Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754759Ab3EPPvi (ORCPT ); Thu, 16 May 2013 11:51:38 -0400 Received: from mail-pb0-f51.google.com ([209.85.160.51]:51082 "EHLO mail-pb0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754704Ab3EPPvf (ORCPT ); Thu, 16 May 2013 11:51:35 -0400 From: Jiang Liu To: Bjorn Helgaas , Yinghai Lu Cc: Jiang Liu , "Rafael J . Wysocki" , Greg Kroah-Hartman , Gu Zheng , Toshi Kani , Myron Stowe , Yijing Wang , Jiang Liu , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH v2, part3 05/11] PCI: enhance PCI core logic to support PCI bus lock Date: Thu, 16 May 2013 23:50:53 +0800 Message-Id: <1368719459-24800-6-git-send-email-jiang.liu@huawei.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1368719459-24800-1-git-send-email-jiang.liu@huawei.com> References: <1368719459-24800-1-git-send-email-jiang.liu@huawei.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4403 Lines: 129 Every new PCI bus will be created with the PCI_BUS_STATE_LOCK bit set, so a typical PCI device hot-add flow is: pci_bus_lock(parent, PCI_BUS_STATE_STARTED, true); pci_scan_slot(parent, PCI_DEVFN(0, 0)); pci_bus_add_devices(parent); pci_bus_unlock(parent, true); // recursively unlock all PCI // buses, including new PCI buses This patch also changes behaviors of interfaces to create PCI root buses: pci_create_root_bus(): return with new PCI root bus locked pci_scan_bus_parented(): return with new PCI root bus locked pci_scan_root_bus(): return with new PCI root bus unlocked pci_scan_bus(): return with new PCI root bus unlocked pci_scan_bus_parented() has already been marked as __deprecated and all in-tree callers have been converted to use other interfaces. So following-on patches will enhance callers of pci_create_root_bus() to unlock returned root buses. Signed-off-by: Jiang Liu Cc: Yinghai Lu Cc: linux-pci@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- drivers/pci/hotplug-pci.c | 4 ++++ drivers/pci/probe.c | 18 ++++++++++++++++++ 2 files changed, 22 insertions(+) diff --git a/drivers/pci/hotplug-pci.c b/drivers/pci/hotplug-pci.c index 18533ed..8faa3c2 100644 --- a/drivers/pci/hotplug-pci.c +++ b/drivers/pci/hotplug-pci.c @@ -10,6 +10,10 @@ int __ref pci_hp_add_bridge(struct pci_dev *dev) int pass, busnr, start = parent->busn_res.start; int end = parent->busn_res.end; + BUG_ON(!pci_bus_is_locked(parent)); + if (pci_bus_get_state(parent) > PCI_BUS_STATE_STARTED) + return 0; + for (busnr = start; busnr <= end; busnr++) { if (!pci_bus_exists(pci_domain_nr(parent), busnr)) break; diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 9fcf3a3..0ddf5b8 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -745,6 +745,10 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass) u8 primary, secondary, subordinate; int broken = 0; + BUG_ON(!pci_bus_is_locked(bus)); + if (pci_bus_get_state(bus) > PCI_BUS_STATE_STARTED) + return max; + pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses); primary = buses & 0xFF; secondary = (buses >> 8) & 0xFF; @@ -799,6 +803,8 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass) pci_bus_insert_busn_res(child, secondary, subordinate); child->bridge_ctl = bctl; pci_bus_get(child); + } else { + BUG_ON(!pci_bus_is_locked(child)); } cmax = pci_scan_child_bus(child); @@ -837,6 +843,8 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass) goto out; pci_bus_insert_busn_res(child, max, 0xff); pci_bus_get(child); + } else { + BUG_ON(!pci_bus_is_locked(child)); } buses = (buses & 0xff000000) | ((unsigned int)(child->primary) << 0) @@ -1322,6 +1330,7 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) { int ret; + BUG_ON(!pci_bus_is_locked(bus)); device_initialize(&dev->dev); dev->dev.release = pci_release_dev; @@ -1369,6 +1378,10 @@ struct pci_dev *__ref pci_scan_single_device(struct pci_bus *bus, int devfn) { struct pci_dev *dev; + BUG_ON(!pci_bus_is_locked(bus)); + if (pci_bus_get_state(bus) > PCI_BUS_STATE_STARTED) + return NULL; + dev = pci_get_slot(bus, devfn); if (dev) { pci_dev_put(dev); @@ -1624,6 +1637,8 @@ unsigned int pci_scan_child_bus(struct pci_bus *bus) unsigned int devfn, pass, max = bus->busn_res.start; struct pci_dev *dev; + BUG_ON(!pci_bus_is_locked(bus)); + BUG_ON(pci_bus_get_state(bus) > PCI_BUS_STATE_STARTED); dev_dbg(&bus->dev, "scanning bus\n"); /* Go find them, Rover! */ @@ -1872,6 +1887,8 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus, pci_bus_update_busn_res_end(b, max); pci_bus_add_devices(b); + pci_bus_unlock(b, true); + return b; } EXPORT_SYMBOL(pci_scan_root_bus); @@ -1908,6 +1925,7 @@ struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops, if (b) { pci_scan_child_bus(b); pci_bus_add_devices(b); + pci_bus_unlock(b, true); } else { pci_free_resource_list(&resources); } -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/