[v4,2/3] doc: update armv8-a IO barrier changes
diff mbox series

Message ID 20200706234333.26310-2-honnappa.nagarahalli@arm.com
State Accepted
Delegated to: David Marchand
Headers show
Series
  • [v4,1/3] eal: adjust barriers for IO on Armv8-a
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Context Check Description
ci/Intel-compilation fail apply issues
ci/checkpatch success coding style OK

Commit Message

Honnappa Nagarahalli July 6, 2020, 11:43 p.m. UTC
Updated the use of DMB instruction in rte_*mb APIs for Armv8-a.

Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>
---
 doc/guides/rel_notes/release_20_08.rst | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

David Marchand July 7, 2020, 8:36 a.m. UTC | #1
On Tue, Jul 7, 2020 at 1:44 AM Honnappa Nagarahalli
<honnappa.nagarahalli@arm.com> wrote:
>
> Updated the use of DMB instruction in rte_*mb APIs for Armv8-a.
>
> Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Acked-by: Jerin Jacob <jerinj@marvell.com>
> ---
>  doc/guides/rel_notes/release_20_08.rst | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/doc/guides/rel_notes/release_20_08.rst b/doc/guides/rel_notes/release_20_08.rst
> index 5cbc4ce14..567ae6b2a 100644
> --- a/doc/guides/rel_notes/release_20_08.rst
> +++ b/doc/guides/rel_notes/release_20_08.rst
> @@ -56,6 +56,13 @@ New Features
>       Also, make sure to start the actual text at the margin.
>       =========================================================
>

This release note update will be squashed with the change itself in patch 1.

> +* **rte_*mb APIs are updated to use DMB instruction for Armv8-a.**

We use "ARMv8" in the release notes, any objection if I update this
when applying?


> +
> +  Armv8-a memory model has been strengthened to require other-multi-copy
> +  atomicity. This allows for using DMB instruction instead of DSB for IO
> +  barriers. rte_*mb APIs, for Armv8-a platforms, are changed to use DMB
> +  instruction to reflect this.
> +
>  * **Updated PCAP driver.**
>
>    Updated PCAP driver with new features and improvements, including:
> --
> 2.17.1
>
Honnappa Nagarahalli July 7, 2020, 6:37 p.m. UTC | #2
<snip>

> Subject: Re: [dpdk-dev] [PATCH v4 2/3] doc: update armv8-a IO barrier
> changes
> 
> On Tue, Jul 7, 2020 at 1:44 AM Honnappa Nagarahalli
> <honnappa.nagarahalli@arm.com> wrote:
> >
> > Updated the use of DMB instruction in rte_*mb APIs for Armv8-a.
> >
> > Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > Acked-by: Jerin Jacob <jerinj@marvell.com>
> > ---
> >  doc/guides/rel_notes/release_20_08.rst | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/doc/guides/rel_notes/release_20_08.rst
> > b/doc/guides/rel_notes/release_20_08.rst
> > index 5cbc4ce14..567ae6b2a 100644
> > --- a/doc/guides/rel_notes/release_20_08.rst
> > +++ b/doc/guides/rel_notes/release_20_08.rst
> > @@ -56,6 +56,13 @@ New Features
> >       Also, make sure to start the actual text at the margin.
> >       =========================================================
> >
> 
> This release note update will be squashed with the change itself in patch 1.
> 
> > +* **rte_*mb APIs are updated to use DMB instruction for Armv8-a.**
> 
> We use "ARMv8" in the release notes, any objection if I update this when
> applying?
No objections.

> 
> 
> > +
> > +  Armv8-a memory model has been strengthened to require
> > + other-multi-copy  atomicity. This allows for using DMB instruction
> > + instead of DSB for IO  barriers. rte_*mb APIs, for Armv8-a
> > + platforms, are changed to use DMB  instruction to reflect this.
> > +
> >  * **Updated PCAP driver.**
> >
> >    Updated PCAP driver with new features and improvements, including:
> > --
> > 2.17.1
> >
> 
> 
> --
> David Marchand

Patch
diff mbox series

diff --git a/doc/guides/rel_notes/release_20_08.rst b/doc/guides/rel_notes/release_20_08.rst
index 5cbc4ce14..567ae6b2a 100644
--- a/doc/guides/rel_notes/release_20_08.rst
+++ b/doc/guides/rel_notes/release_20_08.rst
@@ -56,6 +56,13 @@  New Features
      Also, make sure to start the actual text at the margin.
      =========================================================
 
+* **rte_*mb APIs are updated to use DMB instruction for Armv8-a.**
+
+  Armv8-a memory model has been strengthened to require other-multi-copy
+  atomicity. This allows for using DMB instruction instead of DSB for IO
+  barriers. rte_*mb APIs, for Armv8-a platforms, are changed to use DMB
+  instruction to reflect this.
+
 * **Updated PCAP driver.**
 
   Updated PCAP driver with new features and improvements, including: