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Date:   Thu, 13 May 2021 11:49:20 +0100
From:   Mark Rutland <mark.rutland@arm.com>
To:     linux-kernel@vger.kernel.org, will@kernel.org,
        boqun.feng@gmail.com, peterz@infradead.org
Cc:     aou@eecs.berkeley.edu, arnd@arndb.de, bcain@codeaurora.org,
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        davem@davemloft.net, deanbo422@gmail.com, deller@gmx.de,
        geert@linux-m68k.org, green.hu@gmail.com, guoren@kernel.org,
        ink@jurassic.park.msu.ru, James.Bottomley@HansenPartnership.com,
        jcmvbkbc@gmail.com, jonas@southpole.se, ley.foon.tan@intel.com,
        linux@armlinux.org.uk, mattst88@gmail.com, monstr@monstr.eu,
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        paulus@samba.org, paul.walmsley@sifive.com, rth@twiddle.net,
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        tsbogend@alpha.franken.de, vgupta@synopsys.com,
        ysato@users.sourceforge.jp
Subject: Re: [PATCH 15/33] locking/atomic: arm: move to ARCH_ATOMIC
Message-ID: <20210513104920.GB10886@C02TD0UTHF1T.local>
References: <20210510093753.40683-1-mark.rutland@arm.com>
 <20210510093753.40683-16-mark.rutland@arm.com>
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In-Reply-To: <20210510093753.40683-16-mark.rutland@arm.com>
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On Mon, May 10, 2021 at 10:37:35AM +0100, Mark Rutland wrote:
> We'd like all architectures to convert to ARCH_ATOMIC, as once all
> architectures are converted it will be possible to make significant
> cleanups to the atomics headers, and this will make it much easier to
> generically enable atomic functionality (e.g. debug logic in the
> instrumented wrappers).
> 
> As a step towards that, this patch migrates arm to ARCH_ATOMIC. The arch
> code provides arch_{atomic,atomic64,xchg,cmpxchg}*(), and common code
> wraps these with optional instrumentation to provide the regular
> functions.
> 
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Boqun Feng <boqun.feng@gmail.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: Will Deacon <will@kernel.org>
> ---
>  arch/arm/Kconfig               |  1 +
>  arch/arm/include/asm/atomic.h  | 96 +++++++++++++++++++++---------------------
>  arch/arm/include/asm/cmpxchg.h | 16 +++----
>  3 files changed, 57 insertions(+), 56 deletions(-)

The Kbuild test robot pointed out I'd forgotten to update sync_cmpxchg()
in <asm/sync_bitops.h>, so I've fixed that up in my kernel.org branch
for now.

Mark.

> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 24804f11302d..b7334a6643b9 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -3,6 +3,7 @@ config ARM
>  	bool
>  	default y
>  	select ARCH_32BIT_OFF_T
> +	select ARCH_ATOMIC
>  	select ARCH_HAS_BINFMT_FLAT
>  	select ARCH_HAS_DEBUG_VIRTUAL if MMU
>  	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
> diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
> index 455eb19a5ac1..db8512d9a918 100644
> --- a/arch/arm/include/asm/atomic.h
> +++ b/arch/arm/include/asm/atomic.h
> @@ -22,8 +22,8 @@
>   * strex/ldrex monitor on some implementations. The reason we can use it for
>   * atomic_set() is the clrex or dummy strex done on every exception return.
