[PATCH v1 04/16] mm/memory: simplify calculation in unmap_mapping_range_tree()

David Hildenbrand (Arm)
2026-02-27T20:10:20Z

Let's simplify the calculation a bit further to make it easier to get,
reusing vma_last_pgoff() which we move from interval_tree.c to mm.h.

Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
---
include/linux/mm.h | 5 +++++
mm/interval_tree.c | 5 -----
mm/memory.c | 12 +++++-------
3 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a8138ff7d1fa..d3ef586ee1c0 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -4000,6 +4000,11 @@ static inline unsigned long vma_pages(const struct vm_area_struct *vma)
return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
}

+static inline unsigned long vma_last_pgoff(struct vm_area_struct *vma)
+{
+ return vma->vm_pgoff + vma_pages(vma) - 1;
+}
+
static inline unsigned long vma_desc_size(const struct vm_area_desc *desc)
{
return desc->end - desc->start;
diff --git a/mm/interval_tree.c b/mm/interval_tree.c
index 32e390c42c53..32bcfbfcf15f 100644
--- a/mm/interval_tree.c
+++ b/mm/interval_tree.c
@@ -15,11 +15,6 @@ static inline unsigned long vma_start_pgoff(struct vm_area_struct *v)
return v->vm_pgoff;
}

-static inline unsigned long vma_last_pgoff(struct vm_area_struct *v)
-{
- return v->vm_pgoff + vma_pages(v) - 1;
-}
-
INTERVAL_TREE_DEFINE(struct vm_area_struct, shared.rb,
unsigned long, shared.rb_subtree_last,
vma_start_pgoff, vma_last_pgoff, /* empty */, vma_interval_tree)
diff --git a/mm/memory.c b/mm/memory.c
index 5c47309331f5..e4154f03feac 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4227,17 +4227,15 @@ static inline void unmap_mapping_range_tree(struct rb_root_cached *root,
struct zap_details *details)
{
struct vm_area_struct *vma;
- pgoff_t vba, vea, zba, zea;
unsigned long start, size;
struct mmu_gather tlb;

vma_interval_tree_foreach(vma, root, first_index, last_index) {
- vba = vma->vm_pgoff;
- vea = vba + vma_pages(vma) - 1;
- zba = max(first_index, vba);
- zea = min(last_index, vea);
- start = ((zba - vba) << PAGE_SHIFT) + vma->vm_start;
- size = (zea - zba + 1) << PAGE_SHIFT;
+ const pgoff_t start_idx = max(first_index, vma->vm_pgoff);
+ const pgoff_t end_idx = min(last_index, vma_last_pgoff(vma)) + 1;
+
+ start = vma->vm_start + ((start_idx - vma->vm_pgoff) << PAGE_SHIFT);
+ size = (end_idx - start_idx) << PAGE_SHIFT;

tlb_gather_mmu(&tlb, vma->vm_mm);
zap_page_range_single_batched(&tlb, vma, start, size, details);
--
2.43.0