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1/* SPDX-License-Identifier: MIT */2/*3 * Copyright © 2024 Intel Corporation4 */5 6#ifndef _XE_ARGS_H_7#define _XE_ARGS_H_8 9#include <linux/args.h>10 11/*12 * Why don't the following macros have the XE prefix?13 *14 * Once we find more potential users outside of the Xe driver, we plan to move15 * all of the following macros unchanged to linux/args.h.16 */17 18/**19 * CALL_ARGS - Invoke a macro, but allow parameters to be expanded beforehand.20 * @f: name of the macro to invoke21 * @args: arguments for the macro22 *23 * This macro allows calling macros which names might generated or we want to24 * make sure it's arguments will be correctly expanded.25 *26 * Example:27 *28 * #define foo X,Y,Z,Q29 * #define bar COUNT_ARGS(foo)30 * #define buz CALL_ARGS(COUNT_ARGS, foo)31 *32 * With above definitions bar expands to 1 while buz expands to 4.33 */34#define CALL_ARGS(f, args...) __CALL_ARGS(f, args)35#define __CALL_ARGS(f, args...) f(args)36 37/**38 * DROP_FIRST_ARG - Returns all arguments except the first one.39 * @args: arguments40 *41 * This helper macro allows manipulation the argument list before passing it42 * to the next level macro.43 *44 * Example:45 *46 * #define foo X,Y,Z,Q47 * #define bar CALL_ARGS(COUNT_ARGS, DROP_FIRST_ARG(foo))48 *49 * With above definitions bar expands to 3.50 */51#define DROP_FIRST_ARG(args...) __DROP_FIRST_ARG(args)52#define __DROP_FIRST_ARG(a, b...) b53 54/**55 * FIRST_ARG - Returns the first argument.56 * @args: arguments57 *58 * This helper macro allows manipulation the argument list before passing it59 * to the next level macro.60 *61 * Example:62 *63 * #define foo X,Y,Z,Q64 * #define bar FIRST_ARG(foo)65 *66 * With above definitions bar expands to X.67 */68#define FIRST_ARG(args...) __FIRST_ARG(args)69#define __FIRST_ARG(a, b...) a70 71/**72 * LAST_ARG - Returns the last argument.73 * @args: arguments74 *75 * This helper macro allows manipulation the argument list before passing it76 * to the next level macro.77 *78 * Like COUNT_ARGS() this macro works up to 12 arguments.79 *80 * Example:81 *82 * #define foo X,Y,Z,Q83 * #define bar LAST_ARG(foo)84 *85 * With above definitions bar expands to Q.86 */87#define LAST_ARG(args...) __LAST_ARG(args)88#define __LAST_ARG(args...) PICK_ARG(COUNT_ARGS(args), args)89 90/**91 * PICK_ARG - Returns the n-th argument.92 * @n: argument number to be returned93 * @args: arguments94 *95 * This helper macro allows manipulation the argument list before passing it96 * to the next level macro.97 *98 * Like COUNT_ARGS() this macro supports n up to 12.99 * Specialized macros PICK_ARG1() to PICK_ARG12() are also available.100 *101 * Example:102 *103 * #define foo X,Y,Z,Q104 * #define bar PICK_ARG(2, foo)105 * #define buz PICK_ARG3(foo)106 *107 * With above definitions bar expands to Y and buz expands to Z.108 */109#define PICK_ARG(n, args...) __PICK_ARG(n, args)110#define __PICK_ARG(n, args...) CALL_ARGS(CONCATENATE(PICK_ARG, n), args)111#define PICK_ARG1(args...) FIRST_ARG(args)112#define PICK_ARG2(args...) PICK_ARG1(DROP_FIRST_ARG(args))113#define PICK_ARG3(args...) PICK_ARG2(DROP_FIRST_ARG(args))114#define PICK_ARG4(args...) PICK_ARG3(DROP_FIRST_ARG(args))115#define PICK_ARG5(args...) PICK_ARG4(DROP_FIRST_ARG(args))116#define PICK_ARG6(args...) PICK_ARG5(DROP_FIRST_ARG(args))117#define PICK_ARG7(args...) PICK_ARG6(DROP_FIRST_ARG(args))118#define PICK_ARG8(args...) PICK_ARG7(DROP_FIRST_ARG(args))119#define PICK_ARG9(args...) PICK_ARG8(DROP_FIRST_ARG(args))120#define PICK_ARG10(args...) PICK_ARG9(DROP_FIRST_ARG(args))121#define PICK_ARG11(args...) PICK_ARG10(DROP_FIRST_ARG(args))122#define PICK_ARG12(args...) PICK_ARG11(DROP_FIRST_ARG(args))123 124/**125 * ARGS_SEP_COMMA - Definition of a comma character.126 *127 * This definition can be used in cases where any intermediate macro expects128 * fixed number of arguments, but we want to pass more arguments which can129 * be properly evaluated only by the next level macro.130 *131 * Example:132 *133 * #define foo(f) f(X) f(Y) f(Z) f(Q)134 * #define bar DROP_FIRST_ARG(foo(ARGS_SEP_COMMA __stringify))135 * #define buz CALL_ARGS(COUNT_ARGS, DROP_FIRST_ARG(foo(ARGS_SEP_COMMA)))136 *137 * With above definitions bar expands to138 * "X", "Y", "Z", "Q"139 * and buz expands to 4.140 */141#define ARGS_SEP_COMMA ,142 143#endif144