>   */
> -#define atomic_read(v)	READ_ONCE((v)->counter)
> -#define atomic_set(v,i)	WRITE_ONCE(((v)->counter), (i))
> +#define arch_atomic_read(v)	READ_ONCE((v)->counter)
> +#define arch_atomic_set(v,i)	WRITE_ONCE(((v)->counter), (i))
>  
>  #if __LINUX_ARM_ARCH__ >= 6
>  
> @@ -34,7 +34,7 @@
>   */
>  
>  #define ATOMIC_OP(op, c_op, asm_op)					\
> -static inline void atomic_##op(int i, atomic_t *v)			\
> +static inline void arch_atomic_##op(int i, atomic_t *v)			\
>  {									\
>  	unsigned long tmp;						\
>  	int result;							\
> @@ -52,7 +52,7 @@ static inline void atomic_##op(int i, atomic_t *v)			\
>  }									\
>  
>  #define ATOMIC_OP_RETURN(op, c_op, asm_op)				\
> -static inline int atomic_##op##_return_relaxed(int i, atomic_t *v)	\
> +static inline int arch_atomic_##op##_return_relaxed(int i, atomic_t *v)	\
>  {									\
>  	unsigned long tmp;						\
>  	int result;							\
> @@ -73,7 +73,7 @@ static inline int atomic_##op##_return_relaxed(int i, atomic_t *v)	\
>  }
>  
>  #define ATOMIC_FETCH_OP(op, c_op, asm_op)				\
> -static inline int atomic_fetch_##op##_relaxed(int i, atomic_t *v)	\
> +static inline int arch_atomic_fetch_##op##_relaxed(int i, atomic_t *v)	\
>  {									\
>  	unsigned long tmp;						\
>  	int result, val;						\
> @@ -93,17 +93,17 @@ static inline int atomic_fetch_##op##_relaxed(int i, atomic_t *v)	\
>  	return result;							\
>  }
>  
> -#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 arch_atomic_add_return_relaxed		arch_atomic_add_return_relaxed
> +#define arch_atomic_sub_return_relaxed		arch_atomic_sub_return_relaxed
> +#define arch_atomic_fetch_add_relaxed		arch_atomic_fetch_add_relaxed
> +#define arch_atomic_fetch_sub_relaxed		arch_atomic_fetch_sub_relaxed
>  
> -#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 arch_atomic_fetch_and_relaxed		arch_atomic_fetch_and_relaxed
> +#define arch_atomic_fetch_andnot_relaxed	arch_atomic_fetch_andnot_relaxed
> +#define arch_atomic_fetch_or_relaxed		arch_atomic_fetch_or_relaxed
> +#define arch_atomic_fetch_xor_relaxed		arch_atomic_fetch_xor_relaxed
>  
> -static inline int atomic_cmpxchg_relaxed(atomic_t *ptr, int old, int new)
> +static inline int arch_atomic_cmpxchg_relaxed(atomic_t *ptr, int old, int new)
>  {
>  	int oldval;
>  	unsigned long res;
> @@ -123,9 +123,9 @@ static inline int atomic_cmpxchg_relaxed(atomic_t *ptr, int old, int new)
>  
>  	return oldval;
>  }
> -#define atomic_cmpxchg_relaxed		atomic_cmpxchg_relaxed
> +#define arch_atomic_cmpxchg_relaxed		arch_atomic_cmpxchg_relaxed
>  
> -static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
> +static inline int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
>  {
>  	int oldval, newval;
>  	unsigned long tmp;
> @@ -151,7 +151,7 @@ static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
>  
>  	return oldval;
>  }
> -#define atomic_fetch_add_unless		atomic_fetch_add_unless
> +#define arch_atomic_fetch_add_unless		arch_atomic_fetch_add_unless
>  
>  #else /* ARM_ARCH_6 */
>  
> @@ -160,7 +160,7 @@ static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
>  #endif
>  
>  #define ATOMIC_OP(op, c_op, asm_op)					\
> -static inline void atomic_##op(int i, atomic_t *v)			\
