Commit 86e02a88 authored by Jean-Philippe Brucker's avatar Jean-Philippe Brucker Committed by Will Deacon
Browse files

iommu/of: Support ats-supported device-tree property 



Device-tree declares whether a PCI root-complex supports ATS by setting
the "ats-supported" property. Copy this flag into device fwspec to let
IOMMU drivers quickly check if they can enable ATS for a device.

Tested-by: default avatarKetan Patil <ketanp@nvidia.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarLiviu Dudau <liviu.dudau@arm.com>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
Reviewed-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Signed-off-by: default avatarJean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20240607105415.2501934-4-jean-philippe@linaro.org


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 40929e8e

drivers/iommu/of_iommu.c

+9 −0
Original line number Diff line number Diff line
@@ -105,6 +105,14 @@ static int of_iommu_configure_device(struct device_node *master_np, 
		      of_iommu_configure_dev(master_np, dev);

}



static void of_pci_check_device_ats(struct device *dev, struct device_node *np)

{

	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);



	if (fwspec && of_property_read_bool(np, "ats-supported"))

		fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;

}



/*

 * Returns:

 *  0 on success, an iommu was configured
@@ -147,6 +155,7 @@ int of_iommu_configure(struct device *dev, struct device_node *master_np, 
		pci_request_acs();

		err = pci_for_each_dma_alias(to_pci_dev(dev),

					     of_pci_iommu_init, &info);

		of_pci_check_device_ats(dev, master_np);

	} else {

		err = of_iommu_configure_device(master_np, dev, id);

	}