This protocol is to abstract IOMMU access.

Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Leo Duran <leo.duran@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
---
 MdeModulePkg/Include/Protocol/IoMmu.h | 132 ++++++++++++++++++++
 MdeModulePkg/MdeModulePkg.dec         |   3 +
 2 files changed, 135 insertions(+)

diff --git a/MdeModulePkg/Include/Protocol/IoMmu.h b/MdeModulePkg/Include/Protocol/IoMmu.h
new file mode 100644
index 0000000..55b9c78
--- /dev/null
+++ b/MdeModulePkg/Include/Protocol/IoMmu.h
@@ -0,0 +1,132 @@
+/** @file
+  EFI IOMMU Protocol.
+
+Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
+This program and the accompanying materials are licensed and made available under
+the terms and conditions of the BSD License that 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.
+
+**/
+
+
+#ifndef __IOMMU_H__
+#define __IOMMU_H__
+
+//
+// IOMMU Protocol GUID value
+//
+#define EDKII_IOMMU_PROTOCOL_GUID \
+    { \
+      0x4e939de9, 0xd948, 0x4b0f, { 0x88, 0xed, 0xe6, 0xe1, 0xce, 0x51, 0x7c, 0x1e } \
+    }
+
+//
+// Forward reference for pure ANSI compatability
+//
+typedef struct _EDKII_IOMMU_PROTOCOL  EDKII_IOMMU_PROTOCOL;
+
+//
+// Revision The revision to which the IOMMU interface adheres.
+//          All future revisions must be backwards compatible.
+//          If a future version is not back wards compatible it is not the same GUID.
+//
+#define EDKII_IOMMU_PROTOCOL_REVISION 0x00010000
+
+//
+// IOMMU attribute.
+// These types can be "ORed" together as needed.
+// Any undefined bits are reserved and must be zero.
+//
+#define EDKII_IOMMU_ATTRIBUTE_READ   0x1
+#define EDKII_IOMMU_ATTRIBUTE_WRITE  0x2
+
+/**
+  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 it is.
+  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_ATTRIBUTE_READ.
+     The memory for BusMasterWrite need set EDKII_IOMMU_ATTRIBUTE_WRITE.
+     The memory for BusMasterCommonBuffer need set EDKII_IOMMU_ATTRIBUTE_READ|EDKII_IOMMU_ATTRIBUTE_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_ATTRIBUTE_READ and/or EDKII_IOMMU_ATTRIBUTE_WRITE.
+
+  @param  This              The protocol instance pointer.
+  @param  DeviceHandle      The device who initiates the DMA access request.
+  @param  BaseAddress       The base of system memory address to be used as the DMA memory.
+  @param  Length            The length of system memory address to be used as the DMA memory.
+  @param  IoMmuAttribute    The IOMMU attribute.
+
+  @retval EFI_SUCCESS            The IoMmuAttribute is set for the memory range specified by BaseAddress and Length.
+  @retval EFI_INVALID_PARAMETER  DeviceHandle is an invalid handle.
+  @retval EFI_INVALID_PARAMETER  BaseAddress 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  IoMmuAttribute specified an illegal combination of attributes.
+  @retval EFI_UNSUPPORTED        DeviceHandle is unknown by the IOMMU.
+  @retval EFI_UNSUPPORTED        The bit mask of IoMmuAttribute is not supported by the IOMMU.
+  @retval EFI_UNSUPPORTED        The IOMMU does not support the memory range specified by BaseAddress and Length.
+  @retval EFI_OUT_OF_RESOURCES   There are not enough resources available to modify the IOMMU attribute.
+  @retval EFI_DEVICE_ERROR       The IOMMU device reported an error while attempting the operation.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_IOMMU_SET_ATTRIBUTE)(
+  IN EDKII_IOMMU_PROTOCOL  *This,
+  IN EFI_HANDLE            DeviceHandle,
+  IN UINT64                BaseAddress,
+  IN UINT64                Length,
+  IN UINT64                IoMmuAttribute
+  );
+
+/**
+  Get IOMMU page size.
+
+  This is the minimal supported page size for a IOMMU.
+  For example, if an IOMMU supports 4KiB, 2MiB and 1GiB,
+  4KiB should be returned.
+
+  @param  This      Protocol instance pointer.
+  @param  PageSize  The minimal supported page size for a IOMMU.
+
+  @retval EFI_SUCCESS            The page size is returned.
+  @retval EFI_INVALID_PARAMETER  PageSize is NULL.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_IOMMU_GET_PAGE_SIZE)(
+  IN  EDKII_IOMMU_PROTOCOL  *This,
+  OUT UINTN                 *PageSize
+  );
+
+///
+/// IOMMU Protocol structure.
+///
+struct _EDKII_IOMMU_PROTOCOL {
+  UINT64                       Revision;
+  EDKII_IOMMU_GET_PAGE_SIZE    GetPageSize;
+  EDKII_IOMMU_SET_ATTRIBUTE    SetAttribute;
+};
+
+///
+/// IOMMU Protocol GUID variable.
+///
+extern EFI_GUID gEdkiiIoMmuProtocolGuid;
+
+#endif
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 356b3e1..db596b6 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -540,6 +540,9 @@
   ## Include/Protocol/NonDiscoverableDevice.h
   gEdkiiNonDiscoverableDeviceProtocolGuid = { 0x0d51905b, 0xb77e, 0x452a, {0xa2, 0xc0, 0xec, 0xa0, 0xcc, 0x8d, 0x51, 0x4a } }
 
