Re: [PATCH 2/2] EmbeddedPkg: implement EDK2 IoMmu protocol wrapping DmaLib

["Leif Lindholm" <leif.lindholm@linaro.org>]

On Thu, Nov 21, 2019 at 09:32:27 +0100, Ard Biesheuvel wrote:
> Implement a version of the EDK2 IoMmu protocol that is a simple wrapper
> around DmaLib. This is intended to be used to wrap NonCoherentDmaLib so
> that the generic PCI infrastructure can be used to implement support for
> non cache-coherent DMA.
> 
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

> ---
>  EmbeddedPkg/Drivers/NonCoherentIoMmuDxe/NonCoherentIoMmuDxe.c   | 257 ++++++++++++++++++++
>  EmbeddedPkg/Drivers/NonCoherentIoMmuDxe/NonCoherentIoMmuDxe.inf |  43 ++++
>  EmbeddedPkg/EmbeddedPkg.dsc                                     |   5 +
>  3 files changed, 305 insertions(+)
> 
> diff --git a/EmbeddedPkg/Drivers/NonCoherentIoMmuDxe/NonCoherentIoMmuDxe.c b/EmbeddedPkg/Drivers/NonCoherentIoMmuDxe/NonCoherentIoMmuDxe.c
> new file mode 100644
> index 000000000000..4b0afe47de4c
> --- /dev/null
> +++ b/EmbeddedPkg/Drivers/NonCoherentIoMmuDxe/NonCoherentIoMmuDxe.c
> @@ -0,0 +1,257 @@
> +/** @file
> +
> +  Copyright (c) 2019, Linaro, Ltd. All rights reserved.<BR>
> +
> +  This program and the accompanying materials are licensed and made available
> +  under the terms and conditions of the BSD License which accompanies this
> +  distribution.  The full text of the license may be found at
> +  http://opensource.org/licenses/bsd-license.php
> +
> +  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
> +  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
> +
> +**/
> +
> +#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_UNSUPPORTED;
> +}
> +
> +/**
> +  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);
> +}
> diff --git a/EmbeddedPkg/Drivers/NonCoherentIoMmuDxe/NonCoherentIoMmuDxe.inf b/EmbeddedPkg/Drivers/NonCoherentIoMmuDxe/NonCoherentIoMmuDxe.inf
> new file mode 100644
> index 000000000000..de70cfb4cad7
> --- /dev/null
> +++ b/EmbeddedPkg/Drivers/NonCoherentIoMmuDxe/NonCoherentIoMmuDxe.inf
> @@ -0,0 +1,43 @@
> +#/** @file
> +#
> +#  Copyright (c) 2019, Linaro, Ltd. All rights reserved.<BR>
> +#
> +#  This program and the accompanying materials are licensed and made available
> +#  under the terms and conditions of the BSD License which accompanies this
> +#  distribution.  The full text of the license may be found at
> +#  http://opensource.org/licenses/bsd-license.php
> +#
> +#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
> +#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR
> +#  IMPLIED.
> +#
> +#**/
> +
> +[Defines]
> +  INF_VERSION                    = 1.27
> +  BASE_NAME                      = NonCoherentIoMmuDxe
> +  FILE_GUID                      = 7ed510aa-9cdc-49d2-a306-6e11e359f9b3
> +  MODULE_TYPE                    = DXE_DRIVER
> +  VERSION_STRING                 = 1.0
> +  ENTRY_POINT                    = NonCoherentIoMmuDxeEntryPoint
> +
> +[Sources]
> +  NonCoherentIoMmuDxe.c
> +
> +[Packages]
> +  EmbeddedPkg/EmbeddedPkg.dec
> +  MdeModulePkg/MdeModulePkg.dec
> +  MdePkg/MdePkg.dec
> +
> +[LibraryClasses]
> +  BaseLib
> +  DebugLib
> +  DmaLib
> +  UefiBootServicesTableLib
> +  UefiDriverEntryPoint
> +
> +[Protocols]
> +  gEdkiiIoMmuProtocolGuid                     ## PRODUCES
> +
> +[Depex]
> +  TRUE
> diff --git a/EmbeddedPkg/EmbeddedPkg.dsc b/EmbeddedPkg/EmbeddedPkg.dsc
> index a8a151eb40cb..8842acc4cbf4 100644
> --- a/EmbeddedPkg/EmbeddedPkg.dsc
> +++ b/EmbeddedPkg/EmbeddedPkg.dsc
> @@ -238,6 +238,11 @@ [Components.common]
>    EmbeddedPkg/Drivers/ConsolePrefDxe/ConsolePrefDxe.inf
>    EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.inf
>  
> +  EmbeddedPkg/Drivers/NonCoherentIoMmuDxe/NonCoherentIoMmuDxe.inf {
> +    <LibraryClasses>
> +      DmaLib|EmbeddedPkg/Library/NonCoherentDmaLib/NonCoherentDmaLib.inf
> +  }
> +
>  [Components.ARM]
>    EmbeddedPkg/Drivers/Isp1761UsbDxe/Isp1761UsbDxe.inf
>  
> -- 
> 2.17.1
>