On Tue, Apr 24, 2007 at 11:15:24PM +0700, Darmawan Salihun wrote:
> >Do we need a wrapper for those "map-physical-memory" functions?
>
> I think we don't need it because it has an "equivalent" in Windows'
> kernel mode driver, i.e.
>
> PVOID MmGetSystemAddressForMdlSafe(IN PMDL Mdl, IN
> MM_PAGE_PRIORITY Priority);

Is MmMapIoSpace() strictly for io? Otherwise it may also be a
candidate.

...ah, you're right Peter. It was in the midnight back then when I wrote mail. It should've been
MmMapIoSpace(..), not MmGetSystemAddressForMdlSafe(..) function. I have something in the works right now for the porting of flashrom to Windows. Below is the snippet (in case you are curious about it ;)
----------
    //
    // We have obtained a free mapZone, map the physical address range.
    //
    pUsermodeMem = (MMIO_MAP*) MmGetSystemAddressForMdlSafe( pIrp->MdlAddress, NormalPagePriority );
    if( NULL == pUsermodeMem) {
    return STATUS_INVALID_USER_BUFFER;
    }

    phyAddr.HighPart = 0;
    phyAddr.LowPart = pUsermodeMem->phyAddrStart;

    pDevExt->mapZone[free_idx].sysAddrBase = MmMapIoSpace( phyAddr, pUsermodeMem->size, MmNonCached);
    if(NULL == pDevExt->mapZone[free_idx].sysAddrBase)
    {
    return STATUS_BUFFER_TOO_SMALL;
    }

    pDevExt->mapZone[free_idx].pMdl = IoAllocateMdl(pDevExt->mapZone[free_idx].sysAddrBase,
                            pUsermodeMem->size, FALSE, FALSE, NULL);
    if(NULL == pDevExt->mapZone[free_idx].pMdl)
    {
    MmUnmapIoSpace(pDevExt->mapZone[free_idx].sysAddrBase, pUsermodeMem->size);
    pDevExt->mapZone[free_idx].sysAddrBase = NULL;
    return STATUS_BUFFER_TOO_SMALL;
    }

    pDevExt->mapZone[free_idx].size = pUsermodeMem->size;

    //
    // Map the system virtual address to usermode virtual address
    //
    MmBuildMdlForNonPagedPool(pDevExt->mapZone[free_idx].pMdl);
    pDevExt->mapZone[free_idx].usermodeAddrBase = MmMapLockedPagesSpecifyCache(   pDevExt->mapZone[free_idx].pMdl,
                                       UserMode, MmNonCached,
                                       NULL, FALSE,
                                       NormalPagePriority);
    if(NULL == pDevExt->mapZone[free_idx].usermodeAddrBase)
    {
    IoFreeMdl(pDevExt->mapZone[free_idx].pMdl);
    MmUnmapIoSpace(pDevExt->mapZone[free_idx].sysAddrBase, pDevExt->mapZone[free_idx].size);
    pDevExt->mapZone[free_idx].sysAddrBase = NULL;
    pDevExt->mapZone[free_idx].size = 0;
    return STATUS_BUFFER_TOO_SMALL;
    }
-----------------

It seems an MDL is always specified with a virtual address but I
can't find a phystovirt() in the Mm functions. Admittedly I didn't
look very hard so you may already have found it. :)

Basically, the conversion to User mode virtual address is in the code snippet above ;-)

> The main problem is the mechanism will be a bit different because
> flashrom will be divided into kernel mode driver and user mode
> application in Windows.

I think I like having more of the logic in the kernel driver for
once, this is because the algorithms can benefit in speed, and
because the system will be more stable as long as the kernel driver
is bug free. ;)

Letting the app drive everything is less intrusive of course, but
could also put the system into an unknown state if the app is aborted
halfway through something.

I'll look forward this issue. Thanks.

--Darmawan