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Diffstat (limited to 'drivers/gpu/drm/xe/xe_args.h')
| -rw-r--r-- | drivers/gpu/drm/xe/xe_args.h | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_args.h b/drivers/gpu/drm/xe/xe_args.h new file mode 100644 index 000000000000..4dbc7e53c624 --- /dev/null +++ b/drivers/gpu/drm/xe/xe_args.h @@ -0,0 +1,143 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright © 2024 Intel Corporation + */ + +#ifndef _XE_ARGS_H_ +#define _XE_ARGS_H_ + +#include <linux/args.h> + +/* + * Why don't the following macros have the XE prefix? + * + * Once we find more potential users outside of the Xe driver, we plan to move + * all of the following macros unchanged to linux/args.h. + */ + +/** + * CALL_ARGS - Invoke a macro, but allow parameters to be expanded beforehand. + * @f: name of the macro to invoke + * @args: arguments for the macro + * + * This macro allows calling macros which names might generated or we want to + * make sure it's arguments will be correctly expanded. + * + * Example: + * + * #define foo X,Y,Z,Q + * #define bar COUNT_ARGS(foo) + * #define buz CALL_ARGS(COUNT_ARGS, foo) + * + * With above definitions bar expands to 1 while buz expands to 4. + */ +#define CALL_ARGS(f, args...) __CALL_ARGS(f, args) +#define __CALL_ARGS(f, args...) f(args) + +/** + * DROP_FIRST_ARG - Returns all arguments except the first one. + * @args: arguments + * + * This helper macro allows manipulation the argument list before passing it + * to the next level macro. + * + * Example: + * + * #define foo X,Y,Z,Q + * #define bar CALL_ARGS(COUNT_ARGS, DROP_FIRST_ARG(foo)) + * + * With above definitions bar expands to 3. + */ +#define DROP_FIRST_ARG(args...) __DROP_FIRST_ARG(args) +#define __DROP_FIRST_ARG(a, b...) b + +/** + * FIRST_ARG - Returns the first argument. + * @args: arguments + * + * This helper macro allows manipulation the argument list before passing it + * to the next level macro. + * + * Example: + * + * #define foo X,Y,Z,Q + * #define bar FIRST_ARG(foo) + * + * With above definitions bar expands to X. + */ +#define FIRST_ARG(args...) __FIRST_ARG(args) +#define __FIRST_ARG(a, b...) a + +/** + * LAST_ARG - Returns the last argument. + * @args: arguments + * + * This helper macro allows manipulation the argument list before passing it + * to the next level macro. + * + * Like COUNT_ARGS() this macro works up to 12 arguments. + * + * Example: + * + * #define foo X,Y,Z,Q + * #define bar LAST_ARG(foo) + * + * With above definitions bar expands to Q. + */ +#define LAST_ARG(args...) __LAST_ARG(args) +#define __LAST_ARG(args...) PICK_ARG(COUNT_ARGS(args), args) + +/** + * PICK_ARG - Returns the n-th argument. + * @n: argument number to be returned + * @args: arguments + * + * This helper macro allows manipulation the argument list before passing it + * to the next level macro. + * + * Like COUNT_ARGS() this macro supports n up to 12. + * Specialized macros PICK_ARG1() to PICK_ARG12() are also available. + * + * Example: + * + * #define foo X,Y,Z,Q + * #define bar PICK_ARG(2, foo) + * #define buz PICK_ARG3(foo) + * + * With above definitions bar expands to Y and buz expands to Z. + */ +#define PICK_ARG(n, args...) __PICK_ARG(n, args) +#define __PICK_ARG(n, args...) CALL_ARGS(CONCATENATE(PICK_ARG, n), args) +#define PICK_ARG1(args...) FIRST_ARG(args) +#define PICK_ARG2(args...) PICK_ARG1(DROP_FIRST_ARG(args)) +#define PICK_ARG3(args...) PICK_ARG2(DROP_FIRST_ARG(args)) +#define PICK_ARG4(args...) PICK_ARG3(DROP_FIRST_ARG(args)) +#define PICK_ARG5(args...) PICK_ARG4(DROP_FIRST_ARG(args)) +#define PICK_ARG6(args...) PICK_ARG5(DROP_FIRST_ARG(args)) +#define PICK_ARG7(args...) PICK_ARG6(DROP_FIRST_ARG(args)) +#define PICK_ARG8(args...) PICK_ARG7(DROP_FIRST_ARG(args)) +#define PICK_ARG9(args...) PICK_ARG8(DROP_FIRST_ARG(args)) +#define PICK_ARG10(args...) PICK_ARG9(DROP_FIRST_ARG(args)) +#define PICK_ARG11(args...) PICK_ARG10(DROP_FIRST_ARG(args)) +#define PICK_ARG12(args...) PICK_ARG11(DROP_FIRST_ARG(args)) + +/** + * ARGS_SEP_COMMA - Definition of a comma character. + * + * This definition can be used in cases where any intermediate macro expects + * fixed number of arguments, but we want to pass more arguments which can + * be properly evaluated only by the next level macro. + * + * Example: + * + * #define foo(f) f(X) f(Y) f(Z) f(Q) + * #define bar DROP_FIRST_ARG(foo(ARGS_SEP_COMMA __stringify)) + * #define buz CALL_ARGS(COUNT_ARGS, DROP_FIRST_ARG(foo(ARGS_SEP_COMMA))) + * + * With above definitions bar expands to + * "X", "Y", "Z", "Q" + * and buz expands to 4. + */ +#define ARGS_SEP_COMMA , + +#endif |