+  ## Include/Protocol/IoMmu.h
+  gEdkiiIoMmuProtocolGuid = { 0x4e939de9, 0xd948, 0x4b0f, { 0x88, 0xed, 0xe6, 0xe1, 0xce, 0x51, 0x7c, 0x1e } }
+
 #
 # [Error.gEfiMdeModulePkgTokenSpaceGuid]
 #   0x80000001 | Invalid value provided.
-- 
2.7.4.windows.1

_______________________________________________
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On 25 March 2017 at 09:28, Jiewen Yao <jiewen.yao@intel.com> wrote:
> This protocol is to abstract IOMMU access.
>
> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Leo Duran <leo.duran@amd.com>
> Cc: Brijesh Singh <brijesh.singh@amd.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>

Hello all,

It would be very useful for a IOMMU protocol such as this one to
support non-identity mappings between the host and the PCI bus.

On 64-bit ARM systems, no RAM may exist below 4 GB, and if a IOMMU is
available, it could be used to remap RAM for DMA in a way that makes
it 32-bit addressable for PCI masters that are not 64-bit capable.

The PCI protocols in UEFI already allow such non-identity mappings. If
a IOMMU protocol is introduced, it makes sense to allow it to be
involved in establishing the device address when performing a map
operation.

-- 
Ard.


> ---
>  MdeModulePkg/Include/Protocol/IoMmu.h | 132 ++++++++++++++++++++
>  MdeModulePkg/MdeModulePkg.dec         |   3 +
>  2 files changed, 135 insertions(+)
>
> diff --git a/MdeModulePkg/Include/Protocol/IoMmu.h b/MdeModulePkg/Include/Protocol/IoMmu.h
> new file mode 100644
> index 0000000..55b9c78
> --- /dev/null
> +++ b/MdeModulePkg/Include/Protocol/IoMmu.h
> @@ -0,0 +1,132 @@
> +/** @file
> +  EFI IOMMU Protocol.
> +
> +Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
> +This program and the accompanying materials are licensed and made available under
> +the terms and conditions of the BSD License that 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.
> +
> +**/
> +
> +
> +#ifndef __IOMMU_H__
> +#define __IOMMU_H__
> +
> +//
> +// IOMMU Protocol GUID value
> +//
> +#define EDKII_IOMMU_PROTOCOL_GUID \
> +    { \
> +      0x4e939de9, 0xd948, 0x4b0f, { 0x88, 0xed, 0xe6, 0xe1, 0xce, 0x51, 0x7c, 0x1e } \
> +    }
> +
> +//
> +// Forward reference for pure ANSI compatability
> +//
> +typedef struct _EDKII_IOMMU_PROTOCOL  EDKII_IOMMU_PROTOCOL;
> +
> +//
> +// Revision The revision to which the IOMMU interface adheres.
> +//          All future revisions must be backwards compatible.
> +//          If a future version is not back wards compatible it is not the same GUID.
> +//
> +#define EDKII_IOMMU_PROTOCOL_REVISION 0x00010000
> +
> +//
> +// IOMMU attribute.
> +// These types can be "ORed" together as needed.
> +// Any undefined bits are reserved and must be zero.
> +//
> +#define EDKII_IOMMU_ATTRIBUTE_READ   0x1
> +#define EDKII_IOMMU_ATTRIBUTE_WRITE  0x2
> +
> +/**
> +  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 it is.
> +  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_ATTRIBUTE_READ.
> +     The memory for BusMasterWrite need set EDKII_IOMMU_ATTRIBUTE_WRITE.
> +     The memory for BusMasterCommonBuffer need set EDKII_IOMMU_ATTRIBUTE_READ|EDKII_IOMMU_ATTRIBUTE_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_ATTRIBUTE_READ and/or EDKII_IOMMU_ATTRIBUTE_WRITE.
> +
> +  @param  This              The protocol instance pointer.
> +  @param  DeviceHandle      The device who initiates the DMA access request.
> +  @param  BaseAddress       The base of system memory address to be used as the DMA memory.
> +  @param  Length            The length of system memory address to be used as the DMA memory.
> +  @param  IoMmuAttribute    The IOMMU attribute.
> +
> +  @retval EFI_SUCCESS            The IoMmuAttribute is set for the memory range specified by BaseAddress and Length.
> +  @retval EFI_INVALID_PARAMETER  DeviceHandle is an invalid handle.
> +  @retval EFI_INVALID_PARAMETER  BaseAddress 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  IoMmuAttribute specified an illegal combination of attributes.
> +  @retval EFI_UNSUPPORTED        DeviceHandle is unknown by the IOMMU.
> +  @retval EFI_UNSUPPORTED        The bit mask of IoMmuAttribute is not supported by the IOMMU.
> +  @retval EFI_UNSUPPORTED        The IOMMU does not support the memory range specified by BaseAddress and Length.
> +  @retval EFI_OUT_OF_RESOURCES   There are not enough resources available to modify the IOMMU attribute.
> +  @retval EFI_DEVICE_ERROR       The IOMMU device reported an error while attempting the operation.
> +
> +**/
> +typedef
> +EFI_STATUS
> +(EFIAPI *EDKII_IOMMU_SET_ATTRIBUTE)(
> +  IN EDKII_IOMMU_PROTOCOL  *This,
> +  IN EFI_HANDLE            DeviceHandle,
> +  IN UINT64                BaseAddress,
> +  IN UINT64                Length,
> +  IN UINT64                IoMmuAttribute
> +  );
> +
> +/**
> +  Get IOMMU page size.
> +
> +  This is the minimal supported page size for a IOMMU.
> +  For example, if an IOMMU supports 4KiB, 2MiB and 1GiB,
> +  4KiB should be returned.
> +
> +  @param  This      Protocol instance pointer.
> +  @param  PageSize  The minimal supported page size for a IOMMU.
> +
> +  @retval EFI_SUCCESS            The page size is returned.
> +  @retval EFI_INVALID_PARAMETER  PageSize is NULL.
> +
> +**/
> +typedef
> +EFI_STATUS
> +(EFIAPI *EDKII_IOMMU_GET_PAGE_SIZE)(
> +  IN  EDKII_IOMMU_PROTOCOL  *This,
> +  OUT UINTN                 *PageSize
> +  );
> +
> +///
> +/// IOMMU Protocol structure.
> +///
> +struct _EDKII_IOMMU_PROTOCOL {
> +  UINT64                       Revision;
> +  EDKII_IOMMU_GET_PAGE_SIZE    GetPageSize;
> +  EDKII_IOMMU_SET_ATTRIBUTE    SetAttribute;
> +};
> +
> +///
> +/// IOMMU Protocol GUID variable.
> +///
> +extern EFI_GUID gEdkiiIoMmuProtocolGuid;
> +
> +#endif
> diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
> index 356b3e1..db596b6 100644
> --- a/MdeModulePkg/MdeModulePkg.dec
> +++ b/MdeModulePkg/MdeModulePkg.dec
> @@ -540,6 +540,9 @@
>    ## Include/Protocol/NonDiscoverableDevice.h
>    gEdkiiNonDiscoverableDeviceProtocolGuid = { 0x0d51905b, 0xb77e, 0x452a, {0xa2, 0xc0, 0xec, 0xa0, 0xcc, 0x8d, 0x51, 0x4a } }
>
> +  ## Include/Protocol/IoMmu.h
> +  gEdkiiIoMmuProtocolGuid = { 0x4e939de9, 0xd948, 0x4b0f, { 0x88, 0xed, 0xe6, 0xe1, 0xce, 0x51, 0x7c, 0x1e } }
> +
>  #
>  # [Error.gEfiMdeModulePkgTokenSpaceGuid]
>  #   0x80000001 | Invalid value provided.
> --
> 2.7.4.windows.1
>
> _______________________________________________
> edk2-devel mailing list
> edk2-devel@lists.01.org
> https://lists.01.org/mailman/listinfo/edk2-devel
_______________________________________________
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Ard,

