MdeModulePkg/Universal/Network/SnpDxe/Callback.c - edk2 - Git at Google

 /** @file
   This file contains two sets of callback routines for undi3.0 and undi3.1.
   the callback routines for Undi3.1 have an extra parameter UniqueId which
   stores the interface context for the NIC that snp is trying to talk.

 Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
 http://opensource.org/licenses/bsd-license.php

 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

 **/

 #include "Snp.h"

 //
 // Global variables
 // these 2 global variables are used only for 3.0 undi. we could not place
 // them in the snp structure because we will not know which snp structure
 // in the callback context!
 //
 BOOLEAN              mInitializeLock = TRUE;
 EFI_LOCK             mLock;

 //
 // End Global variables
 //
 extern EFI_PCI_IO_PROTOCOL  *mPciIo;

 /**
   Convert a virtual or CPU address provided by SNP to a physical or device
   address.

   This is a callback routine supplied to UNDI at undi_start time. Since EFI uses
   the identical mapping, this routine returns the physical address same as the
   virtual address for most of the addresses. an address above 4GB cannot
   generally be used as a device address, it needs to be mapped to a lower
   physical address. This routine does not call the map routine itself, but it
   assumes that the mapping was done at the time of providing the address to
   UNDI. This routine just looks up the address in a map table (which is the v2p
   structure chain).

   @param  CpuAddr        Virtual address.
   @param  DeviceAddrPtr  Pointer to the physical address, or 0 in case of any
                          error.

 **/
 VOID
 EFIAPI
 SnpUndi32CallbackV2p30 (
   IN UINT64     CpuAddr,
   IN OUT UINT64 DeviceAddrPtr
   )
 {
   V2P  *V2p;
   //
   // Do nothing if virtual address is zero or physical pointer is NULL.
   // No need to map if the virtual address is within 4GB limit since
   // EFI uses identical mapping
   //
   if ((CpuAddr == 0) || (DeviceAddrPtr == 0)) {
     DEBUG ((EFI_D_NET, "\nv2p: Null virtual address or physical pointer.\n"));
     return ;
   }

   if (CpuAddr < FOUR_GIGABYTES) {
     *(UINT64 *) (UINTN) DeviceAddrPtr = CpuAddr;
     return ;
   }
   //
   // SNP creates a vaddr tp paddr mapping at the time of calling undi with any
   // big address, this callback routine just looks up in the v2p list and
   // returns the physical address for any given virtual address.
   //
   if (FindV2p (&V2p, (VOID *) (UINTN) CpuAddr) != EFI_SUCCESS) {
     *(UINT64 *) (UINTN) DeviceAddrPtr = CpuAddr;
   } else {
     *(UINT64 *) (UINTN) DeviceAddrPtr = V2p->PhysicalAddress;
   }
 }

 /**
   Acquire or release a lock of an exclusive access to a critical section of the
   code/data.

   This is a callback routine supplied to UNDI at undi_start time.

   @param Enable   Non-zero indicates acquire; Zero indicates release.

 **/
 VOID
 EFIAPI
 SnpUndi32CallbackBlock30 (
   IN UINT32 Enable
   )
 {
   //
   // tcpip was calling snp at tpl_notify and if we acquire a lock that was
   // created at a lower level (TPL_CALLBACK) it gives an assert!
   //
   if (mInitializeLock) {
     EfiInitializeLock (&mLock, TPL_NOTIFY);
     mInitializeLock = FALSE;
   }

   if (Enable != 0) {
     EfiAcquireLock (&mLock);
   } else {
     EfiReleaseLock (&mLock);
   }
 }

 /**
   Delay MicroSeconds of micro seconds.

   This is a callback routine supplied to UNDI at undi_start time.

   @param MicroSeconds  Number of micro seconds to pause, ususlly multiple of 10.

 **/
 VOID
 EFIAPI
 SnpUndi32CallbackDelay30 (
   IN UINT64 MicroSeconds
   )
 {
   if (MicroSeconds != 0) {
     gBS->Stall ((UINTN) MicroSeconds);
   }
 }

 /**
   IO routine for UNDI.

