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-rw-r--r--arch/alpha/include/asm/atomic.h300
1 files changed, 300 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h
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+++ b/arch/alpha/include/asm/atomic.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ALPHA_ATOMIC_H
+#define _ALPHA_ATOMIC_H
+
+#include <linux/types.h>
+#include <asm/barrier.h>
+#include <asm/cmpxchg.h>
+
+/*
+ * Atomic operations that C can't guarantee us. Useful for
+ * resource counting etc...
+ *
+ * But use these as seldom as possible since they are much slower
+ * than regular operations.
+ */
+
+/*
+ * To ensure dependency ordering is preserved for the _relaxed and
+ * _release atomics, an smp_mb() is unconditionally inserted into the
+ * _relaxed variants, which are used to build the barriered versions.
+ * Avoid redundant back-to-back fences in the _acquire and _fence
+ * versions.
+ */
+#define __atomic_acquire_fence()
+#define __atomic_post_full_fence()
+
+#define ATOMIC64_INIT(i) { (i) }
+
+#define atomic_read(v) READ_ONCE((v)->counter)
+#define atomic64_read(v) READ_ONCE((v)->counter)
+
+#define atomic_set(v,i) WRITE_ONCE((v)->counter, (i))
+#define atomic64_set(v,i) WRITE_ONCE((v)->counter, (i))
+
+/*
+ * To get proper branch prediction for the main line, we must branch
+ * forward to code at the end of this object's .text section, then
+ * branch back to restart the operation.
+ */
+
+#define ATOMIC_OP(op, asm_op) \
+static __inline__ void atomic_##op(int i, atomic_t * v) \
+{ \
+ unsigned long temp; \
+ __asm__ __volatile__( \
+ "1: ldl_l %0,%1\n" \
+ " " #asm_op " %0,%2,%0\n" \
+ " stl_c %0,%1\n" \
+ " beq %0,2f\n" \
+ ".subsection 2\n" \
+ "2: br 1b\n" \
+ ".previous" \
+ :"=&r" (temp), "=m" (v->counter) \
+ :"Ir" (i), "m" (v->counter)); \
+} \
+
+#define ATOMIC_OP_RETURN(op, asm_op) \
+static inline int atomic_##op##_return_relaxed(int i, atomic_t *v) \
+{ \
+ long temp, result; \
+ __asm__ __volatile__( \
+ "1: ldl_l %0,%1\n" \
+ " " #asm_op " %0,%3,%2\n" \
+ " " #asm_op " %0,%3,%0\n" \
+ " stl_c %0,%1\n" \
+ " beq %0,2f\n" \
+ ".subsection 2\n" \
+ "2: br 1b\n" \
+ ".previous" \
+ :"=&r" (temp), "=m" (v->counter), "=&r" (result) \
+ :"Ir" (i), "m" (v->counter) : "memory"); \
+ smp_mb(); \
+ return result; \
+}
+
+#define ATOMIC_FETCH_OP(op, asm_op) \
+static inline int atomic_fetch_##op##_relaxed(int i, atomic_t *v) \
+{ \
+ long temp, result; \
+ __asm__ __volatile__( \
+ "1: ldl_l %2,%1\n" \
+ " " #asm_op " %2,%3,%0\n" \
+ " stl_c %0,%1\n" \
+ " beq %0,2f\n" \
+ ".subsection 2\n" \
+ "2: br 1b\n" \
+ ".previous" \
+ :"=&r" (temp), "=m" (v->counter), "=&r" (result) \
+ :"Ir" (i), "m" (v->counter) : "memory"); \
+ smp_mb(); \
+ return result; \
+}
+
+#define ATOMIC64_OP(op, asm_op) \
+static __inline__ void atomic64_##op(s64 i, atomic64_t * v) \
+{ \
+ s64 temp; \
+ __asm__ __volatile__( \
+ "1: ldq_l %0,%1\n" \
+ " " #asm_op " %0,%2,%0\n" \
+ " stq_c %0,%1\n" \
+ " beq %0,2f\n" \
+ ".subsection 2\n" \
+ "2: br 1b\n" \
+ ".previous" \
+ :"=&r" (temp), "=m" (v->counter) \
+ :"Ir" (i), "m" (v->counter)); \
+} \
+
+#define ATOMIC64_OP_RETURN(op, asm_op) \
+static __inline__ s64 atomic64_##op##_return_relaxed(s64 i, atomic64_t * v) \
+{ \
+ s64 temp, result; \
+ __asm__ __volatile__( \
+ "1: ldq_l %0,%1\n" \
+ " " #asm_op " %0,%3,%2\n" \
+ " " #asm_op " %0,%3,%0\n" \
+ " stq_c %0,%1\n" \
+ " beq %0,2f\n" \
+ ".subsection 2\n" \
+ "2: br 1b\n" \
+ ".previous" \
+ :"=&r" (temp), "=m" (v->counter), "=&r" (result) \
+ :"Ir" (i), "m" (v->counter) : "memory"); \
+ smp_mb(); \
+ return result; \
+}
+
+#define ATOMIC64_FETCH_OP(op, asm_op) \
+static __inline__ s64 atomic64_fetch_##op##_relaxed(s64 i, atomic64_t * v) \
+{ \
+ s64 temp, result; \
+ __asm__ __volatile__( \
+ "1: ldq_l %2,%1\n" \
+ " " #asm_op " %2,%3,%0\n" \
+ " stq_c %0,%1\n" \
+ " beq %0,2f\n" \
+ ".subsection 2\n" \
+ "2: br 1b\n" \
+ ".previous" \
+ :"=&r" (temp), "=m" (v->counter), "=&r" (result) \
+ :"Ir" (i), "m" (v->counter) : "memory"); \
+ smp_mb(); \
