-----Original Message-----
From: Abdul Lateef Attar <abdattar@...>
Sent: Monday, May 22, 2023 5:29 PM
To: devel@edk2.groups.io
Cc: Attar, AbdulLateef (Abdul Lateef) <AbdulLateef.Attar@...>; Chang,
Abner <Abner.Chang@...>
Subject: [PATCH v2 1/2] AMD/AmdMinBoardPkg: Implements PCI hotplug init
protocol

From: Abdul Lateef Attar <AbdulLateef.Attar@...>

Implements PCI hotplug init protocol.
Adds resources padding based on PCD values.

Cc: Abner Chang <abner.chang@...>

Signed-off-by: Abdul Lateef Attar <AbdulLateef.Attar@...>
---
.../AMD/AmdMinBoardPkg/AmdMinBoardPkg.dec | 16 +
.../AMD/AmdMinBoardPkg/AmdMinBoardPkg.dsc | 14 +-
.../PciHotPlug/PciHotPlugInit.inf | 39 +++
.../PciHotPlug/PciHotPlugInit.c | 331 ++++++++++++++++++
4 files changed, 399 insertions(+), 1 deletion(-)
create mode 100755
Platform/AMD/AmdMinBoardPkg/PciHotPlug/PciHotPlugInit.inf
create mode 100755
Platform/AMD/AmdMinBoardPkg/PciHotPlug/PciHotPlugInit.c

diff --git a/Platform/AMD/AmdMinBoardPkg/AmdMinBoardPkg.dec
b/Platform/AMD/AmdMinBoardPkg/AmdMinBoardPkg.dec
index e37b02c4cf5a..65ba08545021 100644
--- a/Platform/AMD/AmdMinBoardPkg/AmdMinBoardPkg.dec
+++ b/Platform/AMD/AmdMinBoardPkg/AmdMinBoardPkg.dec
@@ -17,3 +17,19 @@ [Defines]
PACKAGE_GUID = 44F9D761-9ECB-43DD-A5AC-177E5048701B
PACKAGE_VERSION = 0.1

+[Guids]
+ gAmdMinBoardPkgTokenSpaceGuid = {0xd4d23d79, 0x73bf, 0x460a,
{0xa1, 0xc7, 0x85, 0xa3, 0xca, 0x71, 0xb9, 0x4c}}
+
+[PcdsFixedAtBuild, PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx]
+ #
+ # PCI HotPlug Resource Padding
+ #
+ # PCI bus padding, number of bus to reserve, default 2 bus
+
gAmdMinBoardPkgTokenSpaceGuid.PcdPciHotPlugResourcePadBus|2|UINT8
|0x10000003
+ # IO Resource padding in bytes, default 4KB
+
gAmdMinBoardPkgTokenSpaceGuid.PcdPciHotPlugResourcePadIo|0x000010
00|UINT32|0x10000000
+ # Non-PreFetch Memory padding in bytes, default 1MB
+
gAmdMinBoardPkgTokenSpaceGuid.PcdPciHotPlugResourcePadMem|0x0010
0000|UINT32|0x10000002
+ # PreFetch Memory padding in bytes, default 2MB
+
gAmdMinBoardPkgTokenSpaceGuid.PcdPciHotPlugResourcePadPMem|0x002
00000|UINT32|0x10000001
+
diff --git a/Platform/AMD/AmdMinBoardPkg/AmdMinBoardPkg.dsc
b/Platform/AMD/AmdMinBoardPkg/AmdMinBoardPkg.dsc
index 273cd74f7842..1a8407250c56 100644
--- a/Platform/AMD/AmdMinBoardPkg/AmdMinBoardPkg.dsc
+++ b/Platform/AMD/AmdMinBoardPkg/AmdMinBoardPkg.dsc
@@ -9,7 +9,7 @@

[Defines]
DSC_SPECIFICATION = 1.30
- PLATFORM_GUID = 88F8A9AE-2FA0-4D58-A6F9-05F635C05F4E
+ PLATFORM_GUID = 939B559B-269B-4B8F-9637-44DF6575C1E2
PLATFORM_NAME = AmdMinBoardPkg
PLATFORM_VERSION = 0.1
OUTPUT_DIRECTORY = Build/$(PLATFORM_NAME)
@@ -25,6 +25,16 @@ [Packages]
[LibraryClasses]
SpcrDeviceLib|AmdMinBoardPkg/Library/SpcrDeviceLib/SpcrDeviceLib.inf

