--- /dev/null
+/*
+ * Based on arch/arm/include/asm/atomic.h
+ *
+ * Copyright (C) 1996 Russell King.
+ * Copyright (C) 2002 Deep Blue Solutions Ltd.
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __ASM_ATOMIC_LL_SC_H
+#define __ASM_ATOMIC_LL_SC_H
+
+#ifndef __ARM64_IN_ATOMIC_IMPL
+#error "please don't include this file directly"
+#endif
+
+/*
+ * AArch64 UP and SMP safe atomic ops. We use load exclusive and
+ * store exclusive to ensure that these are atomic. We may loop
+ * to ensure that the update happens.
+ *
+ * NOTE: these functions do *not* follow the PCS and must explicitly
+ * save any clobbered registers other than x0 (regardless of return
+ * value). This is achieved through -fcall-saved-* compiler flags for
+ * this file, which unfortunately don't work on a per-function basis
+ * (the optimize attribute silently ignores these options).
+ */
+
+#define ATOMIC_OP(op, asm_op) \
+__LL_SC_INLINE void \
+__LL_SC_PREFIX(atomic_##op(int i, atomic_t *v)) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ asm volatile("// atomic_" #op "\n" \
+" prfm pstl1strm, %2\n" \
+"1: ldxr %w0, %2\n" \
+" " #asm_op " %w0, %w0, %w3\n" \
+" stxr %w1, %w0, %2\n" \
+" cbnz %w1, 1b" \
+ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
+ : "Ir" (i)); \
+} \
+__LL_SC_EXPORT(atomic_##op);
+
+#define ATOMIC_OP_RETURN(name, mb, acq, rel, cl, op, asm_op) \
+__LL_SC_INLINE int \
+__LL_SC_PREFIX(atomic_##op##_return##name(int i, atomic_t *v)) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ asm volatile("// atomic_" #op "_return" #name "\n" \
+" prfm pstl1strm, %2\n" \
+"1: ld" #acq "xr %w0, %2\n" \
+" " #asm_op " %w0, %w0, %w3\n" \
+" st" #rel "xr %w1, %w0, %2\n" \
+" cbnz %w1, 1b\n" \
+" " #mb \
+ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
+ : "Ir" (i) \
+ : cl); \
+ \
+ return result; \
+} \
+__LL_SC_EXPORT(atomic_##op##_return##name);
+
+#define ATOMIC_OPS(...) \
+ ATOMIC_OP(__VA_ARGS__) \
+ ATOMIC_OP_RETURN( , dmb ish, , l, "memory", __VA_ARGS__)
+
+#define ATOMIC_OPS_RLX(...) \
+ ATOMIC_OPS(__VA_ARGS__) \
+ ATOMIC_OP_RETURN(_relaxed, , , , , __VA_ARGS__)\
+ ATOMIC_OP_RETURN(_acquire, , a, , "memory", __VA_ARGS__)\
+ ATOMIC_OP_RETURN(_release, , , l, "memory", __VA_ARGS__)
+
+ATOMIC_OPS_RLX(add, add)
+ATOMIC_OPS_RLX(sub, sub)
+
+ATOMIC_OP(and, and)
+ATOMIC_OP(andnot, bic)
+ATOMIC_OP(or, orr)
+ATOMIC_OP(xor, eor)
+
+#undef ATOMIC_OPS_RLX
+#undef ATOMIC_OPS
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#define ATOMIC64_OP(op, asm_op) \
+__LL_SC_INLINE void \
+__LL_SC_PREFIX(atomic64_##op(long i, atomic64_t *v)) \
+{ \
+ long result; \
+ unsigned long tmp; \
+ \
+ asm volatile("// atomic64_" #op "\n" \
+" prfm pstl1strm, %2\n" \
+"1: ldxr %0, %2\n" \
+" " #asm_op " %0, %0, %3\n" \
+" stxr %w1, %0, %2\n" \
+" cbnz %w1, 1b" \
+ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
+ : "Ir" (i)); \
+} \
+__LL_SC_EXPORT(atomic64_##op);
+
+#define ATOMIC64_OP_RETURN(name, mb, acq, rel, cl, op, asm_op) \
+__LL_SC_INLINE long \
+__LL_SC_PREFIX(atomic64_##op##_return##name(long i, atomic64_t *v)) \
+{ \
+ long result; \
+ unsigned long tmp; \
+ \
+ asm volatile("// atomic64_" #op "_return" #name "\n" \
+" prfm pstl1strm, %2\n" \
+"1: ld" #acq "xr %0, %2\n" \
+" " #asm_op " %0, %0, %3\n" \
+" st" #rel "xr %w1, %0, %2\n" \
+" cbnz %w1, 1b\n" \
+" " #mb \
+ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
+ : "Ir" (i) \
+ : cl); \
+ \
+ return result; \
+} \
+__LL_SC_EXPORT(atomic64_##op##_return##name);
+
