183 lines
5.6 KiB
C
183 lines
5.6 KiB
C
/******************************Module*Header**********************************\
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*
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* ***************
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* * SAMPLE CODE *
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* ***************
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*
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* Module Name: mini.c
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*
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* Content:
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*
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* Copyright (c) 1994-1998 3Dlabs Inc. Ltd. All rights reserved.
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* Copyright (c) 1995-1999 Microsoft Corporation. All rights reserved.
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\*****************************************************************************/
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#include "precomp.h"
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//-----------------------------------------------------------------------------
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//
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// AllocateDMABuffer
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//
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// Allocate physical continous memory for DMA operation. This function returns
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// a pointer to a previously allocated DMA buffer if there is still an unfreed
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// allocation left. That way the reallocation of continous memory can be
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// avoided when a new ppdev is created on lets say a mode switch, since
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// allocation of continous memory cannot be guaranteed. The memory is only
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// physically freed after all allocations have called a FreeDMABuffer.
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//
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// Calls to AllocateDMABuffer and FreeDMABuffer should be paired, otherwise
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// the usage count logic in the miniport driver gets confused!
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//
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// The VideoPort currently restricts the size of a DMA buffer to 256kb.
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//
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// hDriver-------videoport driver handle
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// plSize--------pointer to LONG size of requested DMA buffer. Returns size
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// of allocated DMA buffer
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// (return value can be smaller than requested size)
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// ppVirtAddr----returns virtual address of requested DMA buffer.
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// pPhysAddr-----returns physical address of DMA buffer as seen from graphics
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// device.
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//
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// return TRUE, allocation successful
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// FALSE, allocation failed
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//
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//-----------------------------------------------------------------------------
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BOOL
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AllocateDMABuffer( HANDLE hDriver,
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PLONG plSize,
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PULONG *ppVirtAddr,
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LARGE_INTEGER *pPhysAddr)
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{
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LINE_DMA_BUFFER ldb;
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ldb.size = *plSize;
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ldb.virtAddr = 0;
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ldb.cacheEnabled = TRUE;
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*ppVirtAddr=0;
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pPhysAddr->HighPart=
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pPhysAddr->LowPart=0;
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ULONG ulLength = sizeof(LINE_DMA_BUFFER);
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if (EngDeviceIoControl( hDriver,
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IOCTL_VIDEO_QUERY_LINE_DMA_BUFFER,
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(PVOID)&ldb,
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ulLength,
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(PVOID)&ldb,
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ulLength,
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&ulLength))
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{
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return(FALSE);
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}
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*ppVirtAddr=(PULONG)ldb.virtAddr;
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if (ldb.virtAddr!=NULL)
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{
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*pPhysAddr=ldb.physAddr;
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*plSize=ldb.size;
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return TRUE;
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}
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return FALSE;
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}
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//-----------------------------------------------------------------------------
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//
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// FreeDMABuffer
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//
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// free continous buffer previously allocated by AllocateDMABuffer.
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//
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//-----------------------------------------------------------------------------
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BOOL
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FreeDMABuffer( HANDLE hDriver,
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PVOID pVirtAddr)
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{
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LINE_DMA_BUFFER ldb;
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ldb.size = 0;
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ldb.virtAddr = pVirtAddr;
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ULONG ulLength = sizeof(LINE_DMA_BUFFER);
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if (EngDeviceIoControl( hDriver,
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IOCTL_VIDEO_QUERY_LINE_DMA_BUFFER,
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(PVOID)&ldb,
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ulLength,
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NULL,
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0,
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&ulLength))
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{
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return FALSE;
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}
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return TRUE;
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}
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//-----------------------------------------------------------------------------
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//
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// StallExecution
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//
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// calls VideoPortStallExecution in the miniport for defined delay when
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// polling Permedia registers. VideoPortStallexecution does not yield
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// to another process and should only be used in rare cases.
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//
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// hDriver--------handle to videoport
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// ulMicroSeconds-number of microseconds to stall CPU execution
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//
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//-----------------------------------------------------------------------------
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VOID
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StallExecution( HANDLE hDriver, ULONG ulMicroSeconds)
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{
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ULONG Length = 0;
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EngDeviceIoControl(hDriver,
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IOCTL_VIDEO_STALL_EXECUTION,
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&ulMicroSeconds,
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sizeof(ULONG),
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NULL,
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0,
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&Length);
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}
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//-----------------------------------------------------------------------------
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//
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// GetPInterlockedExchange
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//
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// We need to call the same InterlockedExchange function from the display
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// driver and the miniport to make sure they work properly. The miniport
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// will give us a pointer to the function which we will call directly...
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// On Alpha and Risc machines, InterlockedExchange compiles as inline and
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// we don't need to call in the kernel.
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//
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// note: the InterlockedExchange function exported from ntoskrnl has calling
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// convention __fastcall.
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//
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//-----------------------------------------------------------------------------
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#if defined(_X86_)
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PVOID
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GetPInterlockedExchange( HANDLE hDriver)
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{
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ULONG Length = 0;
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PVOID pWorkPtr=NULL;
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if (EngDeviceIoControl( hDriver,
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IOCTL_VIDEO_QUERY_INTERLOCKEDEXCHANGE,
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NULL,
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0,
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&pWorkPtr,
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sizeof(pWorkPtr),
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&Length))
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{
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return NULL;
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}
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return pWorkPtr;
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}
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#endif |