iommu/vt-d: Remove the obsolete per iommu pasid tables

The obsolete per iommu pasid tables are no longer used. Hence,
clean up them.

Cc: Ashok Raj <[email protected]>
Cc: Jacob Pan <[email protected]>
Cc: Kevin Tian <[email protected]>
Cc: Liu Yi L <[email protected]>
Signed-off-by: Lu Baolu <[email protected]>
Reviewed-by: Liu Yi L <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>

Author: LuBaolu

drivers/iommu/intel-iommu.c

@@ -1756,7 +1756,7 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
 	if (pasid_enabled(iommu)) {
 		if (ecap_prs(iommu->ecap))
 			intel_svm_finish_prq(iommu);
-		intel_svm_free_pasid_tables(iommu);
+		intel_svm_exit(iommu);
 	}
 #endif
 }
@@ -3337,7 +3337,7 @@ static int __init init_dmars(void)
 			hw_pass_through = 0;
 #ifdef CONFIG_INTEL_IOMMU_SVM
 		if (pasid_enabled(iommu))
-			intel_svm_alloc_pasid_tables(iommu);
+			intel_svm_init(iommu);
 #endif
 	}
 
@@ -4300,7 +4300,7 @@ static int intel_iommu_add(struct dmar_drhd_unit *dmaru)
 
 #ifdef CONFIG_INTEL_IOMMU_SVM
 	if (pasid_enabled(iommu))
-		intel_svm_alloc_pasid_tables(iommu);
+		intel_svm_init(iommu);
 #endif
 
 	if (dmaru->ignored) {

drivers/iommu/intel-svm.c

@@ -38,7 +38,7 @@ struct pasid_state_entry {
 	u64 val;
 };
 
-int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
+int intel_svm_init(struct intel_iommu *iommu)
 {
 	struct page *pages;
 	int order;
@@ -63,15 +63,6 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
 		iommu->pasid_max = 0x20000;
 
 	order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max);
-	pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
-	if (!pages) {
-		pr_warn("IOMMU: %s: Failed to allocate PASID table\n",
-			iommu->name);
-		return -ENOMEM;
-	}
-	iommu->pasid_table = page_address(pages);
-	pr_info("%s: Allocated order %d PASID table.\n", iommu->name, order);
-
 	if (ecap_dis(iommu->ecap)) {
 		/* Just making it explicit... */
 		BUILD_BUG_ON(sizeof(struct pasid_entry) != sizeof(struct pasid_state_entry));
@@ -86,14 +77,10 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
 	return 0;
 }
 
-int intel_svm_free_pasid_tables(struct intel_iommu *iommu)
+int intel_svm_exit(struct intel_iommu *iommu)
 {
 	int order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max);
 
-	if (iommu->pasid_table) {
-		free_pages((unsigned long)iommu->pasid_table, order);
-		iommu->pasid_table = NULL;
-	}
 	if (iommu->pasid_state_table) {
 		free_pages((unsigned long)iommu->pasid_state_table, order);
 		iommu->pasid_state_table = NULL;

include/linux/intel-iommu.h

@@ -453,7 +453,6 @@ struct intel_iommu {
 	 * devices away to userspace processes (e.g. for DPDK) and don't
 	 * want to trust that userspace will use *only* the PASID it was
 	 * told to. But while it's all driver-arbitrated, we're fine. */
-	struct pasid_entry *pasid_table;
 	struct pasid_state_entry *pasid_state_table;
 	struct page_req_dsc *prq;
 	unsigned char prq_name[16];    /* Name for PRQ interrupt */
@@ -526,8 +525,8 @@ int for_each_device_domain(int (*fn)(struct device_domain_info *info,
 				     void *data), void *data);
 
 #ifdef CONFIG_INTEL_IOMMU_SVM
-extern int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu);
-extern int intel_svm_free_pasid_tables(struct intel_iommu *iommu);
+int intel_svm_init(struct intel_iommu *iommu);
+int intel_svm_exit(struct intel_iommu *iommu);
 extern int intel_svm_enable_prq(struct intel_iommu *iommu);
 extern int intel_svm_finish_prq(struct intel_iommu *iommu);