дескрипторов DMA

    memset(pSGTEx, 0, dma->m_ScatterGatherBlockCnt*DscrSize);

    //printk("<0>%s(): m_SGTableDscr.SystemAddress = %p\n", __FUNCTION__, dma->m_SGTableDscr.SystemAddress );

    //printk("<0>%s(): m_SGTableDscr.LogicalAddress = %zx\n", __FUNCTION__, dma->m_SGTableDscr.LogicalAddress );

    //заполним значениями таблицу цепочек DMA

    for(iBlock=0, iEntry=0; iBlock < dma->m_BlockCount; iBlock++) {

        //адрес и размер DMA блока

        u64     address = pMemDscr[iBlock].LogicalAddress;

        u64     DmaSize = dma->m_BlockSize - 0x1000;

        //заполним поля элментов таблицы дескрипторов

        pSGTEx[iEntry].AddrByte1  = (u8)((address >> 8) & 0xFF);

        pSGTEx[iEntry].AddrByte2  = (u8)((address >> 16) & 0xFF);

        pSGTEx[iEntry].AddrByte3  = (u8)((address >> 24) & 0xFF);

        pSGTEx[iEntry].AddrByte4  = (u8)((address >> 32) & 0xFF);

        pSGTEx[iEntry].SizeByte1  = (u8)((DmaSize >> 8) & 0xFF);

        pSGTEx[iEntry].SizeByte2  = (u8)((DmaSize >> 16) & 0xFF);

        pSGTEx[iEntry].SizeByte3  = (u8)((DmaSize >> 24) & 0xFF);

        pSGTEx[iEntry].Cmd.JumpNextDescr = 1; //перейти к следующему дескриптору

        pSGTEx[iEntry].Cmd.JumpNextBlock = 0; //перейти к следующему блоку дескрипторов

        pSGTEx[iEntry].Cmd.JumpDescr0 = 0;

        pSGTEx[iEntry].Cmd.Res0 = 0;

        pSGTEx[iEntry].Cmd.EndOfTrans = 1;

        pSGTEx[iEntry].Cmd.Res = 0;

        pSGTEx[iEntry].SizeByte1 |= dma->m_DmaDirection;

        {

            //u32 *ptr=(u32*)&pSGTEx[iEntry];

            //printk("<0>%s(): %d: Entry Addr: %p, Data Addr: %llx  %.8X %.8X\n",

            //       __FUNCTION__, iEntry, &pSGTEx[iEntry], address, ptr[1], ptr[0]);

        }

        if(((iEntry+2)%DSCR_BLOCK_SIZE) == 0)

        {

            size_t NextDscrBlockAddr = 0;

            DMA_NEXT_BLOCK *pNextBlock = NULL;

            pSGTEx[iEntry].Cmd.JumpNextBlock = 1;

            pSGTEx[iEntry].Cmd.JumpNextDescr = 0;

            //NextDscrBlockAddr = virt_to_bus((void*)&pSGTEx[iEntry+2]);

            NextDscrBlockAddr = (size_t)((u8*)dma->m_SGTableDscr.LogicalAddress + sizeof(DMA_CHAINING_DESCR_EXT)*(iEntry +2));

            //printk("<0>%s(): NextDscrBlock [PA]: %x\n", __FUNCTION__, NextDscrBlockAddr);

            //printk("<0>%s(): NextDscrBlock [VA]: %p\n", __FUNCTION__, &pSGTEx[iEntry+2]);

            pNextBlock = (DMA_NEXT_BLOCK*)&pSGTEx[iEntry+1];

            //printk("<0>%s(): pNextBlock: %p\n", __FUNCTION__, pNextBlock);

            pNextBlock->NextBlkAddr = (NextDscrBlockAddr >> 8) & 0xFFFFFF;

            pNextBlock->Signature = 0x4953;

            pNextBlock->Crc = 0;

            iEntry++;

        }

        iEntry++;

    }

    //printk("<0>%s(): iEntry = %d\n", __FUNCTION__, iEntry);

    if(((iEntry % DSCR_BLOCK_SIZE)) != 0)

    {

        DMA_NEXT_BLOCK *pNextBlock = NULL;

        u32 i = 0;

        pSGTEx[iEntry-1].Cmd.JumpNextDescr = 0;

        pNextBlock = (DMA_NEXT_BLOCK*)(&pSGTEx[iEntry]);

        pNextBlock->NextBlkAddr = (dma->m_SGTableDscr.LogicalAddress >> 8);

        i = (DSCR_BLOCK_SIZE * dma->m_ScatterGatherBlockCnt) - 1;

        pNextBlock = (DMA_NEXT_BLOCK*)(&pSGTEx[i]);