> +static inline void arch_atomic_##op(int i, atomic_t *v)			\
>  {									\
>  	unsigned long flags;						\
>  									\
> @@ -170,7 +170,7 @@ static inline void atomic_##op(int i, atomic_t *v)			\
>  }									\
>  
>  #define ATOMIC_OP_RETURN(op, c_op, asm_op)				\
> -static inline int atomic_##op##_return(int i, atomic_t *v)		\
> +static inline int arch_atomic_##op##_return(int i, atomic_t *v)		\
>  {									\
>  	unsigned long flags;						\
>  	int val;							\
> @@ -184,7 +184,7 @@ static inline int atomic_##op##_return(int i, atomic_t *v)		\
>  }
>  
>  #define ATOMIC_FETCH_OP(op, c_op, asm_op)				\
> -static inline int atomic_fetch_##op(int i, atomic_t *v)			\
> +static inline int arch_atomic_fetch_##op(int i, atomic_t *v)		\
>  {									\
>  	unsigned long flags;						\
>  	int val;							\
> @@ -197,7 +197,7 @@ static inline int atomic_fetch_##op(int i, atomic_t *v)			\
>  	return val;							\
>  }
>  
> -static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
> +static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
>  {
>  	int ret;
>  	unsigned long flags;
> @@ -211,7 +211,7 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
>  	return ret;
>  }
>  
> -#define atomic_fetch_andnot		atomic_fetch_andnot
> +#define arch_atomic_fetch_andnot		arch_atomic_fetch_andnot
>  
>  #endif /* __LINUX_ARM_ARCH__ */
>  
> @@ -223,7 +223,7 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
>  ATOMIC_OPS(add, +=, add)
>  ATOMIC_OPS(sub, -=, sub)
>  
> -#define atomic_andnot atomic_andnot
> +#define arch_atomic_andnot arch_atomic_andnot
>  
>  #undef ATOMIC_OPS
>  #define ATOMIC_OPS(op, c_op, asm_op)					\
> @@ -240,7 +240,7 @@ ATOMIC_OPS(xor, ^=, eor)
>  #undef ATOMIC_OP_RETURN
>  #undef ATOMIC_OP
>  
> -#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
> +#define arch_atomic_xchg(v, new) (arch_xchg(&((v)->counter), new))
>  
>  #ifndef CONFIG_GENERIC_ATOMIC64
>  typedef struct {
> @@ -250,7 +250,7 @@ typedef struct {
>  #define ATOMIC64_INIT(i) { (i) }
>  
>  #ifdef CONFIG_ARM_LPAE
> -static inline s64 atomic64_read(const atomic64_t *v)
> +static inline s64 arch_atomic64_read(const atomic64_t *v)
>  {
>  	s64 result;
>  
> @@ -263,7 +263,7 @@ static inline s64 atomic64_read(const atomic64_t *v)
>  	return result;
>  }
>  
> -static inline void atomic64_set(atomic64_t *v, s64 i)
> +static inline void arch_atomic64_set(atomic64_t *v, s64 i)
>  {
>  	__asm__ __volatile__("@ atomic64_set\n"
>  "	strd	%2, %H2, [%1]"
> @@ -272,7 +272,7 @@ static inline void atomic64_set(atomic64_t *v, s64 i)
>  	);
>  }
>  #else
> -static inline s64 atomic64_read(const atomic64_t *v)
> +static inline s64 arch_atomic64_read(const atomic64_t *v)
>  {
>  	s64 result;
>  
> @@ -285,7 +285,7 @@ static inline s64 atomic64_read(const atomic64_t *v)
>  	return result;
>  }
>  
> -static inline void atomic64_set(atomic64_t *v, s64 i)
> +static inline void arch_atomic64_set(atomic64_t *v, s64 i)
>  {
>  	s64 tmp;
>  
> @@ -302,7 +302,7 @@ static inline void atomic64_set(atomic64_t *v, s64 i)
>  #endif
>  
>  #define ATOMIC64_OP(op, op1, op2)					\
> -static inline void atomic64_##op(s64 i, atomic64_t *v)			\
> +static inline void arch_atomic64_##op(s64 i, atomic64_t *v)		\