I agree.  And I think the IOMMU protocol should also support flexible
double buffer operations so the extra copies by the host CPU can be
avoided if the logical DMA address can directly map to the original
buffer.

Mike

> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Ard
> Biesheuvel
> Sent: Tuesday, March 28, 2017 3:39 PM
> To: Yao, Jiewen <jiewen.yao@intel.com>
> Cc: Ni, Ruiyu <ruiyu.ni@intel.com>; Leo Duran <leo.duran@amd.com>; edk2-
> devel@lists.01.org; Brijesh Singh <brijesh.singh@amd.com>
> Subject: Re: [edk2] [PATCH 1/3] MdeModulePkg/Include: Add IOMMU protocol
> definition.
> 
> On 25 March 2017 at 09:28, Jiewen Yao <jiewen.yao@intel.com> wrote:
> > This protocol is to abstract IOMMU access.
> >
> > Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> > Cc: Leo Duran <leo.duran@amd.com>
> > Cc: Brijesh Singh <brijesh.singh@amd.com>
> > Contributed-under: TianoCore Contribution Agreement 1.0
> > Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
> 
> Hello all,
> 
> It would be very useful for a IOMMU protocol such as this one to
> support non-identity mappings between the host and the PCI bus.
> 
> On 64-bit ARM systems, no RAM may exist below 4 GB, and if a IOMMU is
> available, it could be used to remap RAM for DMA in a way that makes
> it 32-bit addressable for PCI masters that are not 64-bit capable.
> 
> The PCI protocols in UEFI already allow such non-identity mappings. If
> a IOMMU protocol is introduced, it makes sense to allow it to be
> involved in establishing the device address when performing a map
> operation.
> 
> --
> Ard.
> 
> 
> > ---
> >  MdeModulePkg/Include/Protocol/IoMmu.h | 132 ++++++++++++++++++++
> >  MdeModulePkg/MdeModulePkg.dec         |   3 +
> >  2 files changed, 135 insertions(+)
> >
> > diff --git a/MdeModulePkg/Include/Protocol/IoMmu.h
> b/MdeModulePkg/Include/Protocol/IoMmu.h
> > new file mode 100644
> > index 0000000..55b9c78
> > --- /dev/null
> > +++ b/MdeModulePkg/Include/Protocol/IoMmu.h
> > @@ -0,0 +1,132 @@
> > +/** @file
> > +  EFI IOMMU Protocol.
> > +
> > +Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
> > +This program and the accompanying materials are licensed and made available
> under
> > +the terms and conditions of the BSD License that 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.
> > +
> > +**/
> > +
> > +
> > +#ifndef __IOMMU_H__
> > +#define __IOMMU_H__
> > +
> > +//
> > +// IOMMU Protocol GUID value
> > +//
> > +#define EDKII_IOMMU_PROTOCOL_GUID \
> > +    { \
> > +      0x4e939de9, 0xd948, 0x4b0f, { 0x88, 0xed, 0xe6, 0xe1, 0xce, 0x51, 0x7c,
> 0x1e } \
> > +    }
> > +
> > +//
> > +// Forward reference for pure ANSI compatability
> > +//
> > +typedef struct _EDKII_IOMMU_PROTOCOL  EDKII_IOMMU_PROTOCOL;
> > +
> > +//
> > +// Revision The revision to which the IOMMU interface adheres.
> > +//          All future revisions must be backwards compatible.
> > +//          If a future version is not back wards compatible it is not the same
> GUID.
> > +//
> > +#define EDKII_IOMMU_PROTOCOL_REVISION 0x00010000
> > +
> > +//
> > +// IOMMU attribute.
> > +// These types can be "ORed" together as needed.
> > +// Any undefined bits are reserved and must be zero.
> > +//
> > +#define EDKII_IOMMU_ATTRIBUTE_READ   0x1
> > +#define EDKII_IOMMU_ATTRIBUTE_WRITE  0x2
> > +
> > +/**
> > +  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 it is.
> > +  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_ATTRIBUTE_READ.
> > +     The memory for BusMasterWrite need set EDKII_IOMMU_ATTRIBUTE_WRITE.
> > +     The memory for BusMasterCommonBuffer need set
> EDKII_IOMMU_ATTRIBUTE_READ|EDKII_IOMMU_ATTRIBUTE_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_ATTRIBUTE_READ and/or
> EDKII_IOMMU_ATTRIBUTE_WRITE.
