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From: Leif Lindholm <leif.lindholm@linaro.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: "edk2-devel@lists.01.org" <edk2-devel@lists.01.org>,
	"Duran, Leo" <leo.duran@amd.com>,
	"Yao, Jiewen" <jiewen.yao@intel.com>,
	Alexander Graf <agraf@suse.de>
Subject: Re: [RFC PATCH] ArmPkg: implement generic SMMU driver to remap DRAM for 32-bit PCI DMA
Date: Wed, 24 May 2017 11:30:58 +0100	[thread overview]
Message-ID: <20170524103058.GC32240@bivouac.eciton.net> (raw)
In-Reply-To: <CAKv+Gu-QCxUc+cxBMXUPhhDnLXi-y69p_MXUZkkVL_99VtsO9g@mail.gmail.com>

On Tue, May 23, 2017 at 03:36:24AM -0700, Ard Biesheuvel wrote:
> On 22 May 2017 at 06:49, Leif Lindholm <leif.lindholm@linaro.org> wrote:
> > On Tue, May 02, 2017 at 11:32:02AM +0100, Ard Biesheuvel wrote:
> >> This implements a driver that uses any SMMU compatible with the generic
> >> ARM SMMU architecture to remap the lowest 4 GB of DRAM in a way that
> >> makes it accessible to PCI masters that are only 32-bit DMA capable.
> >>
> >> Note that this driver goes a bit beyond what is strictly necessary to
> >> support 32-bit DMA, given that it also creates an identity map of the
> >> lowest 4 GB of DRAM. This is intended for interoperability with external
> >> drivers that may use the PCI I/O protocol incorrectly (or not at all)
> >> and program host addresses into the DMA registers and/or rings without
> >> any regard for translation or address size. If a platform's base of DRAM
> >> is a power of 2, and if the platform runs UEFI entirely in the lowest
> >> 4 GB of DRAM, any host address access by a PCI master will hit the ID
> >> mapped window, and any truncation that may occur will convert the host
> >> address into the device address.
> >>
> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >> ---
> >>
> >> This is based on Jiewen Yao's IOMMU protocol support series, v4.
> >>
> >> https://lists.01.org/pipermail/edk2-devel/2017-April/010330.html
> >>
> >> Tested with AMD Seattle, which has no DRAM below 4 GB.
> >>
> >>  ArmPkg/ArmPkg.dec                                                        |   7 +
> >>  ArmPkg/ArmPkg.dsc                                                        |   1 +
> >>  ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/BmDma.c                        | 467 ++++++++++++++++++++
> >>  ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/GenericSmmuStaticPciDmaDxe.c   | 323 ++++++++++++++
> >>  ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/GenericSmmuStaticPciDmaDxe.inf |  62 +++
> >>  5 files changed, 860 insertions(+)
> >>
> >> diff --git a/ArmPkg/ArmPkg.dec b/ArmPkg/ArmPkg.dec
> >> index c4b4da2f95bb..96913e3c0713 100644
> >> --- a/ArmPkg/ArmPkg.dec
> >> +++ b/ArmPkg/ArmPkg.dec
> >> @@ -322,3 +322,10 @@ [PcdsFixedAtBuild.common, PcdsDynamic.common]
> >>    #
> >>    gArmTokenSpaceGuid.PcdPciBusMin|0x0|UINT32|0x00000059
> >>    gArmTokenSpaceGuid.PcdPciBusMax|0x0|UINT32|0x0000005A
> >> +
> >> +  #
> >> +  # Base address and context interrupt of the generic SMMU that
> >> +  # translates memory accesses made by PCI masters
> >> +  #
> >> +  gArmTokenSpaceGuid.PcdPciGenericSmmuBase|0x0|UINT64|0x0000005B
> >> +  gArmTokenSpaceGuid.PcdPciGenericSmmuContextInterrupt|0x0|UINT16|0x0000005C
> >> diff --git a/ArmPkg/ArmPkg.dsc b/ArmPkg/ArmPkg.dsc
> >> index 9144334cb821..9bbc71fa2479 100644
> >> --- a/ArmPkg/ArmPkg.dsc
> >> +++ b/ArmPkg/ArmPkg.dsc
> >> @@ -127,6 +127,7 @@ [Components.common]
> >>    ArmPkg/Drivers/ArmGic/ArmGicDxe.inf
> >>    ArmPkg/Drivers/ArmGic/ArmGicLib.inf
> >>    ArmPkg/Drivers/ArmGic/ArmGicSecLib.inf
> >> +  ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/GenericSmmuStaticPciDmaDxe.inf
> >>    ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.inf
> >>    ArmPkg/Drivers/TimerDxe/TimerDxe.inf
> >>
> >> diff --git a/ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/BmDma.c b/ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/BmDma.c
> >> new file mode 100644
> >> index 000000000000..629209e335e5
> >> --- /dev/null
> >> +++ b/ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/BmDma.c
> >> @@ -0,0 +1,467 @@
> >> +/** @file
> >> +  BmDma related function
> >> +
> >> +  Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
> >> +  Copyright (c) 2017, 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 <Protocol/IoMmu.h>
> >> +
> >> +#include <Library/BaseLib.h>
> >> +#include <Library/DebugLib.h>
> >> +#include <Library/BaseMemoryLib.h>
> >> +#include <Library/MemoryAllocationLib.h>
> >> +#include <Library/UefiBootServicesTableLib.h>
> >> +
> >> +STATIC CONST UINT64 mTranslationBase = FixedPcdGet64 (PcdSystemMemoryBase);
> >
> > So, here is the only objection I have to the patch (apart from a
> > question below). I am _really_ not happy about the ARM-specific
> > PcdSystemMemoryBase (in general), although it is less evil than
> > PcdSystemMemorySize.
> >
> > Maybe I'm missing something, but I don't see anything ARM-specific
> > about this driver. If PcdSystemMemoryBase is the reason for placing it
> > under ArmPkg, can we migrate that option across somewhere else?
> >
> 
> Of course it is ARM specific. SMMUs only exist on ARM systems,