>  {									\
>  	s64 result;							\
>  	unsigned long tmp;						\
> @@ -322,7 +322,7 @@ static inline void atomic64_##op(s64 i, atomic64_t *v)			\
>  
>  #define ATOMIC64_OP_RETURN(op, op1, op2)				\
>  static inline s64							\
> -atomic64_##op##_return_relaxed(s64 i, atomic64_t *v)			\
> +arch_atomic64_##op##_return_relaxed(s64 i, atomic64_t *v)		\
>  {									\
>  	s64 result;							\
>  	unsigned long tmp;						\
> @@ -345,7 +345,7 @@ atomic64_##op##_return_relaxed(s64 i, atomic64_t *v)			\
>  
>  #define ATOMIC64_FETCH_OP(op, op1, op2)					\
>  static inline s64							\
> -atomic64_fetch_##op##_relaxed(s64 i, atomic64_t *v)			\
> +arch_atomic64_fetch_##op##_relaxed(s64 i, atomic64_t *v)		\
>  {									\
>  	s64 result, val;						\
>  	unsigned long tmp;						\
> @@ -374,34 +374,34 @@ atomic64_fetch_##op##_relaxed(s64 i, atomic64_t *v)			\
>  ATOMIC64_OPS(add, adds, adc)
>  ATOMIC64_OPS(sub, subs, sbc)
>  
> -#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 arch_atomic64_add_return_relaxed	arch_atomic64_add_return_relaxed
> +#define arch_atomic64_sub_return_relaxed	arch_atomic64_sub_return_relaxed
> +#define arch_atomic64_fetch_add_relaxed		arch_atomic64_fetch_add_relaxed
> +#define arch_atomic64_fetch_sub_relaxed		arch_atomic64_fetch_sub_relaxed
>  
>  #undef ATOMIC64_OPS
>  #define ATOMIC64_OPS(op, op1, op2)					\
>  	ATOMIC64_OP(op, op1, op2)					\
>  	ATOMIC64_FETCH_OP(op, op1, op2)
>  
> -#define atomic64_andnot atomic64_andnot
> +#define arch_atomic64_andnot arch_atomic64_andnot
>  
>  ATOMIC64_OPS(and, and, and)
>  ATOMIC64_OPS(andnot, bic, bic)
>  ATOMIC64_OPS(or,  orr, orr)
>  ATOMIC64_OPS(xor, eor, eor)
>  
> -#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
> +#define arch_atomic64_fetch_and_relaxed		arch_atomic64_fetch_and_relaxed
> +#define arch_atomic64_fetch_andnot_relaxed	arch_atomic64_fetch_andnot_relaxed
> +#define arch_atomic64_fetch_or_relaxed		arch_atomic64_fetch_or_relaxed
> +#define arch_atomic64_fetch_xor_relaxed		arch_atomic64_fetch_xor_relaxed
>  
>  #undef ATOMIC64_OPS
>  #undef ATOMIC64_FETCH_OP
>  #undef ATOMIC64_OP_RETURN
>  #undef ATOMIC64_OP
>  
> -static inline s64 atomic64_cmpxchg_relaxed(atomic64_t *ptr, s64 old, s64 new)
> +static inline s64 arch_atomic64_cmpxchg_relaxed(atomic64_t *ptr, s64 old, s64 new)
>  {
>  	s64 oldval;
>  	unsigned long res;
> @@ -422,9 +422,9 @@ static inline s64 atomic64_cmpxchg_relaxed(atomic64_t *ptr, s64 old, s64 new)
>  
>  	return oldval;
>  }
> -#define atomic64_cmpxchg_relaxed	atomic64_cmpxchg_relaxed
> +#define arch_atomic64_cmpxchg_relaxed	arch_atomic64_cmpxchg_relaxed
>  
> -static inline s64 atomic64_xchg_relaxed(atomic64_t *ptr, s64 new)
> +static inline s64 arch_atomic64_xchg_relaxed(atomic64_t *ptr, s64 new)
>  {
>  	s64 result;
>  	unsigned long tmp;
> @@ -442,9 +442,9 @@ static inline s64 atomic64_xchg_relaxed(atomic64_t *ptr, s64 new)
>  
>  	return result;
>  }
> -#define atomic64_xchg_relaxed		atomic64_xchg_relaxed
> +#define arch_atomic64_xchg_relaxed		arch_atomic64_xchg_relaxed
>  
> -static inline s64 atomic64_dec_if_positive(atomic64_t *v)
> +static inline s64 arch_atomic64_dec_if_positive(atomic64_t *v)
>  {
>  	s64 result;
