/** @file
This driver implements EFI_PCI_HOT_PLUG_INIT_PROTOCOL, providing the PCI bus
driver with resource padding information, for PCIe hotplug purposes.
Copyright (C) 2016, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <IndustryStandard/Acpi10.h>
#include <IndustryStandard/Q35MchIch9.h>
#include <IndustryStandard/QemuPciBridgeCapabilities.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/DevicePathLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/PciCapLib.h>
#include <Library/PciCapPciSegmentLib.h>
#include <Library/PciLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Protocol/PciHotPlugInit.h>
#include <Protocol/PciRootBridgeIo.h>
//
// TRUE if the PCI platform supports extended config space, FALSE otherwise.
//
STATIC BOOLEAN mPciExtConfSpaceSupported;
//
// The protocol interface this driver produces.
//
// Refer to 12.6 "PCI Hot Plug PCI Initialization Protocol" in the Platform
// Init 1.4a Spec, Volume 5.
//
STATIC EFI_PCI_HOT_PLUG_INIT_PROTOCOL mPciHotPlugInit;
//
// Resource padding template for the GetResourcePadding() protocol member
// function.
//
// Refer to Table 8 "ACPI 2.0 & 3.0 QWORD Address Space Descriptor Usage" in
// the Platform Init 1.4a Spec, Volume 5.
//
// This structure is interpreted by the ApplyResourcePadding() function in the
// edk2 PCI Bus UEFI_DRIVER.
//
// We can request padding for at most four resource types, each of which is
// optional, independently of the others:
// (a) bus numbers,
// (b) IO space,
// (c) non-prefetchable MMIO space (32-bit only),
// (d) prefetchable MMIO space (either 32-bit or 64-bit, never both).
//
#pragma pack (1)
typedef struct {
EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR Padding[4];
EFI_ACPI_END_TAG_DESCRIPTOR EndDesc;
} RESOURCE_PADDING;
#pragma pack ()
/**
Initialize a RESOURCE_PADDING object.
@param[out] ResourcePadding The caller-allocated RESOURCE_PADDING object to
initialize.
**/
STATIC
VOID
InitializeResourcePadding (
OUT RESOURCE_PADDING *ResourcePadding
)
{
UINTN Index;
ZeroMem (ResourcePadding, sizeof *ResourcePadding);
//
// Fill in the Padding fields that don't vary across resource types.
//
for (Index = 0; Index < ARRAY_SIZE (ResourcePadding->Padding); ++Index) {
EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *Descriptor;
Descriptor = ResourcePadding->Padding + Index;
Descriptor->Desc = ACPI_ADDRESS_SPACE_DESCRIPTOR;
Descriptor->Len = (UINT16)(
sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) -
OFFSET_OF (
EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR,
ResType
)
);
}
//
// Fill in the End Tag.
//
ResourcePadding->EndDesc.Desc = ACPI_END_TAG_DESCRIPTOR;
}
/**
Set up a descriptor entry for reserving IO space.
@param[in,out] Descriptor The descriptor to configure. The caller shall have
initialized Descriptor earlier, with
InitializeResourcePadding().
@param[in] SizeExponent The size and natural alignment of the reservation
are determined by raising two to this power.
**/
STATIC
VOID
SetIoPadding (
IN OUT EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *Descriptor,
IN UINTN SizeExponent
)
{
Descriptor->ResType = ACPI_ADDRESS_SPACE_TYPE_IO;
Descriptor->AddrLen = LShiftU64 (1, SizeExponent);
Descriptor->AddrRangeMax = Descriptor->AddrLen - 1;
}
/**
Set up a descriptor entry for reserving MMIO space.
@param[in,out] Descriptor The descriptor to configure. The caller shall
have initialized Descriptor earlier, with
InitializeResourcePadding().
@param[in] Prefetchable TRUE if the descriptor should reserve
prefetchable MMIO space. Pass FALSE for
reserving non-prefetchable MMIO space.
