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

[Moritz Fischer]

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 at nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>

Reviewed-by: Moritz Fischer <moritzf at google.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