   This is a callback routine supplied to UNDI at undi_start time. This is not
   currently being used by UNDI3.0 because Undi3.0 uses io/mem offsets relative
   to the beginning of the device io/mem address and so it needs to use the
   PCI_IO_FUNCTION that abstracts the start of the device's io/mem addresses.
   Since SNP cannot retrive the context of the undi3.0 interface it cannot use
   the PCI_IO_FUNCTION that specific for that NIC and uses one global IO
   functions structure, this does not work. This however works fine for EFI1.0
   Undis because they use absolute addresses for io/mem access.

   @param ReadOrWrite  Indicates read or write, IO or Memory.
   @param NumBytes     Number of bytes to read or write.
   @param Address      IO or memory address to read from or write to.
   @param BufferAddr   Memory location to read into or that contains the bytes to
                       write.

 **/
 VOID
 EFIAPI
 SnpUndi32CallbackMemio30 (
   IN UINT8      ReadOrWrite,
   IN UINT8      NumBytes,
   IN UINT64     Address,
   IN OUT UINT64 BufferAddr
   )
 {
   EFI_PCI_IO_PROTOCOL_WIDTH Width;

   switch (NumBytes) {
   case 2:
     Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 1;
     break;

   case 4:
     Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 2;
     break;

   case 8:
     Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 3;
     break;

   default:
     Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 0;
   }

   switch (ReadOrWrite) {
   case PXE_IO_READ:
     mPciIo->Io.Read (
                  mPciIo,
                  Width,
                  1,    // BAR 1, IO base address
                  Address,
                  1,    // count
                  (VOID *) (UINTN) BufferAddr
                  );
     break;

   case PXE_IO_WRITE:
     mPciIo->Io.Write (
                  mPciIo,
                  Width,
                  1,    // BAR 1, IO base address
                  Address,
                  1,    // count
                  (VOID *) (UINTN) BufferAddr
                  );
     break;

   case PXE_MEM_READ:
     mPciIo->Mem.Read (
                   mPciIo,
                   Width,
                   0,  // BAR 0, Memory base address
                   Address,
                   1,  // count
                   (VOID *) (UINTN) BufferAddr
                   );
     break;

   case PXE_MEM_WRITE:
     mPciIo->Mem.Write (
                   mPciIo,
                   Width,
                   0,  // BAR 0, Memory base address
                   Address,
                   1,  // count
                   (VOID *) (UINTN) BufferAddr
                   );
     break;
   }

   return ;
 }

 /**
   Acquire or release a lock of the exclusive access to a critical section of the
   code/data.

   This is a callback routine supplied to UNDI3.1 at undi_start time.
   New callbacks for 3.1: there won't be a virtual2physical callback for UNDI 3.1
   because undi3.1 uses the MemMap call to map the required address by itself!

   @param UniqueId  This was supplied to UNDI at Undi_Start, SNP uses this to
                       store Undi interface context (Undi does not read or write
                       this variable).
   @param Enable    Non-zero indicates acquire; Zero indicates release.

 **/
 VOID
 EFIAPI
 SnpUndi32CallbackBlock (
   IN UINT64 UniqueId,
   IN UINT32 Enable
   )
 {
   SNP_DRIVER  *Snp;

   Snp = (SNP_DRIVER *) (UINTN) UniqueId;
   //
   // tcpip was calling snp at tpl_notify and when we acquire a lock that was
   // created at a lower level (TPL_CALLBACK) it gives an assert!
   //
   if (Enable != 0) {
     EfiAcquireLock (&Snp->Lock);
   } else {
     EfiReleaseLock (&Snp->Lock);
   }
 }

 /**
   Delay MicroSeconds of micro seconds.

   This is a callback routine supplied to UNDI at undi_start time.

   @param UniqueId      This was supplied to UNDI at Undi_Start, SNP uses this to
                        store Undi interface context (Undi does not read or write
                        this variable).
   @param MicroSeconds  Number of micro seconds to pause, ususlly multiple of 10.

 **/
 VOID
 EFIAPI
 SnpUndi32CallbackDelay (
   IN UINT64 UniqueId,
   IN UINT64 MicroSeconds
   )
 {
   if (MicroSeconds != 0) {
     gBS->Stall ((UINTN) MicroSeconds);
   }
 }

 /**
   IO routine for UNDI3.1.

   This is a callback routine supplied to UNDI at undi_start time.

