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authorJani Nikula <jani.nikula@intel.com>2018-11-20 13:14:08 +0200
committerJani Nikula <jani.nikula@intel.com>2018-11-20 13:14:08 +0200
commit2ac5e38ea4203852d6e99edd3cf11f044b0a409f (patch)
tree1ef02da98d56309368ad2b6a4e492bafe5bb4faf /tools/testing/radix-tree/bitmap.c
parentf48cc647f3e196a3179d695d3c2d56c13e9dec98 (diff)
parent9235dd441af43599b9cdcce599a3da4083fcad3c (diff)
Merge drm/drm-next into drm-intel-next-queued
Pull in v4.20-rc3 via drm-next. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'tools/testing/radix-tree/bitmap.c')
-rw-r--r--tools/testing/radix-tree/bitmap.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/tools/testing/radix-tree/bitmap.c b/tools/testing/radix-tree/bitmap.c
new file mode 100644
index 000000000000..66ec4a24a203
--- /dev/null
+++ b/tools/testing/radix-tree/bitmap.c
@@ -0,0 +1,23 @@
+/* lib/bitmap.c pulls in at least two other files. */
+
+#include <linux/bitmap.h>
+
+void bitmap_clear(unsigned long *map, unsigned int start, int len)
+{
+ unsigned long *p = map + BIT_WORD(start);
+ const unsigned int size = start + len;
+ int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
+ unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
+
+ while (len - bits_to_clear >= 0) {
+ *p &= ~mask_to_clear;
+ len -= bits_to_clear;
+ bits_to_clear = BITS_PER_LONG;
+ mask_to_clear = ~0UL;
+ p++;
+ }
+ if (len) {
+ mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
+ *p &= ~mask_to_clear;
+ }
+}