NonCoherentIoMmuDxe.c File Reference

#include <PiDxe.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/DmaLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Protocol/IoMmu.h>

Go to the source code of this file.

Functions
STATIC EFI_STATUS EFIAPI	NonCoherentIoMmuSetAttribute (IN EDKII_IOMMU_PROTOCOL *This, IN EFI_HANDLE DeviceHandle, IN VOID *Mapping, IN UINT64 IoMmuAccess)
STATIC EFI_STATUS EFIAPI	NonCoherentIoMmuMap (IN EDKII_IOMMU_PROTOCOL *This, IN EDKII_IOMMU_OPERATION Operation, IN VOID *HostAddress, IN OUT UINTN *NumberOfBytes, OUT EFI_PHYSICAL_ADDRESS *DeviceAddress, OUT VOID **Mapping)
STATIC EFI_STATUS EFIAPI	NonCoherentIoMmuUnmap (IN EDKII_IOMMU_PROTOCOL *This, IN VOID *Mapping)
STATIC EFI_STATUS EFIAPI	NonCoherentIoMmuAllocateBuffer (IN EDKII_IOMMU_PROTOCOL *This, IN EFI_ALLOCATE_TYPE Type, IN EFI_MEMORY_TYPE MemoryType, IN UINTN Pages, IN OUT VOID **HostAddress, IN UINT64 Attributes)
STATIC EFI_STATUS EFIAPI	NonCoherentIoMmuFreeBuffer (IN EDKII_IOMMU_PROTOCOL *This, IN UINTN Pages, IN VOID *HostAddress)
EFI_STATUS EFIAPI	NonCoherentIoMmuDxeEntryPoint (IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable)

Variables
STATIC EDKII_IOMMU_PROTOCOL	mNonCoherentIoMmuOps

Detailed Description

Copyright (c) 2019, Linaro, Ltd. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file NonCoherentIoMmuDxe.c.

Function Documentation

NonCoherentIoMmuAllocateBuffer()

STATIC EFI_STATUS EFIAPI NonCoherentIoMmuAllocateBuffer	(	IN EDKII_IOMMU_PROTOCOL *	This,
		IN EFI_ALLOCATE_TYPE	Type,
		IN EFI_MEMORY_TYPE	MemoryType,
		IN UINTN	Pages,
		IN OUT VOID **	HostAddress,
		IN UINT64	Attributes
	)

Allocates pages that are suitable for an OperationBusMasterCommonBuffer or OperationBusMasterCommonBuffer64 mapping.

Parameters

This	The protocol instance pointer.
Type	This parameter is not used and must be ignored.
MemoryType	The type of memory to allocate, EfiBootServicesData or EfiRuntimeServicesData.
Pages	The number of pages to allocate.
HostAddress	A pointer to store the base system memory address of the allocated range.
Attributes	The requested bit mask of attributes for the allocated range.

Return values

EFI_SUCCESS	The requested memory pages were allocated.
EFI_UNSUPPORTED	Attributes is unsupported. The only legal attribute bits are MEMORY_WRITE_COMBINE and MEMORY_CACHED.
EFI_INVALID_PARAMETER	One or more parameters are invalid.
EFI_OUT_OF_RESOURCES	The memory pages could not be allocated.

Definition at line 198 of file NonCoherentIoMmuDxe.c.

NonCoherentIoMmuDxeEntryPoint()

EFI_STATUS EFIAPI NonCoherentIoMmuDxeEntryPoint	(	IN EFI_HANDLE	ImageHandle,
		IN EFI_SYSTEM_TABLE *	SystemTable
	)

Definition at line 246 of file NonCoherentIoMmuDxe.c.

NonCoherentIoMmuFreeBuffer()

STATIC EFI_STATUS EFIAPI NonCoherentIoMmuFreeBuffer	(	IN EDKII_IOMMU_PROTOCOL *	This,
		IN UINTN	Pages,
		IN VOID *	HostAddress
	)

Frees memory that was allocated with AllocateBuffer().

Parameters

This	The protocol instance pointer.
Pages	The number of pages to free.
HostAddress	The base system memory address of the allocated range.

Return values

EFI_SUCCESS	The requested memory pages were freed.
EFI_INVALID_PARAMETER	The memory range specified by HostAddress and Pages was not allocated with AllocateBuffer().

Definition at line 226 of file NonCoherentIoMmuDxe.c.

NonCoherentIoMmuMap()

STATIC EFI_STATUS EFIAPI NonCoherentIoMmuMap	(	IN EDKII_IOMMU_PROTOCOL *	This,
		IN EDKII_IOMMU_OPERATION	Operation,
		IN VOID *	HostAddress,
		IN OUT UINTN *	NumberOfBytes,
		OUT EFI_PHYSICAL_ADDRESS *	DeviceAddress,
		OUT VOID **	Mapping
	)

Provides the controller-specific addresses required to access system memory from a DMA bus master. On SEV guest, the DMA operations must be performed on shared buffer hence we allocate a bounce buffer to map the HostAddress to a DeviceAddress. The Encryption attribute is removed from the DeviceAddress buffer.

