Re: [Freedreno] [PATCH v5 0/5] iommu/arm-smmu: Split pagetable support for arm-smmu-v2

From: Jordan Crouse <jcrouse@codeaurora.org>
To: iommu@lists.linux-foundation.org
Cc: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>,
	David Airlie <airlied@linux.ie>,
	dri-devel@lists.freedesktop.org,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	AngeloGioacchino Del Regno <kholk11@gmail.com>,
	Sam Ravnborg <sam@ravnborg.org>, Wen Yang <wen.yang99@zte.com.cn>,
	will@kernel.org, Joerg Roedel <joro@8bytes.org>,
	Ben Dooks <ben.dooks@codethink.co.uk>,
	linux-arm-kernel@lists.infradead.org,
	Wambui Karuga <wambui.karugax@gmail.com>,
	freedreno@lists.freedesktop.org,
	Fritz Koenig <frkoenig@google.com>,
	linux-arm-msm@vger.kernel.org,
	Sharat Masetty <smasetty@codeaurora.org>,
	Jeykumar Sankaran <jsanka@codeaurora.org>,
	Alexios Zavras <alexios.zavras@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>, Sean Paul <sean@poorly.run>,
	Allison Randal <allison@lohutok.net>,
	Enrico Weigelt <info@metux.net>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Douglas Anderson <dianders@chromium.org>,
	linux-kernel@vger.kernel.org, zhengbin <zhengbin13@huawei.com>,
	Rob Clark <robdclark@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
	Drew Davenport <ddavenport@chromium.org>,
	Brian Masney <masneyb@onstation.org>,
	robin.murphy@arm.com, Georgi Djakov <georgi.djakov@linaro.org>
Subject: Re: [Freedreno] [PATCH v5 0/5] iommu/arm-smmu: Split pagetable support for arm-smmu-v2
Date: Thu, 27 Feb 2020 11:45:34 -0700	[thread overview]
Message-ID: <20200227184534.GA25772@jcrouse1-lnx.qualcomm.com> (raw)
In-Reply-To: <1580248819-12644-1-git-send-email-jcrouse@codeaurora.org>

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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