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-rw-r--r--include/asm-generic/bitops/sched.h32
1 files changed, 32 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/sched.h b/include/asm-generic/bitops/sched.h
new file mode 100644
index 000000000..86470cfce
--- /dev/null
+++ b/include/asm-generic/bitops/sched.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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_ */