powerpc: remove mmap linked list walks

Use the VMA iterator instead.

Link: https://lkml.kernel.org/r/20220906194824.2110408-34-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/powerpc/kernel/vdso.c

@@ -113,18 +113,18 @@ struct vdso_data *arch_get_vdso_data(void *vvar_page)
 int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
 {
 	struct mm_struct *mm = task->mm;
+	VMA_ITERATOR(vmi, mm, 0);
 	struct vm_area_struct *vma;
 
 	mmap_read_lock(mm);
-
-	for (vma = mm->mmap; vma; vma = vma->vm_next) {
+	for_each_vma(vmi, vma) {
 		unsigned long size = vma->vm_end - vma->vm_start;
 
 		if (vma_is_special_mapping(vma, &vvar_spec))
 			zap_page_range(vma, vma->vm_start, size);
 	}
-
 	mmap_read_unlock(mm);
+
 	return 0;
 }
 

arch/powerpc/mm/book3s32/tlb.c

@@ -81,14 +81,15 @@ EXPORT_SYMBOL(hash__flush_range);
 void hash__flush_tlb_mm(struct mm_struct *mm)
 {
 	struct vm_area_struct *mp;
+	VMA_ITERATOR(vmi, mm, 0);
 
 	/*
-	 * It is safe to go down the mm's list of vmas when called
-	 * from dup_mmap, holding mmap_lock.  It would also be safe from
-	 * unmap_region or exit_mmap, but not from vmtruncate on SMP -
-	 * but it seems dup_mmap is the only SMP case which gets here.
+	 * It is safe to iterate the vmas when called from dup_mmap,
+	 * holding mmap_lock.  It would also be safe from unmap_region
+	 * or exit_mmap, but not from vmtruncate on SMP - but it seems
+	 * dup_mmap is the only SMP case which gets here.
 	 */
-	for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
+	for_each_vma(vmi, mp)
 		hash__flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
 }
 EXPORT_SYMBOL(hash__flush_tlb_mm);

arch/powerpc/mm/book3s64/subpage_prot.c

@@ -149,24 +149,15 @@ static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr,
 				    unsigned long len)
 {
 	struct vm_area_struct *vma;
+	VMA_ITERATOR(vmi, mm, addr);
 
 	/*
 	 * 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;
+	for_each_vma_range(vmi, vma, addr + len) {
 		vma->vm_flags |= VM_NOHUGEPAGE;
 		walk_page_vma(vma, &subpage_walk_ops, NULL);
-		vma = vma->vm_next;
 	}
 }
 #else