Re: IRQL He11
- From: Slide-O-Mix <SlideOMix@xxxxxxxxxxxxxxxxxxxxxxxxx>
- Date: Wed, 2 Aug 2006 20:31:01 -0700
Ok, that makes sense, I am allocating one of the buffers from the
NonPagedPool as can be seen from my code. The other is being allocated using
AllocateCommonBuffer on a DMA adapter, is there anything special I need to do
for that buffer? I think that might be where my BSOD's are coming from in
relation to the IRQL not less than or equal errors I am seeing.
"Don Burn" wrote:
You can call RtlCopyMemory from any IRQL as long as both buffers are.
non-paged. You should not be building a MDL for this, just allocate the
memory from NonPagedPool. Of course depending on the frequency of DMA
operations, you could also just queue a work item and have it write the data
from the DMA buffer.
--
Don Burn (MVP, Windows DDK)
Windows 2k/XP/2k3 Filesystem and Driver Consulting
http://www.windrvr.com
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"Slide-O-Mix" <SlideOMix@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:AC6A0D46-DBAA-43C7-8D71-BE7C08DC6C97@xxxxxxxxxxxxxxxx
I am currently modifying a driver we use internally that interfaces with a
PCI board. We are adding a DMA capability to the board where we can DMA
data
to and from specific memory regions, that is working correctly and I get
interrupts and get into my DpcForIsr, etc, BUT what I need to do when I
get
data from the DMA is write it out to a file. Now, I know that in my Dpc I
can't call ZwWriteFile to write out to my file that I opened previously,
so I
wrote code to setup a work item to do it for me. I am trying to copy the
data
from the NonPagedPool physical memory that the DMA is going into to
another
buffer that the work item can use to write to the file. I am having major
issues because obviously RtlCopyMemory can't be called in the Dpc either
because the IRQL is wrong. I tried getting an MDL and locking the pages in
memory so they are resident before calling RtlCopyMemory, but I am having
a
heck of a time. If anyone can help out I would appreciate it greatly,
below
is the portion of the code that I am having problems with, it is contained
in
a DpcForIsr.
// allocate a work item context
pWriteCtx = (PWRITECTX_INFO) ExAllocatePoolWithTag(
NonPagedPool,
sizeof(WRITECTX_INFO),
'xtcW'
);
// assign file handle
pWriteCtx->hFile = pDmaStream->hFile;
pWriteCtx->pBuffer = (U32*)ExAllocatePoolWithTag(
NonPagedPool,
pBuffer->Size,
'Wmem'
);
if(pWriteCtx->pBuffer == NULL)
{
DebugPrintf((
"Insufficient resources to allocate work queue buffer\n"
));
ExFreePool(pWriteCtx);
}
else
{
try
{
RtlZeroMemory(pWriteCtx->pBuffer, pBuffer->Size);
pWriteCtx->bufferSize = pBuffer->Size;
pMdl = IoAllocateMdl(
pWriteCtx->pBuffer,
pBuffer->Size,
FALSE,
TRUE,
NULL
);
pMdlDma = IoAllocateMdl(
(PVOID)pBuffer->UserAddr,
pBuffer->Size,
FALSE,
TRUE,
NULL
);
MmBuildMdlForNonPagedPool(
pMdl
);
MmBuildMdlForNonPagedPool(
pMdlDma
);
MmProbeAndLockPages(
pMdl,
KernelMode,
IoWriteAccess
);
MmProbeAndLockPages(
pMdlDma,
KernelMode,
IoReadAccess
);
//
// Map the physical pages described by the MDL into system space.
// Note: double mapping the buffer this way causes lot of
// system overhead for large size buffers.
//
pTempBuf = MmGetSystemAddressForMdlSafe(
pMdl,
NormalPagePriority
);
pTempDmaBuf = MmGetSystemAddressForMdlSafe(
pMdlDma,
NormalPagePriority
);
// copy the data from the buffer into the work queue buffer
RtlCopyMemory(
(VOID*)pTempBuf,
(VOID*)pTempDmaBuf,
pBuffer->Size
);
// unlock the pages and free the MDL
MmUnlockPages(
pMdl
);
MmUnlockPages(
pMdlDma
);
IoFreeMdl(
pMdl
);
IoFreeMdl(
pMdlDma
);
pBuffer is the buffer that represents the DMA buffer where the data from
the
DMA is located. My work item context structure looks like this:
typedef struct _WRITECTX_INFO
{
PIO_WORKITEM item;
DEVICE_EXTENSION *pdx;
U32* pBuffer;
U32 bufferSize;
HANDLE hFile;
} WRITECTX_INFO, *PWRITECTX_INFO;
I am very new to driver development, so I know I am doing something wrong
(obviously or it would be working). Thanks!
- References:
- IRQL He11
- From: Slide-O-Mix
- Re: IRQL He11
- From: Don Burn
- IRQL He11
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