iommu/amd: Move allocation of the top table into v1_alloc_pgtable

All the page table memory should be allocated/free within the io_pgtable
struct. The v2 path is already doing this, make it consistent.

It is hard to see but the free of the root in protection_domain_free() is
a NOP on the success path because v1_free_pgtable() does
amd_iommu_domain_clr_pt_root().

The root memory is already freed because free_sub_pt() put it on the
freelist. The free path in protection_domain_free() is only used during
error unwind of protection_domain_alloc().
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v2-831cdc4d00f3+1a315-amd_iopgtbl_jgg@nvidia.comSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd/io_pgtable.c

@@ -573,20 +573,24 @@ static void v1_free_pgtable(struct io_pgtable *iop)
 	       pgtable->mode > PAGE_MODE_6_LEVEL);
 
 	free_sub_pt(pgtable->root, pgtable->mode, &freelist);
+	iommu_put_pages_list(&freelist);
 
 	/* Update data structure */
 	amd_iommu_domain_clr_pt_root(dom);
 
 	/* Make changes visible to IOMMUs */
 	amd_iommu_domain_update(dom);
-
-	iommu_put_pages_list(&freelist);
 }
 
 static struct io_pgtable *v1_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
 {
 	struct amd_io_pgtable *pgtable = io_pgtable_cfg_to_data(cfg);
 
+	pgtable->root = iommu_alloc_page(GFP_KERNEL);
+	if (!pgtable->root)
+		return NULL;
+	pgtable->mode = PAGE_MODE_3_LEVEL;
+
 	cfg->pgsize_bitmap  = AMD_IOMMU_PGSIZES;
 	cfg->ias            = IOMMU_IN_ADDR_BIT_SIZE;
 	cfg->oas            = IOMMU_OUT_ADDR_BIT_SIZE;

drivers/iommu/amd/iommu.c

@@ -52,8 +52,6 @@
 #define HT_RANGE_START		(0xfd00000000ULL)
 #define HT_RANGE_END		(0xffffffffffULL)
 
-#define DEFAULT_PGTABLE_LEVEL	PAGE_MODE_3_LEVEL
-
 static DEFINE_SPINLOCK(pd_bitmap_lock);
 
 LIST_HEAD(ioapic_map);
@@ -2260,30 +2258,15 @@ void protection_domain_free(struct protection_domain *domain)
 	if (domain->iop.pgtbl_cfg.tlb)
 		free_io_pgtable_ops(&domain->iop.iop.ops);
 
-	if (domain->iop.root)
-		iommu_free_page(domain->iop.root);
-
 	if (domain->id)
 		domain_id_free(domain->id);
 
 	kfree(domain);
 }
 
-static int protection_domain_init_v1(struct protection_domain *domain, int mode)
+static int protection_domain_init_v1(struct protection_domain *domain)
 {
-	u64 *pt_root = NULL;
-
-	BUG_ON(mode < PAGE_MODE_NONE || mode > PAGE_MODE_6_LEVEL);
-
-	if (mode != PAGE_MODE_NONE) {
-		pt_root = iommu_alloc_page(GFP_KERNEL);
-		if (!pt_root)
-			return -ENOMEM;
-	}
-
 	domain->pd_mode = PD_MODE_V1;
-	amd_iommu_domain_set_pgtable(domain, pt_root, mode);
-
 	return 0;
 }
 
@@ -2336,7 +2319,7 @@ struct protection_domain *protection_domain_alloc(unsigned int type)
 
 	switch (pgtable) {
 	case AMD_IOMMU_V1:
-		ret = protection_domain_init_v1(domain, DEFAULT_PGTABLE_LEVEL);
+		ret = protection_domain_init_v1(domain);
 		break;
 	case AMD_IOMMU_V2:
 		ret = protection_domain_init_v2(domain);