* [PATCH 0/2] tools/virtio: remove smp_read_barrier_depends() @ 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 ` [PATCH 2/2] tools/virtio: remove smp_read_barrier_depends() Davidlohr Bueso 0 siblings, 2 replies; 5+ 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] 5+ messages in thread
* [PATCH 1/2] tools/virtio: remove stray characters 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 6:16 ` Xuan Zhuo 2022-11-28 3:43 ` [PATCH 2/2] tools/virtio: remove smp_read_barrier_depends() Davidlohr Bueso 1 sibling, 1 reply; 5+ 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] 5+ messages in thread
* Re: [PATCH 1/2] tools/virtio: remove stray characters 2022-11-28 3:43 ` [PATCH 1/2] tools/virtio: remove stray characters Davidlohr Bueso @ 2022-11-28 6:16 ` Xuan Zhuo 0 siblings, 0 replies; 5+ 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] 5+ messages in thread
* [PATCH 2/2] tools/virtio: remove smp_read_barrier_depends() 2022-11-28 3:43 [PATCH 0/2] tools/virtio: remove smp_read_barrier_depends() 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 1 sibling, 1 reply; 5+ 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] 5+ messages in thread
* Re: [PATCH 2/2] tools/virtio: remove smp_read_barrier_depends() 2022-11-28 3:43 ` [PATCH 2/2] tools/virtio: remove smp_read_barrier_depends() Davidlohr Bueso @ 2022-11-28 6:16 ` Xuan Zhuo 0 siblings, 0 replies; 5+ 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] 5+ messages in thread
end of thread, other threads:[~2022-11-28 6:17 UTC | newest] Thread overview: 5+ 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 ` [PATCH 1/2] tools/virtio: remove stray characters Davidlohr Bueso 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 6:16 ` Xuan Zhuo
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