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

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

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>
---
 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