aboutsummaryrefslogtreecommitdiff
path: root/include/asm-generic/bitops/sched.h
diff options
context:
space:
mode:
authorDmitry Torokhov <dtor_core@ameritech.net>2006-04-02 00:08:05 -0500
committerDmitry Torokhov <dtor_core@ameritech.net>2006-04-02 00:08:05 -0500
commit95d465fd750897ab32462a6702fbfe1b122cbbc0 (patch)
tree65c38b2f11c51bb6932e44dd6c92f15b0091abfe /include/asm-generic/bitops/sched.h
parent642fde17dceceb56c7ba2762733ac688666ae657 (diff)
parent683aa4012f53b2ada0f430487e05d37b0d94e90a (diff)
Manual merge with Linus.
Conflicts: arch/powerpc/kernel/setup-common.c drivers/input/keyboard/hil_kbd.c drivers/input/mouse/hil_ptr.c
Diffstat (limited to 'include/asm-generic/bitops/sched.h')
-rw-r--r--include/asm-generic/bitops/sched.h36
1 files changed, 36 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/sched.h b/include/asm-generic/bitops/sched.h
new file mode 100644
index 00000000000..5ef93a4d009
--- /dev/null
+++ b/include/asm-generic/bitops/sched.h
@@ -0,0 +1,36 @@
+#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 140-bit bitmap where the first 100 bits are
+ * unlikely to be set. It's guaranteed that at least one of the 140
+ * bits is cleared.
+ */
+static inline int sched_find_first_bit(const unsigned long *b)
+{
+#if BITS_PER_LONG == 64
+ if (unlikely(b[0]))
+ return __ffs(b[0]);
+ if (unlikely(b[1]))
+ return __ffs(b[1]) + 64;
+ return __ffs(b[2]) + 128;
+#elif BITS_PER_LONG == 32
+ if (unlikely(b[0]))
+ return __ffs(b[0]);
+ if (unlikely(b[1]))
+ return __ffs(b[1]) + 32;
+ if (unlikely(b[2]))
+ return __ffs(b[2]) + 64;
+ if (b[3])
+ return __ffs(b[3]) + 96;
+ return __ffs(b[4]) + 128;
+#else
+#error BITS_PER_LONG not defined
+#endif
+}
+
+#endif /* _ASM_GENERIC_BITOPS_SCHED_H_ */