From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f174.google.com (mail-qk1-f174.google.com [209.85.222.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2C393A544D for ; Mon, 30 Mar 2026 22:26:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774909606; cv=none; b=NzhOcPdL5nhZP+gHAiCn5CKO3DpieIhmYKE1Gl2NFnTrSfAE8Hw4o7vzvzq3c2c+4EuXOuc0MwfN0FhLMibf7DeCx4qvqJc58qhUMpmiPYabUT/XsaFTb2AK5tjGx/6RxNXcljRNtiShzGP7hi8ko/dxNqCfEYPCzlhfXOLoCeY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774909606; c=relaxed/simple; bh=njYxOmFhF0kKZxmCluaJeRNQJOvHXtTT/LYX+fA/Jes=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eB6XSyYYfI5/joCEDv22UnDo23jc72kvM7VLqGJ3lDnewr6Kye0OjVVazH9YDDe+8O4TzwpJF4sQblPamtfBK9l2foHRJPB4g0ooRC7mzC9/rLxobeN9HeP9pPNwlTki2NuiG1rhwz5r6nlz5Hf7CmbciASrhn6hp8DTeDRztog= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca; spf=pass smtp.mailfrom=ziepe.ca; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b=SRVjkBgu; arc=none smtp.client-ip=209.85.222.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="SRVjkBgu" Received: by mail-qk1-f174.google.com with SMTP id af79cd13be357-8cd77786e97so506331885a.3 for ; Mon, 30 Mar 2026 15:26:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1774909593; x=1775514393; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=MMpjIoYB4wkYY1B4Qvo8YM+LGvG/wS7KH0HgKJnMSKw=; b=SRVjkBguFjfCZK6KyO2Br10O0nqWk6wAn3BLxlEleze8weF4NGKj5VBS1no0JjO5YI g/8icibDzjoJ0tJ3mTX8v++aieNJw05tHkPlWTQpChPxIIwkR+mVcZapcZOaZwamMkGU BxFsK6CI60m3/NSHR9n7W/1RRGEA/BwYPMseTh37M/BCi6MEgkRPdeEMsVaqjQzrH1M2 hfIKXlVf8INWVlRRJtrqNQBeTHeyhxBgPBBJti+7t1bjluyepJUzik8KVlxhpl/B3k5a 5bv6rOSUlHPqk37gDhEw2D5iGe/tdQtZx2u/ofN+hR7axrwuYFIQPz5ctd56nxod8Ysk WMGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774909593; x=1775514393; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=MMpjIoYB4wkYY1B4Qvo8YM+LGvG/wS7KH0HgKJnMSKw=; b=p5VElcmemW0lYrOG6AQDV+eYuQ8S5im6igub1Z9vuPFb82bUHIOsd1MmMnDYV1dnWY 5bMNd+bnckbyFsnDu7l7T2WUAGl/jsuDMzu6l8uhyXXdFoFh0KRYhHqVAzTGSD0oh/sR qZ/otnAGKXYTP3nM+lpg0hTJoNkuLDTSUrCLFt+mRkF/3V7LcvFG2ATqKRheGxtNJKSR mmknrmP9/2NoPVHVLMlppZZ9shf58Ys0Iue2ilV6g9LpozZ4ycWDP3RaPEGllhd/ovqo X0Gt+qQbVm0EE9PUJC0wnp1iizZpEAHO+hrQYVXVaIWaY1a6eM8vHB92KBtyDplABcTZ z4hQ== X-Forwarded-Encrypted: i=1; AJvYcCWhRVz2CkpcI8nGWAyBy47+rY7Uis/p4skyA0dXmN8G1EHFvKn5hylynEUtXBsUUWLa8RPWsmGnLUlN5Fs=@vger.kernel.org X-Gm-Message-State: AOJu0YwaKKf4lGhHbALX/dgWGO7XAKCnkw9iiR9Z2fjrVFsjgZH1xQKV ymyUinAxXVlTL1mnYgd5fvYJqQL16+6hz0wVV8eP1yGStGhy9B+zh33dJ0/0vYxfMq8= X-Gm-Gg: ATEYQzwaTgnTGcO4rS0qfpDPzKplGUJtW6aYbs5tksdEMSflb/SffLEkpxUekXVg2CY 77amrUjpmISwThJ+sqLNRykPeFuCsgonqfsXg3ZEKEgtXTQGRlfW37FTq+aPnAtF1vxKsWp/tmX ev6zw77R5Ho//ymB6qWZr2orH7hAQnAFW5ewkgQyEDzkGm7wbGMQVSIGxC4BMy1s063i4wWLwEM zfyFH4aMSIVUNeVKPyKDC01nIC4Dw3TbrUiuoEF3UYUyrBm6pWRh2X1Yib2UOjZDt+0dEUvIpFO 0nhAXedcAsCWExR3J838BXvq3f9F8HxnVyTt0pstSkfCeCwu9zD/mlgZ/eBA0rcHrMSIZvTJFan 3LaLFNP8hEpkuj0e5Jqksrtt1HHYPbhVGVCKQCj3JVKv+x15PrDam42+/4+tbjLYQX9D1O+lUsE M1lCbOFIl8n2F9mDCSFMfTJ6Q6IptDTLkW/G0tRxttDuxnGah/6YT3cMIWlgtLvrmfTntlOQ== X-Received: by 2002:a05:620a:2991:b0:8cf:cfdf:733e with SMTP id af79cd13be357-8d01c689577mr1767721685a.32.1774909592771; Mon, 30 Mar 2026 15:26:32 -0700 (PDT) Received: from ziepe.ca (mctnnbsa70w-159-2-73-22.dhcp-dynamic.fibreop.nb.bellaliant.net. [159.2.73.22]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8d028090f43sm711572985a.45.2026.03.30.15.26.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Mar 2026 15:26:32 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1w7L43-00000005H5o-0vBI; Mon, 30 Mar 2026 19:26:31 -0300 Date: Mon, 30 Mar 2026 19:26:31 -0300 From: Jason Gunthorpe To: Bjorn Helgaas Cc: Gerd Bayer , Alex Deucher , Christian =?utf-8?B?S8O2bmln?= , Selvin Xavier , Kalesh AP , Leon Romanovsky , Michal Kalderon , Saeed Mahameed , Tariq Toukan , Mark Bloch , Bjorn Helgaas , Jay Cornwall , Felix Kuehling , Ilpo =?utf-8?B?SsOkcnZpbmVu?= , Christian Borntraeger , Niklas Schnelle , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Sven Schnelle , Alexander Schmidt , 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 Message-ID: <20260330222631.GF246076@ziepe.ca> References: <20260330-fix_pciatops-v7-1-f601818417e8@linux.ibm.com> <20260330214253.GA92498@bhelgaas> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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