> > +
> > +  @param  This              The protocol instance pointer.
> > +  @param  DeviceHandle      The device who initiates the DMA access request.
> > +  @param  BaseAddress       The base of system memory address to be used as the
> DMA memory.
> > +  @param  Length            The length of system memory address to be used as
> the DMA memory.
> > +  @param  IoMmuAttribute    The IOMMU attribute.
> > +
> > +  @retval EFI_SUCCESS            The IoMmuAttribute is set for the memory range
> specified by BaseAddress and Length.
> > +  @retval EFI_INVALID_PARAMETER  DeviceHandle is an invalid handle.
> > +  @retval EFI_INVALID_PARAMETER  BaseAddress 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  IoMmuAttribute specified an illegal combination
> of attributes.
> > +  @retval EFI_UNSUPPORTED        DeviceHandle is unknown by the IOMMU.
> > +  @retval EFI_UNSUPPORTED        The bit mask of IoMmuAttribute is not supported
> by the IOMMU.
> > +  @retval EFI_UNSUPPORTED        The IOMMU does not support the memory range
> specified by BaseAddress and Length.
> > +  @retval EFI_OUT_OF_RESOURCES   There are not enough resources available to
> modify the IOMMU attribute.
> > +  @retval EFI_DEVICE_ERROR       The IOMMU device reported an error while
> attempting the operation.
> > +
> > +**/
> > +typedef
> > +EFI_STATUS
> > +(EFIAPI *EDKII_IOMMU_SET_ATTRIBUTE)(
> > +  IN EDKII_IOMMU_PROTOCOL  *This,
> > +  IN EFI_HANDLE            DeviceHandle,
> > +  IN UINT64                BaseAddress,
> > +  IN UINT64                Length,
> > +  IN UINT64                IoMmuAttribute
> > +  );
> > +
> > +/**
> > +  Get IOMMU page size.
> > +
> > +  This is the minimal supported page size for a IOMMU.
> > +  For example, if an IOMMU supports 4KiB, 2MiB and 1GiB,
> > +  4KiB should be returned.
> > +
> > +  @param  This      Protocol instance pointer.
> > +  @param  PageSize  The minimal supported page size for a IOMMU.
> > +
> > +  @retval EFI_SUCCESS            The page size is returned.
> > +  @retval EFI_INVALID_PARAMETER  PageSize is NULL.
> > +
> > +**/
> > +typedef
> > +EFI_STATUS
> > +(EFIAPI *EDKII_IOMMU_GET_PAGE_SIZE)(
> > +  IN  EDKII_IOMMU_PROTOCOL  *This,
> > +  OUT UINTN                 *PageSize
> > +  );
> > +
> > +///
> > +/// IOMMU Protocol structure.
> > +///
> > +struct _EDKII_IOMMU_PROTOCOL {
> > +  UINT64                       Revision;
> > +  EDKII_IOMMU_GET_PAGE_SIZE    GetPageSize;
> > +  EDKII_IOMMU_SET_ATTRIBUTE    SetAttribute;
> > +};
> > +
> > +///
> > +/// IOMMU Protocol GUID variable.
> > +///
> > +extern EFI_GUID gEdkiiIoMmuProtocolGuid;
> > +
> > +#endif
> > diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
> > index 356b3e1..db596b6 100644
> > --- a/MdeModulePkg/MdeModulePkg.dec
> > +++ b/MdeModulePkg/MdeModulePkg.dec
> > @@ -540,6 +540,9 @@
> >    ## Include/Protocol/NonDiscoverableDevice.h
> >    gEdkiiNonDiscoverableDeviceProtocolGuid = { 0x0d51905b, 0xb77e, 0x452a, {0xa2,
> 0xc0, 0xec, 0xa0, 0xcc, 0x8d, 0x51, 0x4a } }
> >
> > +  ## Include/Protocol/IoMmu.h
> > +  gEdkiiIoMmuProtocolGuid = { 0x4e939de9, 0xd948, 0x4b0f, { 0x88, 0xed, 0xe6,
> 0xe1, 0xce, 0x51, 0x7c, 0x1e } }
> > +
> >  #
> >  # [Error.gEfiMdeModulePkgTokenSpaceGuid]
> >  #   0x80000001 | Invalid value provided.
> > --
> > 2.7.4.windows.1
> >
> > _______________________________________________
> > edk2-devel mailing list
> > edk2-devel@lists.01.org
> > https://lists.01.org/mailman/listinfo/edk2-devel
> _______________________________________________
> edk2-devel mailing list
> edk2-devel@lists.01.org
> https://lists.01.org/mailman/listinfo/edk2-devel
_______________________________________________
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Agree. That is a good idea.

