/* atomic.S: These things are too big to do inline. * * Copyright (C) 1999, 2007 2012 David S. Miller (davem@davemloft.net) */ #include <linux/linkage.h> #include <asm/asi.h> #include <asm/backoff.h> .text /* Two versions of the atomic routines, one that * does not return a value and does not perform * memory barriers, and a second which returns * a value and does the barriers. */ #define ATOMIC_OP(op) \ ENTRY(atomic_##op) /* %o0 = increment, %o1 = atomic_ptr */ \ BACKOFF_SETUP(%o2); \ 1: lduw [%o1], %g1; \ op %g1, %o0, %g7; \ cas [%o1], %g1, %g7; \ cmp %g1, %g7; \ bne,pn %icc, BACKOFF_LABEL(2f, 1b); \ nop; \ retl; \ nop; \ 2: BACKOFF_SPIN(%o2, %o3, 1b); \ ENDPROC(atomic_##op); \ #define ATOMIC_OP_RETURN(op) \ ENTRY(atomic_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */ \ BACKOFF_SETUP(%o2); \ 1: lduw [%o1], %g1; \ op %g1, %o0, %g7; \ cas [%o1], %g1, %g7; \ cmp %g1, %g7; \ bne,pn %icc, BACKOFF_LABEL(2f, 1b); \ op %g1, %o0, %g1; \ retl; \ sra %g1, 0, %o0; \ 2: BACKOFF_SPIN(%o2, %o3, 1b); \ ENDPROC(atomic_##op##_return); #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) ATOMIC_OPS(add) ATOMIC_OPS(sub) #undef ATOMIC_OPS #undef ATOMIC_OP_RETURN #undef ATOMIC_OP #define ATOMIC64_OP(op) \ ENTRY(atomic64_##op) /* %o0 = increment, %o1 = atomic_ptr */ \ BACKOFF_SETUP(%o2); \ 1: ldx [%o1], %g1; \ op %g1, %o0, %g7; \ casx [%o1], %g1, %g7; \ cmp %g1, %g7; \ bne,pn %xcc, BACKOFF_LABEL(2f, 1b); \ nop; \ retl; \ nop; \ 2: BACKOFF_SPIN(%o2, %o3, 1b); \ ENDPROC(atomic64_##op); \ #define ATOMIC64_OP_RETURN(op) \ ENTRY(atomic64_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */ \ BACKOFF_SETUP(%o2); \ 1: ldx [%o1], %g1; \ op %g1, %o0, %g7; \ casx [%o1], %g1, %g7; \ cmp %g1, %g7; \ bne,pn %xcc, BACKOFF_LABEL(2f, 1b); \ nop; \ retl; \ op %g1, %o0, %o0; \ 2: BACKOFF_SPIN(%o2, %o3, 1b); \ ENDPROC(atomic64_##op##_return); #define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op) ATOMIC64_OPS(add) ATOMIC64_OPS(sub) #undef ATOMIC64_OPS #undef ATOMIC64_OP_RETURN #undef ATOMIC64_OP ENTRY(atomic64_dec_if_positive) /* %o0 = atomic_ptr */ BACKOFF_SETUP(%o2) 1: ldx [%o0], %g1 brlez,pn %g1, 3f sub %g1, 1, %g7 casx [%o0], %g1, %g7 cmp %g1, %g7 bne,pn %xcc, BACKOFF_LABEL(2f, 1b) nop 3: retl sub %g1, 1, %o0 2: BACKOFF_SPIN(%o2, %o3, 1b) ENDPROC(atomic64_dec_if_positive)