Hi Guo, On Wed, Apr 21, 2021 at 12:53:45PM +0000, guoren@xxxxxxxxxx wrote: > From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > Current GENERIC_ATOMIC64 in atomic-arch-fallback.h is broken. When a 32-bit > arch use atomic-arch-fallback.h will cause compile error. > > In file included from include/linux/atomic.h:81, > from include/linux/rcupdate.h:25, > from include/linux/rculist.h:11, > from include/linux/pid.h:5, > from include/linux/sched.h:14, > from arch/riscv/kernel/asm-offsets.c:10: > include/linux/atomic-arch-fallback.h: In function 'arch_atomic64_inc': > >> include/linux/atomic-arch-fallback.h:1447:2: error: implicit declaration of function 'arch_atomic64_add'; did you mean 'arch_atomic_add'? [-Werror=implicit-function-declaration] > 1447 | arch_atomic64_add(1, v); > | ^~~~~~~~~~~~~~~~~ > | arch_atomic_add This is expected; GENERIC_ATOMIC64 doesn't implement arch_atomic64_*(), and thus violates the expectations of the fallback code. To make GENERIC_ATOMIC64 compatible with ARCH_ATOMIC, the GENERIC_ATOMIC64 implementation *must* provide arch_atomic64_*() functions. > The atomic-arch-fallback.h & atomic-fallback.h & > atomic-instrumented.h are generated by gen-atomic-fallback.sh & > gen-atomic-instrumented.sh, so just take care the bash files. > > Remove the dependency of atomic-*-fallback.h in atomic64.h. Please don't duplicate the fallbacks; this'll make it harder to move other over and eventually remove the non-ARCH_ATOMIC implementations. Does the patch below make things work for you, or have I missed something? I've given this a basic build test on an arm config using GENERIC_ATOMIC64 (but not ARCH_ATOMIC). Thanks, Mark. ---->8---- >From 7f0389c8a1f41ecb5b2700f6ba38ff2ba093eb33 Mon Sep 17 00:00:00 2001 From: Mark Rutland <mark.rutland@xxxxxxx> Date: Thu, 22 Apr 2021 11:26:04 +0100 Subject: [PATCH] asm-generic: atomic64: handle ARCH_ATOMIC builds 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