+ return result; \
+}
+
+#define ATOMIC_OPS(op) \
+ ATOMIC_OP(op, op##l) \
+ ATOMIC_OP_RETURN(op, op##l) \
+ ATOMIC_FETCH_OP(op, op##l) \
+ ATOMIC64_OP(op, op##q) \
+ ATOMIC64_OP_RETURN(op, op##q) \
+ ATOMIC64_FETCH_OP(op, op##q)
+
+ATOMIC_OPS(add)
+ATOMIC_OPS(sub)
+
+#define atomic_add_return_relaxed atomic_add_return_relaxed
+#define atomic_sub_return_relaxed atomic_sub_return_relaxed
+#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed
+#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed
+
+#define atomic64_add_return_relaxed atomic64_add_return_relaxed
+#define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
+#define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed
+#define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed
+
+#define atomic_andnot atomic_andnot
+#define atomic64_andnot atomic64_andnot
+
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(op, asm) \
+ ATOMIC_OP(op, asm) \
+ ATOMIC_FETCH_OP(op, asm) \
+ ATOMIC64_OP(op, asm) \
+ ATOMIC64_FETCH_OP(op, asm)
+
+ATOMIC_OPS(and, and)
+ATOMIC_OPS(andnot, bic)
+ATOMIC_OPS(or, bis)
+ATOMIC_OPS(xor, xor)
+
+#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed
+#define atomic_fetch_andnot_relaxed atomic_fetch_andnot_relaxed
+#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed
+#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed
+
+#define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed
+#define atomic64_fetch_andnot_relaxed atomic64_fetch_andnot_relaxed
+#define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed
+#define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed
+
+#undef ATOMIC_OPS
+#undef ATOMIC64_FETCH_OP
+#undef ATOMIC64_OP_RETURN
+#undef ATOMIC64_OP
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
+#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
+
+#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
+/**
+ * atomic_fetch_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns the old value of @v.
+ */
+static __inline__ int atomic_fetch_add_unless(atomic_t *v, int a, int u)
+{
+ int c, new, old;
+ smp_mb();
+ __asm__ __volatile__(
+ "1: ldl_l %[old],%[mem]\n"
+ " cmpeq %[old],%[u],%[c]\n"
+ " addl %[old],%[a],%[new]\n"
+ " bne %[c],2f\n"
+ " stl_c %[new],%[mem]\n"
+ " beq %[new],3f\n"
+ "2:\n"
+ ".subsection 2\n"
+ "3: br 1b\n"
+ ".previous"
+ : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
+ : [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u)
+ : "memory");
+ smp_mb();
+ return old;
+}
+#define atomic_fetch_add_unless atomic_fetch_add_unless
+
+/**
+ * atomic64_fetch_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic64_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns the old value of @v.
+ */
+static __inline__ s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
+{
+ s64 c, new, old;
+ smp_mb();
+ __asm__ __volatile__(
+ "1: ldq_l %[old],%[mem]\n"
+ " cmpeq %[old],%[u],%[c]\n"
+ " addq %[old],%[a],%[new]\n"
+ " bne %[c],2f\n"
+ " stq_c %[new],%[mem]\n"
+ " beq %[new],3f\n"
+ "2:\n"
+ ".subsection 2\n"
+ "3: br 1b\n"
+ ".previous"
+ : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
+ : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u)
+ : "memory");
+ smp_mb();
+ return old;
+}
+#define atomic64_fetch_add_unless atomic64_fetch_add_unless
+
+/*
+ * atomic64_dec_if_positive - decrement by 1 if old value positive
+ * @v: pointer of type atomic_t
+ *
+ * The function returns the old value of *v minus 1, even if
+ * the atomic variable, v, was not decremented.
+ */
+static inline s64 atomic64_dec_if_positive(atomic64_t *v)
+{
+ s64 old, tmp;
+ smp_mb();
+ __asm__ __volatile__(
+ "1: ldq_l %[old],%[mem]\n"
+ " subq %[old],1,%[tmp]\n"
+ " ble %[old],2f\n"
+ " stq_c %[tmp],%[mem]\n"
+ " beq %[tmp],3f\n"
+ "2:\n"
+ ".subsection 2\n"
+ "3: br 1b\n"
+ ".previous"
+ : [old] "=&r"(old), [tmp] "=&r"(tmp)
+ : [mem] "m"(*v)
+ : "memory");
+ smp_mb();
+ return old - 1;
+}
+#define atomic64_dec_if_positive atomic64_dec_if_positive
+
+#endif /* _ALPHA_ATOMIC_H */
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