Date:   Tue, 21 Mar 2023 10:31:47 +0800
From:   Cai Huoqing <cai.huoqing@linux.dev>
To:     Serge Semin <fancer.lancer@gmail.com>
Cc:     Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
        Vinod Koul <vkoul@kernel.org>,
        Jingoo Han <jingoohan1@gmail.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>,
        Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org,
        linux-pci@vger.kernel.org
Subject: Re: [PATCH v7 0/5] dmaengine: dw-edma: Add support for native HDMA
Message-ID: <ZBkXEzoZZlIy18xB@chq-MS-7D45>
References: <20230315012840.6986-1-cai.huoqing@linux.dev>
 <20230320121401.zkcjbqmghzacpffh@mobilestation>
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On 20 3月 23 15:14:01, Serge Semin wrote:
> Hi Cai
> 
> On Wed, Mar 15, 2023 at 09:28:31AM +0800, Cai Huoqing wrote:
> > Add support for HDMA NATIVE, as long the IP design has set
> > the compatible register map parameter-HDMA_NATIVE,
> > which allows compatibility for native HDMA register configuration.
> > 
> > The HDMA Hyper-DMA IP is an enhancement of the eDMA embedded-DMA IP.
> > And the native HDMA registers are different from eDMA,
> > so this patch add support for HDMA NATIVE mode.
> > 
> > HDMA write and read channels operate independently to maximize
> > the performance of the HDMA read and write data transfer over
> > the link When you configure the HDMA with multiple read channels,
> > then it uses a round robin (RR) arbitration scheme to select
> > the next read channel to be serviced.The same applies when
> > youhave multiple write channels.
> > 
> > The native HDMA driver also supports a maximum of 16 independent
> > channels (8 write + 8 read), which can run simultaneously.
> > Both SAR (Source Address Register) and DAR (Destination Address Register)
> > are aligned to byte.
> 
> It seems like we are getting towards the series finalization. I'll
> test it out on my HW after v8 is submitted. Meanwhile could you please
> clarify whether you have a real device with DW HDMA engine on board?

Our hardware is an AI Accelerartor(PCIE Card).

The device pci.ids is 1d22:3864
in https://github.com/pciutils/pciids/blob/master/pci.ids
line 24737,

"1d22  Baidu Technology
        3684  Kunlun AI Accelerator
        3685  Kunlun2 AI Accelerator [VF]"

And our device driver is not ready to upstream(will cost serveral

months to port DRM etc.),

but I have taken this DW eDMA core into our driver test.

Thanks
Cai-

> You keep submitting the DW eDMA driver core update, but there is no
> glue-driver or low-level device driver patch for a real device which
> would set the EDMA_MF_HDMA_NATIVE mapping.
> 
> -Serge(y)
> 
> > 
> > Cai Huoqing (2):
> >   dmaengine: dw-edma: Add support for native HDMA
> >   dmaengine: dw-edma: Optimization in dw_edma_v0_core_handle_int
> > 
> > Cai huoqing (3):
> >   dmaengine: dw-edma: Rename dw_edma_core_ops structure to
> >     dw_edma_plat_ops
> >   dmaengine: dw-edma: Create a new dw_edma_core_ops structure to
> >     abstract controller operation
> >   dmaengine: dw-edma: Add HDMA DebugFS support
> > 
> > v6->v7:
> >   [1/5]
> >   1.Update the commit log.
> >   [2/5]
> >   2.Revert dw_edma_core_handle_int back to dw-edma-core.h.
> >   3.Fix code style.
> >   [3/5]
> >   4.Move the change of register file from patch[4/5] to patch[3/5].
> >   5.Fix code style.
> > 
> > v6 link:
> >   https://lore.kernel.org/lkml/20230310032342.17395-1-cai.huoqing@linux.dev/
> > 
> >  drivers/dma/dw-edma/Makefile                 |   8 +-
> >  drivers/dma/dw-edma/dw-edma-core.c           |  86 ++----
> >  drivers/dma/dw-edma/dw-edma-core.h           |  58 ++++
> >  drivers/dma/dw-edma/dw-edma-pcie.c           |   4 +-
> >  drivers/dma/dw-edma/dw-edma-v0-core.c        |  91 ++++--
> >  drivers/dma/dw-edma/dw-edma-v0-core.h        |  14 +-
> >  drivers/dma/dw-edma/dw-hdma-v0-core.c        | 277 +++++++++++++++++++
> >  drivers/dma/dw-edma/dw-hdma-v0-core.h        |  17 ++
> >  drivers/dma/dw-edma/dw-hdma-v0-debugfs.c     | 176 ++++++++++++
> >  drivers/dma/dw-edma/dw-hdma-v0-debugfs.h     |  22 ++
> >  drivers/dma/dw-edma/dw-hdma-v0-regs.h        | 130 +++++++++
> >  drivers/pci/controller/dwc/pcie-designware.c |   2 +-
> >  include/linux/dma/edma.h                     |   7 +-
> >  13 files changed, 785 insertions(+), 107 deletions(-)
> >  create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-core.c
> >  create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-core.h
> >  create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-debugfs.c
> >  create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-debugfs.h
> >  create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-regs.h
> > 
> > -- 
> > 2.34.1
> >