        //printk("<0>%s(): %d: pNextBlock: %p\n", __FUNCTION__, i, pNextBlock );

        pNextBlock->NextBlkAddr = 0;

        pNextBlock->Signature = 0x4953;

        pNextBlock->Crc = 0;

    }

    //printk("<0>%s(): DmaDirection = %d, DmaLocalAddress = 0x%X\n", __FUNCTION__, dma->m_DmaDirection, dma->m_DmaLocalAddress);

    //for( ii=0; ii<dma->m_ScatterGatherBlockCnt*DSCR_BLOCK_SIZE; ii++ )

    //{

    //u32 *ptr=(u32*)&pSGTEx[ii];

    //printk("<0>%s(): %d: %.8X %.8X\n", __FUNCTION__, ii, ptr[1], ptr[0]);

    //}

    pDscrBuf = (u64*)dma->m_pScatterGatherTableExt;

    for(iBlkEntry = 0; iBlkEntry < dma->m_ScatterGatherBlockCnt; iBlkEntry++)

    {

        u32 ctrl_code = 0xFFFFFFFF;

        for(iBlock = 0; iBlock < DSCR_BLOCK_SIZE; iBlock++)

        {

            u16 data0 = (u16)(pDscrBuf[iBlock] & 0xFFFF);

            u16 data1 = (u16)((pDscrBuf[iBlock] >> 16) & 0xFFFF);

            u16 data2 = (u16)((pDscrBuf[iBlock] >> 32) & 0xFFFF);

            u16 data3 = (u16)((pDscrBuf[iBlock] >> 48) & 0xFFFF);

            if(iBlock == DSCR_BLOCK_SIZE-1)

            {

                ctrl_code = ctrl_code ^ data0 ^ data1 ^ data2 ^ data3;

                /*

                printk("<0>%s(): DSCR_BLCK[%d] - NextBlkAddr = 0x%8X, Signature = 0x%4X, Crc = 0x%4X\n", __FUNCTION__,

                       iBlkEntry,

                       (u32)(pDscrBuf[iBlock] << 8),

                       (u16)((pDscrBuf[iBlock] >> 32) & 0xFFFF),

                       (u16)ctrl_code);

*/

            }

            else

            {

                u32 ctrl_tmp = 0;

                ctrl_code = ctrl_code ^ data0 ^ data1 ^ data2 ^ data3;

                ctrl_tmp = ctrl_code << 1;

                ctrl_tmp |= (ctrl_code & 0x8000) ? 0: 1;

                ctrl_code = ctrl_tmp;

                //printk("<0>%s(): %d(%d) - PciAddr = 0x%8X, Cmd = 0x%2X, DmaLength = %d(%2X %2X %2X)\n",  __FUNCTION__,

                //                                                                      iBlock, iBlkEntry,

                //                                                                      (u32)(pDscrBuf[iBlock] << 8),

                //                                                                      (u8)(pDscrBuf[iBlock] >> 32),

                //                                                                      (u32)((pDscrBuf[iBlock] >> 41) << 9),

                //                                                                      (u8)(pDscrBuf[iBlock] >> 56),

                //                                                                      (u8)(pDscrBuf[iBlock] >> 48),

                //                                                                      (u8)(pDscrBuf[iBlock] >> 40));

                //printk("<0>%s(): JumpNextDescr = %d, JumpNextBlock = %d, JumpDescr0 = %d, EndOfTrans = %d, Signature = 0x%08X, Crc = 0x%08X\n",

                //                                                                      __FUNCTION__, m_pScatterGatherTable[iEntry].Cmd.EndOfChain,

                //                                                                      m_pScatterGatherTable[iEntry].Cmd.EndOfTrans,

                //                                                                      m_pScatterGatherTable[iEntry].Signature,

                //                                                                      m_pScatterGatherTable[iEntry].Crc

                //                                                                      );

            }

        }

        pNextDscr = (u16*)pDscrBuf;

        pNextDscr[255] |= (u16)ctrl_code;

        pDscrBuf += DSCR_BLOCK_SIZE;

    }

    return 0;

}

//-----------------------------------------------------------------------------

/*

u32 NexDscrAddress(void *pVirtualAddress)

{

    return (u32)(virt_to_bus(pVirtualAddress)>>4);

