1 #ifndef __ASM_SH_ATOMIC_LLSC_H 2 #define __ASM_SH_ATOMIC_LLSC_H 3 4 /* 5 * SH-4A note: 6 * 7 * We basically get atomic_xxx_return() for free compared with 8 * atomic_xxx(). movli.l/movco.l require r0 due to the instruction 9 * encoding, so the retval is automatically set without having to 10 * do any special work. 11 */ 12 /* 13 * To get proper branch prediction for the main line, we must branch 14 * forward to code at the end of this object's .text section, then 15 * branch back to restart the operation. 16 */ 17 18 #define ATOMIC_OP(op) \ 19 static inline void atomic_##op(int i, atomic_t *v) \ 20 { \ 21 unsigned long tmp; \ 22 \ 23 __asm__ __volatile__ ( \ 24 "1: movli.l @%2, %0 ! atomic_" #op "\n" \ 25 " " #op " %1, %0 \n" \ 26 " movco.l %0, @%2 \n" \ 27 " bf 1b \n" \ 28 : "=&z" (tmp) \ 29 : "r" (i), "r" (&v->counter) \ 30 : "t"); \ 31 } 32 33 #define ATOMIC_OP_RETURN(op) \ 34 static inline int atomic_##op##_return(int i, atomic_t *v) \ 35 { \ 36 unsigned long temp; \ 37 \ 38 __asm__ __volatile__ ( \ 39 "1: movli.l @%2, %0 ! atomic_" #op "_return \n" \ 40 " " #op " %1, %0 \n" \ 41 " movco.l %0, @%2 \n" \ 42 " bf 1b \n" \ 43 " synco \n" \ 44 : "=&z" (temp) \ 45 : "r" (i), "r" (&v->counter) \ 46 : "t"); \ 47 \ 48 return temp; \ 49 } 50 51 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) 52 53 ATOMIC_OPS(add) 54 ATOMIC_OPS(sub) 55 ATOMIC_OP(and) 56 ATOMIC_OP(or) 57 ATOMIC_OP(xor) 58 59 #undef ATOMIC_OPS 60 #undef ATOMIC_OP_RETURN 61 #undef ATOMIC_OP 62 63 #endif /* __ASM_SH_ATOMIC_LLSC_H */ 64