   @param UniqueId       This was supplied to UNDI at Undi_Start, SNP uses this
                         to store Undi interface context (Undi does not read or
                         write this variable).
   @param ReadOrWrite    Indicates read or write, IO or Memory.
   @param NumBytes       Number of bytes to read or write.
   @param MemOrPortAddr  IO or memory address to read from or write to.
   @param BufferPtr      Memory location to read into or that contains the bytes
                         to write.

 **/
 VOID
 EFIAPI
 SnpUndi32CallbackMemio (
   IN UINT64     UniqueId,
   IN UINT8      ReadOrWrite,
   IN UINT8      NumBytes,
   IN UINT64     MemOrPortAddr,
   IN OUT UINT64 BufferPtr
   )
 {
   SNP_DRIVER                *Snp;
   EFI_PCI_IO_PROTOCOL_WIDTH Width;

   Snp   = (SNP_DRIVER *) (UINTN) UniqueId;

   Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 0;
   switch (NumBytes) {
   case 2:
     Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 1;
     break;

   case 4:
     Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 2;
     break;

   case 8:
     Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 3;
     break;
   }

   switch (ReadOrWrite) {
   case PXE_IO_READ:
     Snp->PciIo->Io.Read (
                      Snp->PciIo,
                      Width,
                      Snp->IoBarIndex,      // BAR 1 (for 32bit regs), IO base address
                      MemOrPortAddr,
                      1,                    // count
                      (VOID *) (UINTN) BufferPtr
                      );
     break;

   case PXE_IO_WRITE:
     Snp->PciIo->Io.Write (
                      Snp->PciIo,
                      Width,
                      Snp->IoBarIndex,      // BAR 1 (for 32bit regs), IO base address
                      MemOrPortAddr,
                      1,                    // count
                      (VOID *) (UINTN) BufferPtr
                      );
     break;

   case PXE_MEM_READ:
     Snp->PciIo->Mem.Read (
                       Snp->PciIo,
                       Width,
                       Snp->MemoryBarIndex,  // BAR 0, Memory base address
                       MemOrPortAddr,
                       1,                    // count
                       (VOID *) (UINTN) BufferPtr
                       );
     break;

   case PXE_MEM_WRITE:
     Snp->PciIo->Mem.Write (
                       Snp->PciIo,
                       Width,
                       Snp->MemoryBarIndex,  // BAR 0, Memory base address
                       MemOrPortAddr,
                       1,                    // count
                       (VOID *) (UINTN) BufferPtr
                       );
     break;
   }

   return ;
 }

 /**
   Map a CPU address to a device address.

   This is a callback routine supplied to UNDI at undi_start time.

   @param UniqueId      This was supplied to UNDI at Undi_Start, SNP uses this to
                        store Undi interface context (Undi does not read or write
                        this variable).
   @param CpuAddr       Virtual address to be mapped.
   @param NumBytes      Size of memory to be mapped.
   @param Direction     Direction of data flow for this memory's usage:
                        cpu->device, device->cpu or both ways.
   @param DeviceAddrPtr Pointer to return the mapped device address.

 **/
 VOID
 EFIAPI
 SnpUndi32CallbackMap (
   IN UINT64     UniqueId,
   IN UINT64     CpuAddr,
   IN UINT32     NumBytes,
   IN UINT32     Direction,
   IN OUT UINT64 DeviceAddrPtr
   )
 {
   EFI_PHYSICAL_ADDRESS          *DevAddrPtr;
   EFI_PCI_IO_PROTOCOL_OPERATION DirectionFlag;
   UINTN                         BuffSize;
   SNP_DRIVER                    *Snp;
   UINTN                         Index;
   EFI_STATUS                    Status;

   BuffSize    = (UINTN) NumBytes;
   Snp         = (SNP_DRIVER *) (UINTN) UniqueId;
   DevAddrPtr  = (EFI_PHYSICAL_ADDRESS *) (UINTN) DeviceAddrPtr;

   if (CpuAddr == 0) {
     *DevAddrPtr = 0;
     return ;
   }

   switch (Direction) {
   case TO_AND_FROM_DEVICE:
     DirectionFlag = EfiPciIoOperationBusMasterCommonBuffer;
     break;

   case FROM_DEVICE:
     DirectionFlag = EfiPciIoOperationBusMasterWrite;
     break;

   case TO_DEVICE:
     DirectionFlag = EfiPciIoOperationBusMasterRead;
     break;

   default:
     *DevAddrPtr = 0;
     //
     // any non zero indicates error!
     //
     return ;
   }
   //
   // find an unused map_list entry
   //
   for (Index = 0; Index < MAX_MAP_LENGTH; Index++) {
     if (Snp->MapList[Index].VirtualAddress == 0) {
       break;
     }
   }

   if (Index >= MAX_MAP_LENGTH) {
     DEBUG ((EFI_D_INFO, "SNP maplist is FULL\n"));
     *DevAddrPtr = 0;
     return ;
   }

