Re: [PATCH V2 0/6] SourceLevelDebugPkg DebugUsb3: Re-Support IOMMU

["Ni, Ruiyu" <ruiyu.ni@Intel.com>]

On 3/14/2018 5:33 PM, Star Zeng wrote:
> The patch series is also at
> https://github.com/lzeng14/edk2 DebugCommUsb3AfterIOMMUV2 branch.
> 
> Based on the feedbacks from Ray and Hao.
> It is V2 of
> https://lists.01.org/pipermail/edk2-devel/2018-March/022586.html.
> It has no essential difference with V1 about the final code, but
> re-arranges the patches to revert old IOMMU support patches and
> then re-support IOMMU.
> 
> de8373fa07f87ca735139bb86c51e2c29fb1d956 could not handle two cases.
> 1. For the case that the USB3 debug port instance and DMA buffers are
> from PEI HOB with IOMMU enabled, it was to reallocate the DMA buffers
> by AllocateAddress with the memory type accessible by SMM environment.
> But reallocating the DMA buffers by AllocateAddress may fail.
> 
> 2. At S3 resume, after the code is transferred to PiSmmCpuDxeSmm from
> S3Resume2Pei, HOB is still needed to be used for DMA operation, but
> PiSmmCpuDxeSmm has no way to get the HOB at S3 resume.
> 
> The patch is to re-support IOMMU.
> For PEI, allocate granted DMA buffer from IOMMU PPI, register IOMMU PPI
> notification to reinitialize hardware with granted DMA buffer if IOMMU
> PPI is not present yet.
> For DXE, map DMA buffer by PciIo in PciIo notification for early DXE,
> and register DxeSmmReadyToLock notification to reinitialize hardware
> with granted DXE DMA buffer accessible by SMM environment for late DXE.
> 
> DebugAgentLib has been managing the instance as Handle in
> HOB/SystemTable. The Handle(instance) from DebugAgentLib can be used
> directly in DebugCommunicationLibUsb3. Then DebugCommunicationLibUsb3
> could get consistent Handle(instance) from DebugAgentLib.
> 
> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Hao Wu <hao.a.wu@intel.com>
> 
> Star Zeng (6):
>    Revert "DebugUsb3: Check mUsb3Instance before dereferencing it"
>    Revert "DebugUsb3: Fix GCC build failures"
>    Revert "DebugUsb3: Support IOMMU"
>    SourceLevelDebugPkg DebugUsb3: Re-Fix GCC build failures
>    SourceLevelDebugPkg DebugCommUsb3: Refine some formats/comments
>    SourceLevelDebugPkg DebugUsb3: Re-Support IOMMU
> 
>   .../DebugCommunicationLibUsb3Common.c              | 110 +++++-
>   .../DebugCommunicationLibUsb3Dxe.c                 | 375 ++++++++++++---------
>   .../DebugCommunicationLibUsb3Dxe.inf               |  11 +-
>   .../DebugCommunicationLibUsb3Internal.h            |  60 +---
>   .../DebugCommunicationLibUsb3Pei.c                 |  50 ++-
>   .../DebugCommunicationLibUsb3Pei.inf               |   4 +-
>   6 files changed, 351 insertions(+), 259 deletions(-)
> 
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>

-- 
Thanks,
Ray