SMMUs, yes. IOMMUs, no.

> and the
> driver reuses ArmMmuLib defines to populate the page table entries.

Ah, managed to miss that bit.
The remainder of the code looks completely generic.

> In general, I agree with the tendency to keep code out of ArmPkg, but
> in this case, I think it really belongs there.

I'll concede it makes sense to keep it in ArmPkg for now, and
re-engineering it for complete portability when there are no other
potential users is a bit premature.

> > Seems an added shame to put two new generic config options
> > (PcdPciGenericSmmuBase/PcdPciGenericSmmuContextInterrupt) under an
> > architecture-specific directory.
> >
> >> +
> >> +#define MAP_INFO_SIGNATURE  SIGNATURE_32 ('D', 'M', 'A', 'P')
> >> +typedef struct {
> >> +  UINT32                                    Signature;
> >> +  LIST_ENTRY                                Link;
> >> +  EDKII_IOMMU_OPERATION                     Operation;
> >> +  UINTN                                     NumberOfBytes;
> >> +  UINTN                                     NumberOfPages;
> >> +  EFI_PHYSICAL_ADDRESS                      HostAddress;
> >> +  EFI_PHYSICAL_ADDRESS                      MappedHostAddress;
> >> +} MAP_INFO;
> >> +#define MAP_INFO_FROM_LINK(a) CR (a, MAP_INFO, Link, MAP_INFO_SIGNATURE)
> >> +
> >> +STATIC LIST_ENTRY                 mMaps = INITIALIZE_LIST_HEAD_VARIABLE(mMaps);
> >> +
> >> +/**
> >> +  Provides the controller-specific addresses required to access system memory from a
> >> +  DMA bus master.
> >> +
> >> +  @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
> >> +IoMmuMap (
> >> +  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
> >> +  )
> >> +{
> >> +  EFI_STATUS                                        Status;
> >> +  EFI_PHYSICAL_ADDRESS                              PhysicalAddress;
> >> +  MAP_INFO                                          *MapInfo;
> >> +  BOOLEAN                                           NeedRemap;
> >> +
> >> +  if (HostAddress == NULL || NumberOfBytes == NULL || DeviceAddress == NULL ||
> >> +      Mapping == NULL) {
> >> +    return EFI_INVALID_PARAMETER;
> >> +  }
> >> +
> >> +  //
> >> +  // Make sure that Operation is valid
> >> +  //
> >> +  if ((UINT32) Operation >= EdkiiIoMmuOperationMaximum) {
> >> +    return EFI_INVALID_PARAMETER;
> >> +  }
> >> +
> >> +  NeedRemap = FALSE;
> >> +  PhysicalAddress = (UINTN)HostAddress;
> >> +
> >> +  if ((PhysicalAddress + *NumberOfBytes) > mTranslationBase + SIZE_4GB) {
> >> +    //
> >> +    // If the root bridge or the device cannot handle performing DMA above
> >> +    // 4GB but any part of the DMA transfer being mapped is above 4GB, then
> >> +    // map the DMA transfer to a buffer below 4GB.
> >> +    //
> >
> > Request for clarification: is this because this driver is only invoked
> > where the root bridge is incapable? (The test looks unconditional.)
> >
> 
> No, the root bridge driver always invokes the IOMMU protocol if there is one.
> 
> Here we test whether the mapped buffer already lives in the first 4 GB
> of DRAM, otherwise we will use a bounce buffer. This driver never maps
> anything dynamically in the SMMU, it just allocates a bounce buffer
> from the 32-bit addressable range if required.

Right, so could the comment be updated to say something more like

    //
    // If any part of the DMA transfer being mapped is above 4GB, then
    // map the DMA transfer to a buffer below 4GB.
    //

?

The remainder of the comment is also useful, but would it not make
more sense in the function header?