   Snp->MapList[Index].VirtualAddress = (EFI_PHYSICAL_ADDRESS) CpuAddr;

   Status = Snp->PciIo->Map (
                          Snp->PciIo,
                          DirectionFlag,
                          (VOID *) (UINTN) CpuAddr,
                          &BuffSize,
                          DevAddrPtr,
                          &(Snp->MapList[Index].MapCookie)
                          );
   if (Status != EFI_SUCCESS) {
     *DevAddrPtr                        = 0;
     Snp->MapList[Index].VirtualAddress = 0;
   }

   return ;
 }

 /**
   Unmap an address that was previously mapped using map callback.

   This is a callback routine supplied to UNDI at undi_start time.

   @param UniqueId    This was supplied to UNDI at Undi_Start, SNP uses this to
                      store. Undi interface context (Undi does not read or write
                      this variable).
   @param CpuAddr     Virtual address that was mapped.
   @param NumBytes    Size of memory mapped.
   @param Direction   Direction of data flow for this memory's usage:
                      cpu->device, device->cpu or both ways.
   @param DeviceAddr  The mapped device address.

 **/
 VOID
 EFIAPI
 SnpUndi32CallbackUnmap (
   IN UINT64 UniqueId,
   IN UINT64 CpuAddr,
   IN UINT32 NumBytes,
   IN UINT32 Direction,
   IN UINT64 DeviceAddr
   )
 {
   SNP_DRIVER  *Snp;
   UINT16      Index;

   Snp = (SNP_DRIVER *) (UINTN) UniqueId;

   for (Index = 0; Index < MAX_MAP_LENGTH; Index++) {
     if (Snp->MapList[Index].VirtualAddress == CpuAddr) {
       break;
     }
   }

   if (Index >= MAX_MAP_LENGTH) {
     DEBUG ((EFI_D_ERROR, "SNP could not find a mapping, failed to unmap.\n"));
     return ;
   }

   Snp->PciIo->Unmap (Snp->PciIo, Snp->MapList[Index].MapCookie);
   Snp->MapList[Index].VirtualAddress = 0;
   Snp->MapList[Index].MapCookie      = NULL;
   return ;
 }

 /**
   Synchronize the virtual buffer contents with the mapped buffer contents.

   This is a callback routine supplied to UNDI at undi_start time. The virtual
   and mapped buffers need not correspond to the same physical memory (especially
   if the virtual address is > 4GB). Depending on the direction for which the
   buffer is mapped, undi will need to synchronize their contents whenever it
   writes to/reads from the buffer using either the cpu address or the device
   address.
   EFI does not provide a sync call since virt=physical, we should just do the
   synchronization ourselves here.

   @param UniqueId    This was supplied to UNDI at Undi_Start, SNP uses this to
                      store Undi interface context (Undi does not read or write
                      this variable).
   @param CpuAddr     Virtual address that was mapped.
   @param NumBytes    Size of memory mapped.
   @param Direction   Direction of data flow for this memory's usage:
                      cpu->device, device->cpu or both ways.
   @param DeviceAddr  The mapped device address.

 **/
 VOID
 EFIAPI
 SnpUndi32CallbackSync (
   IN UINT64             UniqueId,
   IN UINT64             CpuAddr,
   IN UINT32             NumBytes,
   IN UINT32             Direction,
   IN UINT64             DeviceAddr
   )
 {
   if ((CpuAddr == 0) || (DeviceAddr == 0) || (NumBytes == 0)) {
     return ;

   }

   switch (Direction) {
   case FROM_DEVICE:
     CopyMem ((UINT8 *) (UINTN) CpuAddr, (UINT8 *) (UINTN) DeviceAddr, NumBytes);
     break;

   case TO_DEVICE:
     CopyMem ((UINT8 *) (UINTN) DeviceAddr, (UINT8 *) (UINTN) CpuAddr, NumBytes);
     break;
   }

   return ;
 }
	/** @file
	This file contains two sets of callback routines for undi3.0 and undi3.1.
	the callback routines for Undi3.1 have an extra parameter UniqueId which
	stores the interface context for the NIC that snp is trying to talk.

	Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
	This program and the accompanying materials
	are licensed and made available under the terms and conditions of the BSD License
	which accompanies this distribution. The full text of the license may be found at
	http://opensource.org/licenses/bsd-license.php

	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

	**/

	#include "Snp.h"

	//
	// Global variables
	// these 2 global variables are used only for 3.0 undi. we could not place
	// them in the snp structure because we will not know which snp structure
	// in the callback context!
	//
	BOOLEAN mInitializeLock = TRUE;
	EFI_LOCK mLock;

	//
	// End Global variables
	//
	extern EFI_PCI_IO_PROTOCOL *mPciIo;

	/**
	Convert a virtual or CPU address provided by SNP to a physical or device
	address.

	This is a callback routine supplied to UNDI at undi_start time. Since EFI uses
	the identical mapping, this routine returns the physical address same as the
	virtual address for most of the addresses. an address above 4GB cannot
	generally be used as a device address, it needs to be mapped to a lower
	physical address. This routine does not call the map routine itself, but it
	assumes that the mapping was done at the time of providing the address to
	UNDI. This routine just looks up the address in a map table (which is the v2p
	structure chain).

	@param CpuAddr Virtual address.
	@param DeviceAddrPtr Pointer to the physical address, or 0 in case of any
	error.

	**/
	VOID
	EFIAPI
	SnpUndi32CallbackV2p30 (
	IN UINT64 CpuAddr,
	IN OUT UINT64 DeviceAddrPtr
	)
	{
	V2P *V2p;
	//
	// Do nothing if virtual address is zero or physical pointer is NULL.
	// No need to map if the virtual address is within 4GB limit since
	// EFI uses identical mapping
	//
	if ((CpuAddr == 0) \|\| (DeviceAddrPtr == 0)) {
	DEBUG ((EFI_D_NET, "\nv2p: Null virtual address or physical pointer.\n"));
	return ;
	}

	if (CpuAddr < FOUR_GIGABYTES) {
	(UINT64 ) (UINTN) DeviceAddrPtr = CpuAddr;
	return ;
	}
	//
	// SNP creates a vaddr tp paddr mapping at the time of calling undi with any
	// big address, this callback routine just looks up in the v2p list and
	// returns the physical address for any given virtual address.
	//
	if (FindV2p (&V2p, (VOID *) (UINTN) CpuAddr) != EFI_SUCCESS) {
	(UINT64 ) (UINTN) DeviceAddrPtr = CpuAddr;
	} else {
	(UINT64 ) (UINTN) DeviceAddrPtr = V2p->PhysicalAddress;
	}
	}

	/**
	Acquire or release a lock of an exclusive access to a critical section of the
	code/data.

	This is a callback routine supplied to UNDI at undi_start time.

	@param Enable Non-zero indicates acquire; Zero indicates release.

	**/
	VOID
	EFIAPI
	SnpUndi32CallbackBlock30 (
	IN UINT32 Enable
	)
	{
	//
	// tcpip was calling snp at tpl_notify and if we acquire a lock that was
	// created at a lower level (TPL_CALLBACK) it gives an assert!
	//
	if (mInitializeLock) {
	EfiInitializeLock (&mLock, TPL_NOTIFY);
	mInitializeLock = FALSE;
	}

	if (Enable != 0) {
	EfiAcquireLock (&mLock);
	} else {
	EfiReleaseLock (&mLock);
	}
	}

	/**
	Delay MicroSeconds of micro seconds.

	This is a callback routine supplied to UNDI at undi_start time.

	@param MicroSeconds Number of micro seconds to pause, ususlly multiple of 10.

	**/
	VOID
	EFIAPI
	SnpUndi32CallbackDelay30 (
	IN UINT64 MicroSeconds
	)
	{
	if (MicroSeconds != 0) {
	gBS->Stall ((UINTN) MicroSeconds);
	}
	}

	/**
	IO routine for UNDI.

