summaryrefslogtreecommitdiffstats
path: root/kernel/include/asm-generic/bitops/sched.h
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/include/asm-generic/bitops/sched.h')
-rw-r--r--kernel/include/asm-generic/bitops/sched.h31
1 files changed, 31 insertions, 0 deletions
diff --git a/kernel/include/asm-generic/bitops/sched.h b/kernel/include/asm-generic/bitops/sched.h
new file mode 100644
index 000000000..604fab703
--- /dev/null
+++ b/kernel/include/asm-generic/bitops/sched.h
@@ -0,0 +1,31 @@
+#ifndef _ASM_GENERIC_BITOPS_SCHED_H_
+#define _ASM_GENERIC_BITOPS_SCHED_H_
+
+#include <linux/compiler.h> /* unlikely() */
+#include <asm/types.h>
+
+/*
+ * Every architecture must define this function. It's the fastest
+ * way of searching a 100-bit bitmap. It's guaranteed that at least
+ * one of the 100 bits is cleared.
+ */
+static inline int sched_find_first_bit(const unsigned long *b)
+{
+#if BITS_PER_LONG == 64
+ if (b[0])
+ return __ffs(b[0]);
+ return __ffs(b[1]) + 64;
+#elif BITS_PER_LONG == 32
+ if (b[0])
+ return __ffs(b[0]);
+ if (b[1])
+ return __ffs(b[1]) + 32;
+ if (b[2])
+ return __ffs(b[2]) + 64;
+ return __ffs(b[3]) + 96;
+#else
+#error BITS_PER_LONG not defined
+#endif
+}
+
+#endif /* _ASM_GENERIC_BITOPS_SCHED_H_ */