# \[PATCH v6 05/12\] bitmap: Add bitmap\_allocate() function

- From: Thierry Reding \<thierry.reding@kernel.org\>
- Date: 2026-09-04 10:45:35 
- List: linux-trace-kernel
- Page: https://ratatoskr.run/linux-trace-kernel/2026/09/17512974
- Thread: https://ratatoskr.run/linux-devicetree/2026/09/17512969/t.md

```text
From: Thierry Reding <redacted>

This is similar to bitmap_allocate_region() but allows allocation of
non-power of two pages/bits.

While at it, reimplement bitmap_allocate_region() in terms of this new
helper to remove a sliver of code duplication.

Signed-off-by: Thierry Reding <redacted>
---
 include/linux/bitmap.h | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 7df1573a409c..c2ab02985b5f 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -716,10 +716,10 @@ void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
 }
 
 /**
- * bitmap_allocate_region - allocate bitmap region
+ * bitmap_allocate - allocate bitmap region
  *	@bitmap: array of unsigned longs corresponding to the bitmap
  *	@pos: beginning of bit region to allocate
- *	@order: region size (log base 2 of number of bits) to allocate
+ *	@len: number of bits to allocate
  *
  * Allocate (set bits in) a specified region of a bitmap.
  *
@@ -727,16 +727,31 @@ void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
  * free (not all bits were zero).
  */
 static __always_inline
-int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
+int bitmap_allocate(unsigned long *bitmap, unsigned int pos, unsigned int len)
 {
-	unsigned int len = BIT(order);
-
 	if (find_next_bit(bitmap, pos + len, pos) < pos + len)
 		return -EBUSY;
 	bitmap_set(bitmap, pos, len);
 	return 0;
 }
 
+/**
+ * bitmap_allocate_region - allocate bitmap region
+ *	@bitmap: array of unsigned longs corresponding to the bitmap
+ *	@pos: beginning of bit region to allocate
+ *	@order: region size (log base 2 of number of bits) to allocate
+ *
+ * Allocate (set bits in) a specified region of a bitmap.
+ *
+ * Returns: 0 on success, or %-EBUSY if specified region wasn't
+ * free (not all bits were zero).
+ */
+static __always_inline
+int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
+{
+	return bitmap_allocate(bitmap, pos, BIT(order));
+}
+
 /**
  * bitmap_find_free_region - find a contiguous aligned mem region
  *	@bitmap: array of unsigned longs corresponding to the bitmap

-- 
2.55.0

```