linuxkpi: Move `IS_ENABLED()` and friends to <linux/kconfig.h>

The header is included in <linux/xarray.h> like it is on Linux. Some DRM
code depends on this header "pollution".

Reviewed by:	bz
Approved by:	bz
Differential Revision:	https://reviews.freebsd.org/D38567

3 files changed, 80 insertions, 42 deletions

diff --git a/sys/compat/linuxkpi/common/include/linux/kconfig.h b/sys/compat/linuxkpi/common/include/linux/kconfig.h
new file mode 100644
index 000000000000..b109d664ce8f
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/kconfig.h
@@ -0,0 +1,78 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 The FreeBSD Foundation
+ *
+ * This software was developed by Björn Zeeb under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_LINUXKPI_LINUX_KCONFIG_H_
+#define	_LINUXKPI_LINUX_KCONFIG_H_
+
+/*
+ * Checking if an option is defined would be easy if we could do CPP inside CPP.
+ * The defined case whether -Dxxx or -Dxxx=1 are easy to deal with.  In either
+ * case the defined value is "1". A more general -Dxxx=<c> case will require
+ * more effort to deal with all possible "true" values. Hope we do not have
+ * to do this as well.
+ * The real problem is the undefined case.  To avoid this problem we do the
+ * concat/varargs trick: "yyy" ## xxx can make two arguments if xxx is "1"
+ * by having a #define for yyy_1 which is "ignore,".
+ * Otherwise we will just get "yyy".
+ * Need to be careful about variable substitutions in macros though.
+ * This way we make a (true, false) problem a (don't care, true, false) or a
+ * (don't care true, false).  Then we can use a variadic macro to only select
+ * the always well known and defined argument #2.  And that seems to be
+ * exactly what we need.  Use 1 for true and 0 for false to also allow
+ * #if IS_*() checks pre-compiler checks which do not like #if true.
+ */
+#define ___XAB_1		dontcare,
+#define ___IS_XAB(_ignore, _x, ...)	(_x)
+#define	__IS_XAB(_x)		___IS_XAB(_x 1, 0)
+#define	_IS_XAB(_x)		__IS_XAB(__CONCAT(___XAB_, _x))
+
+/* This is if CONFIG_ccc=y. */
+#define	IS_BUILTIN(_x)		_IS_XAB(_x)
+/* This is if CONFIG_ccc=m. */
+#define	IS_MODULE(_x)		_IS_XAB(_x ## _MODULE)
+/* This is if CONFIG_ccc is compiled in(=y) or a module(=m). */
+#define	IS_ENABLED(_x)		(IS_BUILTIN(_x) || IS_MODULE(_x))
+/*
+ * This is weird case.  If the CONFIG_ccc is builtin (=y) this returns true;
+ * or if the CONFIG_ccc is a module (=m) and the caller is built as a module
+ * (-DMODULE defined) this returns true, but if the callers is not a module
+ * (-DMODULE not defined, which means caller is BUILTIN) then it returns
+ * false.  In other words, a module can reach the kernel, a module can reach
+ * a module, but the kernel cannot reach a module, and code never compiled
+ * cannot be reached either.
+ * XXX -- I'd hope the module-to-module case would be handled by a proper
+ * module dependency definition (MODULE_DEPEND() in FreeBSD).
+ */
+#define	IS_REACHABLE(_x)	(IS_BUILTIN(_x) || \
+				    (IS_MODULE(_x) && IS_BUILTIN(MODULE)))
+
+#endif /* _LINUXKPI_LINUX_KCONFIG_H_ */
diff --git a/sys/compat/linuxkpi/common/include/linux/kernel.h b/sys/compat/linuxkpi/common/include/linux/kernel.h
index aee299efa732..22b25a202395 100644
--- a/sys/compat/linuxkpi/common/include/linux/kernel.h
+++ b/sys/compat/linuxkpi/common/include/linux/kernel.h
@@ -52,6 +52,7 @@
 #include <linux/typecheck.h>
 #include <linux/jiffies.h>
 #include <linux/log2.h>
+#include <linux/kconfig.h>
 
 #include <asm/byteorder.h>
 #include <asm/cpufeature.h>
@@ -760,46 +761,4 @@ mac_pton(const char *macin, uint8_t *macout)
 #define	DECLARE_FLEX_ARRAY(_t, _n)					\
     struct { struct { } __dummy_ ## _n; _t _n[0]; }
 
-/*
- * Checking if an option is defined would be easy if we could do CPP inside CPP.
- * The defined case whether -Dxxx or -Dxxx=1 are easy to deal with.  In either
- * case the defined value is "1". A more general -Dxxx=<c> case will require
- * more effort to deal with all possible "true" values. Hope we do not have
- * to do this as well.
- * The real problem is the undefined case.  To avoid this problem we do the
- * concat/varargs trick: "yyy" ## xxx can make two arguments if xxx is "1"
- * by having a #define for yyy_1 which is "ignore,".
- * Otherwise we will just get "yyy".
- * Need to be careful about variable substitutions in macros though.
- * This way we make a (true, false) problem a (don't care, true, false) or a
- * (don't care true, false).  Then we can use a variadic macro to only select
- * the always well known and defined argument #2.  And that seems to be
- * exactly what we need.  Use 1 for true and 0 for false to also allow
- * #if IS_*() checks pre-compiler checks which do not like #if true.
- */
-#define ___XAB_1		dontcare,
-#define ___IS_XAB(_ignore, _x, ...)	(_x)
-#define	__IS_XAB(_x)		___IS_XAB(_x 1, 0)
-#define	_IS_XAB(_x)		__IS_XAB(__CONCAT(___XAB_, _x))
-
-/* This is if CONFIG_ccc=y. */
-#define	IS_BUILTIN(_x)		_IS_XAB(_x)
-/* This is if CONFIG_ccc=m. */
-#define	IS_MODULE(_x)		_IS_XAB(_x ## _MODULE)
-/* This is if CONFIG_ccc is compiled in(=y) or a module(=m). */
-#define	IS_ENABLED(_x)		(IS_BUILTIN(_x) || IS_MODULE(_x))
-/*
- * This is weird case.  If the CONFIG_ccc is builtin (=y) this returns true;
- * or if the CONFIG_ccc is a module (=m) and the caller is built as a module
- * (-DMODULE defined) this returns true, but if the callers is not a module
- * (-DMODULE not defined, which means caller is BUILTIN) then it returns
- * false.  In other words, a module can reach the kernel, a module can reach
- * a module, but the kernel cannot reach a module, and code never compiled
- * cannot be reached either.
- * XXX -- I'd hope the module-to-module case would be handled by a proper
- * module dependency definition (MODULE_DEPEND() in FreeBSD).
- */
-#define	IS_REACHABLE(_x)	(IS_BUILTIN(_x) || \
-				    (IS_MODULE(_x) && IS_BUILTIN(MODULE)))
-
 #endif	/* _LINUXKPI_LINUX_KERNEL_H_ */
diff --git a/sys/compat/linuxkpi/common/include/linux/xarray.h b/sys/compat/linuxkpi/common/include/linux/xarray.h
index 8a9d8fa3ea41..004efebc55d6 100644
--- a/sys/compat/linuxkpi/common/include/linux/xarray.h
+++ b/sys/compat/linuxkpi/common/include/linux/xarray.h
@@ -31,6 +31,7 @@
 #include <linux/gfp.h>
 #include <linux/radix-tree.h>
 #include <linux/err.h>
+#include <linux/kconfig.h>
 
 #include <sys/lock.h>
 #include <sys/mutex.h>