gart.c

agp windows驱动WDM,WINDDK开发

Agp440FindRangeInGart(
    IN PGART_PTE StartPte,
    IN PGART_PTE EndPte,
    IN ULONG Length,
    IN BOOLEAN SearchBackward,
    IN ULONG SearchState
    )
/*++

Routine Description:

    Finds a contiguous range in the GART. This routine can
    search either from the beginning of the GART forwards or
    the end of the GART backwards.

Arguments:

    StartIndex - Supplies the first GART pte to search

    EndPte - Supplies the last GART to search (inclusive)

    Length - Supplies the number of contiguous free entries
        to search for.

    SearchBackward - TRUE indicates that the search should begin
        at EndPte and search backwards. FALSE indicates that the
        search should begin at StartPte and search forwards

    SearchState - Supplies the PTE state to look for.

Return Value:

    Pointer to the first PTE in the GART if a suitable range
    is found.

    NULL if no suitable range exists.

--*/

{
    PGART_PTE Current;
    PGART_PTE Last;
    LONG Delta;
    ULONG Found;
    PGART_PTE Candidate;

    PAGED_CODE();

    ASSERT(EndPte >= StartPte);
    ASSERT(Length <= (ULONG)(EndPte - StartPte + 1));
    ASSERT(Length != 0);

    if (SearchBackward) {
        Current = EndPte;
        Last = StartPte-1;
        Delta = -1;
    } else {
        Current = StartPte;
        Last = EndPte+1;
        Delta = 1;
    }

    Found = 0;
    while (Current != Last) {
        if (Current->Soft.State == SearchState) {
            if (++Found == Length) {
                //
                // A suitable range was found, return it
                //
                if (SearchBackward) {
                    return(Current);
                } else {
                    return(Current - Length + 1);
                }
            }
        } else {
            Found = 0;
        }
        Current += Delta;
    }

    //
    // A suitable range was not found.
    //
    return(NULL);
}


VOID
Agp440SetGTLB_Enable(
    IN PAGP440_EXTENSION AgpContext,
    IN BOOLEAN Enable
    )
/*++

Routine Description:

    Enables or disables the GTLB by setting or clearing the GTLB_Enable bit
    in the AGPCTRL register

Arguments:

    AgpContext - Supplies the AGP context

    Enable - TRUE, GTLB_Enable is set to 1
             FALSE, GTLB_Enable is set to 0

Return Value:

    None

--*/

{
    AGPCTRL AgpCtrl;

    Read440Config(&AgpCtrl, AGPCTRL_OFFSET, sizeof(AgpCtrl));

    if (Enable) {
        AgpCtrl.GTLB_Enable = 1;
    } else {
        AgpCtrl.GTLB_Enable = 0;
    }
    Write440Config(&AgpCtrl, AGPCTRL_OFFSET, sizeof(AgpCtrl));
}


VOID
AgpFindFreeRun(
    IN PVOID AgpContext,
    IN PAGP_RANGE AgpRange,
    IN ULONG NumberOfPages,
    IN ULONG OffsetInPages,
    OUT ULONG *FreePages,
    OUT ULONG *FreeOffset
    )
/*++

Routine Description:

    Finds the first contiguous run of free pages in the specified
    part of the reserved range.

Arguments:

    AgpContext - Supplies the AGP context

    AgpRange - Supplies the AGP range

    NumberOfPages - Supplies the size of the region to be searched for free pages

    OffsetInPages - Supplies the start of the region to be searched for free pages

    FreePages - Returns the length of the first contiguous run of free pages

    FreeOffset - Returns the start of the first contiguous run of free pages

Return Value:

    None. FreePages == 0 if there are no free pages in the specified range.

--*/

{
    PGART_PTE Pte;
    ULONG i;
    
    Pte = (PGART_PTE)(AgpRange->Context) + OffsetInPages;

    //
    // Find the first free PTE
    //
    for (i=0; i<NumberOfPages; i++) {
        if (Pte[i].Hard.Valid == 0) {
            //
            // Found a free PTE, count the contiguous ones.
            //
            *FreeOffset = i + OffsetInPages;
            *FreePages = 0;
            while ((i<NumberOfPages) && (Pte[i].Hard.Valid == 0)) {
                *FreePages += 1;
                ++i;
            }
            return;
        }
    }

    //
    // No free PTEs in the specified range
    //
    *FreePages = 0;
    return;

}


VOID
AgpGetMappedPages(
    IN PVOID AgpContext,
    IN PAGP_RANGE AgpRange,
    IN ULONG NumberOfPages,
    IN ULONG OffsetInPages,
    OUT PMDL Mdl
    )
/*++

Routine Description:

    Returns the list of physical pages mapped into the specified 
    range in the GART.

Arguments:

    AgpContext - Supplies the AGP context

    AgpRange - Supplies the AGP range

    NumberOfPages - Supplies the number of pages to be returned

    OffsetInPages - Supplies the start of the region 

    Mdl - Returns the list of physical pages mapped in the specified range.

