[PATCH v2 1/9] mm: vmalloc: Add va_alloc() helper

From: Uladzislau Rezki (Sony)
Date: Tue Aug 29 2023 - 04:12:41 EST


Currently __alloc_vmap_area() function contains an open codded
logic that finds and adjusts a VA based on allocation request.

Introduce a va_alloc() helper that adjusts found VA only. It
will be used later at least in two places.

There is no a functional change as a result of this patch.

Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
---
mm/vmalloc.c | 41 ++++++++++++++++++++++++++++-------------
1 file changed, 28 insertions(+), 13 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 93cf99aba335..00afc1ee4756 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1481,6 +1481,32 @@ adjust_va_to_fit_type(struct rb_root *root, struct list_head *head,
return 0;
}

+static unsigned long
+va_alloc(struct vmap_area *va,
+ struct rb_root *root, struct list_head *head,
+ unsigned long size, unsigned long align,
+ unsigned long vstart, unsigned long vend)
+{
+ unsigned long nva_start_addr;
+ int ret;
+
+ if (va->va_start > vstart)
+ nva_start_addr = ALIGN(va->va_start, align);
+ else
+ nva_start_addr = ALIGN(vstart, align);
+
+ /* Check the "vend" restriction. */
+ if (nva_start_addr + size > vend)
+ return vend;
+
+ /* Update the free vmap_area. */
+ ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
+ if (WARN_ON_ONCE(ret))
+ return vend;
+
+ return nva_start_addr;
+}
+
/*
* Returns a start address of the newly allocated area, if success.
* Otherwise a vend is returned that indicates failure.
@@ -1493,7 +1519,6 @@ __alloc_vmap_area(struct rb_root *root, struct list_head *head,
bool adjust_search_size = true;
unsigned long nva_start_addr;
struct vmap_area *va;
- int ret;

/*
* Do not adjust when:
@@ -1511,18 +1536,8 @@ __alloc_vmap_area(struct rb_root *root, struct list_head *head,
if (unlikely(!va))
return vend;

- if (va->va_start > vstart)
- nva_start_addr = ALIGN(va->va_start, align);
- else
- nva_start_addr = ALIGN(vstart, align);
-
- /* Check the "vend" restriction. */
- if (nva_start_addr + size > vend)
- return vend;
-
- /* Update the free vmap_area. */
- ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
- if (WARN_ON_ONCE(ret))
+ nva_start_addr = va_alloc(va, root, head, size, align, vstart, vend);
+ if (nva_start_addr == vend)
return vend;

#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
--
2.30.2