BIG_IOCTL32_Command_struct
BIG_IOCTL32_Command_struct __user *arg32 = arg;
offsetof(BIG_IOCTL32_Command_struct, buf)))
#define CCISS_BIG_PASSTHRU32 _IOWR(CCISS_IOC_MAGIC, 18, BIG_IOCTL32_Command_struct)