From patchwork Thu May 18 10:35:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gabriele Paoloni X-Patchwork-Id: 763908 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3wT77475P8z9s2P for ; Thu, 18 May 2017 20:42:40 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754774AbdERKmi (ORCPT ); Thu, 18 May 2017 06:42:38 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:6355 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754647AbdERKmh (ORCPT ); Thu, 18 May 2017 06:42:37 -0400 Received: from 172.30.72.56 (EHLO dggeml406-hub.china.huawei.com) ([172.30.72.56]) by dggrg02-dlp.huawei.com (MOS 4.4.6-GA FastPath queued) with ESMTP id ANU82665; Thu, 18 May 2017 18:36:13 +0800 (CST) Received: from G00308965-DELL1.china.huawei.com (10.203.181.162) by dggeml406-hub.china.huawei.com (10.3.17.50) with Microsoft SMTP Server id 14.3.301.0; Thu, 18 May 2017 18:36:04 +0800 From: Gabriele Paoloni To: , CC: , , , , , , , Subject: [PATCH v3 1/2] PCI/portdrv: add support for different MSI interrupts for PCIe port services Date: Thu, 18 May 2017 11:35:47 +0100 Message-ID: <1495103748-7876-2-git-send-email-gabriele.paoloni@huawei.com> X-Mailer: git-send-email 2.7.1.windows.1 In-Reply-To: <1495103748-7876-1-git-send-email-gabriele.paoloni@huawei.com> References: <1495103748-7876-1-git-send-email-gabriele.paoloni@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.203.181.162] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090204.591D791F.0021, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 67fe4d3f081e4bd9fb7c90a06486a833 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Currently PCIe port services are assigned with different interrutps only if MSI-x are supported by calling pcie_port_enable_msix(). If a root port supports MSI instead of MSI-x currently we fall back to use a single shared interrupt for all the services. This patch renames and extends pcie_port_enable_msix() to use MSI in case MSI-x allocation fails. Signed-off-by: Gabriele Paoloni Reviewed-by: Christoph Hellwig --- drivers/pci/pcie/portdrv.h | 8 +++++--- drivers/pci/pcie/portdrv_core.c | 43 ++++++++++++++++++++++++----------------- 2 files changed, 30 insertions(+), 21 deletions(-) diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h index 587aef3..1993e2c 100644 --- a/drivers/pci/pcie/portdrv.h +++ b/drivers/pci/pcie/portdrv.h @@ -13,10 +13,12 @@ #define PCIE_PORT_DEVICE_MAXSERVICES 5 /* - * According to the PCI Express Base Specification 2.0, the indices of - * the MSI-X table entries used by port services must not exceed 31 + * According to the PCI Express Base Specification REV. 3.1 and according + * to the PCI Local Bus Specification REV. 3.0 respectively, the indices of + * the MSI-X table entries or the max number of MSI vectors used by port + * services must not exceed 31 */ -#define PCIE_PORT_MAX_MSIX_ENTRIES 32 +#define PCIE_PORT_MAX_MSI_ENTRIES 32 #define get_descriptor_id(type, service) (((type - 4) << 8) | service) diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index cea504f..4d16cf2 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -44,14 +44,15 @@ static void release_pcie_device(struct device *dev) } /** - * pcie_port_enable_msix - try to set up MSI-X as interrupt mode for given port + * pcie_port_enable_irq_vec - try to set up MSI-X or MSI as interrupt mode + * for given port * @dev: PCI Express port to handle * @irqs: Array of interrupt vectors to populate * @mask: Bitmask of port capabilities returned by get_port_device_capability() * * Return value: 0 on success, error code on failure */ -static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) +static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask) { int nr_entries, entry, nvec = 0; @@ -61,8 +62,8 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) * equal to the number of entries this port actually uses, we'll happily * go through without any tricks. */ - nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSIX_ENTRIES, - PCI_IRQ_MSIX); + nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSI_ENTRIES, + PCI_IRQ_MSIX | PCI_IRQ_MSI); if (nr_entries < 0) return nr_entries; @@ -77,7 +78,13 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) * Number field in the PCI Express Capabilities register", where * according to Section 7.8.2 of the specification "For MSI-X, * the value in this field indicates which MSI-X Table entry is - * used to generate the interrupt message." + * used to generate the interrupt message." and "For MSI, the + * value in this field indicates the offset between the base + * Message Data and the interrupt message that is generated." + * + * pci_irq_vector() below is able to handle entry differently + * depending on MSI vs MSI-x case + * */ pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16); entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9; @@ -100,7 +107,10 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) * MSI/MSI-X vectors assigned to the port is going to be used * for AER, where "For MSI-X, the value in this register * indicates which MSI-X Table entry is used to generate the - * interrupt message." + * interrupt message." and "For MSI, the value + * in this field indicates the offset between the base Message + * Data and the interrupt message that is generated." + * */ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32); @@ -124,7 +134,7 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) /* Now allocate the MSI-X vectors for real */ nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec, - PCI_IRQ_MSIX); + PCI_IRQ_MSIX | PCI_IRQ_MSI); if (nr_entries < 0) return nr_entries; } @@ -146,26 +156,23 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) */ static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask) { - unsigned flags = PCI_IRQ_LEGACY | PCI_IRQ_MSI; int ret, i; for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) irqs[i] = -1; /* - * If MSI cannot be used for PCIe PME or hotplug, we have to use - * INTx or other interrupts, e.g. system shared interrupt. + * Make sure MSI can be used for PCIe PME or hotplug. otherwise we have + * to use INTx or other interrupts, e.g. system shared interrupt. */ - if (((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) || - ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) { - flags &= ~PCI_IRQ_MSI; - } else { - /* Try to use MSI-X if supported */ - if (!pcie_port_enable_msix(dev, irqs, mask)) + if (!((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) && + !((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) + /* Try to use MSI-X or MSI if supported */ + if (!pcie_port_enable_irq_vec(dev, irqs, mask)) return 0; - } - ret = pci_alloc_irq_vectors(dev, 1, 1, flags); + /* fall back to legacy IRQ */ + ret = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY); if (ret < 0) return -ENODEV;