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authorTony Lindgren <tony@atomide.com>2016-03-30 20:36:06 +0300
committerTony Lindgren <tony@atomide.com>2016-03-30 20:36:06 +0300
commit1809de7e7d37c585e01a1bcc583ea92b78fc759d (patch)
tree76c5b35c2b04eafce86a1a729c02ab705eba44bc /tools/testing/radix-tree/find_next_bit.c
parentebf24414809200915b9ddf7f109bba7c278c8210 (diff)
parent3ca4a238106dedc285193ee47f494a6584b6fd2f (diff)
downloadlinux-1809de7e7d37c585e01a1bcc583ea92b78fc759d.tar.xz
Merge tag 'for-v4.6-rc/omap-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v4.6/fixes
ARM: OMAP2+: first hwmod fix for v4.6-rc Fix a longstanding bug in the hwmod code that could cause hardware SYSCONFIG register values to not match the kernel's idea of what they should be, and that could result in lower performance during IP block idle entry. Basic build, boot, and PM test logs are available here: http://www.pwsan.com/omap/testlogs/omap-hwmod-fixes-a-for-v4.6-rc/20160326231727/
Diffstat (limited to 'tools/testing/radix-tree/find_next_bit.c')
-rw-r--r--tools/testing/radix-tree/find_next_bit.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/tools/testing/radix-tree/find_next_bit.c b/tools/testing/radix-tree/find_next_bit.c
new file mode 100644
index 000000000000..d1c2178bb2d4
--- /dev/null
+++ b/tools/testing/radix-tree/find_next_bit.c
@@ -0,0 +1,57 @@
+/* find_next_bit.c: fallback find next bit implementation
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/types.h>
+#include <linux/bitops.h>
+
+#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
+
+/*
+ * Find the next set bit in a memory region.
+ */
+unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
+ unsigned long offset)
+{
+ const unsigned long *p = addr + BITOP_WORD(offset);
+ unsigned long result = offset & ~(BITS_PER_LONG-1);
+ unsigned long tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset %= BITS_PER_LONG;
+ if (offset) {
+ tmp = *(p++);
+ tmp &= (~0UL << offset);
+ if (size < BITS_PER_LONG)
+ goto found_first;
+ if (tmp)
+ goto found_middle;
+ size -= BITS_PER_LONG;
+ result += BITS_PER_LONG;
+ }
+ while (size & ~(BITS_PER_LONG-1)) {
+ if ((tmp = *(p++)))
+ goto found_middle;
+ result += BITS_PER_LONG;
+ size -= BITS_PER_LONG;
+ }
+ if (!size)
+ return result;
+ tmp = *p;
+
+found_first:
+ tmp &= (~0UL >> (BITS_PER_LONG - size));
+ if (tmp == 0UL) /* Are any bits set? */
+ return result + size; /* Nope. */
+found_middle:
+ return result + __ffs(tmp);
+}