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

/
    Leif

> >> +    NeedRemap = TRUE;
> >> +  }
> >> +
> >> +  if ((Operation == EdkiiIoMmuOperationBusMasterCommonBuffer ||
> >> +       Operation == EdkiiIoMmuOperationBusMasterCommonBuffer64) &&
> >> +      NeedRemap) {
> >> +    //
> >> +    // Common Buffer operations can not be remapped.  If the common buffer
> >> +    // if above 4GB, then it is not possible to generate a mapping, so return
> >> +    // an error.
> >> +    //
> >> +    return EFI_UNSUPPORTED;
> >> +  }
> >> +
> >> +  //
> >> +  // Allocate a MAP_INFO structure to remember the mapping when Unmap() is
> >> +  // called later.
> >> +  //
> >> +  MapInfo = AllocatePool (sizeof (MAP_INFO));
> >> +  if (MapInfo == NULL) {
> >> +    *NumberOfBytes = 0;
> >> +    return EFI_OUT_OF_RESOURCES;
> >> +  }
> >> +
> >> +  //
> >> +  // Initialize the MAP_INFO structure
> >> +  //
> >> +  MapInfo->Signature         = MAP_INFO_SIGNATURE;
> >> +  MapInfo->Operation         = Operation;
> >> +  MapInfo->NumberOfBytes     = *NumberOfBytes;
> >> +  MapInfo->NumberOfPages     = EFI_SIZE_TO_PAGES (MapInfo->NumberOfBytes);
> >> +  MapInfo->HostAddress       = PhysicalAddress;
> >> +  MapInfo->MappedHostAddress = (EFI_PHYSICAL_ADDRESS)-1;
> >> +
> >> +  //
> >> +  // Allocate a buffer below 4GB to map the transfer to.
> >> +  //
> >> +  if (NeedRemap) {
> >> +    MapInfo->MappedHostAddress = mTranslationBase + SIZE_4GB - 1;
> >> +    Status = gBS->AllocatePages (
> >> +                    AllocateMaxAddress,
> >> +                    EfiBootServicesData,
> >> +                    MapInfo->NumberOfPages,
> >> +                    &MapInfo->MappedHostAddress
> >> +                    );
> >> +    if (EFI_ERROR (Status)) {
> >> +      FreePool (MapInfo);
> >> +      *NumberOfBytes = 0;
> >> +      return Status;
> >> +    }
> >> +
> >> +    //
> >> +    // If this is a read operation from the Bus Master's point of view,
> >> +    // then copy the contents of the real buffer into the mapped buffer
> >> +    // so the Bus Master can read the contents of the real buffer.
> >> +    //
> >> +    if (Operation == EdkiiIoMmuOperationBusMasterRead ||
> >> +        Operation == EdkiiIoMmuOperationBusMasterRead64) {
> >> +      CopyMem (
> >> +        (VOID *)(UINTN)MapInfo->MappedHostAddress,
> >> +        (VOID *)(UINTN)MapInfo->HostAddress,
> >> +        MapInfo->NumberOfBytes
> >> +        );
> >> +    }
> >> +  } else {
> >> +    MapInfo->MappedHostAddress = MapInfo->HostAddress;
> >> +  }
> >> +
> >> +  InsertTailList (&mMaps, &MapInfo->Link);
> >> +
> >> +  //
> >> +  // The DeviceAddress is the address of the maped buffer below 4GB
> >> +  //
> >> +  *DeviceAddress = MapInfo->MappedHostAddress - mTranslationBase;
> >> +
> >> +  //
> >> +  // Return a pointer to the MAP_INFO structure in Mapping
> >> +  //
> >> +  *Mapping       = MapInfo;
> >> +
> >> +  return EFI_SUCCESS;
> >> +}
> >> +
> >> +/**
> >> +  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
> >> +IoMmuUnmap (
> >> +  IN  EDKII_IOMMU_PROTOCOL                     *This,
> >> +  IN  VOID                                     *Mapping
> >> +  )
> >> +{
> >> +  MAP_INFO                 *MapInfo;
> >> +  LIST_ENTRY               *Link;
> >> +
> >> +  if (Mapping == NULL) {
> >> +    return EFI_INVALID_PARAMETER;
> >> +  }
> >> +
> >> +  MapInfo = NULL;
> >> +  for (Link = GetFirstNode (&mMaps)
> >> +       ; !IsNull (&mMaps, Link)
> >> +       ; Link = GetNextNode (&mMaps, Link)
> >> +       ) {
> >> +    MapInfo = MAP_INFO_FROM_LINK (Link);
> >> +    if (MapInfo == Mapping) {
> >> +      break;
> >> +    }
> >> +  }
> >> +  //