@param[in] ThirtyTwoBitOnly TRUE if the reservation should be limited to
32-bit address space. FALSE if the reservation
can be satisfied from 64-bit address space.
ThirtyTwoBitOnly is ignored if Prefetchable is
FALSE; in that case ThirtyTwoBitOnly is always
considered TRUE.
@param[in] SizeExponent The size and natural alignment of the
reservation are determined by raising two to
this power.
**/
STATIC
VOID
SetMmioPadding (
IN OUT EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *Descriptor,
IN BOOLEAN Prefetchable,
IN BOOLEAN ThirtyTwoBitOnly,
IN UINTN SizeExponent
)
{
Descriptor->ResType = ACPI_ADDRESS_SPACE_TYPE_MEM;
if (Prefetchable) {
Descriptor->SpecificFlag =
EFI_ACPI_MEMORY_RESOURCE_SPECIFIC_FLAG_CACHEABLE_PREFETCHABLE;
Descriptor->AddrSpaceGranularity = ThirtyTwoBitOnly ? 32 : 64;
} else {
Descriptor->SpecificFlag =
EFI_ACPI_MEMORY_RESOURCE_SPECIFIC_FLAG_NON_CACHEABLE;
Descriptor->AddrSpaceGranularity = 32;
}
Descriptor->AddrLen = LShiftU64 (1, SizeExponent);
Descriptor->AddrRangeMax = Descriptor->AddrLen - 1;
}
/**
Round up a positive 32-bit value to the next whole power of two, and return
the bit position of the highest bit set in the result. Equivalent to
ceil(log2(x)).
@param[in] Operand The 32-bit operand to evaluate.
@retval -1 Operand is zero.
@retval -1 Operand is positive, not a whole power of two, and rounding it
up to the next power of two does not fit into 32 bits.
@retval 0..31 Otherwise, return ceil(log2(Value)).
**/
STATIC
INTN
HighBitSetRoundUp32 (
IN UINT32 Operand
)
{
INTN HighBit;
HighBit = HighBitSet32 (Operand);
if (HighBit == -1) {
//
// Operand is zero.
//
return HighBit;
}
if ((Operand & (Operand - 1)) != 0) {
//
// Operand is not a whole power of two.
//
++HighBit;
}
return (HighBit < 32) ? HighBit : -1;
}
/**
Round up a positive 64-bit value to the next whole power of two, and return
the bit position of the highest bit set in the result. Equivalent to
ceil(log2(x)).
@param[in] Operand The 64-bit operand to evaluate.
@retval -1 Operand is zero.
@retval -1 Operand is positive, not a whole power of two, and rounding it
up to the next power of two does not fit into 64 bits.
@retval 0..63 Otherwise, return ceil(log2(Value)).
**/
STATIC
INTN
HighBitSetRoundUp64 (
IN UINT64 Operand
)
{
INTN HighBit;
HighBit = HighBitSet64 (Operand);
if (HighBit == -1) {
//
// Operand is zero.
//
return HighBit;
}
if ((Operand & (Operand - 1)) != 0) {
//
// Operand is not a whole power of two.
//
++HighBit;
}
return (HighBit < 64) ? HighBit : -1;
}
/**
Look up the QEMU-specific Resource Reservation capability in the conventional
config space of a Hotplug Controller (that is, PCI Bridge).
On error, the contents of ReservationHint are indeterminate.
@param[in] HpcPciAddress The address of the PCI Bridge -- Bus, Device,
Function -- in UEFI (not PciLib) encoding.
@param[out] ReservationHint The caller-allocated capability structure to
populate from the PCI Bridge's config space.
@retval EFI_SUCCESS The capability has been found, ReservationHint has
been populated.
@retval EFI_NOT_FOUND The capability is missing.
@return Error codes from PciCapPciSegmentLib and PciCapLib.
**/
STATIC
EFI_STATUS
QueryReservationHint (
IN CONST EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS *HpcPciAddress,
OUT QEMU_PCI_BRIDGE_CAPABILITY_RESOURCE_RESERVATION *ReservationHint
)
{
UINT16 PciVendorId;
EFI_STATUS Status;
PCI_CAP_DEV *PciDevice;
PCI_CAP_LIST *CapList;
UINT16 VendorInstance;
PCI_CAP *VendorCap;
//
// Check the vendor identifier.
