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* [PATCH 0/2] tools/virtio: remove smp_read_barrier_depends()
@ 2022-11-28  3:43 ` Davidlohr Bueso
  0 siblings, 0 replies; 10+ messages in thread
From: Davidlohr Bueso @ 2022-11-28  3:43 UTC (permalink / raw)
  To: mst; +Cc: virtualization, linux-kernel, dave

Hi,

To my surprise, this call is still git-greppable in the
tree, the kernel having gotten rid of it a while back.

Thanks!

Davidlohr Bueso (2):
  tools/virtio: remove stray characters
  tools/virtio: remove smp_read_barrier_depends()

 tools/virtio/ringtest/main.h | 37 +++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 17 deletions(-)

-- 
2.38.1


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [PATCH 0/2] tools/virtio: remove smp_read_barrier_depends()
@ 2022-11-28  3:43 ` Davidlohr Bueso
  0 siblings, 0 replies; 10+ messages in thread
From: Davidlohr Bueso @ 2022-11-28  3:43 UTC (permalink / raw)
  To: mst; +Cc: dave, linux-kernel, virtualization

Hi,

To my surprise, this call is still git-greppable in the
tree, the kernel having gotten rid of it a while back.

Thanks!

Davidlohr Bueso (2):
  tools/virtio: remove stray characters
  tools/virtio: remove smp_read_barrier_depends()

 tools/virtio/ringtest/main.h | 37 +++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 17 deletions(-)

-- 
2.38.1

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 10+ messages in thread
* [PATCH 1/2] tools/virtio: remove stray characters
  2022-11-28  3:43 ` Davidlohr Bueso
@ 2022-11-28  3:43   ` Davidlohr Bueso
  -1 siblings, 0 replies; 10+ messages in thread
From: Davidlohr Bueso @ 2022-11-28  3:43 UTC (permalink / raw)
  To: mst; +Cc: virtualization, linux-kernel, dave

__read_once_size() is not a macro, remove those '/'s.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
---
 tools/virtio/ringtest/main.h | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h
index 6d1fccd3d86c..9ed09caa659e 100644
--- a/tools/virtio/ringtest/main.h
+++ b/tools/virtio/ringtest/main.h
@@ -149,16 +149,16 @@ static inline void busy_wait(void)
 static __always_inline
 void __read_once_size(const volatile void *p, void *res, int size)
 {
-        switch (size) {                                                 \
-        case 1: *(unsigned char *)res = *(volatile unsigned char *)p; break;              \
-        case 2: *(unsigned short *)res = *(volatile unsigned short *)p; break;            \
-        case 4: *(unsigned int *)res = *(volatile unsigned int *)p; break;            \
-        case 8: *(unsigned long long *)res = *(volatile unsigned long long *)p; break;            \
-        default:                                                        \
-                barrier();                                              \
-                __builtin_memcpy((void *)res, (const void *)p, size);   \
-                barrier();                                              \
-        }                                                               \
+	switch (size) {
+	case 1: *(unsigned char *)res = *(volatile unsigned char *)p; break;
+	case 2: *(unsigned short *)res = *(volatile unsigned short *)p; break;
+	case 4: *(unsigned int *)res = *(volatile unsigned int *)p; break;
+	case 8: *(unsigned long long *)res = *(volatile unsigned long long *)p; break;
+	default:
+		barrier();
+		__builtin_memcpy((void *)res, (const void *)p, size);
+		barrier();
+	}
 }
 
 static __always_inline void __write_once_size(volatile void *p, void *res, int size)
-- 
2.38.1


^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH 1/2] tools/virtio: remove stray characters
@ 2022-11-28  3:43   ` Davidlohr Bueso
  0 siblings, 0 replies; 10+ messages in thread
From: Davidlohr Bueso @ 2022-11-28  3:43 UTC (permalink / raw)
  To: mst; +Cc: dave, linux-kernel, virtualization

