From patchwork Wed Oct 2 10:48:21 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Gordeev X-Patchwork-Id: 279959 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id F20BF2C06A4 for ; Thu, 3 Oct 2013 03:27:03 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755250Ab3JBR0y (ORCPT ); Wed, 2 Oct 2013 13:26:54 -0400 Received: from 221-186-24-89.in-addr.arpa ([89.24.186.221]:26116 "EHLO dhcp-26-207.brq.redhat.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754760Ab3JBR0u (ORCPT ); Wed, 2 Oct 2013 13:26:50 -0400 Received: from dhcp-26-207.brq.redhat.com (localhost [127.0.0.1]) by dhcp-26-207.brq.redhat.com (8.14.5/8.14.5) with ESMTP id r92Aq0rv002382; Wed, 2 Oct 2013 12:52:01 +0200 Received: (from agordeev@localhost) by dhcp-26-207.brq.redhat.com (8.14.5/8.14.5/Submit) id r92ApugG002381; Wed, 2 Oct 2013 12:51:56 +0200 From: Alexander Gordeev To: linux-kernel@vger.kernel.org Cc: Alexander Gordeev , 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, Inc." , linux-scsi@vger.kernel.org Subject: [PATCH RFC 05/77] PCI/MSI: Convert pci_msix_table_size() to a public interface Date: Wed, 2 Oct 2013 12:48:21 +0200 Message-Id: X-Mailer: git-send-email 1.7.7.6 In-Reply-To: References: Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Make pci_msix_table_size() to return a error code if the device does not support MSI-X. This update is needed to facilitate a forthcoming re-design MSI/MSI-X interrupts enabling pattern. Device drivers will use this interface to obtain maximum number of MSI-X interrupts the device supports and use that value in the following call to pci_enable_msix() interface. Signed-off-by: Alexander Gordeev --- Documentation/PCI/MSI-HOWTO.txt | 13 +++++++++++++ drivers/pci/msi.c | 5 ++++- drivers/pci/pcie/portdrv_core.c | 2 ++ 3 files changed, 19 insertions(+), 1 deletions(-) diff --git a/Documentation/PCI/MSI-HOWTO.txt b/Documentation/PCI/MSI-HOWTO.txt index a091780..35b2d64 100644 --- a/Documentation/PCI/MSI-HOWTO.txt +++ b/Documentation/PCI/MSI-HOWTO.txt @@ -255,6 +255,19 @@ MSI-X Table. This address is mapped by the PCI subsystem, and should not be accessed directly by the device driver. If the driver wishes to mask or unmask an interrupt, it should call disable_irq() / enable_irq(). +4.3.4 pci_msix_table_size + +int pci_msix_table_size(struct pci_dev *dev) + +This function could be used to retrieve number of entries in the device +MSI-X table. + +If this function returns a negative number, it indicates the device is +not capable of sending MSI-Xs. + +If this function returns a positive number, it indicates the maximum +number of MSI-X interrupt vectors that could be allocated. + 4.4 Handling devices implementing both MSI and MSI-X capabilities If a device implements both MSI and MSI-X capabilities, it can diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index b43f391..875c353 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -928,11 +928,12 @@ int pci_msix_table_size(struct pci_dev *dev) u16 control; if (!dev->msix_cap) - return 0; + return -EINVAL; pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control); return msix_table_size(control); } +EXPORT_SYMBOL(pci_msix_table_size); /** * pci_enable_msix - configure device's MSI-X capability structure @@ -962,6 +963,8 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec) return status; nr_entries = pci_msix_table_size(dev); + if (nr_entries < 0) + return nr_entries; if (nvec > nr_entries) return nr_entries; diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index 31063ac..b4d86eb 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -80,6 +80,8 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *vectors, int mask) u32 reg32; nr_entries = pci_msix_table_size(dev); + if (nr_entries < 0) + return nr_entries; if (!nr_entries) return -EINVAL; if (nr_entries > PCIE_PORT_MAX_MSIX_ENTRIES)