iommu/amd: Introduce free_sub_pt() function

The function is a more generic version of free_pagetable()
and will be used to free only specific sub-trees of a
page-table.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 2655bd9..1186571 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1367,12 +1367,10 @@ DEFINE_FREE_PT_FN(l4, free_pt_l3)
 DEFINE_FREE_PT_FN(l5, free_pt_l4)
 DEFINE_FREE_PT_FN(l6, free_pt_l5)
 
-static void free_pagetable(struct protection_domain *domain)
+static struct page *free_sub_pt(unsigned long root, int mode,
+                               struct page *freelist)
 {
-       unsigned long root = (unsigned long)domain->pt_root;
-       struct page *freelist = NULL;
-
-       switch (domain->mode) {
+       switch (mode) {
        case PAGE_MODE_NONE:
                break;
        case PAGE_MODE_1_LEVEL:
@@ -1397,6 +1395,16 @@ static void free_pagetable(struct protection_domain *domain)
                BUG();
        }
 
+       return freelist;
+}
+
+static void free_pagetable(struct protection_domain *domain)
+{
+       unsigned long root = (unsigned long)domain->pt_root;
+       struct page *freelist = NULL;
+
+       free_sub_pt(root, domain->mode, freelist);
+
        free_page_list(freelist);
 }