Parameters

This	The protocol instance pointer.
Operation	Indicates if the bus master is going to read or write to system memory.
HostAddress	The system memory address to map to the PCI controller.
NumberOfBytes	On input the number of bytes to map. On output the number of bytes that were mapped.
DeviceAddress	The resulting map address for the bus master PCI controller to use to access the hosts HostAddress.
Mapping	A resulting value to pass to Unmap().

Return values

EFI_SUCCESS	The range was mapped for the returned NumberOfBytes.
EFI_UNSUPPORTED	The HostAddress cannot be mapped as a common buffer.
EFI_INVALID_PARAMETER	One or more parameters are invalid.
EFI_OUT_OF_RESOURCES	The request could not be completed due to a lack of resources.
EFI_DEVICE_ERROR	The system hardware could not map the requested address.

Definition at line 109 of file NonCoherentIoMmuDxe.c.

NonCoherentIoMmuSetAttribute()

STATIC EFI_STATUS EFIAPI NonCoherentIoMmuSetAttribute	(	IN EDKII_IOMMU_PROTOCOL *	This,
		IN EFI_HANDLE	DeviceHandle,
		IN VOID *	Mapping,
		IN UINT64	IoMmuAccess
	)

Set IOMMU attribute for a system memory.

If the IOMMU protocol exists, the system memory cannot be used for DMA by default.

When a device requests a DMA access for a system memory, the device driver need use SetAttribute() to update the IOMMU attribute to request DMA access (read and/or write).

The DeviceHandle is used to identify which device submits the request. The IOMMU implementation need translate the device path to an IOMMU device ID, and set IOMMU hardware register accordingly. 1) DeviceHandle can be a standard PCI device. The memory for BusMasterRead need set EDKII_IOMMU_ACCESS_READ. The memory for BusMasterWrite need set EDKII_IOMMU_ACCESS_WRITE. The memory for BusMasterCommonBuffer need set EDKII_IOMMU_ACCESS_READ|EDKII_IOMMU_ACCESS_WRITE. After the memory is used, the memory need set 0 to keep it being protected. 2) DeviceHandle can be an ACPI device (ISA, I2C, SPI, etc). The memory for DMA access need set EDKII_IOMMU_ACCESS_READ and/or EDKII_IOMMU_ACCESS_WRITE.

Parameters

[in]	This	The protocol instance pointer.
[in]	DeviceHandle	The device who initiates the DMA access request.
[in]	Mapping	The mapping value returned from Map().
[in]	IoMmuAccess	The IOMMU access.

Return values

EFI_SUCCESS	The IoMmuAccess is set for the memory range specified by DeviceAddress and Length.
EFI_INVALID_PARAMETER	DeviceHandle is an invalid handle.
EFI_INVALID_PARAMETER	Mapping is not a value that was returned by Map().
EFI_INVALID_PARAMETER	IoMmuAccess specified an illegal combination of access.
EFI_UNSUPPORTED	DeviceHandle is unknown by the IOMMU.
EFI_UNSUPPORTED	The bit mask of IoMmuAccess is not supported by the IOMMU.
EFI_UNSUPPORTED	The IOMMU does not support the memory range specified by Mapping.
EFI_OUT_OF_RESOURCES	There are not enough resources available to modify the IOMMU access.
EFI_DEVICE_ERROR	The IOMMU device reported an error while attempting the operation.

Definition at line 66 of file NonCoherentIoMmuDxe.c.

NonCoherentIoMmuUnmap()

STATIC EFI_STATUS EFIAPI NonCoherentIoMmuUnmap	(	IN EDKII_IOMMU_PROTOCOL *	This,
		IN VOID *	Mapping
	)

Completes the Map() operation and releases any corresponding resources.

Parameters

This	The protocol instance pointer.
Mapping	The mapping value returned from Map().

Return values

EFI_SUCCESS	The range was unmapped.
EFI_INVALID_PARAMETER	Mapping is not a value that was returned by Map().
EFI_DEVICE_ERROR	The data was not committed to the target system memory.

Definition at line 165 of file NonCoherentIoMmuDxe.c.

Variable Documentation

mNonCoherentIoMmuOps

STATIC EDKII_IOMMU_PROTOCOL mNonCoherentIoMmuOps

Initial value:

= {
  EDKII_IOMMU_PROTOCOL_REVISION,
  NonCoherentIoMmuSetAttribute,
  NonCoherentIoMmuMap,
  NonCoherentIoMmuUnmap,
  NonCoherentIoMmuAllocateBuffer,
  NonCoherentIoMmuFreeBuffer,
}

Definition at line 235 of file NonCoherentIoMmuDxe.c.