> >> +  // Mapping is not a valid value returned by Map()
> >> +  //
> >> +  if (MapInfo != Mapping) {
> >> +    return EFI_INVALID_PARAMETER;
> >> +  }
> >> +  RemoveEntryList (&MapInfo->Link);
> >> +
> >> +  if (MapInfo->MappedHostAddress != MapInfo->HostAddress) {
> >> +    //
> >> +    // If this is a write operation from the Bus Master's point of view,
> >> +    // then copy the contents of the mapped buffer into the real buffer
> >> +    // so the processor can read the contents of the real buffer.
> >> +    //
> >> +    if (MapInfo->Operation == EdkiiIoMmuOperationBusMasterWrite ||
> >> +        MapInfo->Operation == EdkiiIoMmuOperationBusMasterWrite64) {
> >> +      CopyMem (
> >> +        (VOID *)(UINTN)MapInfo->HostAddress,
> >> +        (VOID *)(UINTN)MapInfo->MappedHostAddress,
> >> +        MapInfo->NumberOfBytes
> >> +        );
> >> +    }
> >> +
> >> +    //
> >> +    // Free the mapped buffer and the MAP_INFO structure.
> >> +    //
> >> +    gBS->FreePages (MapInfo->MappedHostAddress, MapInfo->NumberOfPages);
> >> +  }
> >> +
> >> +  FreePool (Mapping);
> >> +  return EFI_SUCCESS;
> >> +}
> >> +
> >> +/**
> >> +  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
> >> +IoMmuAllocateBuffer (
> >> +  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
> >> +  )
> >> +{
> >> +  EFI_STATUS                Status;
> >> +  EFI_PHYSICAL_ADDRESS      PhysicalAddress;
> >> +
> >> +  //
> >> +  // Validate Attributes
> >> +  //
> >> +  if ((Attributes & EDKII_IOMMU_ATTRIBUTE_INVALID_FOR_ALLOCATE_BUFFER) != 0) {
> >> +    return EFI_UNSUPPORTED;
> >> +  }
> >> +
> >> +  //
> >> +  // Check for invalid inputs
> >> +  //
> >> +  if (HostAddress == NULL) {
> >> +    return EFI_INVALID_PARAMETER;
> >> +  }
> >> +
> >> +  //
> >> +  // The only valid memory types are EfiBootServicesData and
> >> +  // EfiRuntimeServicesData
> >> +  //
> >> +  if (MemoryType != EfiBootServicesData &&
> >> +      MemoryType != EfiRuntimeServicesData) {
> >> +    return EFI_INVALID_PARAMETER;
> >> +  }
> >> +
> >> +  //
> >> +  // Limit allocations to memory covered by the remapped window.
> >> +  //
> >> +  PhysicalAddress = mTranslationBase + SIZE_4GB - 1;
> >> +  Status = gBS->AllocatePages (
> >> +                  AllocateMaxAddress,
> >> +                  MemoryType,
> >> +                  Pages,
> >> +                  &PhysicalAddress
> >> +                  );
> >> +  if (!EFI_ERROR (Status)) {
> >> +    *HostAddress = (VOID *)(UINTN)PhysicalAddress;
> >> +  }
> >> +
> >> +  return Status;
> >> +}
> >> +
> >> +/**
> >> +  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
> >> +IoMmuFreeBuffer (
> >> +  IN  EDKII_IOMMU_PROTOCOL                     *This,
> >> +  IN  UINTN                                    Pages,
> >> +  IN  VOID                                     *HostAddress
> >> +  )
> >> +{
> >> +  return gBS->FreePages ((EFI_PHYSICAL_ADDRESS) (UINTN) HostAddress, Pages);
> >> +}
> >> +
> >> +/**
> >> +  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]  DeviceAddress     The base of device memory address to be used as the DMA memory.
> >> +  @param[in]  Length            The length of device memory address to be used as the DMA memory.
> >> +  @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  DeviceAddress is not IoMmu Page size aligned.
> >> +  @retval EFI_INVALID_PARAMETER  Length is not IoMmu Page size aligned.
> >> +  @retval EFI_INVALID_PARAMETER  Length is 0.
> >> +  @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 DeviceAddress and Length.
> >> +  @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.
> >> +
> >> +**/
> >> +EFI_STATUS
> >> +EFIAPI
> >> +IoMmuSetAttribute (
> >> +  IN EDKII_IOMMU_PROTOCOL  *This,