}

*/

//-----------------------------------------------------------------------------

// размещение в системном адресном пространстве памяти,

// доступной для операций ПДП и отображаемой в пользовательское пространство

//-----------------------------------------------------------------------------

int RequestSysBuf(struct CDmaChannel *dma, void **pMemPhysAddr)

{

    u32 iBlock = 0;

    u32 order = 0;

    SHARED_MEMORY_DESCRIPTION *pMemDscr = (SHARED_MEMORY_DESCRIPTION*)dma->m_pBufDscr.SystemAddress;

    //printk("<0>%s()\n", __FUNCTION__);

    order = get_order(dma->m_BlockSize);

    for(iBlock = 0; iBlock < dma->m_BlockCount; iBlock++)

    {

        dma_addr_t       LogicalAddress;

        void            *pSystemAddress = NULL;

        u32 *buffer = NULL;

        int iii=0;

        pSystemAddress = dma_alloc_coherent(  dma->m_dev, dma->m_BlockSize, &LogicalAddress, GFP_KERNEL );

        //pSystemAddress = (void*)__get_free_pages(GFP_KERNEL, order);

        if(!pSystemAddress) {

            printk("<0>%s(): Not enought memory for %i block location. m_BlockSize = %X, BlockOrder = %d\n",

                   __FUNCTION__, (int)iBlock, (int)dma->m_BlockSize, (int)order );

            return -ENOMEM;

        }

        pMemDscr[iBlock].SystemAddress = pSystemAddress;

        pMemDscr[iBlock].LogicalAddress = LogicalAddress;

        //pMemDscr[iBlock].LogicalAddress = virt_to_bus(pSystemAddress);

        lock_pages( pMemDscr[iBlock].SystemAddress, dma->m_BlockSize );

        pMemPhysAddr[iBlock] = (void*)pMemDscr[iBlock].LogicalAddress;

        buffer = (u32*)pMemDscr[iBlock].SystemAddress;

        for(iii=0; iii<dma->m_BlockSize/4; iii++) {

            buffer[iii] = 0x12345678;

        }

        //printk("<0>%s(): %i: %p\n", __FUNCTION__, iBlock, pMemPhysAddr[iBlock]);

    }

    dma->m_BlockCount = iBlock;

    dma->m_ScatterGatherTableEntryCnt = iBlock;

    return 0;

}

//-----------------------------------------------------------------------------

void ReleaseSysBuf(struct CDmaChannel *dma)

{

    u32 iBlock = 0;

    //u32 order = 0;

    SHARED_MEMORY_DESCRIPTION *pMemDscr = (SHARED_MEMORY_DESCRIPTION*)dma->m_pBufDscr.SystemAddress;

    //printk("<0>%s()\n", __FUNCTION__);

    //order = get_order(dma->m_BlockSize);

    if(!dma->m_UseCount) {

        printk("<0> ReleaseSysBuf(): Memory not allocated.\n");

        return;

    }

    for(iBlock = 0; iBlock < dma->m_BlockCount; iBlock++)

    {

        unlock_pages( pMemDscr[iBlock].SystemAddress, dma->m_BlockSize );

        dma_free_coherent( dma->m_dev, dma->m_BlockSize, pMemDscr[iBlock].SystemAddress, pMemDscr[iBlock].LogicalAddress );

        //free_pages((size_t)pMemDscr[iBlock].SystemAddress, order);

        pMemDscr[iBlock].SystemAddress = NULL;

        pMemDscr[iBlock].LogicalAddress = 0;

    }

}

//-----------------------------------------------------------------------------

int RequestStub(struct CDmaChannel *dma, void **pStubPhysAddr)

{

    dma_addr_t LogicalAddress = 0;

    u32 StubSize = 0;

    //printk("<0>%s()\n", __FUNCTION__ );

    if(!dma)

        return -EINVAL;

    StubSize = sizeof(AMB_STUB) > PAGE_SIZE ? sizeof(AMB_STUB) : PAGE_SIZE;

    //printk("<0>%s() 0\n", __FUNCTION__ );

    if(!dma->m_UseCount)

    {

        void *pStub = dma_alloc_coherent( dma->m_dev, StubSize, &LogicalAddress, GFP_KERNEL );

        if(!pStub)

        {

            printk("<0>%s(): Not enought memory for stub\n", __FUNCTION__);

            return -ENOMEM;

        }

        lock_pages( pStub, StubSize );

