On 2020-11-12 12:55, Jean-Philippe Brucker wrote:
Copy the dma-can-stall property into the fwspec structure.
Can't we just handle this as a regular device property? It's not part of the actual IOMMU specifier, it doesn't need to be translated in any way, and AFAICS it's used a grand total of once, in a slow path. Simply treating it as the per-device property that it is should require zero additional code for DT, and a simple device_add_properties() call for IORT.
TBH that appears to be true of pasid-num-bits as well. Robin.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx> --- include/linux/iommu.h | 2 ++ drivers/iommu/of_iommu.c | 5 ++++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index a1c78c4cdeb1..9076fb592c8f 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -572,6 +572,7 @@ struct iommu_group *fsl_mc_device_group(struct device *dev); * @iommu_fwnode: firmware handle for this device's IOMMU * @iommu_priv: IOMMU driver private data for this device * @num_pasid_bits: number of PASID bits supported by this device + * @can_stall: the device is allowed to stall * @num_ids: number of associated device IDs * @ids: IDs which this device may present to the IOMMU */ @@ -579,6 +580,7 @@ struct iommu_fwspec { const struct iommu_ops *ops; struct fwnode_handle *iommu_fwnode; u32 num_pasid_bits; + bool can_stall; unsigned int num_ids; u32 ids[]; }; diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index e505b9130a1c..d6255ca823d8 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -212,9 +212,12 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, err = of_iommu_configure_device(master_np, dev, id);fwspec = dev_iommu_fwspec_get(dev);- if (!err && fwspec) + if (!err && fwspec) { of_property_read_u32(master_np, "pasid-num-bits", &fwspec->num_pasid_bits); + fwspec->can_stall = of_property_read_bool(master_np, + "dma-can-stall"); + } }/*