	This is a callback routine supplied to UNDI at undi_start time. This is not
	currently being used by UNDI3.0 because Undi3.0 uses io/mem offsets relative
	to the beginning of the device io/mem address and so it needs to use the
	PCI_IO_FUNCTION that abstracts the start of the device's io/mem addresses.
	Since SNP cannot retrive the context of the undi3.0 interface it cannot use
	the PCI_IO_FUNCTION that specific for that NIC and uses one global IO
	functions structure, this does not work. This however works fine for EFI1.0
	Undis because they use absolute addresses for io/mem access.

	@param ReadOrWrite Indicates read or write, IO or Memory.
	@param NumBytes Number of bytes to read or write.
	@param Address IO or memory address to read from or write to.
	@param BufferAddr Memory location to read into or that contains the bytes to
	write.

	**/
	VOID
	EFIAPI
	SnpUndi32CallbackMemio30 (
	IN UINT8 ReadOrWrite,
	IN UINT8 NumBytes,
	IN UINT64 Address,
	IN OUT UINT64 BufferAddr
	)
	{
	EFI_PCI_IO_PROTOCOL_WIDTH Width;

	switch (NumBytes) {
	case 2:
	Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 1;
	break;

	case 4:
	Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 2;
	break;

	case 8:
	Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 3;
	break;

	default:
	Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 0;
	}

	switch (ReadOrWrite) {
	case PXE_IO_READ:
	mPciIo->Io.Read (
	mPciIo,
	Width,
	1, // BAR 1, IO base address
	Address,
	1, // count
	(VOID *) (UINTN) BufferAddr
	);
	break;

	case PXE_IO_WRITE:
	mPciIo->Io.Write (
	mPciIo,
	Width,
	1, // BAR 1, IO base address
	Address,
	1, // count
	(VOID *) (UINTN) BufferAddr
	);
	break;

	case PXE_MEM_READ:
	mPciIo->Mem.Read (
	mPciIo,
	Width,
	0, // BAR 0, Memory base address
	Address,
	1, // count
	(VOID *) (UINTN) BufferAddr
	);
	break;

	case PXE_MEM_WRITE:
	mPciIo->Mem.Write (
	mPciIo,
	Width,
	0, // BAR 0, Memory base address
	Address,
	1, // count
	(VOID *) (UINTN) BufferAddr
	);
	break;
	}

	return ;
	}

	/**
	Acquire or release a lock of the exclusive access to a critical section of the
	code/data.

	This is a callback routine supplied to UNDI3.1 at undi_start time.
	New callbacks for 3.1: there won't be a virtual2physical callback for UNDI 3.1
	because undi3.1 uses the MemMap call to map the required address by itself!

	@param UniqueId This was supplied to UNDI at Undi_Start, SNP uses this to
	store Undi interface context (Undi does not read or write
	this variable).
	@param Enable Non-zero indicates acquire; Zero indicates release.

	**/
	VOID
	EFIAPI
	SnpUndi32CallbackBlock (
	IN UINT64 UniqueId,
	IN UINT32 Enable
	)
	{
	SNP_DRIVER *Snp;

	Snp = (SNP_DRIVER *) (UINTN) UniqueId;
	//
	// tcpip was calling snp at tpl_notify and when we acquire a lock that was
	// created at a lower level (TPL_CALLBACK) it gives an assert!
	//
	if (Enable != 0) {
	EfiAcquireLock (&Snp->Lock);
	} else {
	EfiReleaseLock (&Snp->Lock);
	}
	}

	/**
	Delay MicroSeconds of micro seconds.

	This is a callback routine supplied to UNDI at undi_start time.

	@param UniqueId This was supplied to UNDI at Undi_Start, SNP uses this to
	store Undi interface context (Undi does not read or write
	this variable).
	@param MicroSeconds Number of micro seconds to pause, ususlly multiple of 10.

	**/
	VOID
	EFIAPI
	SnpUndi32CallbackDelay (
	IN UINT64 UniqueId,
	IN UINT64 MicroSeconds
	)
	{
	if (MicroSeconds != 0) {
	gBS->Stall ((UINTN) MicroSeconds);
	}
	}

	/**
	IO routine for UNDI3.1.

	This is a callback routine supplied to UNDI at undi_start time.