        //printk("<0>%s() 1\n", __FUNCTION__ );

        dma->m_StubDscr.SystemAddress = pStub;

        dma->m_StubDscr.LogicalAddress = LogicalAddress;

        dma->m_pStub = (AMB_STUB*)pStub;          //может быть в этом нет необходимости,

        //но в дальнейшем в модуле используется dma->m_pStub

    }

    //printk("<0>%s() 2\n", __FUNCTION__ );

    pStubPhysAddr[0] = (void*)dma->m_StubDscr.LogicalAddress;

    //printk("<0>%s(): Stub physical address: %zx\n", __FUNCTION__, dma->m_StubDscr.LogicalAddress);

    //printk("<0>%s(): Stub virtual address: %p\n", __FUNCTION__, dma->m_StubDscr.SystemAddress);

    return 0;

}

//-----------------------------------------------------------------------------

void ReleaseStub(struct CDmaChannel *dma)

{

    u32 StubSize = sizeof(AMB_STUB) > PAGE_SIZE ? sizeof(AMB_STUB) : PAGE_SIZE;

    //printk("<0>%s()\n", __FUNCTION__);

    if(!dma->m_UseCount)

    {

        unlock_pages(dma->m_StubDscr.SystemAddress, StubSize);

        dma_free_coherent(dma->m_dev, StubSize,

                          dma->m_StubDscr.SystemAddress,

                          dma->m_StubDscr.LogicalAddress);

        dma->m_pStub = NULL;

        dma->m_StubDscr.SystemAddress = NULL;

        dma->m_StubDscr.LogicalAddress = 0;

    }

}

//-----------------------------------------------------------------------------

// вызываем только при первичном размещении буфера

//-----------------------------------------------------------------------------

int RequestSGList(struct CDmaChannel *dma)

{

    u32 SGListMemSize = 0;

    u32 SGListSize = 0;

    dma_addr_t PhysicalAddress;

    //printk("<0>%s()\n", __FUNCTION__);

    if(dma->m_idBlockFifo == PE_EXT_FIFO_ID)

    {

        dma->m_ScatterGatherBlockCnt = dma->m_ScatterGatherTableEntryCnt / (DSCR_BLOCK_SIZE-1);

        dma->m_ScatterGatherBlockCnt = (dma->m_ScatterGatherTableEntryCnt % (DSCR_BLOCK_SIZE-1)) ? (dma->m_ScatterGatherBlockCnt+1) : dma->m_ScatterGatherBlockCnt;

        SGListSize = sizeof(DMA_CHAINING_DESCR_EXT) * DSCR_BLOCK_SIZE * dma->m_ScatterGatherBlockCnt;

        //printk("<0>%s(): SGBlockCnt = %d, SGListSize = %d.\n", __FUNCTION__, dma->m_ScatterGatherBlockCnt, SGListSize);

    }

    SGListMemSize = (SGListSize >= PAGE_SIZE) ? SGListSize : PAGE_SIZE;

    //  выделяем память под список

    dma->m_SGTableDscr.SystemAddress = dma_alloc_coherent( dma->m_dev, SGListMemSize, &PhysicalAddress, GFP_KERNEL);

    if(!dma->m_SGTableDscr.SystemAddress)

    {

        printk("<0>%s(): Not enought memory for scatter/gather list\n", __FUNCTION__);

        return -ENOMEM;

    }

    dma->m_SGTableDscr.LogicalAddress = PhysicalAddress;

    // закрепляем список в физической памяти

    lock_pages(dma->m_SGTableDscr.SystemAddress, SGListMemSize);

    return 0;

}

//-----------------------------------------------------------------------------

void ReleaseSGList(struct CDmaChannel *dma)

{

    u32 SGListMemSize = 0;

    u32 SGListSize = 0;

    //printk("<0>%s()\n", __FUNCTION__);

    if(dma->m_idBlockFifo == PE_EXT_FIFO_ID)

    {

        SGListSize = sizeof(DMA_CHAINING_DESCR_EXT) * DSCR_BLOCK_SIZE * dma->m_ScatterGatherBlockCnt;

    }

    SGListMemSize = (SGListSize >= PAGE_SIZE) ? SGListSize : PAGE_SIZE;

    // закрепляем список в физической памяти

    unlock_pages(dma->m_SGTableDscr.SystemAddress, SGListMemSize);

    dma_free_coherent( dma->m_dev, SGListMemSize,

                       dma->m_SGTableDscr.SystemAddress,

                       dma->m_SGTableDscr.LogicalAddress );

    dma->m_SGTableDscr.SystemAddress = NULL;

    dma->m_SGTableDscr.LogicalAddress = 0;

}

//-----------------------------------------------------------------------------

int StartDmaTransfer(struct CDmaChannel *dma, u32 IsCycling)