//
PciVendorId = PciRead16 (
PCI_LIB_ADDRESS (
HpcPciAddress->Bus,
HpcPciAddress->Device,
HpcPciAddress->Function,
PCI_VENDOR_ID_OFFSET
)
);
if (PciVendorId != QEMU_PCI_BRIDGE_VENDOR_ID_REDHAT) {
return EFI_NOT_FOUND;
}
//
// Parse the capabilities lists.
//
Status = PciCapPciSegmentDeviceInit (
mPciExtConfSpaceSupported ? PciCapExtended : PciCapNormal,
0, // Segment
HpcPciAddress->Bus,
HpcPciAddress->Device,
HpcPciAddress->Function,
&PciDevice
);
if (EFI_ERROR (Status)) {
return Status;
}
Status = PciCapListInit (PciDevice, &CapList);
if (EFI_ERROR (Status)) {
goto UninitPciDevice;
}
//
// Scan the vendor capability instances for the Resource Reservation
// capability.
//
VendorInstance = 0;
for (;;) {
UINT8 VendorLength;
UINT8 BridgeCapType;
Status = PciCapListFindCap (
CapList,
PciCapNormal,
EFI_PCI_CAPABILITY_ID_VENDOR,
VendorInstance++,
&VendorCap
);
if (EFI_ERROR (Status)) {
goto UninitCapList;
}
//
// Check the vendor capability length.
//
Status = PciCapRead (
PciDevice,
VendorCap,
OFFSET_OF (EFI_PCI_CAPABILITY_VENDOR_HDR, Length),
&VendorLength,
sizeof VendorLength
);
if (EFI_ERROR (Status)) {
goto UninitCapList;
}
if (VendorLength != sizeof *ReservationHint) {
continue;
}
//
// Check the vendor bridge capability type.
//
Status = PciCapRead (
PciDevice,
VendorCap,
OFFSET_OF (QEMU_PCI_BRIDGE_CAPABILITY_HDR, Type),
&BridgeCapType,
sizeof BridgeCapType
);
if (EFI_ERROR (Status)) {
goto UninitCapList;
}
if (BridgeCapType ==
QEMU_PCI_BRIDGE_CAPABILITY_TYPE_RESOURCE_RESERVATION) {
//
// We have a match.
//
break;
}
}
//
// Populate ReservationHint.
//
Status = PciCapRead (
PciDevice,
VendorCap,
0, // SourceOffsetInCap
ReservationHint,
sizeof *ReservationHint
);
UninitCapList:
PciCapListUninit (CapList);
UninitPciDevice:
PciCapPciSegmentDeviceUninit (PciDevice);
return Status;
}
/**
Returns a list of root Hot Plug Controllers (HPCs) that require
initialization during the boot process.
This procedure returns a list of root HPCs. The PCI bus driver must
initialize these controllers during the boot process. The PCI bus driver may
or may not be able to detect these HPCs. If the platform includes a
PCI-to-CardBus bridge, it can be included in this list if it requires
initialization. The HpcList must be self consistent. An HPC cannot control
any of its parent buses. Only one HPC can control a PCI bus. Because this
list includes only root HPCs, no HPC in the list can be a child of another
HPC. This policy must be enforced by the EFI_PCI_HOT_PLUG_INIT_PROTOCOL.
The PCI bus driver may not check for such invalid conditions. The callee
allocates the buffer HpcList
@param[in] This Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL
instance.
@param[out] HpcCount The number of root HPCs that were returned.
@param[out] HpcList The list of root HPCs. HpcCount defines the number of
elements in this list.
@retval EFI_SUCCESS HpcList was returned.
@retval EFI_OUT_OF_RESOURCES HpcList was not returned due to insufficient
resources.
@retval EFI_INVALID_PARAMETER HpcCount is NULL or HpcList is NULL.