I will add that in V2 patch.

Thank you
Yao Jiewen

From: Kinney, Michael D
Sent: Wednesday, March 29, 2017 7:03 AM
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>; Yao, Jiewen <jiewen.yao@intel.com>; Kinney, Michael D <michael.d.kinney@intel.com>
Cc: Ni, Ruiyu <ruiyu.ni@intel.com>; Leo Duran <leo.duran@amd.com>; edk2-devel@lists.01.org; Brijesh Singh <brijesh.singh@amd.com>
Subject: RE: [edk2] [PATCH 1/3] MdeModulePkg/Include: Add IOMMU protocol definition.

Ard,

I agree.  And I think the IOMMU protocol should also support flexible
double buffer operations so the extra copies by the host CPU can be
avoided if the logical DMA address can directly map to the original
buffer.

Mike

> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Ard
> Biesheuvel
> Sent: Tuesday, March 28, 2017 3:39 PM
> To: Yao, Jiewen <jiewen.yao@intel.com<mailto:jiewen.yao@intel.com>>
> Cc: Ni, Ruiyu <ruiyu.ni@intel.com<mailto:ruiyu.ni@intel.com>>; Leo Duran <leo.duran@amd.com<mailto:leo.duran@amd.com>>; edk2-
> devel@lists.01.org<mailto:devel@lists.01.org>; Brijesh Singh <brijesh.singh@amd.com<mailto:brijesh.singh@amd.com>>
> Subject: Re: [edk2] [PATCH 1/3] MdeModulePkg/Include: Add IOMMU protocol
> definition.
>
> On 25 March 2017 at 09:28, Jiewen Yao <jiewen.yao@intel.com<mailto:jiewen.yao@intel.com>> wrote:
> > This protocol is to abstract IOMMU access.
> >
> > Cc: Ruiyu Ni <ruiyu.ni@intel.com<mailto:ruiyu.ni@intel.com>>
> > Cc: Leo Duran <leo.duran@amd.com<mailto:leo.duran@amd.com>>
> > Cc: Brijesh Singh <brijesh.singh@amd.com<mailto:brijesh.singh@amd.com>>
> > Contributed-under: TianoCore Contribution Agreement 1.0
> > Signed-off-by: Jiewen Yao <jiewen.yao@intel.com<mailto:jiewen.yao@intel.com>>
>
> Hello all,
>
> It would be very useful for a IOMMU protocol such as this one to
> support non-identity mappings between the host and the PCI bus.
>
> On 64-bit ARM systems, no RAM may exist below 4 GB, and if a IOMMU is
> available, it could be used to remap RAM for DMA in a way that makes
> it 32-bit addressable for PCI masters that are not 64-bit capable.
>
> The PCI protocols in UEFI already allow such non-identity mappings. If
> a IOMMU protocol is introduced, it makes sense to allow it to be
> involved in establishing the device address when performing a map
> operation.
>
> --
> Ard.
>
>
> > ---
> >  MdeModulePkg/Include/Protocol/IoMmu.h | 132 ++++++++++++++++++++
> >  MdeModulePkg/MdeModulePkg.dec         |   3 +
> >  2 files changed, 135 insertions(+)
> >
> > diff --git a/MdeModulePkg/Include/Protocol/IoMmu.h
> b/MdeModulePkg/Include/Protocol/IoMmu.h
> > new file mode 100644
> > index 0000000..55b9c78
> > --- /dev/null
> > +++ b/MdeModulePkg/Include/Protocol/IoMmu.h
> > @@ -0,0 +1,132 @@
> > +/** @file
> > +  EFI IOMMU Protocol.
> > +
> > +Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
> > +This program and the accompanying materials are licensed and made available
> under
> > +the terms and conditions of the BSD License that 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.
> > +
> > +**/
> > +
> > +
> > +#ifndef __IOMMU_H__
> > +#define __IOMMU_H__
> > +
> > +//
> > +// IOMMU Protocol GUID value
> > +//
> > +#define EDKII_IOMMU_PROTOCOL_GUID \
> > +    { \
> > +      0x4e939de9, 0xd948, 0x4b0f, { 0x88, 0xed, 0xe6, 0xe1, 0xce, 0x51, 0x7c,
> 0x1e } \
> > +    }
> > +
> > +//
> > +// Forward reference for pure ANSI compatability
> > +//
> > +typedef struct _EDKII_IOMMU_PROTOCOL  EDKII_IOMMU_PROTOCOL;
> > +
> > +//
> > +// Revision The revision to which the IOMMU interface adheres.
> > +//          All future revisions must be backwards compatible.
> > +//          If a future version is not back wards compatible it is not the same
> GUID.
> > +//
> > +#define EDKII_IOMMU_PROTOCOL_REVISION 0x00010000
> > +
> > +//
> > +// IOMMU attribute.
> > +// These types can be "ORed" together as needed.
> > +// Any undefined bits are reserved and must be zero.
> > +//
> > +#define EDKII_IOMMU_ATTRIBUTE_READ   0x1
> > +#define EDKII_IOMMU_ATTRIBUTE_WRITE  0x2
> > +
> > +/**
> > +  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 it is.
> > +  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_ATTRIBUTE_READ.
