[PATCH v6 05/12] bitmap: Add bitmap_allocate() function
From: Thierry Reding <thierry.reding@kernel.org>
Date: 2026-09-04 10:45:35
Also in:
dri-devel, linux-devicetree, linux-iommu, linux-media, linux-mm, linux-s390, linux-tegra, lkml
Subsystem:
bitmap api, the rest · Maintainers:
Yury Norov, Linus Torvalds
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
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2.55.0