On 6/3/23 2:22 AM, Jacob Pan wrote:
+ioasid_t iommu_alloc_global_pasid_dev(struct device *dev)
+{
+ int ret;
+ ioasid_t max;
+
+ max = dev->iommu->max_pasids;
+ /*
+ * max_pasids is set up by vendor driver based on number of PASID bits
+ * supported but the IDA allocation is inclusive.
+ */
+ ret = ida_alloc_range(&iommu_global_pasid_ida, IOMMU_FIRST_GLOBAL_PASID, max - 1, GFP_KERNEL);
+ if (ret < 0)
+ return IOMMU_PASID_INVALID;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_alloc_global_pasid_dev);
"dev->iommu->max_pasids == 0" indicates no pasid support on the device.
The code should return IOMMU_PASID_INVALID explicitly. Perhaps we can
make this function like this:
ioasid_t iommu_alloc_global_pasid_dev(struct device *dev)
{
int ret;
if (!dev->iommu->max_pasids)
return IOMMU_PASID_INVALID;
/*
* max_pasids is set up by vendor driver based on number of
PASID bits
* supported but the IDA allocation is inclusive.
*/
ret = ida_alloc_range(&iommu_global_pasid_ida,
IOMMU_FIRST_GLOBAL_PASID,
dev->iommu->max_pasids - 1, GFP_KERNEL);
return ret < 0 ? IOMMU_PASID_INVALID : ret;
}
EXPORT_SYMBOL_GPL(iommu_alloc_global_pasid_dev);
Other change in this series looks good to me.
I hope I can queue this series including above change as part of my VT-d
update for v6.5 to Joerg if no objection.
Let's try to re-enable this key feature of Intel idxd driver in v6.5.
Best regards,
baolu