> >> +  IN EFI_HANDLE            DeviceHandle,
> >> +  IN EFI_PHYSICAL_ADDRESS  DeviceAddress,
> >> +  IN UINT64                Length,
> >> +  IN UINT64                IoMmuAccess
> >> +  )
> >> +{
> >> +  return EFI_UNSUPPORTED;
> >> +}
> >> +
> >> +/**
> >> +  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
> >> +IoMmuSetMappingAttribute (
> >> +  IN EDKII_IOMMU_PROTOCOL  *This,
> >> +  IN EFI_HANDLE            DeviceHandle,
> >> +  IN VOID                  *Mapping,
> >> +  IN UINT64                IoMmuAccess
> >> +  )
> >> +{
> >> +  //
> >> +  // We only support a static remapping of DRAM into the PCI address space
> >> +  // so there is nothing we need to do to handle invocations of this protocol
> >> +  // method.
> >> +  //
> >> +  return EFI_SUCCESS;
> >> +}
> >> +
> >> +EDKII_IOMMU_PROTOCOL  mGenericSmmuIommuProtocol = {
> >> +  EDKII_IOMMU_PROTOCOL_REVISION,
> >> +  IoMmuSetAttribute,
> >> +  IoMmuMap,
> >> +  IoMmuUnmap,
> >> +  IoMmuAllocateBuffer,
> >> +  IoMmuFreeBuffer,
> >> +  IoMmuSetMappingAttribute,
> >> +};
> >> diff --git a/ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/GenericSmmuStaticPciDmaDxe.c b/ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/GenericSmmuStaticPciDmaDxe.c
> >> new file mode 100644
> >> index 000000000000..8f5093af14ea
> >> --- /dev/null
> >> +++ b/ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/GenericSmmuStaticPciDmaDxe.c
> >> @@ -0,0 +1,323 @@
> >> +/** @file
> >> +
> >> +  Copyright (c) 2017, 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/IoLib.h>
> >> +#include <Library/UefiBootServicesTableLib.h>
> >> +
> >> +#include <Protocol/Cpu.h>
> >> +#include <Protocol/HardwareInterrupt.h>
> >> +#include <Protocol/IoMmu.h>
> >> +
> >> +#include <Chipset/AArch64Mmu.h>
> >> +
> >> +#define GL_CR0                          0x0
> >> +#define GL_CR0_CLIENTPD                 BIT0
> >> +
> >> +#define GL_IDR0                         0x20
> >> +#define GL_IDR1                         0x24
> >> +#define GL_STLBIALL                     0x60
> >> +#define GL_TLBIALLNSNH                  0x68
> >> +#define GL_SMR0                         0x800
> >> +#define GL_S2CR0                        0xc00
> >> +#define GL_CBA2R0                       0x1800
> >> +
> >> +#define GL_IDR0_NUMSMRG_MASK            0xff
> >> +
> >> +#define GL_IDR1_NUMPAGENDXB_MASK        0x7
> >> +#define GL_IDR1_NUMPAGENDXB_SHIFT       28
> >> +#define GL_IDR1_PAGE_SIZE_64KB          BIT31
> >> +
> >> +#define CB_BASE(i)                      (mContextBankOffset + ((i) * SIZE_4KB))
> >> +
> >> +#define CB_SCTLR_OFFSET                 0x0
> >> +#define CB_TTBR0_OFFSET                 0x20
> >> +#define CB_TTBCR_OFFSET                 0x30
> >> +
> >> +#define CB_FAR                          0x60
> >> +#define CB_FSR                          0x58
> >> +#define CB_FSYNR0                       0x68
> >> +#define CB_FSYNR1                       0x6c
> >> +
> >> +#define TT_S2_MEMATTR_CACHED            (0xF << 2)
> >> +#define TT_S2_AP_READ_WRITE             (0x3 << 6)
> >> +
> >> +#define TT_ENTRY_ATTRIBUTES             (TT_TYPE_BLOCK_ENTRY | \
> >> +                                         TT_SH_INNER_SHAREABLE | \
> >> +                                         TT_S2_AP_READ_WRITE | \
> >> +                                         TT_S2_MEMATTR_CACHED | \
> >> +                                         TT_AF)
> >> +
> >> +#define TCR_T0SZ(bits)                  ((UINT32)(32 - (bits)) & 0x3f)
> >> +#define TCR_SL0_LEVEL1                  BIT6
> >> +#define TCR_SL0_LEVEL2                  0
> >> +
> >> +#define SCTLR_M_ENABLE                  BIT0
> >> +#define SCTLR_TR_ENABLE                 BIT1