+#define ATOMIC64_OPS(...) \
+ ATOMIC64_OP(__VA_ARGS__) \
+ ATOMIC64_OP_RETURN(, dmb ish, , l, "memory", __VA_ARGS__)
+
+#define ATOMIC64_OPS_RLX(...) \
+ ATOMIC64_OPS(__VA_ARGS__) \
+ ATOMIC64_OP_RETURN(_relaxed,, , , , __VA_ARGS__) \
+ ATOMIC64_OP_RETURN(_acquire,, a, , "memory", __VA_ARGS__) \
+ ATOMIC64_OP_RETURN(_release,, , l, "memory", __VA_ARGS__)
+
+ATOMIC64_OPS_RLX(add, add)
+ATOMIC64_OPS_RLX(sub, sub)
+
+ATOMIC64_OP(and, and)
+ATOMIC64_OP(andnot, bic)
+ATOMIC64_OP(or, orr)
+ATOMIC64_OP(xor, eor)
+
+#undef ATOMIC64_OPS_RLX
+#undef ATOMIC64_OPS
+#undef ATOMIC64_OP_RETURN
+#undef ATOMIC64_OP
+
+__LL_SC_INLINE long
+__LL_SC_PREFIX(atomic64_dec_if_positive(atomic64_t *v))
+{
+ long result;
+ unsigned long tmp;
+
+ asm volatile("// atomic64_dec_if_positive\n"
+" prfm pstl1strm, %2\n"
+"1: ldxr %0, %2\n"
+" subs %0, %0, #1\n"
+" b.lt 2f\n"
+" stlxr %w1, %0, %2\n"
+" cbnz %w1, 1b\n"
+" dmb ish\n"
+"2:"
+ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter)
+ :
+ : "cc", "memory");
+
+ return result;
+}
+__LL_SC_EXPORT(atomic64_dec_if_positive);
+
+#define __CMPXCHG_CASE(w, sz, name, mb, acq, rel, cl) \
+__LL_SC_INLINE unsigned long \
+__LL_SC_PREFIX(__cmpxchg_case_##name(volatile void *ptr, \
+ unsigned long old, \
+ unsigned long new)) \
+{ \
+ unsigned long tmp, oldval; \
+ \
+ asm volatile( \
+ " prfm pstl1strm, %[v]\n" \
+ "1: ld" #acq "xr" #sz "\t%" #w "[oldval], %[v]\n" \
+ " eor %" #w "[tmp], %" #w "[oldval], %" #w "[old]\n" \
+ " cbnz %" #w "[tmp], 2f\n" \
+ " st" #rel "xr" #sz "\t%w[tmp], %" #w "[new], %[v]\n" \
+ " cbnz %w[tmp], 1b\n" \
+ " " #mb "\n" \
+ " mov %" #w "[oldval], %" #w "[old]\n" \
+ "2:" \
+ : [tmp] "=&r" (tmp), [oldval] "=&r" (oldval), \
+ [v] "+Q" (*(unsigned long *)ptr) \
+ : [old] "Lr" (old), [new] "r" (new) \
+ : cl); \
+ \
+ return oldval; \
+} \
+__LL_SC_EXPORT(__cmpxchg_case_##name);
+
+__CMPXCHG_CASE(w, b, 1, , , , )
+__CMPXCHG_CASE(w, h, 2, , , , )
+__CMPXCHG_CASE(w, , 4, , , , )
+__CMPXCHG_CASE( , , 8, , , , )
+__CMPXCHG_CASE(w, b, acq_1, , a, , "memory")
+__CMPXCHG_CASE(w, h, acq_2, , a, , "memory")
+__CMPXCHG_CASE(w, , acq_4, , a, , "memory")
+__CMPXCHG_CASE( , , acq_8, , a, , "memory")
+__CMPXCHG_CASE(w, b, rel_1, , , l, "memory")
+__CMPXCHG_CASE(w, h, rel_2, , , l, "memory")
+__CMPXCHG_CASE(w, , rel_4, , , l, "memory")
+__CMPXCHG_CASE( , , rel_8, , , l, "memory")
+__CMPXCHG_CASE(w, b, mb_1, dmb ish, , l, "memory")
+__CMPXCHG_CASE(w, h, mb_2, dmb ish, , l, "memory")
+__CMPXCHG_CASE(w, , mb_4, dmb ish, , l, "memory")
+__CMPXCHG_CASE( , , mb_8, dmb ish, , l, "memory")
+
+#undef __CMPXCHG_CASE
+
+#define __CMPXCHG_DBL(name, mb, rel, cl) \
+__LL_SC_INLINE long \
+__LL_SC_PREFIX(__cmpxchg_double##name(unsigned long old1, \
+ unsigned long old2, \
+ unsigned long new1, \
+ unsigned long new2, \
+ volatile void *ptr)) \
+{ \
+ unsigned long tmp, ret; \
+ \
+ asm volatile("// __cmpxchg_double" #name "\n" \
+ " prfm pstl1strm, %2\n" \
+ "1: ldxp %0, %1, %2\n" \
+ " eor %0, %0, %3\n" \
+ " eor %1, %1, %4\n" \
+ " orr %1, %0, %1\n" \
+ " cbnz %1, 2f\n" \
+ " st" #rel "xp %w0, %5, %6, %2\n" \
+ " cbnz %w0, 1b\n" \
+ " " #mb "\n" \
+ "2:" \
+ : "=&r" (tmp), "=&r" (ret), "+Q" (*(unsigned long *)ptr) \
+ : "r" (old1), "r" (old2), "r" (new1), "r" (new2) \
+ : cl); \
+ \
+ return ret; \
+} \
+__LL_SC_EXPORT(__cmpxchg_double##name);
+
+__CMPXCHG_DBL( , , , )
+__CMPXCHG_DBL(_mb, dmb ish, l, "memory")
+
+#undef __CMPXCHG_DBL
+
+#endif /* __ASM_ATOMIC_LL_SC_H */
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