> > +     The memory for BusMasterWrite need set EDKII_IOMMU_ATTRIBUTE_WRITE.
> > +     The memory for BusMasterCommonBuffer need set
> EDKII_IOMMU_ATTRIBUTE_READ|EDKII_IOMMU_ATTRIBUTE_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_ATTRIBUTE_READ and/or
> EDKII_IOMMU_ATTRIBUTE_WRITE.
> > +
> > +  @param  This              The protocol instance pointer.
> > +  @param  DeviceHandle      The device who initiates the DMA access request.
> > +  @param  BaseAddress       The base of system memory address to be used as the
> DMA memory.
> > +  @param  Length            The length of system memory address to be used as
> the DMA memory.
> > +  @param  IoMmuAttribute    The IOMMU attribute.
> > +
> > +  @retval EFI_SUCCESS            The IoMmuAttribute is set for the memory range
> specified by BaseAddress and Length.
> > +  @retval EFI_INVALID_PARAMETER  DeviceHandle is an invalid handle.
> > +  @retval EFI_INVALID_PARAMETER  BaseAddress 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  IoMmuAttribute specified an illegal combination
> of attributes.
> > +  @retval EFI_UNSUPPORTED        DeviceHandle is unknown by the IOMMU.
> > +  @retval EFI_UNSUPPORTED        The bit mask of IoMmuAttribute is not supported
> by the IOMMU.
> > +  @retval EFI_UNSUPPORTED        The IOMMU does not support the memory range
> specified by BaseAddress and Length.
> > +  @retval EFI_OUT_OF_RESOURCES   There are not enough resources available to
> modify the IOMMU attribute.
> > +  @retval EFI_DEVICE_ERROR       The IOMMU device reported an error while
> attempting the operation.
> > +
> > +**/
> > +typedef
> > +EFI_STATUS
> > +(EFIAPI *EDKII_IOMMU_SET_ATTRIBUTE)(
> > +  IN EDKII_IOMMU_PROTOCOL  *This,
> > +  IN EFI_HANDLE            DeviceHandle,
> > +  IN UINT64                BaseAddress,
> > +  IN UINT64                Length,
> > +  IN UINT64                IoMmuAttribute
> > +  );
> > +
> > +/**
> > +  Get IOMMU page size.
> > +
> > +  This is the minimal supported page size for a IOMMU.
> > +  For example, if an IOMMU supports 4KiB, 2MiB and 1GiB,
> > +  4KiB should be returned.
> > +
> > +  @param  This      Protocol instance pointer.
> > +  @param  PageSize  The minimal supported page size for a IOMMU.
> > +
> > +  @retval EFI_SUCCESS            The page size is returned.
> > +  @retval EFI_INVALID_PARAMETER  PageSize is NULL.
> > +
> > +**/
> > +typedef
> > +EFI_STATUS
> > +(EFIAPI *EDKII_IOMMU_GET_PAGE_SIZE)(
> > +  IN  EDKII_IOMMU_PROTOCOL  *This,
> > +  OUT UINTN                 *PageSize
> > +  );
> > +
> > +///
> > +/// IOMMU Protocol structure.
> > +///
> > +struct _EDKII_IOMMU_PROTOCOL {
> > +  UINT64                       Revision;
> > +  EDKII_IOMMU_GET_PAGE_SIZE    GetPageSize;
> > +  EDKII_IOMMU_SET_ATTRIBUTE    SetAttribute;
> > +};
> > +
> > +///
> > +/// IOMMU Protocol GUID variable.
> > +///
> > +extern EFI_GUID gEdkiiIoMmuProtocolGuid;
> > +
> > +#endif
> > diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
> > index 356b3e1..db596b6 100644
> > --- a/MdeModulePkg/MdeModulePkg.dec
> > +++ b/MdeModulePkg/MdeModulePkg.dec
> > @@ -540,6 +540,9 @@
> >    ## Include/Protocol/NonDiscoverableDevice.h
> >    gEdkiiNonDiscoverableDeviceProtocolGuid = { 0x0d51905b, 0xb77e, 0x452a, {0xa2,
> 0xc0, 0xec, 0xa0, 0xcc, 0x8d, 0x51, 0x4a } }
> >
> > +  ## Include/Protocol/IoMmu.h
> > +  gEdkiiIoMmuProtocolGuid = { 0x4e939de9, 0xd948, 0x4b0f, { 0x88, 0xed, 0xe6,
> 0xe1, 0xce, 0x51, 0x7c, 0x1e } }
> > +
> >  #
> >  # [Error.gEfiMdeModulePkgTokenSpaceGuid]
> >  #   0x80000001 | Invalid value provided.
> > --
> > 2.7.4.windows.1
> >
> > _______________________________________________
> > edk2-devel mailing list
> > edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>
> > https://lists.01.org/mailman/listinfo/edk2-devel
> _______________________________________________
> edk2-devel mailing list
> edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>
> https://lists.01.org/mailman/listinfo/edk2-devel
_______________________________________________
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On 29 March 2017 at 00:45, Yao, Jiewen <jiewen.yao@intel.com> wrote:
> Agree. That is a good idea.
>
>
>
> I will add that in V2 patch.
>

