[PATCH] asm-generic: atomic64: handle ARCH_ATOMIC builds

From: Mark Rutland
Date: Thu Apr 22 2021 - 06:26:04 EST

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We'd like all architectures to convert to ARCH_ATOMIC, as this will
enable functionality, and once all architectures are converted it will
be possible to make significant cleanups to the atomic headers.

A number of architectures use GENERIC_ATOMIC64, and it's impractical to
convert them all in one go. To make it possible to convert them
one-by-one, let's make the GENERIC_ATOMIC64 implementation function as
either atomic64_*() or arch_atomic64_*() depending on whether
ARCH_ATOMIC is selected. To do this, the C implementations are prefixed
as generic_atomic64_*(), and the asm-generic/atomic64.h header maps
atomic64_*()/arch_atomic64_*() onto these as appropriate via teh
preprocessor.

Once all users are moved over to ARCH_ATOMIC the ifdeffery in the header
can be simplified and/or removed entirely.

For existing users (none of which select ARCH_ATOMIC), there should be
no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
include/asm-generic/atomic64.h | 74 ++++++++++++++++++++++++++++++++++--------
lib/atomic64.c | 36 ++++++++++----------
2 files changed, 79 insertions(+), 31 deletions(-)

diff --git a/include/asm-generic/atomic64.h b/include/asm-generic/atomic64.h
index 370f01d4450f..45c7ff8c9477 100644
--- a/include/asm-generic/atomic64.h
+++ b/include/asm-generic/atomic64.h
@@ -15,19 +15,17 @@ typedef struct {

#define ATOMIC64_INIT(i) { (i) }

-extern s64 atomic64_read(const atomic64_t *v);
-extern void atomic64_set(atomic64_t *v, s64 i);
-
-#define atomic64_set_release(v, i) atomic64_set((v), (i))
+extern s64 generic_atomic64_read(const atomic64_t *v);
+extern void generic_atomic64_set(atomic64_t *v, s64 i);

#define ATOMIC64_OP(op) \
-extern void atomic64_##op(s64 a, atomic64_t *v);
+extern void generic_atomic64_##op(s64 a, atomic64_t *v);

#define ATOMIC64_OP_RETURN(op) \
-extern s64 atomic64_##op##_return(s64 a, atomic64_t *v);
+extern s64 generic_atomic64_##op##_return(s64 a, atomic64_t *v);

#define ATOMIC64_FETCH_OP(op) \
-extern s64 atomic64_fetch_##op(s64 a, atomic64_t *v);
+extern s64 generic_atomic64_fetch_##op(s64 a, atomic64_t *v);

#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op) ATOMIC64_FETCH_OP(op)

@@ -46,11 +44,61 @@ ATOMIC64_OPS(xor)
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP

-extern s64 atomic64_dec_if_positive(atomic64_t *v);
-#define atomic64_dec_if_positive atomic64_dec_if_positive
-extern s64 atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n);
-extern s64 atomic64_xchg(atomic64_t *v, s64 new);
-extern s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u);
-#define atomic64_fetch_add_unless atomic64_fetch_add_unless
+extern s64 generic_atomic64_dec_if_positive(atomic64_t *v);
+extern s64 generic_atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n);
+extern s64 generic_atomic64_xchg(atomic64_t *v, s64 new);
+extern s64 generic_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u);
+
+#ifdef ARCH_ATOMIC
+
+#define arch_atomic64_read generic_atomic64_read
+#define arch_atomic64_set generic_atomic64_set
+#define arch_atomic64_set_release generic_atomic64_set
+
+#define arch_atomic64_add generic_atomic64_add
+#define arch_atomic64_add_return generic_atomic64_add_return
+#define arch_atomic64_fetch_add generic_atomic64_fetch_add
+#define arch_atomic64_sub generic_atomic64_sub
+#define arch_atomic64_sub_return generic_atomic64_sub_return
+#define arch_atomic64_fetch_sub generic_atomic64_fetch_sub
+
+#define arch_atomic64_and generic_atomic64_and
+#define arch_atomic64_fetch_and generic_atomic64_fetch_and
+#define arch_atomic64_or generic_atomic64_or
+#define arch_atomic64_fetch_or generic_atomic64_fetch_or
+#define arch_atomic64_xor generic_atomic64_xor
+#define arch_atomic64_fetch_xor generic_atomic64_fetch_xor
+
+#define arch_atomic64_dec_if_positive generic_atomic64_dec_if_positive
+#define arch_atomic64_cmpxchg generic_atomic64_cmpxchg
+#define arch_atomic64_xchg generic_atomic64_xchg
+#define arch_atomic64_fetch_add_unless generic_atomic64_fetch_add_unless
+
+#else /* ARCH_ATOMIC */
+
+#define atomic64_read generic_atomic64_read
+#define atomic64_set generic_atomic64_set
+#define atomic64_set_release generic_atomic64_set
+
+#define atomic64_add generic_atomic64_add
+#define atomic64_add_return generic_atomic64_add_return
+#define atomic64_fetch_add generic_atomic64_fetch_add
+#define atomic64_sub generic_atomic64_sub
+#define atomic64_sub_return generic_atomic64_sub_return
+#define atomic64_fetch_sub generic_atomic64_fetch_sub
+
+#define atomic64_and generic_atomic64_and
+#define atomic64_fetch_and generic_atomic64_fetch_and
+#define atomic64_or generic_atomic64_or
+#define atomic64_fetch_or generic_atomic64_fetch_or
+#define atomic64_xor generic_atomic64_xor
+#define atomic64_fetch_xor generic_atomic64_fetch_xor
+
+#define atomic64_dec_if_positive generic_atomic64_dec_if_positive
+#define atomic64_cmpxchg generic_atomic64_cmpxchg
+#define atomic64_xchg generic_atomic64_xchg
+#define atomic64_fetch_add_unless generic_atomic64_fetch_add_unless
+
+#endif /* ARCH_ATOMIC */

