From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH RFC 00/77] Re-design MSI/MSI-X interrupts enablement pattern Date: Tue, 08 Oct 2013 20:55:03 -0700 Message-ID: <5254D397.9030307@zytor.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-subscribe: List-owner: List-post: List-archive: To: Alexander Gordeev Cc: linux-kernel@vger.kernel.org, Bjorn Helgaas , Ralf Baechle , Michael Ellerman , Benjamin Herrenschmidt , Martin Schwidefsky , Ingo Molnar , Tejun Heo , Dan Williams , Andy King , Jon Mason , Matt Porter , linux-pci@vger.kernel.org, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, linux390@de.ibm.com, linux-s390@vger.kernel.org, x86@kernel.org, linux-ide@vger.kernel.org, iss_storagedev@hp.com, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, e1000-devel@lists.sourceforge.net, linux-dr List-Id: linux-ide@vger.kernel.org On 10/02/2013 03:29 AM, Alexander Gordeev wrote: > > As result, device drivers will cease to use the overcomplicated > repeated fallbacks technique and resort to a straightforward > pattern - determine the number of MSI/MSI-X interrupts required > before calling pci_enable_msi_block() and pci_enable_msix() > interfaces: > > > rc = pci_msix_table_size(adapter->pdev); > if (rc < 0) > return rc; > > nvec = min(nvec, rc); > if (nvec < FOO_DRIVER_MINIMUM_NVEC) { > return -ENOSPC; > > for (i = 0; i < nvec; i++) > adapter->msix_entries[i].entry = i; > > rc = pci_enable_msix(adapter->pdev, > adapter->msix_entries, nvec); > return rc; > Why not add a minimum number to pci_enable_msix(), i.e.: pci_enable_msix(pdev, msix_entries, nvec, minvec) ... which means "nvec" is the number of interrupts *requested*, and "minvec" is the minimum acceptable number (otherwise fail). -hpa From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 09 Oct 2013 05:56:43 +0200 (CEST) Received: from terminus.zytor.com ([198.137.202.10]:45103 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S6817326Ab3JID4edv3YQ (ORCPT ); Wed, 9 Oct 2013 05:56:34 +0200 Received: from tazenda.hos.anvin.org ([IPv6:2601:9:3340:50:3c60:74ff:feb0:5242]) (authenticated bits=0) by mail.zytor.com (8.14.5/8.14.5) with ESMTP id r993tsTL009705 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO); Tue, 8 Oct 2013 20:55:56 -0700 Message-ID: <5254D397.9030307@zytor.com> Date: Tue, 08 Oct 2013 20:55:03 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130923 Thunderbird/17.0.9 MIME-Version: 1.0 To: Alexander Gordeev CC: linux-kernel@vger.kernel.org, Bjorn Helgaas , Ralf Baechle , Michael Ellerman , Benjamin Herrenschmidt , Martin Schwidefsky , Ingo Molnar , Tejun Heo , Dan Williams , Andy King , Jon Mason , Matt Porter , linux-pci@vger.kernel.org, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, linux390@de.ibm.com, linux-s390@vger.kernel.org, x86@kernel.org, linux-ide@vger.kernel.org, iss_storagedev@hp.com, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, e1000-devel@lists.sourceforge.net, linux-driver@qlogic.com, Solarflare linux maintainers , VMware@dhcp-26-207.brq.redhat.com, "Inc." , linux-scsi@vger.kernel.org Subject: Re: [PATCH RFC 00/77] Re-design MSI/MSI-X interrupts enablement pattern References: In-Reply-To: X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 38278 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: hpa@zytor.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 10/02/2013 03:29 AM, Alexander Gordeev wrote: > > As result, device drivers will cease to use the overcomplicated > repeated fallbacks technique and resort to a straightforward > pattern - determine the number of MSI/MSI-X interrupts required > before calling pci_enable_msi_block() and pci_enable_msix() > interfaces: > > > rc = pci_msix_table_size(adapter->pdev); > if (rc < 0) > return rc; > > nvec = min(nvec, rc); > if (nvec < FOO_DRIVER_MINIMUM_NVEC) { > return -ENOSPC; > > for (i = 0; i < nvec; i++) > adapter->msix_entries[i].entry = i; > > rc = pci_enable_msix(adapter->pdev, > adapter->msix_entries, nvec); > return rc; > Why not add a minimum number to pci_enable_msix(), i.e.: pci_enable_msix(pdev, msix_entries, nvec, minvec) ... which means "nvec" is the number of interrupts *requested*, and "minvec" is the minimum acceptable number (otherwise fail). -hpa From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.zytor.com (terminus.zytor.com [IPv6:2001:1868:205::10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id B13722C008A for ; Wed, 9 Oct 2013 15:08:44 +1100 (EST) Message-ID: <5254D397.9030307@zytor.com> Date: Tue, 08 Oct 2013 20:55:03 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 To: Alexander Gordeev Subject: Re: [PATCH RFC 00/77] Re-design MSI/MSI-X interrupts enablement pattern References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-mips@linux-mips.org, VMware@dhcp-26-207.brq.redhat.com, "Inc." , linux-nvme@lists.infradead.org, linux-ide@vger.kernel.org, linux-s390@vger.kernel.org, Andy King , linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org, x86@kernel.org, Ingo Molnar , linux-pci@vger.kernel.org, iss_storagedev@hp.com, linux-driver@qlogic.com, Tejun Heo , Bjorn Helgaas , Dan Williams , Jon Mason , Solarflare linux maintainers , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Ralf Baechle , e1000-devel@lists.sourceforge.net, Martin Schwidefsky , linux390@de.ibm.com, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 10/02/2013 03:29 AM, Alexander Gordeev wrote: > > As result, device drivers will cease to use the overcomplicated > repeated fallbacks technique and resort to a straightforward > pattern - determine the number of MSI/MSI-X interrupts required > before calling pci_enable_msi_block() and pci_enable_msix() > interfaces: > > > rc = pci_msix_table_size(adapter->pdev); > if (rc < 0) > return rc; > > nvec = min(nvec, rc); > if (nvec < FOO_DRIVER_MINIMUM_NVEC) { > return -ENOSPC; > > for (i = 0; i < nvec; i++) > adapter->msix_entries[i].entry = i; > > rc = pci_enable_msix(adapter->pdev, > adapter->msix_entries, nvec); > return rc; > Why not add a minimum number to pci_enable_msix(), i.e.: pci_enable_msix(pdev, msix_entries, nvec, minvec) ... which means "nvec" is the number of interrupts *requested*, and "minvec" is the minimum acceptable number (otherwise fail). -hpa