> >> +#define SCTLR_AF_ENABLE                 BIT2
> >> +#define SCTLR_CTX_FAULT_ENABLE          BIT5
> >> +#define SCTLR_CTX_INT_ENABLE            BIT6
> >> +
> >> +#define DRAM_BASE                       FixedPcdGet64 (PcdSystemMemoryBase)
> >> +
> >> +extern EDKII_IOMMU_PROTOCOL             mGenericSmmuIommuProtocol;
> >> +
> >> +//
> >> +// Create a static stage 2 mapping of the first 4 GB of DRAM in the start
> >> +// of the IOVA space, and as an ID mapping at the original offset.
> >> +//
> >> +STATIC CONST UINT64 mPciTranslation[1024] __attribute__((aligned(SIZE_8KB))) = {
> >> +  [0] = TT_ENTRY_ATTRIBUTES | (DRAM_BASE),
> >> +  [1] = TT_ENTRY_ATTRIBUTES | (DRAM_BASE + SIZE_1GB),
> >> +  [2] = TT_ENTRY_ATTRIBUTES | (DRAM_BASE + SIZE_1GB * 2UL),
> >> +  [3] = TT_ENTRY_ATTRIBUTES | (DRAM_BASE + SIZE_1GB * 3UL),
> >> +
> >> +  //
> >> +  // The ID mapping of the first 4 GB of DRAM is a workaround for buggy
> >> +  // drivers that violate the UEFI spec by ignoring the device address
> >> +  // returned by the PCI I/O map/unmap routines, and program host
> >> +  // addresses into the DMA h/w registers or rings instead.
> >> +  //
> >> +  [(DRAM_BASE >> 30)]     = TT_ENTRY_ATTRIBUTES | (DRAM_BASE),
> >> +  [(DRAM_BASE >> 30) + 1] = TT_ENTRY_ATTRIBUTES | (DRAM_BASE + SIZE_1GB),
> >> +  [(DRAM_BASE >> 30) + 2] = TT_ENTRY_ATTRIBUTES | (DRAM_BASE + SIZE_1GB * 2UL),
> >> +  [(DRAM_BASE >> 30) + 3] = TT_ENTRY_ATTRIBUTES | (DRAM_BASE + SIZE_1GB * 3UL),
> >> +};
> >> +
> >> +STATIC EFI_HARDWARE_INTERRUPT_PROTOCOL    *mInterrupt;
> >> +STATIC EFI_EVENT                          mEfiExitBootServicesEvent;
> >> +STATIC UINTN                              mContextBankOffset;
> >> +
> >> +STATIC
> >> +UINT32
> >> +ReadGlobalReg32 (
> >> +  IN  UINT64    Offset
> >> +  )
> >> +{
> >> +  return MmioRead32 (FixedPcdGet64 (PcdPciGenericSmmuBase) + Offset);
> >> +}
> >> +
> >> +STATIC
> >> +VOID
> >> +WriteGlobalReg32 (
> >> +  IN  UINT64    Offset,
> >> +  IN  UINT64    Value
> >> +  )
> >> +{
> >> +  MmioWrite32 (FixedPcdGet64 (PcdPciGenericSmmuBase) + Offset, Value);
> >> +}
> >> +
> >> +STATIC
> >> +UINT32
> >> +ReadCbReg32 (
> >> +  IN  UINTN     Bank,
> >> +  IN  UINT64    Offset
> >> +  )
> >> +{
> >> +  return MmioRead32 (FixedPcdGet64 (PcdPciGenericSmmuBase) + CB_BASE(Bank) +
> >> +                     Offset);
> >> +}
> >> +
> >> +STATIC
> >> +VOID
> >> +WriteCbReg32 (
> >> +  IN  UINTN     Bank,
> >> +  IN  UINT64    Offset,
> >> +  IN  UINT32    Value
> >> +  )
> >> +{
> >> +  MmioWrite32 (FixedPcdGet64 (PcdPciGenericSmmuBase) + CB_BASE(Bank) + Offset,
> >> +               Value);
> >> +}
> >> +
> >> +STATIC
> >> +UINT64
> >> +ReadCbReg64 (
> >> +  IN  UINTN     Bank,
> >> +  IN  UINT64    Offset
> >> +  )
> >> +{
> >> +  return MmioRead64 (FixedPcdGet64 (PcdPciGenericSmmuBase) + CB_BASE(Bank) +
> >> +                     Offset);
> >> +}
> >> +
> >> +STATIC
> >> +VOID
> >> +WriteCbReg64 (
> >> +  IN  UINTN     Bank,
> >> +  IN  UINT64    Offset,
> >> +  IN  UINT64    Value
> >> +  )
> >> +{
> >> +  MmioWrite64 (FixedPcdGet64 (PcdPciGenericSmmuBase) + CB_BASE(Bank) + Offset,
> >> +               Value);
> >> +}
> >> +
> >> +STATIC
> >> +VOID
> >> +EFIAPI
> >> +ContextInterruptHandler (
> >> +  IN  HARDWARE_INTERRUPT_SOURCE   Source,
> >> +  IN  EFI_SYSTEM_CONTEXT          SystemContext
> >> +  )
> >> +{
> >> +  //
> >> +  // Dump the SMMU context fault registers when taking a context interrupt
> >> +  //
> >> +  DEBUG ((DEBUG_WARN,
> >> +    "Context interrupt asserted by SMMU:\n\n"
> >> +    "SMMU_CB0_FAR        0x%016llx \n"
> >> +    "SMMU_CB0_FSR        0x%08llx \n"
