dsb
#define dsb(option) __asm__ __volatile__ ("dsb " #option : : : "memory")
#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
#define dsb(opt) asm volatile("dsb " #opt : : : "memory")
struct dsb {
#define dsb(a)
#define dsb(opt) asm volatile("dsb " #opt : : : "memory")