From: Jason Gunthorpe <jgg@ziepe.ca>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: "Gerd Bayer" <gbayer@linux.ibm.com>,
"Alex Deucher" <alexander.deucher@amd.com>,
"Christian König" <christian.koenig@amd.com>,
"Selvin Xavier" <selvin.xavier@broadcom.com>,
"Kalesh AP" <kalesh-anakkur.purayil@broadcom.com>,
"Leon Romanovsky" <leon@kernel.org>,
"Michal Kalderon" <mkalderon@marvell.com>,
"Saeed Mahameed" <saeedm@nvidia.com>,
"Tariq Toukan" <tariqt@nvidia.com>,
"Mark Bloch" <mbloch@nvidia.com>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Jay Cornwall" <Jay.Cornwall@amd.com>,
"Felix Kuehling" <Felix.Kuehling@amd.com>,
"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
"Christian Borntraeger" <borntraeger@linux.ibm.com>,
"Niklas Schnelle" <schnelle@linux.ibm.com>,
"Gerald Schaefer" <gerald.schaefer@linux.ibm.com>,
"Heiko Carstens" <hca@linux.ibm.com>,
"Vasily Gorbik" <gor@linux.ibm.com>,
"Alexander Gordeev" <agordeev@linux.ibm.com>,
"Sven Schnelle" <svens@linux.ibm.com>,
"Alexander Schmidt" <alexs@linux.ibm.com>,
linux-s390@vger.kernel.org, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
linux-rdma@vger.kernel.org
Subject: Re: [PATCH v7 1/3] PCI: AtomicOps: Do not enable requests by RCiEPs
Date: Mon, 30 Mar 2026 19:26:31 -0300 [thread overview]
Message-ID: <20260330222631.GF246076@ziepe.ca> (raw)
In-Reply-To: <20260330214253.GA92498@bhelgaas>
On Mon, Mar 30, 2026 at 04:42:53PM -0500, Bjorn Helgaas wrote:
> [+to amdgpu, bnxe_re, mlx5 IB, qedr, mlx5 maintainers]
>
> On Mon, Mar 30, 2026 at 03:09:44PM +0200, Gerd Bayer wrote:
> > Since root complex integrated end points (RCiEPs) attach to a bus that
> > has no bridge device describing the root port, the capability to
> > complete AtomicOps requests cannot be determined with PCIe methods.
> >
> > Change default of pci_enable_atomic_ops_to_root() to not enable
> > AtomicOps requests on RCiEPs.
>
> I know I suggested this because there's nothing explicit that tells us
> whether the RC supports atomic ops from RCiEPs [1]. But I'm concerned
> that GPUs, infiniband HCAs, and NICs that use atomic ops may be
> implemented as RCiEPs and would be broken by this.
AFAIK none of the NICs are integrated into root complexes in their
topology model..
Jason
next prev parent reply other threads:[~2026-03-30 22:26 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-30 13:09 [PATCH v7 0/3] PCI: AtomicOps: Fix pci_enable_atomic_ops_to_root() Gerd Bayer
2026-03-30 13:09 ` [PATCH v7 1/3] PCI: AtomicOps: Do not enable requests by RCiEPs Gerd Bayer
2026-03-30 21:42 ` Bjorn Helgaas
2026-03-30 22:26 ` Jason Gunthorpe [this message]
2026-03-31 0:01 ` Kuehling, Felix
2026-03-31 18:09 ` Bjorn Helgaas
2026-03-31 18:39 ` Kuehling, Felix
2026-03-31 19:01 ` Bjorn Helgaas
2026-03-31 20:12 ` Kuehling, Felix
2026-03-30 13:09 ` [PATCH v7 2/3] PCI: AtomicOps: Do not enable without support in root port Gerd Bayer
2026-04-01 17:27 ` Bjorn Helgaas
2026-04-02 14:44 ` Gerd Bayer
2026-03-30 13:09 ` [PATCH v7 3/3] PCI: AtomicOps: Update references to PCIe spec Gerd Bayer
2026-04-02 16:38 ` [PATCH v7 0/3] PCI: AtomicOps: Fix pci_enable_atomic_ops_to_root() Bjorn Helgaas
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