**/
STATIC
EFI_STATUS
EFIAPI
GetRootHpcList (
IN EFI_PCI_HOT_PLUG_INIT_PROTOCOL *This,
OUT UINTN *HpcCount,
OUT EFI_HPC_LOCATION **HpcList
)
{
if (HpcCount == NULL || HpcList == NULL) {
return EFI_INVALID_PARAMETER;
}
//
// There are no top-level (i.e., un-enumerable) hot-plug controllers in QEMU
// that would require special initialization.
//
*HpcCount = 0;
*HpcList = NULL;
return EFI_SUCCESS;
}
/**
Initializes one root Hot Plug Controller (HPC). This process may causes
initialization of its subordinate buses.
This function initializes the specified HPC. At the end of initialization,
the hot-plug slots or sockets (controlled by this HPC) are powered and are
connected to the bus. All the necessary registers in the HPC are set up. For
a Standard (PCI) Hot Plug Controller (SHPC), the registers that must be set
up are defined in the PCI Standard Hot Plug Controller and Subsystem
Specification.
@param[in] This Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL
instance.
@param[in] HpcDevicePath The device path to the HPC that is being
initialized.
@param[in] HpcPciAddress The address of the HPC function on the PCI bus.
@param[in] Event The event that should be signaled when the HPC
initialization is complete. Set to NULL if the
caller wants to wait until the entire
initialization process is complete.
@param[out] HpcState The state of the HPC hardware. The state is
EFI_HPC_STATE_INITIALIZED or
EFI_HPC_STATE_ENABLED.
@retval EFI_SUCCESS If Event is NULL, the specific HPC was
successfully initialized. If Event is not
NULL, Event will be signaled at a later time
when initialization is complete.
@retval EFI_UNSUPPORTED This instance of
EFI_PCI_HOT_PLUG_INIT_PROTOCOL does not
support the specified HPC.
@retval EFI_OUT_OF_RESOURCES Initialization failed due to insufficient
resources.
@retval EFI_INVALID_PARAMETER HpcState is NULL.
**/
STATIC
EFI_STATUS
EFIAPI
InitializeRootHpc (
IN EFI_PCI_HOT_PLUG_INIT_PROTOCOL *This,
IN EFI_DEVICE_PATH_PROTOCOL *HpcDevicePath,
IN UINT64 HpcPciAddress,
IN EFI_EVENT Event, OPTIONAL
OUT EFI_HPC_STATE *HpcState
)
{
//
// This function should never be called, due to the information returned by
// GetRootHpcList().
//
ASSERT (FALSE);
if (HpcState == NULL) {
return EFI_INVALID_PARAMETER;
}
return EFI_UNSUPPORTED;
}
/**
Returns the resource padding that is required by the PCI bus that is
controlled by the specified Hot Plug Controller (HPC).
This function returns the resource padding that is required by the PCI bus
that is controlled by the specified HPC. This member function is called for
all the root HPCs and nonroot HPCs that are detected by the PCI bus
enumerator. This function will be called before PCI resource allocation is
completed. This function must be called after all the root HPCs, with the
possible exception of a PCI-to-CardBus bridge, have completed
initialization.
@param[in] This Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL
instance.
@param[in] HpcDevicePath The device path to the HPC.
@param[in] HpcPciAddress The address of the HPC function on the PCI bus.
@param[in] HpcState The state of the HPC hardware.
@param[out] Padding The amount of resource padding that is required
by the PCI bus under the control of the specified
HPC.
@param[out] Attributes Describes how padding is accounted for. The
padding is returned in the form of ACPI 2.0
resource descriptors.
@retval EFI_SUCCESS The resource padding was successfully
returned.
@retval EFI_UNSUPPORTED This instance of the
EFI_PCI_HOT_PLUG_INIT_PROTOCOL does not
support the specified HPC.
@retval EFI_NOT_READY This function was called before HPC
initialization is complete.
@retval EFI_INVALID_PARAMETER HpcState or Padding or Attributes is NULL.