#endif /* _ASM_GENERIC_ATOMIC64_H */
diff --git a/lib/atomic64.c b/lib/atomic64.c
index e98c85a99787..3df653994177 100644
--- a/lib/atomic64.c
+++ b/lib/atomic64.c
@@ -42,7 +42,7 @@ static inline raw_spinlock_t *lock_addr(const atomic64_t *v)
return &atomic64_lock[addr & (NR_LOCKS - 1)].lock;
}

-s64 atomic64_read(const atomic64_t *v)
+s64 generic_atomic64_read(const atomic64_t *v)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -53,9 +53,9 @@ s64 atomic64_read(const atomic64_t *v)
raw_spin_unlock_irqrestore(lock, flags);
return val;
}
-EXPORT_SYMBOL(atomic64_read);
+EXPORT_SYMBOL(generic_atomic64_read);

-void atomic64_set(atomic64_t *v, s64 i)
+void generic_atomic64_set(atomic64_t *v, s64 i)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -64,10 +64,10 @@ void atomic64_set(atomic64_t *v, s64 i)
v->counter = i;
raw_spin_unlock_irqrestore(lock, flags);
}
-EXPORT_SYMBOL(atomic64_set);
+EXPORT_SYMBOL(generic_atomic64_set);

#define ATOMIC64_OP(op, c_op) \
-void atomic64_##op(s64 a, atomic64_t *v) \
+void generic_atomic64_##op(s64 a, atomic64_t *v) \
{ \
unsigned long flags; \
raw_spinlock_t *lock = lock_addr(v); \
@@ -76,10 +76,10 @@ void atomic64_##op(s64 a, atomic64_t *v) \
v->counter c_op a; \
raw_spin_unlock_irqrestore(lock, flags); \
} \
-EXPORT_SYMBOL(atomic64_##op);
+EXPORT_SYMBOL(generic_atomic64_##op);

#define ATOMIC64_OP_RETURN(op, c_op) \
-s64 atomic64_##op##_return(s64 a, atomic64_t *v) \
+s64 generic_atomic64_##op##_return(s64 a, atomic64_t *v) \
{ \
unsigned long flags; \
raw_spinlock_t *lock = lock_addr(v); \
@@ -90,10 +90,10 @@ s64 atomic64_##op##_return(s64 a, atomic64_t *v) \
raw_spin_unlock_irqrestore(lock, flags); \
return val; \
} \
-EXPORT_SYMBOL(atomic64_##op##_return);
+EXPORT_SYMBOL(generic_atomic64_##op##_return);

#define ATOMIC64_FETCH_OP(op, c_op) \
-s64 atomic64_fetch_##op(s64 a, atomic64_t *v) \
+s64 generic_atomic64_fetch_##op(s64 a, atomic64_t *v) \
{ \
unsigned long flags; \
raw_spinlock_t *lock = lock_addr(v); \
@@ -105,7 +105,7 @@ s64 atomic64_fetch_##op(s64 a, atomic64_t *v) \
raw_spin_unlock_irqrestore(lock, flags); \
return val; \
} \
-EXPORT_SYMBOL(atomic64_fetch_##op);
+EXPORT_SYMBOL(generic_atomic64_fetch_##op);

#define ATOMIC64_OPS(op, c_op) \
ATOMIC64_OP(op, c_op) \
@@ -130,7 +130,7 @@ ATOMIC64_OPS(xor, ^=)
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP

-s64 atomic64_dec_if_positive(atomic64_t *v)
+s64 generic_atomic64_dec_if_positive(atomic64_t *v)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -143,9 +143,9 @@ s64 atomic64_dec_if_positive(atomic64_t *v)
raw_spin_unlock_irqrestore(lock, flags);
return val;
}
-EXPORT_SYMBOL(atomic64_dec_if_positive);
+EXPORT_SYMBOL(generic_atomic64_dec_if_positive);

-s64 atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n)
+s64 generic_atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -158,9 +158,9 @@ s64 atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n)
raw_spin_unlock_irqrestore(lock, flags);
return val;
}
-EXPORT_SYMBOL(atomic64_cmpxchg);
+EXPORT_SYMBOL(generic_atomic64_cmpxchg);

-s64 atomic64_xchg(atomic64_t *v, s64 new)
+s64 generic_atomic64_xchg(atomic64_t *v, s64 new)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -172,9 +172,9 @@ s64 atomic64_xchg(atomic64_t *v, s64 new)
raw_spin_unlock_irqrestore(lock, flags);
return val;
}
-EXPORT_SYMBOL(atomic64_xchg);
+EXPORT_SYMBOL(generic_atomic64_xchg);

-s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
+s64 generic_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -188,4 +188,4 @@ s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)

return val;
}
-EXPORT_SYMBOL(atomic64_fetch_add_unless);
+EXPORT_SYMBOL(generic_atomic64_fetch_add_unless);
--
2.11.0

Next message: Daniel Lezcano: "Re: [PATCH v3 3/3] thermal: create a helper __thermal_cdev_update() without a lock"
Previous message: Jiri Olsa: "Re: [PATCH v4 14/25] perf stat: Add default hybrid events"
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