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locking/atomic: atomic64: support ARCH_ATOMIC
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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 asm-generic/atomic64.h, and it's
impractical to convert the header and all these architectures in one go.
To make it possible to convert them one-by-one, let's make the
asm-generic implementation function as either atomic64_*() or
arch_atomic64_*() depending on whether ARCH_ATOMIC is selected. To do
this, the generic implementations are prefixed as generic_atomic64_*(),
and preprocessor definitions map atomic64_*()/arch_atomic64_*() onto
these as appropriate.

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@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-11-mark.rutland@arm.com
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Mark Rutland authored and Peter Zijlstra committed May 26, 2021
1 parent f8b6455 commit 1bdadf4
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Showing 2 changed files with 79 additions and 31 deletions.
74 changes: 61 additions & 13 deletions include/asm-generic/atomic64.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)

Expand All @@ -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 CONFIG_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 /* CONFIG_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 /* CONFIG_ARCH_ATOMIC */

#endif /* _ASM_GENERIC_ATOMIC64_H */
36 changes: 18 additions & 18 deletions lib/atomic64.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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);
Expand All @@ -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); \
Expand All @@ -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); \
Expand All @@ -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); \
Expand All @@ -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) \
Expand All @@ -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);
Expand All @@ -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);
Expand All @@ -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);
Expand All @@ -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);
Expand All @@ -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);

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