Re: [PATCH 2/3] vringh: kill off ACCESS_ONCE()

[Jason Wang]

On 2016年11月24日 18:25, Mark Rutland wrote:

Despite living under drivers/ vringh.c is also used as part of the userspace
virtio tools. Before we can kill off the ACCESS_ONCE()definition in the tools,
we must convert vringh.c to use {READ,WRITE}_ONCE().

This patch does so, along with the required include of  for
the relevant definitions. The userspace tools provide their own definitions in
their own .

Signed-off-by: Mark Rutland 
Cc: Jason Wang 
Cc: Michael S. Tsirkin 
Cc: k...@vger.kernel.org
Cc: linux-ker...@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: virtualizat...@lists.linux-foundation.org
---
  drivers/vhost/vringh.c | 5 +++--
  1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 3bb02c6..bb8971f 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -3,6 +3,7 @@
   *
   * Since these may be in userspace, we use (inline) accessors.
   */
+#include 
  #include 
  #include 
  #include 
@@ -820,13 +821,13 @@ EXPORT_SYMBOL(vringh_need_notify_user);
  static inline int getu16_kern(const struct vringh *vrh,
  u16 *val, const __virtio16 *p)
  {
-   *val = vringh16_to_cpu(vrh, ACCESS_ONCE(*p));
+   *val = vringh16_to_cpu(vrh, READ_ONCE(*p));
return 0;
  }
  
  static inline int putu16_kern(const struct vringh *vrh, __virtio16 *p, u16 val)

  {
-   ACCESS_ONCE(*p) = cpu_to_vringh16(vrh, val);
+   WRITE_ONCE(*p, cpu_to_vringh16(vrh, val));
return 0;
  }
  


Reviewed-by: Jason Wang 

Re: [PATCH 2/3] vringh: kill off ACCESS_ONCE()

[Cornelia Huck]

On Thu, 24 Nov 2016 10:25:13 +
Mark Rutland  wrote:

> Despite living under drivers/ vringh.c is also used as part of the userspace
> virtio tools. Before we can kill off the ACCESS_ONCE()definition in the tools,
> we must convert vringh.c to use {READ,WRITE}_ONCE().
> 
> This patch does so, along with the required include of  for
> the relevant definitions. The userspace tools provide their own definitions in
> their own .
> 
> Signed-off-by: Mark Rutland 
> Cc: Jason Wang 
> Cc: Michael S. Tsirkin 
> Cc: k...@vger.kernel.org
> Cc: linux-ker...@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Cc: virtualizat...@lists.linux-foundation.org
> ---
>  drivers/vhost/vringh.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)

Reviewed-by: Cornelia Huck 

Re: [PATCH 2/3] vringh: kill off ACCESS_ONCE()

[Christian Borntraeger]

On 11/24/2016 11:25 AM, Mark Rutland wrote:
> Despite living under drivers/ vringh.c is also used as part of the userspace
> virtio tools. Before we can kill off the ACCESS_ONCE()definition in the tools,
> we must convert vringh.c to use {READ,WRITE}_ONCE().
> 
> This patch does so, along with the required include of  for
> the relevant definitions. The userspace tools provide their own definitions in
> their own .
> 
> Signed-off-by: Mark Rutland 
> Cc: Jason Wang 
> Cc: Michael S. Tsirkin 
> Cc: k...@vger.kernel.org
> Cc: linux-ker...@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Cc: virtualizat...@lists.linux-foundation.org
> ---
>  drivers/vhost/vringh.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
> index 3bb02c6..bb8971f 100644
> --- a/drivers/vhost/vringh.c
> +++ b/drivers/vhost/vringh.c
> @@ -3,6 +3,7 @@
>   *
>   * Since these may be in userspace, we use (inline) accessors.
>   */
> +#include 
>  #include 
>  #include 
>  #include 
> @@ -820,13 +821,13 @@ EXPORT_SYMBOL(vringh_need_notify_user);
>  static inline int getu16_kern(const struct vringh *vrh,
> u16 *val, const __virtio16 *p)
>  {
> - *val = vringh16_to_cpu(vrh, ACCESS_ONCE(*p));
> + *val = vringh16_to_cpu(vrh, READ_ONCE(*p));
>   return 0;
>  }
> 
>  static inline int putu16_kern(const struct vringh *vrh, __virtio16 *p, u16 
> val)
>  {
> - ACCESS_ONCE(*p) = cpu_to_vringh16(vrh, val);
> + WRITE_ONCE(*p, cpu_to_vringh16(vrh, val));
>   return 0;
>  }
> 

Makes sense

Reviewed-by: Christian Borntraeger