> >> +    "SMMU_CB0_FSYNR0     0x%08llx \n"
> >> +    "SMMU_CB0_FSYNR1     0x%08llx \n",
> >> +    ReadCbReg64 (0, CB_FAR),
> >> +    ReadCbReg32 (0, CB_FSR),
> >> +    ReadCbReg32 (0, CB_FSYNR0),
> >> +    ReadCbReg32 (0, CB_FSYNR1)));
> >> +
> >> +  mInterrupt->EndOfInterrupt (mInterrupt, Source);
> >> +}
> >> +
> >> +STATIC
> >> +VOID
> >> +EFIAPI
> >> +ExitBootServicesEvent (
> >> +  IN EFI_EVENT  Event,
> >> +  IN VOID       *Context
> >> +  )
> >> +{
> >> +  //
> >> +  // Put the SMMU back into bypass mode
> >> +  //
> >> +  MmioOr32 (FixedPcdGet64 (PcdPciGenericSmmuBase) + GL_CR0, GL_CR0_CLIENTPD);
> >> +}
> >> +
> >> +EFI_STATUS
> >> +GenericSmmuStaticPciDmaDxeInitialize (
> >> +  IN EFI_HANDLE        ImageHandle,
> >> +  IN EFI_SYSTEM_TABLE  *SystemTable
> >> +  )
> >> +{
> >> +  EFI_STATUS        Status;
> >> +  UINTN             Idx;
> >> +  UINT32            IdVal;
> >> +  UINTN             NumStreamMappingRegisters;
> >> +
> >> +  //
> >> +  // The static mapping uses 1 GB block mappings, whose VAs and PAs should
> >> +  // be equal modulo the block size.
> >> +  //
> >> +  ASSERT ((DRAM_BASE % SIZE_1GB) == 0);
> >> +
> >> +  if ((DRAM_BASE & (DRAM_BASE - 1)) != 0) {
> >> +    //
> >> +    // Buggy drivers that use truncated host addresses instead of device
> >> +    // addresses for DMA may still work correctly if such truncation is
> >> +    // guaranteed to produce the remapped alias. This is the case if
> >> +    // DRAM_BASE is a power of 2.
> >> +    //
> >> +    DEBUG ((DEBUG_WARN,
> >> +      "%a: this driver will work better if DRAM_BASE is a power of 2!\n",
> >> +      __FUNCTION__));
> >> +  }
> >> +
> >> +  Status = gBS->LocateProtocol (&gHardwareInterruptProtocolGuid, NULL,
> >> +                  (VOID **)&mInterrupt);
> >> +  ASSERT_EFI_ERROR (Status);
> >> +
> >> +  Status = mInterrupt->RegisterInterruptSource (mInterrupt,
> >> +                         PcdGet16 (PcdPciGenericSmmuContextInterrupt),
> >> +                         ContextInterruptHandler);
> >> +  ASSERT_EFI_ERROR (Status);
> >> +  if (EFI_ERROR (Status)) {
> >> +    return Status;
> >> +  }
> >> +
> >> +  Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES,
> >> +                  TPL_NOTIFY, ExitBootServicesEvent, NULL,
> >> +                  &mEfiExitBootServicesEvent);
> >> +  ASSERT_EFI_ERROR (Status);
> >> +
> >> +  Status = gBS->InstallMultipleProtocolInterfaces (
> >> +                  &ImageHandle,
> >> +                  &gEdkiiIoMmuProtocolGuid, &mGenericSmmuIommuProtocol,
> >> +                  NULL
> >> +                  );
> >> +  ASSERT_EFI_ERROR (Status);
> >> +
> >> +  IdVal = ReadGlobalReg32 (GL_IDR1);
> >> +  mContextBankOffset = (IdVal & GL_IDR1_PAGE_SIZE_64KB) ? SIZE_64KB : SIZE_4KB;
> >> +  mContextBankOffset <<= (1 + ((IdVal >> GL_IDR1_NUMPAGENDXB_SHIFT) &
> >> +                               GL_IDR1_NUMPAGENDXB_MASK));
> >> +
> >> +  //
> >> +  // Clear all stream mappings
> >> +  //
> >> +  NumStreamMappingRegisters = ReadGlobalReg32 (GL_IDR0) & GL_IDR0_NUMSMRG_MASK;
> >> +  for (Idx = 0; Idx < NumStreamMappingRegisters; Idx++) {
> >> +    WriteGlobalReg32 (GL_SMR0 + Idx * sizeof(UINT32), 0x0);
> >> +    WriteGlobalReg32 (GL_S2CR0 + Idx * sizeof(UINT32), 0x0);
> >> +  }
> >> +
> >> +  //
> >> +  // Set stream match register 0 to match all streams, and map onto
> >> +  // context bank 0
> >> +  //
> >> +  WriteGlobalReg32 (GL_SMR0, 0xffff0000);
> >> +  WriteGlobalReg32 (GL_S2CR0, 0x0);
> >> +
> >> +  //
> >> +  // Disable the context bank
> >> +  //
> >> +  WriteCbReg32 (0, CB_SCTLR_OFFSET, 0);
> >> +
> >> +  //
> >> +  // Assign the translation base register for context bank 0
> >> +  //