Hello Jiewen,

As a bit of background, what I have in mind is an enhancement of the
PCI root bridge I/O allocate, map and unmap methods so that situations
that would currently lead to failure or to suboptimal performance are
left for the IOMMU protocol to handle if one is present. Note that
this may imply having IOMMU protocol instances for each PCI root
bridge, and for other masters as well. (For example, AMD Seattle has
separate IOMMUs for PCI and for the networking controllers, which are
wired to the internal interconnect directly)

So in RootBridgeIoMap(), for instance, we have this condition

  PhysicalAddress = (EFI_PHYSICAL_ADDRESS) (UINTN) HostAddress;
  if ((!RootBridge->DmaAbove4G ||
       (Operation != EfiPciOperationBusMasterRead64 &&
        Operation != EfiPciOperationBusMasterWrite64 &&
        Operation != EfiPciOperationBusMasterCommonBuffer64)) &&
      ((PhysicalAddress + *NumberOfBytes) > SIZE_4GB)) {

to decide whether bounce buffering is necessary (or even possible).
The mapping between DeviceAddress and HostAddress could be supplied by
the IOMMU protocol instance, which also means we should reinterpret
DmaAbove4G and other variables related to 32-bit addressing to apply
to the device address and not the physical address.

Similarly, in RootBridgeIoAllocateBuffer(), a failure to allocate
below 4 GB may not be an error if the IOMMU protocol instance can
provide a 32-bit addressable mapping for it.

I am aware that this complicates matters for you, but having IOMMU
support in the generic PCI host bridge driver is extremely useful for
us. I am happy to help out in any way I can.

Thanks,
Ard.
_______________________________________________
edk2-devel mailing list
edk2-devel@lists.01.org
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Thanks for the info.

Comment inline.




From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org]
Sent: Wednesday, March 29, 2017 10:23 PM
To: Yao, Jiewen <jiewen.yao@intel.com>
Cc: Kinney, Michael D <michael.d.kinney@intel.com>; Ni, Ruiyu <ruiyu.ni@intel.com>; Leo Duran <leo.duran@amd.com>; edk2-devel@lists.01.org; Brijesh Singh <brijesh.singh@amd.com>
Subject: Re: [edk2] [PATCH 1/3] MdeModulePkg/Include: Add IOMMU protocol definition.

On 29 March 2017 at 00:45, Yao, Jiewen <jiewen.yao@intel.com<mailto:jiewen.yao@intel.com>> wrote:
> Agree. That is a good idea.
>
>
>
> I will add that in V2 patch.
>

Hello Jiewen,

As a bit of background, what I have in mind is an enhancement of the
PCI root bridge I/O allocate, map and unmap methods so that situations
that would currently lead to failure or to suboptimal performance are
left for the IOMMU protocol to handle if one is present. Note that
this may imply having IOMMU protocol instances for each PCI root
bridge, and for other masters as well. (For example, AMD Seattle has
separate IOMMUs for PCI and for the networking controllers, which are
wired to the internal interconnect directly)

[Jiewen] I am not very sure what do you mean.

Fist, let me explain Intel platform.

There might be multiple IOMMU engines on one platform. one for graphic and one for rest PCI device (such as ATA/USB).
But all IOMMU engines are reported by one “DMAR” ACPI table.

In such case, the Intel IOMMU driver just produces one IOMMU protocol, based upon DMAR ACPI table.

This IOMMU protocol provider can use UEFI device path to distinguish if the device is graphic or ATA/USB, and find out corresponding IOMMU engine.

I know AMD has “IVRS” ACPI table and ARM has “IORT” ACPI table.

In such case, I assume AMD may have one IOMMU protocol based upon IVRS table, and ARM may have one IOMMU protocol based upon IORT table.
And this single IOMMU protocol provider can handle multiple IOMMU engines on one system.

Is that understand same as yours?




So in RootBridgeIoMap(), for instance, we have this condition

  PhysicalAddress = (EFI_PHYSICAL_ADDRESS) (UINTN) HostAddress;
  if ((!RootBridge->DmaAbove4G ||
       (Operation != EfiPciOperationBusMasterRead64 &&
        Operation != EfiPciOperationBusMasterWrite64 &&
        Operation != EfiPciOperationBusMasterCommonBuffer64)) &&
      ((PhysicalAddress + *NumberOfBytes) > SIZE_4GB)) {

to decide whether bounce buffering is necessary (or even possible).
The mapping between DeviceAddress and HostAddress could be supplied by
the IOMMU protocol instance, which also means we should reinterpret
DmaAbove4G and other variables related to 32-bit addressing to apply
to the device address and not the physical address.

