From patchwork Mon Dec 16 08:35:01 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Gordeev X-Patchwork-Id: 3356301 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 3A21B9F380 for ; Mon, 16 Dec 2013 18:48:07 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0D155201FE for ; Mon, 16 Dec 2013 18:48:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BF8BE20181 for ; Mon, 16 Dec 2013 18:48:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755002Ab3LPSsD (ORCPT ); Mon, 16 Dec 2013 13:48:03 -0500 Received: from 221-186-24-89.in-addr.arpa ([89.24.186.221]:28717 "EHLO dhcp-26-207.brq.redhat.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754988Ab3LPSsD (ORCPT ); Mon, 16 Dec 2013 13:48:03 -0500 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 rBG8Zhlg016642; Mon, 16 Dec 2013 09:35:43 +0100 Received: (from agordeev@localhost) by dhcp-26-207.brq.redhat.com (8.14.5/8.14.5/Submit) id rBG8Zgij016641; Mon, 16 Dec 2013 09:35:42 +0100 From: Alexander Gordeev To: linux-kernel@vger.kernel.org Cc: Alexander Gordeev , Bjorn Helgaas , Michael Ellerman , Benjamin Herrenschmidt , Tejun Heo , Ben Hutchings , David Laight , Mark Lord , "H. Peter Anvin" , linux-pci@vger.kernel.org Subject: [PATCH v4 8/9] PCI/MSI: Introduce pci_get_msix_vec_count() interface Date: Mon, 16 Dec 2013 09:35:01 +0100 Message-Id: <7f63ab07cfeff8e87eda141d850ecee3d4791c1c.1387140921.git.agordeev@redhat.com> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: References: Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This update is needed to create a consistent MSI-X counterpart for pci_get_msi_vec_count() MSI interface. Device drivers can use this function to obtain maximum number of MSI-X interrupts the device supports and i.e. use that number in a following call to pci_enable_msix() interface. Interface pci_get_msix_vec_count() supersedes pci_msix_table_size() function and returns a negative errno if device does not support MSI-X interrupts. After this update callers must always check the returned value. The only user of pci_msix_table_size() function was PCI-Express port driver, which is also updated by this change. Signed-off-by: Alexander Gordeev Reviewed-by: Tejun Heo --- Documentation/PCI/MSI-HOWTO.txt | 13 +++++++++++++ drivers/pci/msi.c | 18 +++++++++++++----- drivers/pci/pcie/portdrv_core.c | 7 ++++--- include/linux/pci.h | 6 +++--- 4 files changed, 33 insertions(+), 11 deletions(-) diff --git a/Documentation/PCI/MSI-HOWTO.txt b/Documentation/PCI/MSI-HOWTO.txt index 8d35d62..7d19656 100644 --- a/Documentation/PCI/MSI-HOWTO.txt +++ b/Documentation/PCI/MSI-HOWTO.txt @@ -243,6 +243,19 @@ 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_get_msix_vec_count + +int pci_get_msix_vec_count(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 de1acb9..18e877f5 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -939,19 +939,25 @@ void pci_disable_msi(struct pci_dev *dev) EXPORT_SYMBOL(pci_disable_msi); /** - * pci_msix_table_size - return the number of device's MSI-X table entries + * pci_get_msix_vec_count - return the number of device's MSI-X table entries * @dev: pointer to the pci_dev data structure of MSI-X device function - */ -int pci_msix_table_size(struct pci_dev *dev) + + * This function returns the number of device's MSI-X table entries and + * therefore the number of MSI-X vectors device is capable to send. + * It returns a negative errno if the device is not capable sending MSI-X + * interrupts. + **/ +int pci_get_msix_vec_count(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_get_msix_vec_count); /** * pci_enable_msix - configure device's MSI-X capability structure @@ -980,7 +986,9 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec) if (status) return status; - nr_entries = pci_msix_table_size(dev); + nr_entries = pci_get_msix_vec_count(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 ce9d9ae..8ba9db0 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -79,9 +79,10 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *vectors, int mask) u16 reg16; u32 reg32; - nr_entries = pci_msix_table_size(dev); - if (!nr_entries) - return -EINVAL; + nr_entries = pci_get_msix_vec_count(dev); + if (nr_entries < 0) + return nr_entries; + BUG_ON(!nr_entries); if (nr_entries > PCIE_PORT_MAX_MSIX_ENTRIES) nr_entries = PCIE_PORT_MAX_MSIX_ENTRIES; diff --git a/include/linux/pci.h b/include/linux/pci.h index 8d9eb6b..7941f06 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1169,9 +1169,9 @@ static inline void pci_msi_shutdown(struct pci_dev *dev) static inline void pci_disable_msi(struct pci_dev *dev) { } -static inline int pci_msix_table_size(struct pci_dev *dev) +static inline int pci_get_msix_vec_count(struct pci_dev *dev) { - return 0; + return -ENOSYS; } static inline int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec) @@ -1198,7 +1198,7 @@ int pci_get_msi_vec_count(struct pci_dev *dev); int pci_enable_msi_block(struct pci_dev *dev, int nvec); void pci_msi_shutdown(struct pci_dev *dev); void pci_disable_msi(struct pci_dev *dev); -int pci_msix_table_size(struct pci_dev *dev); +int pci_get_msix_vec_count(struct pci_dev *dev); int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec); void pci_msix_shutdown(struct pci_dev *dev); void pci_disable_msix(struct pci_dev *dev);