RE: [PATCH v4 3/7] iommu: Support allocation of global PASIDs outside SVA

Tian, Kevin
2023-04-11T08:04:33Z

> From: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Sent: Saturday, April 8, 2023 2:06 AM
> @@ -28,8 +26,8 @@ static int iommu_sva_alloc_pasid(struct mm_struct
> *mm, ioasid_t min, ioasid_t ma
> goto out;
> }
>
> - ret = ida_alloc_range(&iommu_global_pasid_ida, min, max,
> GFP_KERNEL);
> - if (ret < min)
> + ret = iommu_alloc_global_pasid(min, max);

I wonder whether this can take a device pointer so dev->iommu->max_pasids
is enforced inside the alloc function.

and do we even need the min/max parameters? With special pasids reserved
then what driver needs is just to get a free pasid from the global space within
dev->iommu->max_pasids constraint...

iommu_sva_alloc_pasid() can be reworked to avoid min/max by taking a
device pointer too.