lib/interval_tree: add test case for interval_tree_iter_xxx() helpers

Verify interval_tree_iter_xxx() helpers could find intersection ranges
as expected.

[[email protected]: some of tools/ uses -Wno-unused-parameter]
  Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Wei Yang <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michel Lespinasse <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 20 insertions, 0 deletions

diff --git a/tools/lib/bitmap.c b/tools/lib/bitmap.c
index 2178862bb114..51255c69754d 100644
--- a/tools/lib/bitmap.c
+++ b/tools/lib/bitmap.c
@@ -101,6 +101,26 @@ bool __bitmap_intersects(const unsigned long *bitmap1,
 	return false;
 }
 
+void __bitmap_set(unsigned long *map, unsigned int start, int len)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const unsigned int size = start + len;
+	int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
+	unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
+
+	while (len - bits_to_set >= 0) {
+		*p |= mask_to_set;
+		len -= bits_to_set;
+		bits_to_set = BITS_PER_LONG;
+		mask_to_set = ~0UL;
+		p++;
+	}
+	if (len) {
+		mask_to_set &= BITMAP_LAST_WORD_MASK(size);
+		*p |= mask_to_set;
+	}
+}
+
 void __bitmap_clear(unsigned long *map, unsigned int start, int len)
 {
 	unsigned long *p = map + BIT_WORD(start);