Implement pud_free_pmd_page() and pmd_free_pte_page() on x86, which
clear a given pud/pmd entry and free up lower level page table(s).
Address range associated with the pud/pmd entry must have been purged
by INVLPG.

Signed-off-by: Toshi Kani <toshi.k...@hpe.com>
Cc: Michal Hocko <mho...@suse.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: Borislav Petkov <b...@suse.de>
---
 arch/x86/mm/pgtable.c |   28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 942f4fa341f1..121c0114439e 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -710,7 +710,22 @@ int pmd_clear_huge(pmd_t *pmd)
  */
 int pud_free_pmd_page(pud_t *pud)
 {
-       return pud_none(*pud);
+       pmd_t *pmd;
+       int i;
+
+       if (pud_none(*pud))
+               return 1;
+
+       pmd = (pmd_t *)pud_page_vaddr(*pud);
+
+       for (i = 0; i < PTRS_PER_PMD; i++)
+               if (!pmd_free_pte_page(&pmd[i]))
+                       return 0;
+
+       pud_clear(pud);
+       free_page((unsigned long)pmd);
+
+       return 1;
 }
 
 /**
@@ -720,6 +735,15 @@ int pud_free_pmd_page(pud_t *pud)
  */
 int pmd_free_pte_page(pmd_t *pmd)
 {
-       return pmd_none(*pmd);
+       pte_t *pte;
+
+       if (pmd_none(*pmd))
+               return 1;
+
+       pte = (pte_t *)pmd_page_vaddr(*pmd);
+       pmd_clear(pmd);
+       free_page((unsigned long)pte);
+
+       return 1;
 }
 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */

Reply via email to