+[LibraryClasses.common]
+ BaseLib|MdePkg/Library/BaseLib/BaseLib.inf
+
BaseMemoryLib|MdePkg/Library/BaseMemoryLibRepStr/BaseMemoryLibRe
pStr.inf
+ DebugLib|MdePkg/Library/BaseDebugLibNull/BaseDebugLibNull.inf
+
MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemor
yAllocationLib.inf
+ PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
+
RegisterFilterLib|MdePkg/Library/RegisterFilterLibNull/RegisterFilterLibNull.inf
+
UefiBootServicesTableLib|MdePkg/Library/UefiBootServicesTableLib/UefiBoo
tServicesTableLib.inf
+
UefiDriverEntryPoint|MdePkg/Library/UefiDriverEntryPoint/UefiDriverEntryP
oint.inf
+
[LibraryClasses.common.PEIM]

SetCacheMtrrLib|AmdMinBoardPkg/Library/SetCacheMtrrLib/SetCacheMtrrLi
b.inf

@@ -34,3 +44,5 @@ [Components]
[Components.IA32]
AmdMinBoardPkg/Library/SetCacheMtrrLib/SetCacheMtrrLib.inf

+[Components.X64]
+ AmdMinBoardPkg/PciHotPlug/PciHotPlugInit.inf
diff --git a/Platform/AMD/AmdMinBoardPkg/PciHotPlug/PciHotPlugInit.inf
b/Platform/AMD/AmdMinBoardPkg/PciHotPlug/PciHotPlugInit.inf
new file mode 100755
index 000000000000..44564df38718
--- /dev/null
+++ b/Platform/AMD/AmdMinBoardPkg/PciHotPlug/PciHotPlugInit.inf
@@ -0,0 +1,39 @@
+## @file
+# This driver implements EFI_PCI_HOT_PLUG_INIT_PROTOCOL.
+# Adds resource padding information, for PCIe hotplug purposes.
+#
+# Copyright (C) 2023 Advanced Micro Devices, Inc. All rights reserved
+# SPDX-License-Identifier: BSD-2-Clause-Patent ##
+
+[Defines]
+ INF_VERSION = 1.29
+ BASE_NAME = PciHotPlugInit
+ FILE_GUID = 85F78A6D-6438-4BCC-B796-759A48D00C72
+ MODULE_TYPE = DXE_DRIVER
+ VERSION_STRING = 0.1
+ ENTRY_POINT = PciHotPlugInitialize
+
+[Sources]
+ PciHotPlugInit.c
+
+[Packages]
+ AmdMinBoardPkg/AmdMinBoardPkg.dec
+ MdeModulePkg/MdeModulePkg.dec
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ MemoryAllocationLib
+ UefiBootServicesTableLib
+ UefiDriverEntryPoint
+
+[Protocols]
+ gEfiPciHotPlugInitProtocolGuid
+
+[Pcd]
+ gAmdMinBoardPkgTokenSpaceGuid.PcdPciHotPlugResourcePadBus
+ gAmdMinBoardPkgTokenSpaceGuid.PcdPciHotPlugResourcePadIo
+ gAmdMinBoardPkgTokenSpaceGuid.PcdPciHotPlugResourcePadMem
+ gAmdMinBoardPkgTokenSpaceGuid.PcdPciHotPlugResourcePadPMem
+
+[Depex]
+ TRUE
diff --git a/Platform/AMD/AmdMinBoardPkg/PciHotPlug/PciHotPlugInit.c
b/Platform/AMD/AmdMinBoardPkg/PciHotPlug/PciHotPlugInit.c
new file mode 100755
index 000000000000..a26ca16741b8
--- /dev/null
+++ b/Platform/AMD/AmdMinBoardPkg/PciHotPlug/PciHotPlugInit.c
@@ -0,0 +1,331 @@
+/** @file
+ This file declares EFI PCI Hot Plug Init Protocol.
+
+ This protocol provides the necessary functionality to initialize the Hot Plug
+ Controllers (HPCs) and the buses that they control. This protocol also
provides
+ information regarding resource padding.
+
+ @par Note:
+ This source has the reference of OVMF PciHotPluginit.c and Intel platform
PciHotPlug.c.
+
+ This protocol is required only on platforms that support one or more PCI
Hot
+ Plug* slots or CardBus sockets.
+
+ The EFI_PCI_HOT_PLUG_INIT_PROTOCOL provides a mechanism for the PCI
bus enumerator
+ to properly initialize the HPCs and CardBus sockets that require initialization.
+ The HPC initialization takes place before the PCI enumeration process is
complete.
+ There cannot be more than one instance of this protocol in a system. This
protocol
+ is installed on its own separate handle.
+
+ Because the system may include multiple HPCs, one instance of this protocol
+ should represent all of them. The protocol functions use the device path of