{

    //printk("<0>%s()\n", __FUNCTION__);

    dma->m_DmaCycling = IsCycling;

    dma->m_DoneBlock = -1;

    dma->m_DoneFlag = 1;

    dma->m_CycleNum     = 0;

    dma->m_BlocksRemaining      = dma->m_BlockCount;

    dma->m_CurBlockNum = 0;

    dma->m_preBlockCount1 = 1;

    dma->m_preBlockCount2 = 2;

    dma->m_preBlockCount3 = 3;

    if(dma->m_idBlockFifo == PE_EXT_FIFO_ID)

    {

        u64 *pDscrBuf = NULL;

        u32 ctrl_code = ~0;

        u16* pDscr = NULL;

        int iEntry = 0;

        u32 iLastEntry = dma->m_ScatterGatherTableEntryCnt + dma->m_ScatterGatherBlockCnt - 1;

        if(dma->m_ScatterGatherBlockCnt == 1)

            dma->m_pScatterGatherTableExt[iLastEntry - 1].Cmd.JumpDescr0 = dma->m_DmaCycling;

        else

            dma->m_pScatterGatherTableExt[iLastEntry - 1].Cmd.JumpNextBlock = dma->m_DmaCycling;

        //printk("<0>%s(): m_DmaCycling = %d\n", __FUNCTION__, dma->m_DmaCycling);

        pDscrBuf = (u64*)dma->m_pScatterGatherTableExt + DSCR_BLOCK_SIZE * (dma->m_ScatterGatherBlockCnt - 1);

        ctrl_code = 0xFFFFFFFF;

        pDscr = (u16*)pDscrBuf;

        pDscr[255] = 0;

        for(iEntry = 0; iEntry < DSCR_BLOCK_SIZE; iEntry++)

        {

            u16 data0 = (u16)(pDscrBuf[iEntry] & 0xFFFF);

            u16 data1 = (u16)((pDscrBuf[iEntry] >> 16) & 0xFFFF);

            u16 data2 = (u16)((pDscrBuf[iEntry] >> 32) & 0xFFFF);

            u16 data3 = (u16)((pDscrBuf[iEntry] >> 48) & 0xFFFF);

            if(iEntry == DSCR_BLOCK_SIZE-1)

            {

                ctrl_code = ctrl_code ^ data0 ^ data1 ^ data2 ^ data3;

                /*

                printk("<0>%s(): DSCR_BLK[%d] - NextBlkAddr = 0x%08X, Signature = 0x%04X, Crc = 0x%04X\n",

                       __FUNCTION__,

                       dma->m_ScatterGatherBlockCnt-1,

                       (u32)(pDscrBuf[iEntry] << 8),

                       (u16)((pDscrBuf[iEntry] >> 32) & 0xFFFF),

                       (u16)ctrl_code);

*/

            }

            else

            {

                u32 ctrl_tmp = 0;

                ctrl_code = ctrl_code ^ data0 ^ data1 ^ data2 ^ data3;

                ctrl_tmp = ctrl_code << 1;

                ctrl_tmp |= (ctrl_code & 0x8000) ? 0: 1;

                ctrl_code = ctrl_tmp;

                // 3 способа циклического сдвига влево 32-разрядного значения

                // (у нас оказалось не совсем то: значение берется 16-разрядное и старший бит при переносе в младший инвертируется)

                //_rotl(ctrl_code, 1);

                //ctrl_code = (ctrl_code << 1) | (ctrl_code >> 31);

                //__asm {

                //      rol ctrl_code,1

                //}

                //printk("<0>%s(): %d(%d) - PciAddr = 0x%08X, Cmd = 0x%02X, DmaLength = %d(%02X %02X %02X)\n",

                //                                                                      __FUNCTION__,

                //                                                                      iEntry, dma->m_ScatterGatherBlockCnt-1,

                //                                                                      (u32)(pDscrBuf[iEntry] << 8),

                //                                                                      (u16)(pDscrBuf[iEntry] >> 32),

                //                                                                      (u32)((pDscrBuf[iEntry] >> 41) << 9),

                //                                                                      (u8)(pDscrBuf[iEntry] >> 56), (u8)(pDscrBuf[iEntry] >> 48), (u8)(pDscrBuf[iEntry] >> 40));

            }

        }

        pDscr[255] |= (u16)ctrl_code;

    }

    dma->m_pStub->lastBlock = -1;

    dma->m_pStub->totalCounter = 0;

    dma->m_pStub->state = STATE_RUN;