[U-Boot] [PATCH v3 2/5] linux/const.h: import from kernel
Baruch Siach
baruch at tkos.co.il
Thu Nov 8 12:24:11 UTC 2018
Combine the uapi/linux/const.h header into the kernel linux/const.h. The
next commit will use the _AC macro this header instead of the common.h
definition.
Signed-off-by: Baruch Siach <baruch at tkos.co.il>
---
v3: New patch in this series
---
include/linux/const.h | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)
create mode 100644 include/linux/const.h
diff --git a/include/linux/const.h b/include/linux/const.h
new file mode 100644
index 000000000000..379c88923269
--- /dev/null
+++ b/include/linux/const.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _LINUX_CONST_H
+#define _LINUX_CONST_H
+
+/* const.h: Macros for dealing with constants. */
+
+/* Some constant macros are used in both assembler and
+ * C code. Therefore we cannot annotate them always with
+ * 'UL' and other type specifiers unilaterally. We
+ * use the following macros to deal with this.
+ *
+ * Similarly, _AT() will cast an expression with a type in C, but
+ * leave it unchanged in asm.
+ */
+
+#ifdef __ASSEMBLY__
+#define _AC(X,Y) X
+#define _AT(T,X) X
+#else
+#define __AC(X,Y) (X##Y)
+#define _AC(X,Y) __AC(X,Y)
+#define _AT(T,X) ((T)(X))
+#endif
+
+#define _UL(x) (_AC(x, UL))
+#define _ULL(x) (_AC(x, ULL))
+
+#define _BITUL(x) (_UL(1) << (x))
+#define _BITULL(x) (_ULL(1) << (x))
+
+#define UL(x) (_UL(x))
+#define ULL(x) (_ULL(x))
+
+#endif /* _LINUX_CONST_H */
--
2.19.1
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