express.c File Reference

#include <pci.h>
#include <debug.h>

Include dependency graph for express.c:

Go to the source code of this file.

Macros
#define	NDEBUG

Functions
static BOOLEAN NTAPI	PciIsExtendedCapabilityOffsetValid (_In_ ULONG Offset)
ULONG NTAPI	PciReadDeviceExtendedCapability (_In_ PPCI_PDO_EXTENSION DeviceExtension, _In_ ULONG CapabilityId, _Out_writes_bytes_(Length) PPCI_EXPRESS_ENHANCED_CAPABILITY_HEADER Buffer, _In_ ULONG Length)
	Finds an extended capability and reads it into the caller's buffer.
VOID NTAPI	PciGetExpressCapabilities (_Inout_ PPCI_PDO_EXTENSION PdoExtension)
	Records the Express capability of a new function and whether its extended configuration space can be reached.

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 12 of file express.c.

Function Documentation

PciGetExpressCapabilities()

VOID NTAPI PciGetExpressCapabilities

(

_Inout_ PPCI_PDO_EXTENSION

PdoExtension

)

Records the Express capability of a new function and whether its extended configuration space can be reached.

Parameters

[in,out]

PdoExtension

The PDO extension of the function being enumerated.

Definition at line 99 of file express.c.

{
    PCI_EXPRESS_CAPABILITY Express;
    PPCI_FDO_EXTENSION ParentFdo;
    PPCI_PDO_EXTENSION ParentBridge;
    UCHAR Offset;
    PAGED_CODE();
 
    PdoExtension->ExpressCapabilityPtr = 0;
    PdoExtension->ExpressDeviceType = 0;
    PdoExtension->IsExtendedConfigReachable = FALSE;
 
    if (!PdoExtension->CapabilitiesPtr)
        return;
 
    if (PdoExtension->HackFlags & PCI_HACK_NO_EXPRESS_CAP)
        return;
 
    /* Only the capabilities register is needed */
    Offset = PciReadDeviceCapability(PdoExtension,
                                     PdoExtension->CapabilitiesPtr,
                                     PCI_CAPABILITY_ID_PCI_EXPRESS,
                                     &Express.Header,
                                     RTL_SIZEOF_THROUGH_FIELD(PCI_EXPRESS_CAPABILITY,
                                                              ExpressCapabilities));
    if (!Offset)
        return;
 
    PdoExtension->ExpressCapabilityPtr = Offset;
    PdoExtension->ExpressDeviceType = (UCHAR)Express.ExpressCapabilities.DeviceType;
 
    /* Every bridge between the root and this function has to pass extended config cycles */
    ParentFdo = PdoExtension->ParentFdoExtension;
    if (PCI_IS_ROOT_FDO(ParentFdo))
    {
        PdoExtension->IsExtendedConfigReachable = PciEcamVerified;
    }
    else
    {
        ParentBridge = (PPCI_PDO_EXTENSION)ParentFdo->PhysicalDeviceObject->DeviceExtension;
        ASSERT_PDO(ParentBridge);
        PdoExtension->IsExtendedConfigReachable = ParentBridge->IsExtendedConfigReachable;
    }
 
    DPRINT1("PCI - Express capability at 0x%x, port type %u, version %u\n",
            PdoExtension->ExpressCapabilityPtr,
            PdoExtension->ExpressDeviceType,
            Express.ExpressCapabilities.CapabilityVersion);
}

Referenced by PciGetEnhancedCapabilities().

PciIsExtendedCapabilityOffsetValid()

static BOOLEAN NTAPI PciIsExtendedCapabilityOffsetValid ( _In_ ULONG  Offset )

static

Definition at line 20 of file express.c.

{
    if ((Offset & 3) || (Offset < PCI_LEGACY_CONFIG_LENGTH))
        return FALSE;
 
    return (Offset + sizeof(PCI_EXPRESS_ENHANCED_CAPABILITY_HEADER)) <=
           PCI_EXTENDED_CONFIG_LENGTH;
}

Referenced by PciReadDeviceExtendedCapability().

PciReadDeviceExtendedCapability()

ULONG NTAPI PciReadDeviceExtendedCapability	(	_In_ PPCI_PDO_EXTENSION	DeviceExtension,
		_In_ ULONG	CapabilityId,
		_Out_writes_bytes_(Length) PPCI_EXPRESS_ENHANCED_CAPABILITY_HEADER	Buffer,
		_In_ ULONG	Length
	)

Finds an extended capability and reads it into the caller's buffer.

Returns

The offset of the capability, or 0 if it was not found.

Definition at line 39 of file express.c.

{
    PCI_EXPRESS_ENHANCED_CAPABILITY_HEADER Header;
    ULONG Offset, EntriesLeft;
 
    ASSERT(DeviceExtension->ExtensionType == PciPdoExtensionType);
    ASSERT(Length >= sizeof(PCI_EXPRESS_ENHANCED_CAPABILITY_HEADER));
 
    if (!DeviceExtension->IsExtendedConfigReachable)
        return 0;
 
    /* More entries than aligned offsets means the list loops */
    EntriesLeft = (PCI_EXTENDED_CONFIG_LENGTH - PCI_LEGACY_CONFIG_LENGTH) / sizeof(ULONG);
 
    for (Offset = PCI_LEGACY_CONFIG_LENGTH; Offset != 0; Offset = Header.Next)
    {
        if (!PciIsExtendedCapabilityOffsetValid(Offset))
            return 0;
 
        if (EntriesLeft == 0)
        {
            DPRINT1("PCI device %p extended capabilities list is broken\n",
                    DeviceExtension);
            return 0;
        }
        EntriesLeft--;
 
        PciReadDeviceConfig(DeviceExtension, &Header, Offset, sizeof(Header));
 
        /* A function that does not decode extended space reads back all ones */
        if (Header.CapabilityID == 0xFFFF)
            return 0;
 
        if (Header.CapabilityID != CapabilityId)
            continue;
 
        if (Length > (PCI_EXTENDED_CONFIG_LENGTH - Offset))
            return 0;
 
        PciReadDeviceConfig(DeviceExtension, Buffer, Offset, Length);
        return Offset;
    }
 
    return 0;
}