@retval EFI_OUT_OF_RESOURCES ACPI 2.0 resource descriptors for Padding
cannot be allocated due to insufficient
resources.
**/
STATIC
EFI_STATUS
EFIAPI
GetResourcePadding (
IN EFI_PCI_HOT_PLUG_INIT_PROTOCOL *This,
IN EFI_DEVICE_PATH_PROTOCOL *HpcDevicePath,
IN UINT64 HpcPciAddress,
OUT EFI_HPC_STATE *HpcState,
OUT VOID **Padding,
OUT EFI_HPC_PADDING_ATTRIBUTES *Attributes
)
{
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS *Address;
BOOLEAN DefaultIo;
BOOLEAN DefaultMmio;
RESOURCE_PADDING ReservationRequest;
EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *FirstResource;
EFI_STATUS ReservationHintStatus;
QEMU_PCI_BRIDGE_CAPABILITY_RESOURCE_RESERVATION ReservationHint;
Address = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS *)&HpcPciAddress;
DEBUG_CODE (
CHAR16 *DevicePathString;
DevicePathString = ConvertDevicePathToText (HpcDevicePath, FALSE, FALSE);
DEBUG ((DEBUG_VERBOSE, "%a: Address=%02x:%02x.%x DevicePath=%s\n",
__FUNCTION__, Address->Bus, Address->Device, Address->Function,
(DevicePathString == NULL) ? L"<unavailable>" : DevicePathString));
if (DevicePathString != NULL) {
FreePool (DevicePathString);
}
);
if (HpcState == NULL || Padding == NULL || Attributes == NULL) {
return EFI_INVALID_PARAMETER;
}
DefaultIo = TRUE;
DefaultMmio = TRUE;
//
// Init ReservationRequest, and point FirstResource one past the last
// descriptor entry. We're going to build the entries backwards from
// ReservationRequest.EndDesc.
//
InitializeResourcePadding (&ReservationRequest);
FirstResource = ReservationRequest.Padding +
ARRAY_SIZE (ReservationRequest.Padding);
//
// Try to get the QEMU-specific Resource Reservation capability.
//
ReservationHintStatus = QueryReservationHint (Address, &ReservationHint);
if (!EFI_ERROR (ReservationHintStatus)) {
INTN HighBit;
DEBUG ((
DEBUG_VERBOSE,
"%a: BusNumbers=0x%x Io=0x%Lx NonPrefetchable32BitMmio=0x%x\n"
"%a: Prefetchable32BitMmio=0x%x Prefetchable64BitMmio=0x%Lx\n",
__FUNCTION__,
ReservationHint.BusNumbers,
ReservationHint.Io,
ReservationHint.NonPrefetchable32BitMmio,
__FUNCTION__,
ReservationHint.Prefetchable32BitMmio,
ReservationHint.Prefetchable64BitMmio
));
//
// (a) Reserve bus numbers.
//
switch (ReservationHint.BusNumbers) {
case 0:
//
// No reservation needed.
//
break;
case MAX_UINT32:
//
// Firmware default (unspecified). Treat it as "no reservation needed".
//
break;
default:
//
// Request the specified amount.
//
--FirstResource;
FirstResource->ResType = ACPI_ADDRESS_SPACE_TYPE_BUS;
FirstResource->AddrLen = ReservationHint.BusNumbers;
break;
}
//
// (b) Reserve IO space.
//
switch (ReservationHint.Io) {
case 0:
//
// No reservation needed, disable our built-in.
//
DefaultIo = FALSE;
break;
case MAX_UINT64:
//
// Firmware default (unspecified). Stick with our built-in.
//
break;
default:
//
// Round the specified amount up to the next power of two. If rounding is
// successful, reserve the rounded value. Fall back to the default
// otherwise.
//
HighBit = HighBitSetRoundUp64 (ReservationHint.Io);
if (HighBit != -1) {
SetIoPadding (--FirstResource, (UINTN)HighBit);
DefaultIo = FALSE;
}
break;
}
//
// (c) Reserve non-prefetchable MMIO space (32-bit only).
