1 files changed, 48 insertions, 0 deletions

diff --git a/arch/powerpc/mm/subpage-prot.c b/arch/powerpc/mm/subpage-prot.c
index 7c415ddde948..aa74acb0fdfc 100644
--- a/arch/powerpc/mm/subpage-prot.c
+++ b/arch/powerpc/mm/subpage-prot.c
@@ -130,6 +130,53 @@ static void subpage_prot_clear(unsigned long addr, unsigned long len)
         up_write(&mm->mmap_sem);
 }
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static int subpage_walk_pmd_entry(pmd_t *pmd, unsigned long addr,
+                                  unsigned long end, struct mm_walk *walk)
+{
+        struct vm_area_struct *vma = walk->private;
+        split_huge_page_pmd(vma, addr, pmd);
+        return 0;
+}
+
+static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr,
+                                    unsigned long len)
+{
+        struct vm_area_struct *vma;
+        struct mm_walk subpage_proto_walk = {
+                .mm = mm,
+                .pmd_entry = subpage_walk_pmd_entry,
+        };
+
+        /*
+         * We don't try too hard, we just mark all the vma in that range
+         * VM_NOHUGEPAGE and split them.
+         */
+        vma = find_vma(mm, addr);
+        /*
+         * If the range is in unmapped range, just return
+         */
+        if (vma && ((addr + len) <= vma->vm_start))
+                return;
+
+        while (vma) {
+                if (vma->vm_start >= (addr + len))
+                        break;
+                vma->vm_flags |= VM_NOHUGEPAGE;
+                subpage_proto_walk.private = vma;
+                walk_page_range(vma->vm_start, vma->vm_end,
+                                &subpage_proto_walk);
+                vma = vma->vm_next;
+        }
+}
+#else
+static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr,
+                                    unsigned long len)
+{
+        return;
+}
+#endif
+
 /*
  * Copy in a subpage protection map for an address range.
  * The map has 2 bits per 4k subpage, so 32 bits per 64k page.
@@ -168,6 +215,7 @@ long sys_subpage_prot(unsigned long addr, unsigned long len, u32 __user *map)
                 return -EFAULT;
 
         down_write(&mm->mmap_sem);
+        subpage_mark_vma_nohuge(mm, addr, len);
         for (limit = addr + len; addr < limit; addr = next) {
                 next = pmd_addr_end(addr, limit);
                 err = -ENOMEM;