From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A54BF2F3C10; Tue, 4 Aug 2026 22:07:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=204.191.154.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785881251; cv=none; b=GXEtTcZHDJhWIbo5FP/4imCovdaEYBUG6+SqnsheZqkl2f4ZaSfeDzm9eyL4SGTlLcAc3AxQRdS7AXAbaDKDL9hdl0niiVu4WBHRatyIwtRRTk+boUJNOSpXRrPZBsim+koWTul4IwgxxAxAzi4aLpG6qU7GTbLY7hRJ4/5Sk8o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785881251; c=relaxed/simple; bh=tr4gX5SugrlZEdS4jIbWiBibKVFwFlv4KjtFsEp+v4w=; h=Message-ID:Date:MIME-Version:To:Cc:References:From:In-Reply-To: Content-Type:Subject; b=UCT+cZGHZxWCqG4gO6/IQDtlMavRMsRLIQhh+pJnhby+VIRzywOzVmh/ENjDXeCBMrleRePFv0ePXwg+decLFBUPr+x4zj1qAmGdE092TKC83fDvr7f0V0R0aCSlQBqUaipr0QXAvdA5FAmoVpcOW0wYkgijsdFPDmTdJlR4XE0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=deltatee.com; spf=pass smtp.mailfrom=deltatee.com; dkim=pass (2048-bit key) header.d=deltatee.com header.i=@deltatee.com header.b=BthX7k0h; arc=none smtp.client-ip=204.191.154.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=deltatee.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=deltatee.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=deltatee.com header.i=@deltatee.com header.b="BthX7k0h" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:In-Reply-To:From:References:Cc:To: MIME-Version:Date:Message-ID:content-disposition; bh=ezcZ0mk4rxjrcephDtzUCmBZDny0RSLvrsscZbYVmuQ=; b=BthX7k0hxi7PkXg+4gT1rBA1bx m1putEqavkEBeEcXum1ooYIX8JwT/43AFkfBPOM0L6pEHeH1ZyMdjm3WzdQoNxi8lTFww+yplpDyK PwcURsoOw/SwV6N03Hc7QsaYh+VHDnBaRbGR0SkZbc94IlGphImRj6hWVbM1tz5ylN3EvkY/0IHC2 iZp+QbB4peqAqpNeJPQHZ6HU4sekApdTC7G05MBeDTxC1b1vA8o6cuZMvdEB2n0n4qsBUpEBbK/x7 Z+NVQUIWJiW+MGAJT4TX3j6fDxSMqQEV2hm0ZDoA78B+iSL4K/5tW6G/fUi0Dbou047YPeQsU8t3+ mkpaw85g==; Received: from guinness.priv.deltatee.com ([172.16.1.162]) by ale.deltatee.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.98.2) (envelope-from ) id 1wrNIG-000000002tS-1wMm; Tue, 04 Aug 2026 16:07:29 -0600 Message-ID: <461ab877-a5ab-44bd-8c24-1a77e42e9746@deltatee.com> Date: Tue, 4 Aug 2026 16:07:27 -0600 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Leon Romanovsky , Bjorn Helgaas , Jonathan Corbet , Shuah Khan , Alex Williamson Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, "Claude Opus 4.8" References: <20260802-fix-p2p-acs-v1-0-a7c5eb64fff6@nvidia.com> <20260802-fix-p2p-acs-v1-10-a7c5eb64fff6@nvidia.com> Content-Language: en-CA From: Logan Gunthorpe In-Reply-To: <20260802-fix-p2p-acs-v1-10-a7c5eb64fff6@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.162 X-SA-Exim-Rcpt-To: leon@kernel.org, bhelgaas@google.com, corbet@lwn.net, skhan@linuxfoundation.org, alex@shazbot.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, noreply@anthropic.com X-SA-Exim-Mail-From: logang@deltatee.com X-Spam-Level: Subject: Re: [PATCH 10/13] PCI/P2PDMA: Extract pure ACS routing decision helpers X-SA-Exim-Version: 4.2.1 (built Sun, 23 Feb 2025 07:57:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) On 2026-08-02 09:09, Leon Romanovsky wrote: > static enum pci_acs_p2pdma_state > pci_acs_p2pdma_state(struct pci_dev *pdev, struct pci_dev *target) > { > - int pos, ret; > + int egress = 0; > u16 ctrl; > > - pos = pdev->acs_cap; > - if (!pos) > + if (!pdev->acs_cap) > return PCI_ACS_P2PDMA_DIRECT; I don't necessarily disagree with the change, but removing pos in this patch seems unnecessary and makes the patch more difficult to review than it needed to be. > @@ -1046,6 +1047,22 @@ resource_size_t pci_min_window_alignment(struct pci_bus *bus, > void pci_acs_init(struct pci_dev *dev); > void pci_enable_acs(struct pci_dev *dev); > int pci_acs_egress_ctrl_set(struct pci_dev *pdev, struct pci_dev *target); > + > +/* > + * Peer-to-peer routing decision for an ACS-capable ingress port, per > + * PCIe r7.0, sec 6.12.3, table 6-11. > + */ > +enum pci_acs_p2pdma_state { > + PCI_ACS_P2PDMA_DIRECT, /* peer-to-peer permitted directly */ > + PCI_ACS_P2PDMA_REDIRECT, /* redirected upstream to host bridge */ > + PCI_ACS_P2PDMA_NOT_SUPPORTED, /* no usable peer-to-peer route */ > +}; > + > +#if IS_ENABLED(CONFIG_KUNIT) > +bool pci_acs_egress_port_valid(u16 acs_caps, u8 target_port); > +enum pci_acs_p2pdma_state pci_acs_p2pdma_decision(u16 ctrl, bool has_target, > + int egress); > +#endif One minor weird whitespace issue here. Probably the empty line should come after #endif But both of these are very minor points, so: Reviewed-by: Logan Gunthorpe