	@param UniqueId This was supplied to UNDI at Undi_Start, SNP uses this
	to store Undi interface context (Undi does not read or
	write this variable).
	@param ReadOrWrite Indicates read or write, IO or Memory.
	@param NumBytes Number of bytes to read or write.
	@param MemOrPortAddr IO or memory address to read from or write to.
	@param BufferPtr Memory location to read into or that contains the bytes
	to write.

	**/
	VOID
	EFIAPI
	SnpUndi32CallbackMemio (
	IN UINT64 UniqueId,
	IN UINT8 ReadOrWrite,
	IN UINT8 NumBytes,
	IN UINT64 MemOrPortAddr,
	IN OUT UINT64 BufferPtr
	)
	{
	SNP_DRIVER *Snp;
	EFI_PCI_IO_PROTOCOL_WIDTH Width;

	Snp = (SNP_DRIVER *) (UINTN) UniqueId;

	Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 0;
	switch (NumBytes) {
	case 2:
	Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 1;
	break;

	case 4:
	Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 2;
	break;

	case 8:
	Width = (EFI_PCI_IO_PROTOCOL_WIDTH) 3;
	break;
	}

	switch (ReadOrWrite) {
	case PXE_IO_READ:
	Snp->PciIo->Io.Read (
	Snp->PciIo,
	Width,
	Snp->IoBarIndex, // BAR 1 (for 32bit regs), IO base address
	MemOrPortAddr,
	1, // count
	(VOID *) (UINTN) BufferPtr
	);
	break;

	case PXE_IO_WRITE:
	Snp->PciIo->Io.Write (
	Snp->PciIo,
	Width,
	Snp->IoBarIndex, // BAR 1 (for 32bit regs), IO base address
	MemOrPortAddr,
	1, // count
	(VOID *) (UINTN) BufferPtr
	);
	break;

	case PXE_MEM_READ:
	Snp->PciIo->Mem.Read (
	Snp->PciIo,
	Width,
	Snp->MemoryBarIndex, // BAR 0, Memory base address
	MemOrPortAddr,
	1, // count
	(VOID *) (UINTN) BufferPtr
	);
	break;

	case PXE_MEM_WRITE:
	Snp->PciIo->Mem.Write (
	Snp->PciIo,
	Width,
	Snp->MemoryBarIndex, // BAR 0, Memory base address
	MemOrPortAddr,
	1, // count
	(VOID *) (UINTN) BufferPtr
	);
	break;
	}

	return ;
	}

	/**
	Map a CPU address to a device address.

	This is a callback routine supplied to UNDI at undi_start time.

	@param UniqueId This was supplied to UNDI at Undi_Start, SNP uses this to
	store Undi interface context (Undi does not read or write
	this variable).
	@param CpuAddr Virtual address to be mapped.
	@param NumBytes Size of memory to be mapped.
	@param Direction Direction of data flow for this memory's usage:
	cpu->device, device->cpu or both ways.
	@param DeviceAddrPtr Pointer to return the mapped device address.

	**/
	VOID
	EFIAPI
	SnpUndi32CallbackMap (
	IN UINT64 UniqueId,
	IN UINT64 CpuAddr,
	IN UINT32 NumBytes,
	IN UINT32 Direction,
	IN OUT UINT64 DeviceAddrPtr
	)
	{
	EFI_PHYSICAL_ADDRESS *DevAddrPtr;
	EFI_PCI_IO_PROTOCOL_OPERATION DirectionFlag;
	UINTN BuffSize;
	SNP_DRIVER *Snp;
	UINTN Index;
	EFI_STATUS Status;

	BuffSize = (UINTN) NumBytes;
	Snp = (SNP_DRIVER *) (UINTN) UniqueId;
	DevAddrPtr = (EFI_PHYSICAL_ADDRESS *) (UINTN) DeviceAddrPtr;

	if (CpuAddr == 0) {
	*DevAddrPtr = 0;
	return ;
	}

	switch (Direction) {
	case TO_AND_FROM_DEVICE:
	DirectionFlag = EfiPciIoOperationBusMasterCommonBuffer;
	break;

	case FROM_DEVICE:
	DirectionFlag = EfiPciIoOperationBusMasterWrite;
	break;

	case TO_DEVICE:
	DirectionFlag = EfiPciIoOperationBusMasterRead;
	break;

	default:
	*DevAddrPtr = 0;
	//
	// any non zero indicates error!
	//
	return ;
	}
	//
	// find an unused map_list entry
	//
	for (Index = 0; Index < MAX_MAP_LENGTH; Index++) {
	if (Snp->MapList[Index].VirtualAddress == 0) {
	break;
	}
	}

	if (Index >= MAX_MAP_LENGTH) {
	DEBUG ((EFI_D_INFO, "SNP maplist is FULL\n"));
	*DevAddrPtr = 0;
	return ;
	}

