Simple bitops for the new x86 setup code.

A simple collection of bitops for the new x86 setup code.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/arch/i386/boot/bitops.h b/arch/i386/boot/bitops.h
new file mode 100644
index 00000000000..8dcc8dc7db8
--- /dev/null
+++ b/arch/i386/boot/bitops.h
@@ -0,0 +1,45 @@
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ *   This file is part of the Linux kernel, and is made available under
+ *   the terms of the GNU General Public License version 2.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * arch/i386/boot/bitops.h
+ *
+ * Very simple bitops for the boot code.
+ */
+
+#ifndef BOOT_BITOPS_H
+#define BOOT_BITOPS_H
+#define _LINUX_BITOPS_H         /* Inhibit inclusion of <linux/bitops.h> */
+
+static inline int constant_test_bit(int nr, const void *addr)
+{
+        const u32 *p = (const u32 *)addr;
+        return ((1UL << (nr & 31)) & (p[nr >> 5])) != 0;
+}
+static inline int variable_test_bit(int nr, const void *addr)
+{
+        u8 v;
+        const u32 *p = (const u32 *)addr;
+
+        asm("btl %2,%1; setc %0" : "=qm" (v) : "m" (*p), "Ir" (nr));
+        return v;
+}
+
+#define test_bit(nr,addr) \
+(__builtin_constant_p(nr) ? \
+ constant_test_bit((nr),(addr)) : \
+ variable_test_bit((nr),(addr)))
+
+static inline void set_bit(int nr, void *addr)
+{
+        asm("btsl %1,%0" : "+m" (*(u32 *)addr) : "Ir" (nr));
+}
+
+#endif /* BOOT_BITOPS_H */