__read_once_size() is not a macro, remove those '/'s.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
---
 tools/virtio/ringtest/main.h | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h
index 6d1fccd3d86c..9ed09caa659e 100644
--- a/tools/virtio/ringtest/main.h
+++ b/tools/virtio/ringtest/main.h
@@ -149,16 +149,16 @@ static inline void busy_wait(void)
 static __always_inline
 void __read_once_size(const volatile void *p, void *res, int size)
 {
-        switch (size) {                                                 \
-        case 1: *(unsigned char *)res = *(volatile unsigned char *)p; break;              \
-        case 2: *(unsigned short *)res = *(volatile unsigned short *)p; break;            \
-        case 4: *(unsigned int *)res = *(volatile unsigned int *)p; break;            \
-        case 8: *(unsigned long long *)res = *(volatile unsigned long long *)p; break;            \
-        default:                                                        \
-                barrier();                                              \
-                __builtin_memcpy((void *)res, (const void *)p, size);   \
-                barrier();                                              \
-        }                                                               \
+	switch (size) {
+	case 1: *(unsigned char *)res = *(volatile unsigned char *)p; break;
+	case 2: *(unsigned short *)res = *(volatile unsigned short *)p; break;
+	case 4: *(unsigned int *)res = *(volatile unsigned int *)p; break;
+	case 8: *(unsigned long long *)res = *(volatile unsigned long long *)p; break;
+	default:
+		barrier();
+		__builtin_memcpy((void *)res, (const void *)p, size);
+		barrier();
+	}
 }
 
 static __always_inline void __write_once_size(volatile void *p, void *res, int size)
-- 
2.38.1

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH 2/2] tools/virtio: remove smp_read_barrier_depends()
  2022-11-28  3:43 ` Davidlohr Bueso
@ 2022-11-28  3:43   ` Davidlohr Bueso
  -1 siblings, 0 replies; 10+ messages in thread
From: Davidlohr Bueso @ 2022-11-28  3:43 UTC (permalink / raw)
  To: mst; +Cc: dave, linux-kernel, virtualization

This gets rid of the last references to smp_read_barrier_depends()
 which for the kernel side was removed in v5.9. The serialization
required for Alpha is done inside READ_ONCE() instead of having
users deal with it. Simply use a full barrier, the architecture
does not have rmb in the first place.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
---
 tools/virtio/ringtest/main.h | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h
index 9ed09caa659e..b68920d52750 100644
--- a/tools/virtio/ringtest/main.h
+++ b/tools/virtio/ringtest/main.h
@@ -140,12 +140,6 @@ static inline void busy_wait(void)
 #define smp_wmb() smp_release()
 #endif
 
-#ifdef __alpha__
-#define smp_read_barrier_depends() smp_acquire()
-#else
-#define smp_read_barrier_depends() do {} while(0)
-#endif
-
 static __always_inline
 void __read_once_size(const volatile void *p, void *res, int size)
 {
@@ -175,13 +169,22 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 	}
 }
 
+#ifdef __alpha__
 #define READ_ONCE(x) \
 ({									\
 	union { typeof(x) __val; char __c[1]; } __u;			\
 	__read_once_size(&(x), __u.__c, sizeof(x));		\
-	smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \
+	smp_mb(); /* Enforce dependency ordering from x */		\
 	__u.__val;							\
 })
+#else
+#define READ_ONCE(x)							\
+({									\
+	union { typeof(x) __val; char __c[1]; } __u;			\
+	__read_once_size(&(x), __u.__c, sizeof(x));			\
+	__u.__val;							\
+})
+#endif
 
 #define WRITE_ONCE(x, val) \
 ({							\
-- 
2.38.1

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH 2/2] tools/virtio: remove smp_read_barrier_depends()
@ 2022-11-28  3:43   ` Davidlohr Bueso
  0 siblings, 0 replies; 10+ messages in thread
From: Davidlohr Bueso @ 2022-11-28  3:43 UTC (permalink / raw)
  To: mst; +Cc: virtualization, linux-kernel, dave

