[RFC PATCH 04/30] iommu/arm-smmu-v3: Add support for PCI ATS

[Tomasz Nowicki]

Hi Jean,

On 27.02.2017 20:54, Jean-Philippe Brucker wrote:
> +/*
> + * Returns -ENOSYS if ATS is not supported either by the device or by the SMMU
> + */
> +static int arm_smmu_enable_ats(struct arm_smmu_master_data *master)
> +{
> +	int ret;
> +	size_t stu;
> +	struct pci_dev *pdev;
> +	struct arm_smmu_device *smmu = master->smmu;
> +
> +	if (!(smmu->features & ARM_SMMU_FEAT_ATS) || !dev_is_pci(master->dev))
> +		return -ENOSYS;
> +
> +	pdev = to_pci_dev(master->dev);
> +
> +#ifdef CONFIG_PCI_ATS
> +	if (!pdev->ats_cap)
> +		return -ENOSYS;
> +#else
> +	return -ENOSYS;
> +#endif

Nit: This deserves to be another helper in ats.c like:

int pci_ats_supported(struct pci_dev *dev) {
         if (!pdev->ats_cap)
                 return 0;

         return 1;
}

Thanks,
Tomasz