/*- * 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. */ #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))) /* * On Linux, the CONFIG_PGTABLE_LEVELS value is defined by the config/build * system. Here, we take the per-architecture default value defined in * `arch/$ARCH/Kconfig` files upstream. */ #if defined(__amd64__) #define CONFIG_PGTABLE_LEVELS 4 #elif defined(__aarch64__) #define CONFIG_PGTABLE_LEVELS 4 #elif defined(__i386__) #define CONFIG_PGTABLE_LEVELS 2 #elif defined(__powerpc__) #if defined(__powerpc64__) #define CONFIG_PGTABLE_LEVELS 4 #else #define CONFIG_PGTABLE_LEVELS 2 #endif #elif defined(__riscv) #if defined(__riscv_xlen) && __riscv_xlen == 64 #define CONFIG_PGTABLE_LEVELS 5 #else #define CONFIG_PGTABLE_LEVELS 2 #endif #endif #endif /* _LINUXKPI_LINUX_KCONFIG_H_ */
