iommu/amd: Remove conditions from domain free paths

Don't use tlb as some flag to indicate if protection_domain_alloc()
completed. Have protection_domain_alloc() unwind itself in the normal
kernel style and require protection_domain_free() only be called on
successful results of protection_domain_alloc().

Also, the amd_iommu_domain_free() op is never called by the core code with
a NULL argument, so remove all the NULL tests as well.
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/10-v2-831cdc4d00f3+1a315-amd_iopgtbl_jgg@nvidia.comSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd/iommu.c

@@ -2253,17 +2253,9 @@ static void cleanup_domain(struct protection_domain *domain)
 
 void protection_domain_free(struct protection_domain *domain)
 {
-	if (!domain)
-		return;
-
 	WARN_ON(!list_empty(&domain->dev_list));
-
-	if (domain->iop.pgtbl.cfg.tlb)
-		free_io_pgtable_ops(&domain->iop.pgtbl.ops);
-
-	if (domain->id)
-		domain_id_free(domain->id);
-
+	free_io_pgtable_ops(&domain->iop.pgtbl.ops);
+	domain_id_free(domain->id);
 	kfree(domain);
 }
 
@@ -2279,7 +2271,7 @@ struct protection_domain *protection_domain_alloc(unsigned int type, int nid)
 
 	domain->id = domain_id_alloc();
 	if (!domain->id)
-		goto out_err;
+		goto err_free;
 
 	spin_lock_init(&domain->lock);
 	INIT_LIST_HEAD(&domain->dev_list);
@@ -2302,7 +2294,7 @@ struct protection_domain *protection_domain_alloc(unsigned int type, int nid)
 		pgtable = AMD_IOMMU_V1;
 		break;
 	default:
-		goto out_err;
+		goto err_id;
 	}
 
 	switch (pgtable) {
@@ -2313,17 +2305,19 @@ struct protection_domain *protection_domain_alloc(unsigned int type, int nid)
 		domain->pd_mode = PD_MODE_V2;
 		break;
 	default:
-		goto out_err;
+		goto err_id;
 	}
 
 	pgtbl_ops =
 		alloc_io_pgtable_ops(pgtable, &domain->iop.pgtbl.cfg, domain);
 	if (!pgtbl_ops)
-		goto out_err;
+		goto err_id;
 
 	return domain;
-out_err:
-	protection_domain_free(domain);
+err_id:
+	domain_id_free(domain->id);
+err_free:
+	kfree(domain);
 	return NULL;
 }
 
@@ -2412,9 +2406,6 @@ void amd_iommu_domain_free(struct iommu_domain *dom)
 	struct protection_domain *domain;
 	unsigned long flags;
 
-	if (!dom)
-		return;
-
 	domain = to_pdomain(dom);
 
 	spin_lock_irqsave(&domain->lock, flags);