bitmap: move bitmap_*_region() functions to bitmap.h

Now that bitmap_*_region() functions are implemented as thin wrappers
around others, it's worth to move them to the header, as it opens room
for compile-time optimizations.

CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: Rasmus Villemoes <linux@rasmusvillemoes.dk>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

1 files changed, 61 insertions, 3 deletions

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 1cca950a54ae..99451431e4d6 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -6,6 +6,7 @@
 
 #include <linux/align.h>
 #include <linux/bitops.h>
+#include <linux/errno.h>
 #include <linux/find.h>
 #include <linux/limits.h>
 #include <linux/string.h>
@@ -209,9 +210,6 @@ void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 		const unsigned long *relmap, unsigned int bits);
 void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 		unsigned int sz, unsigned int nbits);
-int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
-void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
-int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
 
 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
@@ -498,6 +496,66 @@ static inline void bitmap_next_set_region(unsigned long *bitmap,
 }
 
 /**
+ * bitmap_release_region - release allocated bitmap region
+ *	@bitmap: array of unsigned longs corresponding to the bitmap
+ *	@pos: beginning of bit region to release
+ *	@order: region size (log base 2 of number of bits) to release
+ *
+ * This is the complement to __bitmap_find_free_region() and releases
+ * the found region (by clearing it in the bitmap).
+ */
+static inline void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
+{
+	bitmap_clear(bitmap, pos, BIT(order));
+}
+
+/**
+ * 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 inline int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
+{
+	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_find_free_region - find a contiguous aligned mem region
+ *	@bitmap: array of unsigned longs corresponding to the bitmap
+ *	@bits: number of bits in the bitmap
+ *	@order: region size (log base 2 of number of bits) to find
+ *
+ * Find a region of free (zero) bits in a @bitmap of @bits bits and
+ * allocate them (set them to one).  Only consider regions of length
+ * a power (@order) of two, aligned to that power of two, which
+ * makes the search algorithm much faster.
+ *
+ * Returns: the bit offset in bitmap of the allocated region,
+ * or -errno on failure.
+ */
+static inline int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
+{
+	unsigned int pos, end;		/* scans bitmap by regions of size order */
+
+	for (pos = 0; (end = pos + BIT(order)) <= bits; pos = end) {
+		if (!bitmap_allocate_region(bitmap, pos, order))
+			return pos;
+	}
+	return -ENOMEM;
+}
+
+/**
  * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
  * @n: u64 value
  *