>  	unsigned long tmp;
> @@ -470,9 +470,9 @@ static inline s64 atomic64_dec_if_positive(atomic64_t *v)
>  
>  	return result;
>  }
> -#define atomic64_dec_if_positive atomic64_dec_if_positive
> +#define arch_atomic64_dec_if_positive arch_atomic64_dec_if_positive
>  
> -static inline s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
> +static inline s64 arch_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
>  {
>  	s64 oldval, newval;
>  	unsigned long tmp;
> @@ -500,7 +500,7 @@ static inline s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
>  
>  	return oldval;
>  }
> -#define atomic64_fetch_add_unless atomic64_fetch_add_unless
> +#define arch_atomic64_fetch_add_unless arch_atomic64_fetch_add_unless
>  
>  #endif /* !CONFIG_GENERIC_ATOMIC64 */
>  #endif
> diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h
> index 06bd8cea861a..4dfe538dfc68 100644
> --- a/arch/arm/include/asm/cmpxchg.h
> +++ b/arch/arm/include/asm/cmpxchg.h
> @@ -114,7 +114,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size
>  	return ret;
>  }
>  
> -#define xchg_relaxed(ptr, x) ({						\
> +#define arch_xchg_relaxed(ptr, x) ({					\
>  	(__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr),		\
>  				   sizeof(*(ptr)));			\
>  })
> @@ -128,20 +128,20 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size
>  #error "SMP is not supported on this platform"
>  #endif
>  
> -#define xchg xchg_relaxed
> +#define arch_xchg arch_xchg_relaxed
>  
>  /*
>   * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
>   * them available.
>   */
> -#define cmpxchg_local(ptr, o, n) ({					\
> +#define arch_cmpxchg_local(ptr, o, n) ({				\
>  	(__typeof(*ptr))__generic_cmpxchg_local((ptr),			\
>  					        (unsigned long)(o),	\
>  					        (unsigned long)(n),	\
>  					        sizeof(*(ptr)));	\
>  })
>  
> -#define cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
> +#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
>  
>  #include <asm-generic/cmpxchg.h>
>  
> @@ -207,7 +207,7 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
>  	return oldval;
>  }
>  
> -#define cmpxchg_relaxed(ptr,o,n) ({					\
> +#define arch_cmpxchg_relaxed(ptr,o,n) ({				\
>  	(__typeof__(*(ptr)))__cmpxchg((ptr),				\
>  				      (unsigned long)(o),		\
>  				      (unsigned long)(n),		\
> @@ -234,7 +234,7 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr,
>  	return ret;
>  }
>  
> -#define cmpxchg_local(ptr, o, n) ({					\
> +#define arch_cmpxchg_local(ptr, o, n) ({				\
>  	(__typeof(*ptr))__cmpxchg_local((ptr),				\
>  				        (unsigned long)(o),		\
>  				        (unsigned long)(n),		\
> @@ -266,13 +266,13 @@ static inline unsigned long long __cmpxchg64(unsigned long long *ptr,
>  	return oldval;
>  }
>  
> -#define cmpxchg64_relaxed(ptr, o, n) ({					\
> +#define arch_cmpxchg64_relaxed(ptr, o, n) ({				\
>  	(__typeof__(*(ptr)))__cmpxchg64((ptr),				\
>  					(unsigned long long)(o),	\
>  					(unsigned long long)(n));	\
>  })
>  
> -#define cmpxchg64_local(ptr, o, n) cmpxchg64_relaxed((ptr), (o), (n))
> +#define arch_cmpxchg64_local(ptr, o, n) arch_cmpxchg64_relaxed((ptr), (o), (n))
>  
>  #endif	/* __LINUX_ARM_ARCH__ >= 6 */
>  
> -- 
> 2.11.0
>