+ the HPC to identify the HPC. When the PCI bus enumerator finds a root HPC,
it
+ will call EFI_PCI_HOT_PLUG_INIT_PROTOCOL.InitializeRootHpc(). If
InitializeRootHpc()
+ is unable to initialize a root HPC, the PCI enumerator will ignore that root
HPC
+ and continue the enumeration process. If the HPC is not initialized, the
devices
+ that it controls may not be initialized, and no resource padding will be
provided.
+
+ From the standpoint of the PCI bus enumerator, HPCs are divided into the
following
+ two classes:
+
+ - Root HPC:
+ These HPCs must be initialized by calling InitializeRootHpc() during the
+ enumeration process. These HPCs will also require resource padding. The
+ platform code must have a priori knowledge of these devices and must
know
+ how to initialize them. There may not be any way to access their PCI
+ configuration space before the PCI enumerator programs all the
upstream
+ bridges and thus enables the path to these devices. The PCI bus
enumerator
+ is responsible for determining the PCI bus address of the HPC before it
+ calls InitializeRootHpc().
+ - Nonroot HPC:
+ These HPCs will not need explicit initialization during enumeration
process.
+ These HPCs will require resource padding. The platform code does not
have
+ to have a priori knowledge of these devices.
+
+ Copyright (c) 2007 - 2018, Intel Corporation. All rights reserved.<BR>
+ Copyright (C) 2016, Red Hat, Inc.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+ @par Revision Reference:
+ This Protocol is defined in UEFI Platform Initialization Specification 1.2
+ Volume 5: Standards
+
+**/
+
+#include <Uefi/UefiBaseType.h>
+#include <Uefi/UefiSpec.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Protocol/PciHotPlugInit.h>
+
+//
+// The protocol interface this driver produces.
+//
+STATIC EFI_PCI_HOT_PLUG_INIT_PROTOCOL mPciHotPlugInit;
+
+/**
+ 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_INVALID_PARAMETER HpcCount is NULL or HpcList is NULL.
+
+**/
+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;
+ }
+
+ //
+ // Platform BIOS not doing any extra/special HPC initialization
+ // Hence returning the HpcCount as zero and HpcList as NULL
+ //
+ *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_UNSUPPORTED This instance of
EFI_PCI_HOT_PLUG_INIT_PROTOCOL
+ does not support the specified HPC.
+ @retval EFI_INVALID_PARAMETER HpcState is NULL.
+
+**/
+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
+ )
+{
+ if (HpcState == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // HPC is initialized by respective platform PI modules.
+ // Hence no extra initialization required.
+ //
+ 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_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.
+
+**/
+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_ACPI_ADDRESS_SPACE_DESCRIPTOR *PaddingResource;
+
+ if ((HpcState == NULL) || (Padding == NULL) || (Attributes == NULL)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // Need total 5 resources
+ // 1 - IO resource
+ // 2 - Mem resource
+ // 3 - PMem resource
+ // 4 - Bus resource
+ // 5 - end tag resource
+ PaddingResource = AllocateZeroPool (4 * sizeof
(EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) + sizeof
(EFI_ACPI_END_TAG_DESCRIPTOR));
+ if (PaddingResource == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ *Padding = (VOID *)PaddingResource;
+
+ //
+ // Padding for bus
+ //
+ *Attributes = EfiPaddingPciBus;
+
+ PaddingResource->Desc = ACPI_ADDRESS_SPACE_DESCRIPTOR;