This gets rid of the last references to smp_read_barrier_depends()
 which for the kernel side was removed in v5.9. The serialization
required for Alpha is done inside READ_ONCE() instead of having
users deal with it. Simply use a full barrier, the architecture
does not have rmb in the first place.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
---
 tools/virtio/ringtest/main.h | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h
index 9ed09caa659e..b68920d52750 100644
--- a/tools/virtio/ringtest/main.h
+++ b/tools/virtio/ringtest/main.h
@@ -140,12 +140,6 @@ static inline void busy_wait(void)
 #define smp_wmb() smp_release()
 #endif
 
-#ifdef __alpha__
-#define smp_read_barrier_depends() smp_acquire()
-#else
-#define smp_read_barrier_depends() do {} while(0)
-#endif
-
 static __always_inline
 void __read_once_size(const volatile void *p, void *res, int size)
 {
@@ -175,13 +169,22 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 	}
 }
 
+#ifdef __alpha__
 #define READ_ONCE(x) \
 ({									\
 	union { typeof(x) __val; char __c[1]; } __u;			\
 	__read_once_size(&(x), __u.__c, sizeof(x));		\
-	smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \
+	smp_mb(); /* Enforce dependency ordering from x */		\
 	__u.__val;							\
 })
+#else
+#define READ_ONCE(x)							\
+({									\
+	union { typeof(x) __val; char __c[1]; } __u;			\
+	__read_once_size(&(x), __u.__c, sizeof(x));			\
+	__u.__val;							\
+})
+#endif
 
 #define WRITE_ONCE(x, val) \
 ({							\
-- 
2.38.1


^ permalink raw reply related	[flat|nested] 10+ messages in thread
* Re: [PATCH 1/2] tools/virtio: remove stray characters
  2022-11-28  3:43   ` Davidlohr Bueso
@ 2022-11-28  6:16     ` Xuan Zhuo
  -1 siblings, 0 replies; 10+ messages in thread
From: Xuan Zhuo @ 2022-11-28  6:16 UTC (permalink / raw)
  To: Davidlohr Bueso; +Cc: dave, linux-kernel, virtualization, mst

On Sun, 27 Nov 2022 19:43:46 -0800, Davidlohr Bueso <dave@stgolabs.net> wrote:
> __read_once_size() is not a macro, remove those '/'s.
>
> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>

Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

> ---
>  tools/virtio/ringtest/main.h | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h
> index 6d1fccd3d86c..9ed09caa659e 100644
> --- a/tools/virtio/ringtest/main.h
> +++ b/tools/virtio/ringtest/main.h
> @@ -149,16 +149,16 @@ static inline void busy_wait(void)
>  static __always_inline
>  void __read_once_size(const volatile void *p, void *res, int size)
>  {
> -        switch (size) {                                                 \
> -        case 1: *(unsigned char *)res = *(volatile unsigned char *)p; break;              \
> -        case 2: *(unsigned short *)res = *(volatile unsigned short *)p; break;            \
> -        case 4: *(unsigned int *)res = *(volatile unsigned int *)p; break;            \
> -        case 8: *(unsigned long long *)res = *(volatile unsigned long long *)p; break;            \
> -        default:                                                        \
> -                barrier();                                              \
> -                __builtin_memcpy((void *)res, (const void *)p, size);   \
> -                barrier();                                              \
> -        }                                                               \
> +	switch (size) {
> +	case 1: *(unsigned char *)res = *(volatile unsigned char *)p; break;
> +	case 2: *(unsigned short *)res = *(volatile unsigned short *)p; break;
> +	case 4: *(unsigned int *)res = *(volatile unsigned int *)p; break;
> +	case 8: *(unsigned long long *)res = *(volatile unsigned long long *)p; break;
> +	default:
> +		barrier();
> +		__builtin_memcpy((void *)res, (const void *)p, size);
> +		barrier();
> +	}
>  }
>
>  static __always_inline void __write_once_size(volatile void *p, void *res, int size)
> --
> 2.38.1
>
> _______________________________________________
> Virtualization mailing list
> Virtualization@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 10+ messages in thread
* Re: [PATCH 1/2] tools/virtio: remove stray characters
@ 2022-11-28  6:16     ` Xuan Zhuo
  0 siblings, 0 replies; 10+ messages in thread
From: Xuan Zhuo @ 2022-11-28  6:16 UTC (permalink / raw)
  To: Davidlohr Bueso; +Cc: dave, mst, linux-kernel, virtualization