> >> +  WriteCbReg64 (0, CB_TTBR0_OFFSET, (UINTN)mPciTranslation);
> >> +
> >> +  //
> >> +  // Flush TLBS.
> >> +  //
> >> +  WriteGlobalReg32 (GL_STLBIALL, 0);
> >> +  WriteGlobalReg32 (GL_TLBIALLNSNH, 0);
> >> +
> >> +  //
> >> +  // Configure the size of the translation space, the number of levels,
> >> +  // and the cacheability attributes of the PTW memory accesses.
> >> +  //
> >> +  WriteCbReg32 (0, CB_TTBCR_OFFSET, TCR_T0SZ(40) |
> >> +                                    TCR_SH_INNER_SHAREABLE |
> >> +                                    TCR_RGN_INNER_WRITE_BACK_NO_ALLOC |
> >> +                                    TCR_RGN_OUTER_WRITE_BACK_NO_ALLOC |
> >> +                                    TCR_SL0_LEVEL1);
> >> +
> >> +  //
> >> +  // Enable the context bank
> >> +  //
> >> +  WriteCbReg32 (0, CB_SCTLR_OFFSET, SCTLR_TR_ENABLE |
> >> +                                    SCTLR_AF_ENABLE |
> >> +                                    SCTLR_CTX_INT_ENABLE |
> >> +                                    SCTLR_CTX_FAULT_ENABLE |
> >> +                                    SCTLR_M_ENABLE);
> >> +
> >> +  //
> >> +  // Get the SMMU out of bypass mode
> >> +  //
> >> +  MmioAnd32 (FixedPcdGet64 (PcdPciGenericSmmuBase) + GL_CR0, ~GL_CR0_CLIENTPD);
> >> +
> >> +  return EFI_SUCCESS;
> >> +}
> >> diff --git a/ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/GenericSmmuStaticPciDmaDxe.inf b/ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/GenericSmmuStaticPciDmaDxe.inf
> >> new file mode 100644
> >> index 000000000000..02c17e755c4a
> >> --- /dev/null
> >> +++ b/ArmPkg/Drivers/GenericSmmuStaticPciDmaDxe/GenericSmmuStaticPciDmaDxe.inf
> >> @@ -0,0 +1,62 @@
> >> +## @file
> >> +#
> >> +# Copyright (c) 2017, 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                    = 0x00010019
> >> +  BASE_NAME                      = GenericSmmuStaticPciDmaDxe
> >> +  FILE_GUID                      = 59b5e69f-88b7-4632-a2ab-6abe6bdedda2
> >> +  MODULE_TYPE                    = DXE_DRIVER
> >> +  VERSION_STRING                 = 1.0
> >> +  ENTRY_POINT                    = GenericSmmuStaticPciDmaDxeInitialize
> >> +
> >> +#
> >> +# The following information is for reference only and not required by the build tools.
> >> +#
> >> +#  VALID_ARCHITECTURES           = ARM AARCH64
> >> +#
> >> +#
> >> +
> >> +[Sources]
> >> +  GenericSmmuStaticPciDmaDxe.c
> >> +  BmDma.c
> >> +
> >> +[Packages]
> >> +  ArmPkg/ArmPkg.dec
> >> +  EmbeddedPkg/EmbeddedPkg.dec
> >> +  MdeModulePkg/MdeModulePkg.dec
> >> +  MdePkg/MdePkg.dec
> >> +
> >> +[LibraryClasses]
> >> +  DebugLib
> >> +  BaseLib
> >> +  BaseMemoryLib
> >> +  IoLib
> >> +  MemoryAllocationLib
> >> +  UefiBootServicesTableLib
> >> +  UefiDriverEntryPoint
> >> +
> >> +[Protocols]
> >> +  gEdkiiIoMmuProtocolGuid                     ## PRODUCES
> >> +  gEfiPciIoProtocolGuid                       ## CONSUMES
> >> +  gHardwareInterruptProtocolGuid              ## CONSUMES
> >> +
> >> +[Pcd]
> >> +  gArmTokenSpaceGuid.PcdPciGenericSmmuBase
> >> +  gArmTokenSpaceGuid.PcdPciGenericSmmuContextInterrupt
> >> +
> >> +[FixedPcd]
> >> +  gArmTokenSpaceGuid.PcdSystemMemoryBase
> >> +
> >> +[Depex]
> >> +  gHardwareInterruptProtocolGuid
> >> --
> >> 2.9.3
> >>


  reply	other threads:[~2017-05-24 10:31 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-02 10:32 [RFC PATCH] ArmPkg: implement generic SMMU driver to remap DRAM for 32-bit PCI DMA Ard Biesheuvel
2017-05-19 13:36 ` Ard Biesheuvel
2017-05-22 13:49 ` Leif Lindholm
2017-05-23 10:36   ` Ard Biesheuvel
2017-05-24 10:30     ` Leif Lindholm [this message]
2017-05-24 13:20       ` Ard Biesheuvel

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