Re: [PATCH 0/3] iommu/drm/msm: Allow non-coherent masters to use system cache

From: Georgi Djakov <djakov@kernel.org>
To: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Cc: Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>,
	Jordan Crouse <jcrouse@codeaurora.org>,
	Rob Clark <robdclark@gmail.com>,
	Akhil P Oommen <akhilpo@codeaurora.org>,
	isaacm@codeaurora.org, iommu@lists.linux-foundation.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	freedreno <freedreno@lists.freedesktop.org>,
	Kristian H Kristensen <hoegsberg@google.com>,
	Sean Paul <sean@poorly.run>, David Airlie <airlied@linux.ie>,
	Daniel Vetter <daniel@ffwll.ch>,
	dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 0/3] iommu/drm/msm: Allow non-coherent masters to use system cache
Date: Wed, 28 Jul 2021 17:00:53 +0300	[thread overview]
Message-ID: <20210728140052.GB22887@mms-0441> (raw)
In-Reply-To: <cover.1610372717.git.saiprakash.ranjan@codeaurora.org>

On Mon, Jan 11, 2021 at 07:45:02PM +0530, Sai Prakash Ranjan wrote:
> commit ecd7274fb4cd ("iommu: Remove unused IOMMU_SYS_CACHE_ONLY flag")
> removed unused IOMMU_SYS_CACHE_ONLY prot flag and along with it went
> the memory type setting required for the non-coherent masters to use
> system cache. Now that system cache support for GPU is added, we will
> need to set the right PTE attribute for GPU buffers to be sys cached.
> Without this, the system cache lines are not allocated for GPU.
> 
> So the patches in this series introduces a new prot flag IOMMU_LLC,
> renames IO_PGTABLE_QUIRK_ARM_OUTER_WBWA to IO_PGTABLE_QUIRK_PTW_LLC
> and makes GPU the user of this protection flag.

Hi Sai,

Thank you for the patchset! Are you planning to refresh it, as it does
not apply anymore?

Thanks,
Georgi

> 
> The series slightly depends on following 2 patches posted earlier and
> is based on msm-next branch:
>  * https://lore.kernel.org/patchwork/patch/1363008/
>  * https://lore.kernel.org/patchwork/patch/1363010/
> 
> Sai Prakash Ranjan (3):
>   iommu/io-pgtable: Rename last-level cache quirk to
>     IO_PGTABLE_QUIRK_PTW_LLC
>   iommu/io-pgtable-arm: Add IOMMU_LLC page protection flag
>   drm/msm: Use IOMMU_LLC page protection flag to map gpu buffers
> 
>  drivers/gpu/drm/msm/adreno/a6xx_gpu.c   | 3 +++
>  drivers/gpu/drm/msm/adreno/adreno_gpu.c | 2 +-
>  drivers/gpu/drm/msm/msm_iommu.c         | 3 +++
>  drivers/gpu/drm/msm/msm_mmu.h           | 4 ++++
>  drivers/iommu/io-pgtable-arm.c          | 9 ++++++---
>  include/linux/io-pgtable.h              | 6 +++---
>  include/linux/iommu.h                   | 6 ++++++
>  7 files changed, 26 insertions(+), 7 deletions(-)
> 
> 
> base-commit: 00fd44a1a4700718d5d962432b55c09820f7e709
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
> 

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