+ PaddingResource->Len = (UINT16)(
+ sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) -
+ OFFSET_OF (
+ EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR,
+ ResType
+ )
+ );
+ PaddingResource->ResType = ACPI_ADDRESS_SPACE_TYPE_BUS;
+ PaddingResource->GenFlag = 0x0;
+ PaddingResource->SpecificFlag = 0;
+ PaddingResource->AddrRangeMin = 0;
+ PaddingResource->AddrRangeMax = 0;
+ PaddingResource->AddrLen = PcdGet8 (PcdPciHotPlugResourcePadBus);
+
+ //
+ // Padding for non-prefetchable memory
+ //
+ PaddingResource++;
+ PaddingResource->Desc = ACPI_ADDRESS_SPACE_DESCRIPTOR;
+ PaddingResource->Len = (UINT16)(
+ sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) -
+ OFFSET_OF (
+ EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR,
+ ResType
+ )
+ );
+ PaddingResource->ResType = ACPI_ADDRESS_SPACE_TYPE_MEM;
+ PaddingResource->GenFlag = 0x0;
+ PaddingResource->AddrSpaceGranularity = 32;
+ PaddingResource->SpecificFlag =
EFI_ACPI_MEMORY_RESOURCE_SPECIFIC_FLAG_NON_CACHEABLE;
+ PaddingResource->AddrRangeMin = 0;
+ PaddingResource->AddrLen = (UINT64)PcdGet32
(PcdPciHotPlugResourcePadMem);
+ PaddingResource->AddrRangeMax = PaddingResource->AddrLen - 1;
+
+ //
+ // Padding for prefetchable memory
+ //
+ PaddingResource++;
+ PaddingResource->Desc = ACPI_ADDRESS_SPACE_DESCRIPTOR;
+ PaddingResource->Len = (UINT16)(
+ sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) -
+ OFFSET_OF (
+ EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR,
+ ResType
+ )
+ );
+ PaddingResource->ResType = ACPI_ADDRESS_SPACE_TYPE_MEM;
+ PaddingResource->GenFlag = 0x0;
+ PaddingResource->AddrSpaceGranularity = 32;
+ PaddingResource->SpecificFlag =
EFI_ACPI_MEMORY_RESOURCE_SPECIFIC_FLAG_CACHEABLE_PREFETCHABLE;
+ PaddingResource->AddrLen = (UINT64)PcdGet32
(PcdPciHotPlugResourcePadPMem);
+ PaddingResource->AddrRangeMax = PaddingResource->AddrLen - 1;
+
+ //
+ // Padding for I/O
+ //
+ PaddingResource++;
+ PaddingResource->Desc = ACPI_ADDRESS_SPACE_DESCRIPTOR;
+ PaddingResource->Len = (UINT16)(
+ sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) -
+ OFFSET_OF (
+ EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR,
+ ResType
+ )
+ );
+ PaddingResource->ResType = ACPI_ADDRESS_SPACE_TYPE_IO;
+ PaddingResource->GenFlag = 0x0;
+ PaddingResource->SpecificFlag = 0;
+ PaddingResource->AddrRangeMin = 0;
+ PaddingResource->AddrLen = (UINT64)PcdGet32
(PcdPciHotPlugResourcePadIo);
+ PaddingResource->AddrRangeMax = PaddingResource->AddrLen - 1;
+
+ //
+ // Terminate the entries.
+ //
+ PaddingResource++;
+ ((EFI_ACPI_END_TAG_DESCRIPTOR *)PaddingResource)->Desc =
ACPI_END_TAG_DESCRIPTOR;
+ ((EFI_ACPI_END_TAG_DESCRIPTOR *)PaddingResource)->Checksum = 0x0;
+
+ *HpcState = EFI_HPC_STATE_INITIALIZED | EFI_HPC_STATE_ENABLED;
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Entry point for this driver.
+
+ @param[in] ImageHandle Image handle of this driver.
+ @param[in] SystemTable Pointer to SystemTable.
+
+ @retval EFI_SUCCESS Driver has loaded successfully.
+ @return Error codes from lower level functions.
+
+**/
+EFI_STATUS
+EFIAPI
+PciHotPlugInitialize (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ mPciHotPlugInit.GetRootHpcList = GetRootHpcList;
+ mPciHotPlugInit.InitializeRootHpc = InitializeRootHpc;
+ mPciHotPlugInit.GetResourcePadding = GetResourcePadding;
+ return gBS->InstallMultipleProtocolInterfaces (
+ &ImageHandle,
+ &gEfiPciHotPlugInitProtocolGuid,
+ &mPciHotPlugInit,
+ NULL
+ );
+}
--
2.25.1