* Bug#894995: rdma-core: Please add support for new architecture "riscv64" (RISC-V 64 bits little-endian)
[not found] <152297424964.29286.16311629290309565149.reportbug@reva.itsari.org>
@ 2018-04-19 12:00 ` Benjamin Drung
2018-04-20 15:31 ` Jason Gunthorpe
0 siblings, 1 reply; 2+ messages in thread
From: Benjamin Drung @ 2018-04-19 12:00 UTC (permalink / raw)
To: Manuel A. Fernandez Montecelo, 894995, List Linux RDMA Mailing
Hi,
Thanks for reporting this bug.
Am Freitag, den 06.04.2018, 02:24 +0200 schrieb Manuel A. Fernandez
Montecelo:
> Source: rdma-core
> Version: 17.1-1
> Severity: normal
> Tags: patch
> User: debian-riscv@lists.debian.org
> Usertags: riscv64
>
> Hello,
>
> The current version of this package doesn't build for the riscv64
> port.
>
> First it fails to be considered to build (due to missing valgrind)
> and, when
> fixing that problem, FBTFS, because of missing files (see at bottom).
I'll apply that part of the patch.
> I applied the same fix as for many other arches, which is to add the
> arch to the
> list of NO_COHERENT_DMA_ARCHS in debian/rules.
>
> I am not sure if support could be added at a later date, but for the
> time being,
> seems to be the best way to get it working -- I don't know enough
> details of the
> architecture or the assembly language to get the necessary
> incantations in
> place.
RISC-V has a FENCE instruction and the A extension (which is part of
the G instruction set) provides atomic memory operations. So the
architecture should provide coherent DMA support. To enable support,
util/udma_barrier.h needs to be adjusted. I am including
linux-rdma@vger.kernel.org in the loop for help.
^ permalink raw reply [flat|nested] 2+ messages in thread
* Bug#894995: rdma-core: Please add support for new architecture "riscv64" (RISC-V 64 bits little-endian)
2018-04-19 12:00 ` Bug#894995: rdma-core: Please add support for new architecture "riscv64" (RISC-V 64 bits little-endian) Benjamin Drung
@ 2018-04-20 15:31 ` Jason Gunthorpe
0 siblings, 0 replies; 2+ messages in thread
From: Jason Gunthorpe @ 2018-04-20 15:31 UTC (permalink / raw)
To: Benjamin Drung
Cc: Manuel A. Fernandez Montecelo, 894995, List Linux RDMA Mailing
On Thu, Apr 19, 2018 at 02:00:18PM +0200, Benjamin Drung wrote:
> > I applied the same fix as for many other arches, which is to add the
> > arch to the
> > list of NO_COHERENT_DMA_ARCHS in debian/rules.
> >
> > I am not sure if support could be added at a later date, but for the
> > time being,
> > seems to be the best way to get it working -- I don't know enough
> > details of the
> > architecture or the assembly language to get the necessary
> > incantations in
> > place.
>
> RISC-V has a FENCE instruction and the A extension (which is part of
> the G instruction set) provides atomic memory operations. So the
> architecture should provide coherent DMA support. To enable support,
> util/udma_barrier.h needs to be adjusted. I am including
> linux-rdma@vger.kernel.org in the loop for help.
You can't tell from the instruction set if a chip is DMA coherent or
not. It depends how the cache's are designed, and if they have a
'snoop controller' or otherwise.
Generally if *any* DMA coherent implementations exist then we should
add the fences, otherwise better to just not compile the drivers that
have no chance of working.
Jason
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2018-04-20 15:31 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[not found] <152297424964.29286.16311629290309565149.reportbug@reva.itsari.org>
2018-04-19 12:00 ` Bug#894995: rdma-core: Please add support for new architecture "riscv64" (RISC-V 64 bits little-endian) Benjamin Drung
2018-04-20 15:31 ` Jason Gunthorpe
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.