lib: bitmap: add alignment offset for bitmap_find_next_zero_area()

[cascardo/linux.git] / lib / bitmap.c

diff --git a/lib/bitmap.c b/lib/bitmap.c
index b499ab6..969ae8f 100644 (file)
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -326,30 +326,32 @@ void bitmap_clear(unsigned long *map, unsigned int start, int len)
 }
 EXPORT_SYMBOL(bitmap_clear);
 
-/*
- * bitmap_find_next_zero_area - find a contiguous aligned zero area
+/**
+ * bitmap_find_next_zero_area_off - find a contiguous aligned zero area
  * @map: The address to base the search on
  * @size: The bitmap size in bits
  * @start: The bitnumber to start searching at
  * @nr: The number of zeroed bits we're looking for
  * @align_mask: Alignment mask for zero area
+ * @align_offset: Alignment offset for zero area.
  *
  * The @align_mask should be one less than a power of 2; the effect is that
- * the bit offset of all zero areas this function finds is multiples of that
- * power of 2. A @align_mask of 0 means no alignment is required.
+ * the bit offset of all zero areas this function finds plus @align_offset
+ * is multiple of that power of 2.
  */
-unsigned long bitmap_find_next_zero_area(unsigned long *map,
-                                        unsigned long size,
-                                        unsigned long start,
-                                        unsigned int nr,
-                                        unsigned long align_mask)
+unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
+                                            unsigned long size,
+                                            unsigned long start,
+                                            unsigned int nr,
+                                            unsigned long align_mask,
+                                            unsigned long align_offset)
 {
        unsigned long index, end, i;
 again:
        index = find_next_zero_bit(map, size, start);
 
        /* Align allocation */
-       index = __ALIGN_MASK(index, align_mask);
+       index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
 
        end = index + nr;
        if (end > size)
@@ -361,7 +363,7 @@ again:
        }
        return index;
 }
-EXPORT_SYMBOL(bitmap_find_next_zero_area);
+EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
 
 /*
  * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,