Similarly, in RootBridgeIoAllocateBuffer(), a failure to allocate
below 4 GB may not be an error if the IOMMU protocol instance can
provide a 32-bit addressable mapping for it.

[Jiewen] It is a good idea to remap based upon IOMMU.

However, one potential problem is that the memory size if not IOMMU page aligned.
In such case, PciRootBridge driver has to allocate another IOMMU page aligned memory for DMA buffer.

I believe the benefit will be got, only if the device driver who submit DMA request allocate IOMMU page aligned memory for DMA request.



I am aware that this complicates matters for you, but having IOMMU
support in the generic PCI host bridge driver is extremely useful for
us. I am happy to help out in any way I can.
[Jiewen] Yes, I definitely need comment for ARM/AMD/other system architecture.



Thanks,
Ard.
_______________________________________________
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel

On 30 March 2017 at 13:37, Yao, Jiewen <jiewen.yao@intel.com> wrote:
> Thanks for the info.
>
>
>
> Comment inline.
>
>
>
>
>
>
>
>
>
> From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org]
> Sent: Wednesday, March 29, 2017 10:23 PM
> To: Yao, Jiewen <jiewen.yao@intel.com>
> Cc: Kinney, Michael D <michael.d.kinney@intel.com>; Ni, Ruiyu
> <ruiyu.ni@intel.com>; Leo Duran <leo.duran@amd.com>;
> edk2-devel@lists.01.org; Brijesh Singh <brijesh.singh@amd.com>
> Subject: Re: [edk2] [PATCH 1/3] MdeModulePkg/Include: Add IOMMU protocol
> definition.
>
>
>
> On 29 March 2017 at 00:45, Yao, Jiewen <jiewen.yao@intel.com> wrote:
>> Agree. That is a good idea.
>>
>>
>>
>> I will add that in V2 patch.
>>
>
> Hello Jiewen,
>
> As a bit of background, what I have in mind is an enhancement of the
> PCI root bridge I/O allocate, map and unmap methods so that situations
> that would currently lead to failure or to suboptimal performance are
> left for the IOMMU protocol to handle if one is present. Note that
> this may imply having IOMMU protocol instances for each PCI root
> bridge, and for other masters as well. (For example, AMD Seattle has
> separate IOMMUs for PCI and for the networking controllers, which are
> wired to the internal interconnect directly)
>
>
>
> [Jiewen] I am not very sure what do you mean.
>
>
>
> Fist, let me explain Intel platform.
>
>
>
> There might be multiple IOMMU engines on one platform. one for graphic and
> one for rest PCI device (such as ATA/USB).
>
> But all IOMMU engines are reported by one “DMAR” ACPI table.
>
>
>
> In such case, the Intel IOMMU driver just produces one IOMMU protocol, based
> upon DMAR ACPI table.
>
>
>
> This IOMMU protocol provider can use UEFI device path to distinguish if the
> device is graphic or ATA/USB, and find out corresponding IOMMU engine.
>
>
>
> I know AMD has “IVRS” ACPI table and ARM has “IORT” ACPI table.
>
>
>
> In such case, I assume AMD may have one IOMMU protocol based upon IVRS
> table, and ARM may have one IOMMU protocol based upon IORT table.
>
> And this single IOMMU protocol provider can handle multiple IOMMU engines on
> one system.
>
>
>
> Is that understand same as yours?
>

OK, that works for me.

>
>
>
>
>
>
> So in RootBridgeIoMap(), for instance, we have this condition
>
>   PhysicalAddress = (EFI_PHYSICAL_ADDRESS) (UINTN) HostAddress;
>   if ((!RootBridge->DmaAbove4G ||
>        (Operation != EfiPciOperationBusMasterRead64 &&
>         Operation != EfiPciOperationBusMasterWrite64 &&
>         Operation != EfiPciOperationBusMasterCommonBuffer64)) &&
>       ((PhysicalAddress + *NumberOfBytes) > SIZE_4GB)) {
>
> to decide whether bounce buffering is necessary (or even possible).
> The mapping between DeviceAddress and HostAddress could be supplied by
> the IOMMU protocol instance, which also means we should reinterpret
> DmaAbove4G and other variables related to 32-bit addressing to apply
> to the device address and not the physical address.
>
> Similarly, in RootBridgeIoAllocateBuffer(), a failure to allocate
> below 4 GB may not be an error if the IOMMU protocol instance can
> provide a 32-bit addressable mapping for it.
>
> [Jiewen] It is a good idea to remap based upon IOMMU.
>
>
>
> However, one potential problem is that the memory size if not IOMMU page
> aligned.
>
> In such case, PciRootBridge driver has to allocate another IOMMU page
> aligned memory for DMA buffer.
>
>
>
> I believe the benefit will be got, only if the device driver who submit DMA
> request allocate IOMMU page aligned memory for DMA request.
>

Well, allocating memory and remapping host memory into the PCI address
space are not the same thing. In the absence of concerns about
isolation, I don't think it should be a problem to round up IOMMU
mappings to sizes it can handle [efficiently].


>
>
>
>
>
> I am aware that this complicates matters for you, but having IOMMU
> support in the generic PCI host bridge driver is extremely useful for
> us. I am happy to help out in any way I can.
> [Jiewen] Yes, I definitely need comment for ARM/AMD/other system
> architecture.
>
>
>
>
>
>
> Thanks,
> Ard.
_______________________________________________
edk2-devel mailing list
edk2-devel@lists.01.org
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