//
switch (ReservationHint.NonPrefetchable32BitMmio) {
case 0:
//
// No reservation needed, disable our built-in.
//
DefaultMmio = FALSE;
break;
case MAX_UINT32:
//
// Firmware default (unspecified). Stick with our built-in.
//
break;
default:
//
// Round the specified amount up to the next power of two. If rounding is
// successful, reserve the rounded value. Fall back to the default
// otherwise.
//
HighBit = HighBitSetRoundUp32 (ReservationHint.NonPrefetchable32BitMmio);
if (HighBit != -1) {
SetMmioPadding (--FirstResource, FALSE, TRUE, (UINTN)HighBit);
DefaultMmio = FALSE;
}
break;
}
//
// (d) Reserve prefetchable MMIO space (either 32-bit or 64-bit, never
// both).
//
// For either space, we treat 0 as "no reservation needed", and the maximum
// value as "firmware default". The latter is unspecified, and we interpret
// it as the former.
//
// Otherwise, round the specified amount up to the next power of two. If
// rounding is successful, reserve the rounded value. Do not reserve
// prefetchable MMIO space otherwise.
//
if (ReservationHint.Prefetchable32BitMmio > 0 &&
ReservationHint.Prefetchable32BitMmio < MAX_UINT32) {
HighBit = HighBitSetRoundUp32 (ReservationHint.Prefetchable32BitMmio);
if (HighBit != -1) {
SetMmioPadding (--FirstResource, TRUE, TRUE, (UINTN)HighBit);
}
} else if (ReservationHint.Prefetchable64BitMmio > 0 &&
ReservationHint.Prefetchable64BitMmio < MAX_UINT64) {
HighBit = HighBitSetRoundUp64 (ReservationHint.Prefetchable64BitMmio);
if (HighBit != -1) {
SetMmioPadding (--FirstResource, TRUE, FALSE, (UINTN)HighBit);
}
}
}
if (DefaultIo) {
//
// Request defaults.
//
SetIoPadding (--FirstResource, (UINTN)HighBitSetRoundUp64 (512));
}
if (DefaultMmio) {
//
// Request defaults.
//
SetMmioPadding (
--FirstResource,
FALSE,
TRUE,
(UINTN)HighBitSetRoundUp32 (SIZE_2MB)
);
}
//
// Output a copy of ReservationRequest from the lowest-address populated
// entry until the end of the structure (including
// ReservationRequest.EndDesc). If no reservations are necessary, we'll only
// output the End Tag.
//
*Padding = AllocateCopyPool (
(UINT8 *)(&ReservationRequest + 1) - (UINT8 *)FirstResource,
FirstResource
);
if (*Padding == NULL) {
return EFI_OUT_OF_RESOURCES;
}
//
// Resource padding is required.
//
*HpcState = EFI_HPC_STATE_INITIALIZED | EFI_HPC_STATE_ENABLED;
//
// The padding should be applied at PCI bus level, and considered by upstream
// bridges, recursively.
//
*Attributes = EfiPaddingPciBus;
return EFI_SUCCESS;
}
/**
Entry point for this driver.
@param[in] ImageHandle Image handle of this driver.
@param[in] SystemTable Pointer to SystemTable.
@retval EFI_SUCESS Driver has loaded successfully.
@return Error codes from lower level functions.
**/
EFI_STATUS
EFIAPI
DriverInitialize (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
mPciExtConfSpaceSupported = (PcdGet16 (PcdOvmfHostBridgePciDevId) ==
INTEL_Q35_MCH_DEVICE_ID);
mPciHotPlugInit.GetRootHpcList = GetRootHpcList;
mPciHotPlugInit.InitializeRootHpc = InitializeRootHpc;
mPciHotPlugInit.GetResourcePadding = GetResourcePadding;
Status = gBS->InstallMultipleProtocolInterfaces (&ImageHandle,
&gEfiPciHotPlugInitProtocolGuid, &mPciHotPlugInit, NULL);
return Status;
}