include/asm/atomic-llsc.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002
0003 #ifndef _ASM_ARC_ATOMIC_LLSC_H
0004 #define _ASM_ARC_ATOMIC_LLSC_H
0005
0006 #define arch_atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
0007
0008 #define ATOMIC_OP(op, asm_op)                   \
0009 static inline void arch_atomic_##op(int i, atomic_t *v)         \
0010 {                                   \
0011     unsigned int val;                       \
0012                                     \
0013     __asm__ __volatile__(                       \
0014     "1: llock   %[val], [%[ctr]]        \n"     \
0015     "   " #asm_op " %[val], %[val], %[i]    \n"     \
0016     "   scond   %[val], [%[ctr]]        \n"     \
0017     "   bnz     1b              \n"     \
0018     : [val] "=&r"   (val) /* Early clobber to prevent reg reuse */  \
0019     : [ctr] "r" (&v->counter), /* Not "m": llock only supports reg direct addr mode */  \
0020       [i]   "ir"    (i)                     \
0021     : "cc");                            \
0022 }                                   \
0023
0024 #define ATOMIC_OP_RETURN(op, asm_op)                \
0025 static inline int arch_atomic_##op##_return_relaxed(int i, atomic_t *v) \
0026 {                                   \
0027     unsigned int val;                       \
0028                                     \
0029     __asm__ __volatile__(                       \
0030     "1: llock   %[val], [%[ctr]]        \n"     \
0031     "   " #asm_op " %[val], %[val], %[i]    \n"     \
0032     "   scond   %[val], [%[ctr]]        \n"     \
0033     "   bnz     1b              \n"     \
0034     : [val] "=&r"   (val)                       \
0035     : [ctr] "r" (&v->counter),                  \
0036       [i]   "ir"    (i)                     \
0037     : "cc");                            \
0038                                     \
0039     return val;                         \
0040 }
0041
0042 #define arch_atomic_add_return_relaxed      arch_atomic_add_return_relaxed
0043 #define arch_atomic_sub_return_relaxed      arch_atomic_sub_return_relaxed
0044
0045 #define ATOMIC_FETCH_OP(op, asm_op)             \
0046 static inline int arch_atomic_fetch_##op##_relaxed(int i, atomic_t *v)  \
0047 {                                   \
0048     unsigned int val, orig;                     \
0049                                     \
0050     __asm__ __volatile__(                       \
0051     "1: llock   %[orig], [%[ctr]]       \n"     \
0052     "   " #asm_op " %[val], %[orig], %[i]   \n"     \
0053     "   scond   %[val], [%[ctr]]        \n"     \
0054     "   bnz     1b              \n"     \
0055     : [val] "=&r"   (val),                      \
0056       [orig] "=&r" (orig)                       \
0057     : [ctr] "r" (&v->counter),                  \
0058       [i]   "ir"    (i)                     \
0059     : "cc");                            \
0060                                     \
0061     return orig;                            \
0062 }
0063
0064 #define arch_atomic_fetch_add_relaxed       arch_atomic_fetch_add_relaxed
0065 #define arch_atomic_fetch_sub_relaxed       arch_atomic_fetch_sub_relaxed
0066
0067 #define arch_atomic_fetch_and_relaxed       arch_atomic_fetch_and_relaxed
0068 #define arch_atomic_fetch_andnot_relaxed    arch_atomic_fetch_andnot_relaxed
0069 #define arch_atomic_fetch_or_relaxed        arch_atomic_fetch_or_relaxed
0070 #define arch_atomic_fetch_xor_relaxed       arch_atomic_fetch_xor_relaxed
0071
0072 #define ATOMIC_OPS(op, asm_op)                  \
0073     ATOMIC_OP(op, asm_op)                   \
0074     ATOMIC_OP_RETURN(op, asm_op)                \
0075     ATOMIC_FETCH_OP(op, asm_op)
0076
0077 ATOMIC_OPS(add, add)
0078 ATOMIC_OPS(sub, sub)
0079
0080 #undef ATOMIC_OPS
0081 #define ATOMIC_OPS(op, asm_op)                  \
0082     ATOMIC_OP(op, asm_op)                   \
0083     ATOMIC_FETCH_OP(op, asm_op)
0084
0085 ATOMIC_OPS(and, and)
0086 ATOMIC_OPS(andnot, bic)
0087 ATOMIC_OPS(or, or)
0088 ATOMIC_OPS(xor, xor)
0089
0090 #define arch_atomic_andnot      arch_atomic_andnot
0091
0092 #undef ATOMIC_OPS
0093 #undef ATOMIC_FETCH_OP
0094 #undef ATOMIC_OP_RETURN
0095 #undef ATOMIC_OP
0096
0097 #endif