	Snp->MapList[Index].VirtualAddress = (EFI_PHYSICAL_ADDRESS) CpuAddr;

	Status = Snp->PciIo->Map (
	Snp->PciIo,
	DirectionFlag,
	(VOID *) (UINTN) CpuAddr,
	&BuffSize,
	DevAddrPtr,
	&(Snp->MapList[Index].MapCookie)
	);
	if (Status != EFI_SUCCESS) {
	*DevAddrPtr = 0;
	Snp->MapList[Index].VirtualAddress = 0;
	}

	return ;
	}

	/**
	Unmap an address that was previously mapped using map callback.

	This is a callback routine supplied to UNDI at undi_start time.

	@param UniqueId This was supplied to UNDI at Undi_Start, SNP uses this to
	store. Undi interface context (Undi does not read or write
	this variable).
	@param CpuAddr Virtual address that was mapped.
	@param NumBytes Size of memory mapped.
	@param Direction Direction of data flow for this memory's usage:
	cpu->device, device->cpu or both ways.
	@param DeviceAddr The mapped device address.

	**/
	VOID
	EFIAPI
	SnpUndi32CallbackUnmap (
	IN UINT64 UniqueId,
	IN UINT64 CpuAddr,
	IN UINT32 NumBytes,
	IN UINT32 Direction,
	IN UINT64 DeviceAddr
	)
	{
	SNP_DRIVER *Snp;
	UINT16 Index;

	Snp = (SNP_DRIVER *) (UINTN) UniqueId;

	for (Index = 0; Index < MAX_MAP_LENGTH; Index++) {
	if (Snp->MapList[Index].VirtualAddress == CpuAddr) {
	break;
	}
	}

	if (Index >= MAX_MAP_LENGTH) {
	DEBUG ((EFI_D_ERROR, "SNP could not find a mapping, failed to unmap.\n"));
	return ;
	}

	Snp->PciIo->Unmap (Snp->PciIo, Snp->MapList[Index].MapCookie);
	Snp->MapList[Index].VirtualAddress = 0;
	Snp->MapList[Index].MapCookie = NULL;
	return ;
	}

	/**
	Synchronize the virtual buffer contents with the mapped buffer contents.

	This is a callback routine supplied to UNDI at undi_start time. The virtual
	and mapped buffers need not correspond to the same physical memory (especially
	if the virtual address is > 4GB). Depending on the direction for which the
	buffer is mapped, undi will need to synchronize their contents whenever it
	writes to/reads from the buffer using either the cpu address or the device
	address.
	EFI does not provide a sync call since virt=physical, we should just do the
	synchronization ourselves here.

	@param UniqueId This was supplied to UNDI at Undi_Start, SNP uses this to
	store Undi interface context (Undi does not read or write
	this variable).
	@param CpuAddr Virtual address that was mapped.
	@param NumBytes Size of memory mapped.
	@param Direction Direction of data flow for this memory's usage:
	cpu->device, device->cpu or both ways.
	@param DeviceAddr The mapped device address.

	**/
	VOID
	EFIAPI
	SnpUndi32CallbackSync (
	IN UINT64 UniqueId,
	IN UINT64 CpuAddr,
	IN UINT32 NumBytes,
	IN UINT32 Direction,
	IN UINT64 DeviceAddr
	)
	{
	if ((CpuAddr == 0) \|\| (DeviceAddr == 0) \|\| (NumBytes == 0)) {
	return ;

	}

	switch (Direction) {
	case FROM_DEVICE:
	CopyMem ((UINT8 ) (UINTN) CpuAddr, (UINT8 ) (UINTN) DeviceAddr, NumBytes);
	break;

	case TO_DEVICE:
	CopyMem ((UINT8 ) (UINTN) DeviceAddr, (UINT8 ) (UINTN) CpuAddr, NumBytes);
	break;
	}

	return ;
	}