On Sun, 27 Nov 2022 19:43:46 -0800, Davidlohr Bueso <dave@stgolabs.net> wrote:
> __read_once_size() is not a macro, remove those '/'s.
>
> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>

Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

> ---
>  tools/virtio/ringtest/main.h | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h
> index 6d1fccd3d86c..9ed09caa659e 100644
> --- a/tools/virtio/ringtest/main.h
> +++ b/tools/virtio/ringtest/main.h
> @@ -149,16 +149,16 @@ static inline void busy_wait(void)
>  static __always_inline
>  void __read_once_size(const volatile void *p, void *res, int size)
>  {
> -        switch (size) {                                                 \
> -        case 1: *(unsigned char *)res = *(volatile unsigned char *)p; break;              \
> -        case 2: *(unsigned short *)res = *(volatile unsigned short *)p; break;            \
> -        case 4: *(unsigned int *)res = *(volatile unsigned int *)p; break;            \
> -        case 8: *(unsigned long long *)res = *(volatile unsigned long long *)p; break;            \
> -        default:                                                        \
> -                barrier();                                              \
> -                __builtin_memcpy((void *)res, (const void *)p, size);   \
> -                barrier();                                              \
> -        }                                                               \
> +	switch (size) {
> +	case 1: *(unsigned char *)res = *(volatile unsigned char *)p; break;
> +	case 2: *(unsigned short *)res = *(volatile unsigned short *)p; break;
> +	case 4: *(unsigned int *)res = *(volatile unsigned int *)p; break;
> +	case 8: *(unsigned long long *)res = *(volatile unsigned long long *)p; break;
> +	default:
> +		barrier();
> +		__builtin_memcpy((void *)res, (const void *)p, size);
> +		barrier();
> +	}
>  }
>
>  static __always_inline void __write_once_size(volatile void *p, void *res, int size)
> --
> 2.38.1
>
> _______________________________________________
> Virtualization mailing list
> Virtualization@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 10+ messages in thread
* Re: [PATCH 2/2] tools/virtio: remove smp_read_barrier_depends()
  2022-11-28  3:43   ` Davidlohr Bueso
@ 2022-11-28  6:16     ` Xuan Zhuo
  -1 siblings, 0 replies; 10+ messages in thread
From: Xuan Zhuo @ 2022-11-28  6:16 UTC (permalink / raw)
  To: Davidlohr Bueso; +Cc: dave, linux-kernel, virtualization, mst

On Sun, 27 Nov 2022 19:43:47 -0800, Davidlohr Bueso <dave@stgolabs.net> wrote:
> This gets rid of the last references to smp_read_barrier_depends()
>  which for the kernel side was removed in v5.9. The serialization
> required for Alpha is done inside READ_ONCE() instead of having
> users deal with it. Simply use a full barrier, the architecture
> does not have rmb in the first place.
>
> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>

Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

> ---
>  tools/virtio/ringtest/main.h | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h
> index 9ed09caa659e..b68920d52750 100644
> --- a/tools/virtio/ringtest/main.h
> +++ b/tools/virtio/ringtest/main.h
> @@ -140,12 +140,6 @@ static inline void busy_wait(void)
>  #define smp_wmb() smp_release()
>  #endif
>
> -#ifdef __alpha__
> -#define smp_read_barrier_depends() smp_acquire()
> -#else
> -#define smp_read_barrier_depends() do {} while(0)
> -#endif
> -
>  static __always_inline
>  void __read_once_size(const volatile void *p, void *res, int size)
>  {
> @@ -175,13 +169,22 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
>  	}
>  }
>
> +#ifdef __alpha__
>  #define READ_ONCE(x) \
>  ({									\
>  	union { typeof(x) __val; char __c[1]; } __u;			\
>  	__read_once_size(&(x), __u.__c, sizeof(x));		\
> -	smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \
> +	smp_mb(); /* Enforce dependency ordering from x */		\
>  	__u.__val;							\
>  })
> +#else
> +#define READ_ONCE(x)							\
> +({									\
> +	union { typeof(x) __val; char __c[1]; } __u;			\
> +	__read_once_size(&(x), __u.__c, sizeof(x));			\
> +	__u.__val;							\
> +})
> +#endif
>
>  #define WRITE_ONCE(x, val) \
>  ({							\
> --
> 2.38.1
>
> _______________________________________________
> Virtualization mailing list
> Virtualization@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 10+ messages in thread
* Re: [PATCH 2/2] tools/virtio: remove smp_read_barrier_depends()
@ 2022-11-28  6:16     ` Xuan Zhuo
  0 siblings, 0 replies; 10+ messages in thread
From: Xuan Zhuo @ 2022-11-28  6:16 UTC (permalink / raw)
  To: Davidlohr Bueso; +Cc: dave, mst, linux-kernel, virtualization

On Sun, 27 Nov 2022 19:43:47 -0800, Davidlohr Bueso <dave@stgolabs.net> wrote:
> This gets rid of the last references to smp_read_barrier_depends()
>  which for the kernel side was removed in v5.9. The serialization
> required for Alpha is done inside READ_ONCE() instead of having
> users deal with it. Simply use a full barrier, the architecture
> does not have rmb in the first place.
>
> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>

Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

> ---
>  tools/virtio/ringtest/main.h | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h
> index 9ed09caa659e..b68920d52750 100644
> --- a/tools/virtio/ringtest/main.h
> +++ b/tools/virtio/ringtest/main.h
> @@ -140,12 +140,6 @@ static inline void busy_wait(void)
>  #define smp_wmb() smp_release()
>  #endif
>
> -#ifdef __alpha__
> -#define smp_read_barrier_depends() smp_acquire()
> -#else
> -#define smp_read_barrier_depends() do {} while(0)
> -#endif
> -
>  static __always_inline
>  void __read_once_size(const volatile void *p, void *res, int size)
>  {
> @@ -175,13 +169,22 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
>  	}
>  }
>
> +#ifdef __alpha__
>  #define READ_ONCE(x) \
>  ({									\
>  	union { typeof(x) __val; char __c[1]; } __u;			\
>  	__read_once_size(&(x), __u.__c, sizeof(x));		\
> -	smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \
> +	smp_mb(); /* Enforce dependency ordering from x */		\
>  	__u.__val;							\
>  })
> +#else
> +#define READ_ONCE(x)							\
> +({									\
> +	union { typeof(x) __val; char __c[1]; } __u;			\
> +	__read_once_size(&(x), __u.__c, sizeof(x));			\
> +	__u.__val;							\
> +})
> +#endif
>
>  #define WRITE_ONCE(x, val) \
>  ({							\
> --
> 2.38.1
>
> _______________________________________________
> Virtualization mailing list
> Virtualization@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 10+ messages in thread
end of thread, other threads:[~2022-11-28  6:17 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-11-28  3:43 [PATCH 0/2] tools/virtio: remove smp_read_barrier_depends() Davidlohr Bueso
2022-11-28  3:43 ` Davidlohr Bueso
2022-11-28  3:43 ` [PATCH 1/2] tools/virtio: remove stray characters Davidlohr Bueso
2022-11-28  3:43   ` Davidlohr Bueso
2022-11-28  6:16   ` Xuan Zhuo
2022-11-28  6:16     ` Xuan Zhuo
2022-11-28  3:43 ` [PATCH 2/2] tools/virtio: remove smp_read_barrier_depends() Davidlohr Bueso
2022-11-28  3:43   ` Davidlohr Bueso
2022-11-28  6:16   ` Xuan Zhuo
2022-11-28  6:16     ` Xuan Zhuo

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