iommu/vt-d: Use iommu_sva_alloc(free)_pasid() helpers

Align the pasid alloc/free code with the generic helpers defined in the
iommu core. This also refactored the SVA binding code to improve the
readability.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210520031531.712333-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20210610020115.1637656-8-baolu.lu@linux.intel.comSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/intel/Kconfig

@@ -42,6 +42,7 @@ config INTEL_IOMMU_SVM
 	select PCI_PRI
 	select MMU_NOTIFIER
 	select IOASID
+	select IOMMU_SVA_LIB
 	help
 	  Shared Virtual Memory (SVM) provides a facility for devices
 	  to access DMA resources through process address space by

drivers/iommu/intel/iommu.c

@@ -5411,6 +5411,9 @@ intel_iommu_dev_enable_feat(struct device *dev, enum iommu_dev_features feat)
 		if (!info)
 			return -EINVAL;
 
+		if (intel_iommu_enable_pasid(info->iommu, dev))
+			return -ENODEV;
+
 		if (!info->pasid_enabled || !info->pri_enabled || !info->ats_enabled)
 			return -EINVAL;
 

include/linux/intel-iommu.h

@@ -791,7 +791,6 @@ struct intel_svm {
 	u32 pasid;
 	int gpasid; /* In case that guest PASID is different from host PASID */
 	struct list_head devs;
-	struct list_head list;
 };
 #else
 static inline void intel_svm_check(struct intel_iommu *iommu) {}