Return Value:

    None

--*/

{
    PGART_PTE Pte;
    ULONG i;
    PULONG Pages;
    
    ASSERT(NumberOfPages * PAGE_SIZE == Mdl->ByteCount);

    Pages = (PULONG)(Mdl + 1);
    Pte = (PGART_PTE)(AgpRange->Context) + OffsetInPages;

    for (i=0; i<NumberOfPages; i++) {
        ASSERT(Pte[i].Hard.Valid == 1);
        Pages[i] = Pte[i].Hard.Page;
    }
    return;
}


NTSTATUS
AgpSpecialTarget(
    IN PAGP440_EXTENSION AgpContext,
    IN ULONGLONG DeviceFlags
    )
/*++

Routine Description:

    This routine makes "special" tweaks to the AGP chipset

Arguments:

    AgpContext - Supplies the AGP context
 
    DeviceFlags - Flags indicating what tweaks to perform

Return Value:

    STATUS_SUCCESS, or error

--*/
{
    NTSTATUS Status;

    //
    // Should we change the AGP rate?
    //
    if (DeviceFlags & AGP_FLAG_SPECIAL_RESERVE) {

        Status = Agp440SetRate(AgpContext,
                               (ULONG)((DeviceFlags & AGP_FLAG_SPECIAL_RESERVE)
                                       >> AGP_FLAG_SET_RATE_SHIFT));
        
        if (!NT_SUCCESS(Status)) {
            return Status;
        }
    }

    //
    // Add more tweaks here...
    //

    AgpContext->SpecialTarget |= DeviceFlags;

    return STATUS_SUCCESS;
}


NTSTATUS
Agp440SetRate(
    IN PAGP440_EXTENSION AgpContext,
    IN ULONG AgpRate
    )
/*++

Routine Description:

    This routine sets the AGP rate

Arguments:

    AgpContext - Supplies the AGP context
 
    AgpRate - Rate to set

Return Value:

    STATUS_SUCCESS, or error status

--*/
{
    NTSTATUS Status;
    ULONG TargetEnable;
    ULONG MasterEnable;
    PCI_AGP_CAPABILITY TargetCap;
    PCI_AGP_CAPABILITY MasterCap;
    BOOLEAN ReverseInit;

    //
    // Read capabilities
    //
    Status = AgpLibGetPciDeviceCapability(0, 0, &TargetCap);

    if (!NT_SUCCESS(Status)) {
        AGPLOG(AGP_WARNING, ("AGP440SetRate: AgpLibGetPciDeviceCapability "
                             "failed %08lx\n", Status));
        return Status;
    }

    Status = AgpLibGetMasterCapability(AgpContext, &MasterCap);

    if (!NT_SUCCESS(Status)) {
        AGPLOG(AGP_WARNING, ("AGP440SetRate: AgpLibGetMasterCapability "
                             "failed %08lx\n", Status));
        return Status;
    }

    //
    // Verify the requested rate is supported by both master and target
    //
    if (!(AgpRate & TargetCap.AGPStatus.Rate & MasterCap.AGPStatus.Rate)) {
        return STATUS_INVALID_PARAMETER;
    }

    //
    // Disable AGP while the pull the rug out from underneath
    //
    TargetEnable = TargetCap.AGPCommand.AGPEnable;
    TargetCap.AGPCommand.AGPEnable = 0;

    Status = AgpLibSetPciDeviceCapability(0, 0, &TargetCap);
    
    if (!NT_SUCCESS(Status)) {
        AGPLOG(AGP_WARNING,
               ("AGP440SetRate: AgpLibSetPciDeviceCapability %08lx for "
                "Target failed %08lx\n",
                &TargetCap,
                Status));
        return Status;
    }
    
    MasterEnable = MasterCap.AGPCommand.AGPEnable;
    MasterCap.AGPCommand.AGPEnable = 0;

    Status = AgpLibSetMasterCapability(AgpContext, &MasterCap);
    
    if (!NT_SUCCESS(Status)) {
        AGPLOG(AGP_WARNING,
               ("AGP440SetRate: AgpLibSetMasterCapability %08lx failed "
                "%08lx\n",
                &MasterCap,
                Status));
        return Status;
    }

    //
    // Fire up AGP with new rate
    //
    ReverseInit =
        (AgpContext->SpecialTarget & AGP_FLAG_REVERSE_INITIALIZATION) ==
        AGP_FLAG_REVERSE_INITIALIZATION;
    if (ReverseInit) {
        MasterCap.AGPCommand.Rate = AgpRate;
        MasterCap.AGPCommand.AGPEnable = MasterEnable;
        
        Status = AgpLibSetMasterCapability(AgpContext, &MasterCap);
        
        if (!NT_SUCCESS(Status)) {
            AGPLOG(AGP_WARNING,
                   ("AGP440SetRate: AgpLibSetMasterCapability %08lx failed "
                    "%08lx\n",
                    &MasterCap,
                    Status));
        }
    }

    TargetCap.AGPCommand.Rate = AgpRate;
    TargetCap.AGPCommand.AGPEnable = TargetEnable;
        
    Status = AgpLibSetPciDeviceCapability(0, 0, &TargetCap);
    
    if (!NT_SUCCESS(Status)) {
        AGPLOG(AGP_WARNING,
               ("AGP440SetRate: AgpLibSetPciDeviceCapability %08lx for "
                "Target failed %08lx\n",
                &TargetCap,
                Status));
        return Status;
    }

    if (!ReverseInit) {
        MasterCap.AGPCommand.Rate = AgpRate;
        MasterCap.AGPCommand.AGPEnable = MasterEnable;
        
        Status = AgpLibSetMasterCapability(AgpContext, &MasterCap);
        
        if (!NT_SUCCESS(Status)) {
            AGPLOG(AGP_WARNING,
                   ("AGP440SetRate: AgpLibSetMasterCapability %08lx failed "
                    "%08lx\n",
                    &MasterCap,
                    Status));
        }
    }

    return Status;
}