EmbeddedPkg/Drivers/NonCoherentIoMmuDxe/NonCoherentIoMmuDxe.c

/** @file

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

**/

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

/**
  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.

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

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

**/
STATIC
EFI_STATUS
EFIAPI
NonCoherentIoMmuSetAttribute (
  IN EDKII_IOMMU_PROTOCOL  *This,
  IN EFI_HANDLE            DeviceHandle,
  IN VOID                  *Mapping,
  IN UINT64                IoMmuAccess
  )
{
  return EFI_SUCCESS;
}

/**
  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.

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

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

**/
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
  )
{
  DMA_MAP_OPERATION  DmaOperation;

  switch (Operation) {
    case EdkiiIoMmuOperationBusMasterRead:
    case EdkiiIoMmuOperationBusMasterRead64:
      DmaOperation = MapOperationBusMasterRead;
      break;

    case EdkiiIoMmuOperationBusMasterWrite:
    case EdkiiIoMmuOperationBusMasterWrite64:
      DmaOperation = MapOperationBusMasterWrite;
      break;

    case EdkiiIoMmuOperationBusMasterCommonBuffer:
    case EdkiiIoMmuOperationBusMasterCommonBuffer64:
      DmaOperation = MapOperationBusMasterCommonBuffer;
      break;

    default:
      ASSERT (FALSE);
      return EFI_INVALID_PARAMETER;
  }

  return DmaMap (
           DmaOperation,
           HostAddress,
           NumberOfBytes,
           DeviceAddress,
           Mapping
           );
}

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

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

  @retval EFI_SUCCESS           The range was unmapped.
  @retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
                                Map().
  @retval EFI_DEVICE_ERROR      The data was not committed to the target system
                                memory.
**/
STATIC
EFI_STATUS
EFIAPI
NonCoherentIoMmuUnmap (
  IN  EDKII_IOMMU_PROTOCOL  *This,
  IN  VOID                  *Mapping
  )
{
  return DmaUnmap (Mapping);
}

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

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

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

**/
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
  )
{
  return DmaAllocateBuffer (MemoryType, Pages, HostAddress);
}

/**
  Frees memory that was allocated with AllocateBuffer().

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

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

**/
STATIC
EFI_STATUS
EFIAPI
NonCoherentIoMmuFreeBuffer (
  IN  EDKII_IOMMU_PROTOCOL  *This,
  IN  UINTN                 Pages,
  IN  VOID                  *HostAddress
  )
{
  return DmaFreeBuffer (Pages, HostAddress);
}

STATIC EDKII_IOMMU_PROTOCOL  mNonCoherentIoMmuOps = {
  EDKII_IOMMU_PROTOCOL_REVISION,
  NonCoherentIoMmuSetAttribute,
  NonCoherentIoMmuMap,
  NonCoherentIoMmuUnmap,
  NonCoherentIoMmuAllocateBuffer,
  NonCoherentIoMmuFreeBuffer,
};

EFI_STATUS
EFIAPI
NonCoherentIoMmuDxeEntryPoint (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  return gBS->InstallMultipleProtocolInterfaces (
                &ImageHandle,
                &gEdkiiIoMmuProtocolGuid,
                &mNonCoherentIoMmuOps,
                NULL
                );
}