diff options
Diffstat (limited to 'include/linux/kernel.h')
| -rw-r--r-- | include/linux/kernel.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 4cb8d3df414e..91d375ca15bc 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -500,4 +500,39 @@ struct sysinfo { #define NUMA_BUILD 0 #endif +/* If fn is of type ok1 or ok2, cast to desttype */ +#define __typesafe_cb(desttype, fn, ok1, ok2) \ + cast_if_type(cast_if_type((fn), ok1, desttype), ok2, desttype) + +/** + * typesafe_cb - cast a callback function if it matches the arg + * @rettype: the return type of the callback function + * @fn: the callback function to cast + * @arg: the (pointer) argument to hand to the callback function. + * + * If a callback function takes a single argument, this macro does + * appropriate casts to a function which takes a single void * argument if the + * callback provided matches the @arg (or a const or volatile version). + * + * It is assumed that @arg is of pointer type: usually @arg is passed + * or assigned to a void * elsewhere anyway. + */ +#define typesafe_cb(rettype, fn, arg) \ + __typesafe_cb(rettype (*)(void *), (fn), \ + rettype (*)(const typeof(arg)), \ + rettype (*)(typeof(arg))) + +/** + * typesafe_cb_preargs - cast a callback function if it matches the arg + * @rettype: the return type of the callback function + * @fn: the callback function to cast + * @arg: the (pointer) argument to hand to the callback function. + * + * This is a version of typesafe_cb() for callbacks that take other arguments + * before the @arg. + */ +#define typesafe_cb_preargs(rettype, fn, arg, ...) \ + __typesafe_cb(rettype (*)(__VA_ARGS__, void *), (fn), \ + rettype (*)(__VA_ARGS__, const typeof(arg)), \ + rettype (*)(__VA_ARGS__, typeof(arg))) #endif |