linux-kernel - [PATCH v14 33/70] powerpc: remove mmap linked list walks

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Date:   Tue, 6 Sep 2022 19:48:53 +0000
From:   Liam Howlett <liam.howlett@...cle.com>
To:     "maple-tree@...ts.infradead.org" <maple-tree@...ts.infradead.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Andrew Morton <akpm@...ux-foundation.org>
CC:     "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Christophe Leroy <christophe.leroy@...roup.eu>,
        Liam Howlett <liam.howlett@...cle.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Davidlohr Bueso <dave@...olabs.net>
Subject: [PATCH v14 33/70] powerpc: remove mmap linked list walks

From: "Matthew Wilcox (Oracle)" <willy@...radead.org>

Use the VMA iterator instead.

Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@...cle.com>
Reviewed-by: Vlastimil Babka <vbabka@...e.cz>
Reviewed-by: Davidlohr Bueso <dave@...olabs.net>
---
 arch/powerpc/kernel/vdso.c              |  6 +++---
 arch/powerpc/mm/book3s32/tlb.c          | 11 ++++++-----
 arch/powerpc/mm/book3s64/subpage_prot.c | 13 ++-----------
 3 files changed, 11 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 0da287544054..94a8fa5017c3 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/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;
 }
 
diff --git a/arch/powerpc/mm/book3s32/tlb.c b/arch/powerpc/mm/book3s32/tlb.c
index 19f0ef950d77..9ad6b56bfec9 100644
--- a/arch/powerpc/mm/book3s32/tlb.c
+++ b/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);
diff --git a/arch/powerpc/mm/book3s64/subpage_prot.c b/arch/powerpc/mm/book3s64/subpage_prot.c
index 60c6ea16a972..d73b3b4176e8 100644
--- a/arch/powerpc/mm/book3s64/subpage_prot.c
+++ b/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
-- 
2.35.1