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authorJo-Philipp Wich <jo@mein.io>2021-09-19 11:18:19 +0200
committerGitHub <noreply@github.com>2021-09-19 11:18:19 +0200
commit0ea5ee8d78454191eb32251fce1b77b1a4c41c77 (patch)
tree5cdad08b66b6aae878eb0f236c79f9dc79a6248f /include/linux/const.h
parent64e4f68cc70466f736b6ba98c5ec8c9800bee351 (diff)
parentdd86e1dadab228c1a20bdb5504d216706cdd8624 (diff)
Merge pull request #20 from jow-/lib-add-rtnl
lib: introduce Linux route netlink binding
Diffstat (limited to 'include/linux/const.h')
-rw-r--r--include/linux/const.h36
1 files changed, 36 insertions, 0 deletions
diff --git a/include/linux/const.h b/include/linux/const.h
new file mode 100644
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--- /dev/null
+++ b/include/linux/const.h
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+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* const.h: Macros for dealing with constants. */
+
+#ifndef _LINUX_CONST_H
+#define _LINUX_CONST_H
+
+/* 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 __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
+#define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask))
+
+#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
+
+#endif /* _LINUX_CONST_H */