Re: [PATCH v5 02/27] iommu/arm-smmu-v3: Do not ATC invalidate the entire domain

From: Mostafa Saleh <smostafa@google.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: iommu@lists.linux.dev, Joerg Roedel <joro@8bytes.org>,
	linux-arm-kernel@lists.infradead.org,
	Robin Murphy <robin.murphy@arm.com>,
	Will Deacon <will@kernel.org>, Eric Auger <eric.auger@redhat.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	Moritz Fischer <mdf@kernel.org>,
	Michael Shavit <mshavit@google.com>,
	Nicolin Chen <nicolinc@nvidia.com>,
	patches@lists.linux.dev,
	Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
Subject: Re: [PATCH v5 02/27] iommu/arm-smmu-v3: Do not ATC invalidate the entire domain
Date: Fri, 22 Mar 2024 17:51:03 +0000	[thread overview]
Message-ID: <Zf3FB3N0yjALqscA@google.com> (raw)
In-Reply-To: <2-v5-9a37e0c884ce+31e3-smmuv3_newapi_p2_jgg@nvidia.com>

Hi Jason,

On Mon, Mar 04, 2024 at 07:43:50PM -0400, Jason Gunthorpe wrote:
> At this point we know which master we are going to change the PCI config
> on, this is the only device we need to invalidate. Switch
> arm_smmu_atc_inv_domain() for arm_smmu_atc_inv_master().
> 
> Tested-by: Nicolin Chen <nicolinc@nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index d1bc151a5dff8c..9e9233331c4636 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2447,7 +2447,10 @@ static void arm_smmu_enable_ats(struct arm_smmu_master *master,
>  	pdev = to_pci_dev(master->dev);
>  
>  	atomic_inc(&smmu_domain->nr_ats_masters);
> -	arm_smmu_atc_inv_domain(smmu_domain, IOMMU_NO_PASID, 0, 0);
> +	/*
> +	 * ATC invalidation of PASID 0 causes the entire ATC to be flushed.
> +	 */
> +	arm_smmu_atc_inv_master(master);
>  	if (pci_enable_ats(pdev, stu))
>  		dev_err(master->dev, "Failed to enable ATS (STU %zu)\n", stu);
>  }
> -- 
> 2.43.2

Reviewed-by: Mostafa Saleh <smostafa@google.com>

Thanks,
Mostafa

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