Message-ID: <20200227184534.GA25772@jcrouse1-lnx.qualcomm.com>
Date:   Thu, 27 Feb 2020 11:45:34 -0700
From:   Jordan Crouse <jcrouse@...eaurora.org>
To:     iommu@...ts.linux-foundation.org
Cc:     Jeffrey Hugo <jeffrey.l.hugo@...il.com>,
        David Airlie <airlied@...ux.ie>,
        dri-devel@...ts.freedesktop.org,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        AngeloGioacchino Del Regno <kholk11@...il.com>,
        Sam Ravnborg <sam@...nborg.org>,
        Wen Yang <wen.yang99@....com.cn>, will@...nel.org,
        Joerg Roedel <joro@...tes.org>,
        Ben Dooks <ben.dooks@...ethink.co.uk>,
        linux-arm-kernel@...ts.infradead.org,
        Wambui Karuga <wambui.karugax@...il.com>,
        freedreno@...ts.freedesktop.org,
        Fritz Koenig <frkoenig@...gle.com>,
        linux-arm-msm@...r.kernel.org,
        Sharat Masetty <smasetty@...eaurora.org>,
        Jeykumar Sankaran <jsanka@...eaurora.org>,
        Alexios Zavras <alexios.zavras@...el.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Sean Paul <sean@...rly.run>,
        Allison Randal <allison@...utok.net>,
        Enrico Weigelt <info@...ux.net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Douglas Anderson <dianders@...omium.org>,
        linux-kernel@...r.kernel.org, zhengbin <zhengbin13@...wei.com>,
        Rob Clark <robdclark@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Drew Davenport <ddavenport@...omium.org>,
        Brian Masney <masneyb@...tation.org>, robin.murphy@....com,
        Georgi Djakov <georgi.djakov@...aro.org>
Subject: Re: [Freedreno] [PATCH v5 0/5] iommu/arm-smmu: Split pagetable
 support for arm-smmu-v2

On Tue, Jan 28, 2020 at 03:00:14PM -0700, Jordan Crouse wrote:
> This is another iteration for the split pagetable support based on the
> suggestions from Robin and Will [1].
> 
> Background: In order to support per-context pagetables the GPU needs to enable
> split tables so that we can store global buffers in the TTBR1 space leaving the
> GPU free to program the TTBR0 register with the address of a context specific
> pagetable.
> 
> If the DOMAIN_ATTR_SPLIT_TABLES attribute is set on the domain before attaching,
> the context bank assigned to the domain will be programmed to allow translations
> in the TTBR1 space. Translations in the TTBR0 region will be disallowed because,
> as Robin pointe out, having a un-programmed TTBR0 register is dangerous.
> 
> The driver can determine if TTBR1 was successfully programmed by querying
> DOMAIN_ATTR_SPLIT_TABLES after attaching. The domain geometry will also be
> updated to reflect the virtual address space for the TTBR1 range.
> 
> Upcoming changes will allow auxiliary domains to be attached to the device which
> will enable and program TTBR0.
> 
> This patchset is based on top of linux-next-20200127.

Quick ping for feedback so I can respin for (maybe?) 5.6.

Thanks,
Jordan

> Change log:
> 
> v4: Only program TTBR1 when split pagetables are requested. TTBR0 will be
> enabled later when an auxiliary domain is attached
> v3: Remove the implementation specific and make split pagetable support
> part of the generic configuration
> 
> [1] https://lists.linuxfoundation.org/pipermail/iommu/2020-January/041373.html
> 
> Jordan Crouse (5):
>   iommu: Add DOMAIN_ATTR_SPLIT_TABLES
>   iommu/arm-smmu: Add support for TTBR1
>   drm/msm: Attach the IOMMU device during initialization
>   drm/msm: Refactor address space initialization
>   drm/msm/a6xx: Support split pagetables
> 
>  drivers/gpu/drm/msm/adreno/a2xx_gpu.c    | 16 ++++++++++
>  drivers/gpu/drm/msm/adreno/a3xx_gpu.c    |  1 +
>  drivers/gpu/drm/msm/adreno/a4xx_gpu.c    |  1 +
>  drivers/gpu/drm/msm/adreno/a5xx_gpu.c    |  1 +
>  drivers/gpu/drm/msm/adreno/a6xx_gpu.c    | 51 ++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/msm/adreno/adreno_gpu.c  | 23 ++++++++++----
>  drivers/gpu/drm/msm/adreno/adreno_gpu.h  |  8 +++++
>  drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c  | 18 ++++-------
>  drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c | 18 +++++------
>  drivers/gpu/drm/msm/disp/mdp5/mdp5_cfg.c |  4 ---
>  drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 18 +++++------
>  drivers/gpu/drm/msm/msm_drv.h            |  8 ++---
>  drivers/gpu/drm/msm/msm_gem_vma.c        | 36 ++++------------------
>  drivers/gpu/drm/msm/msm_gpu.c            | 49 ++----------------------------
>  drivers/gpu/drm/msm/msm_gpu.h            |  4 +--
>  drivers/gpu/drm/msm/msm_gpummu.c         |  6 ----
>  drivers/gpu/drm/msm/msm_iommu.c          | 18 ++++++-----
>  drivers/gpu/drm/msm/msm_mmu.h            |  1 -
>  drivers/iommu/arm-smmu.c                 | 48 +++++++++++++++++++++++++-----
>  drivers/iommu/arm-smmu.h                 | 22 ++++++++++----
>  include/linux/iommu.h                    |  2 ++
>  21 files changed, 198 insertions(+), 155 deletions(-)
> 
> -- 
> 2.7.4
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> Freedreno@...ts.freedesktop.org
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