From patchwork Fri Mar 20 20:56:31 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Chiang X-Patchwork-Id: 13381 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n2KKufKB001652 for ; Fri, 20 Mar 2009 20:56:43 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758718AbZCTU4f (ORCPT ); Fri, 20 Mar 2009 16:56:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758413AbZCTU4e (ORCPT ); Fri, 20 Mar 2009 16:56:34 -0400 Received: from g5t0008.atlanta.hp.com ([15.192.0.45]:39094 "EHLO g5t0008.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759192AbZCTU4d (ORCPT ); Fri, 20 Mar 2009 16:56:33 -0400 Received: from smtp2.fc.hp.com (smtp.fc.hp.com [15.11.136.114]) by g5t0008.atlanta.hp.com (Postfix) with ESMTP id 87A6824461; Fri, 20 Mar 2009 20:56:31 +0000 (UTC) Received: from localhost.localdomain (lart.fc.hp.com [15.11.146.31]) by smtp2.fc.hp.com (Postfix) with ESMTP id A248C2BD791; Fri, 20 Mar 2009 20:33:03 +0000 (UTC) Received: from bob.kio (localhost [127.0.0.1]) by localhost.localdomain (Postfix) with ESMTP id 165782615B; Fri, 20 Mar 2009 14:56:31 -0600 (MDT) From: Alex Chiang Subject: [PATCH v5 08/13] PCI: Introduce /sys/bus/pci/rescan To: jbarnes@virtuousgeek.org Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Trent Piepho , Alex Chiang Date: Fri, 20 Mar 2009 14:56:31 -0600 Message-ID: <20090320205631.12275.99348.stgit@bob.kio> In-Reply-To: <20090320204327.12275.43010.stgit@bob.kio> References: <20090320204327.12275.43010.stgit@bob.kio> User-Agent: StGIT/0.14.3.215.gff3d MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org This interface allows the user to force a rescan of all PCI buses in system, and rediscover devices that have been removed earlier. pci_bus_attrs implementation from Trent Piepho. Thanks to Vegard Nossum for discovering locking issues with the sysfs interface. Cc: Trent Piepho Signed-off-by: Alex Chiang --- Documentation/ABI/testing/sysfs-bus-pci | 9 +++++++++ drivers/pci/pci-driver.c | 1 + drivers/pci/pci-sysfs.c | 26 ++++++++++++++++++++++++++ drivers/pci/pci.h | 6 ++++++ drivers/pci/probe.c | 4 ++-- 5 files changed, 44 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index 3d29793..1697a16 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -57,6 +57,15 @@ Description: match the driver to the device. For example: # echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id +What: /sys/bus/pci/rescan +Date: January 2009 +Contact: Linux PCI developers +Description: + Writing a non-zero value to this attribute will + force a rescan of all PCI buses in the system, and + re-discover previously removed devices. + Depends on CONFIG_HOTPLUG. + What: /sys/bus/pci/devices/.../vpd Date: February 2008 Contact: Ben Hutchings diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 87a5ddb..95d1985 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1049,6 +1049,7 @@ struct bus_type pci_bus_type = { .remove = pci_device_remove, .shutdown = pci_device_shutdown, .dev_attrs = pci_dev_attrs, + .bus_attrs = pci_bus_attrs, .pm = PCI_PM_OPS_PTR, }; diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index ec7a175..be7468a 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -219,6 +219,32 @@ msi_bus_store(struct device *dev, struct device_attribute *attr, return count; } +#ifdef CONFIG_HOTPLUG +static DEFINE_MUTEX(pci_remove_rescan_mutex); +static ssize_t bus_rescan_store(struct bus_type *bus, const char *buf, + size_t count) +{ + unsigned long val; + struct pci_bus *b = NULL; + + if (strict_strtoul(buf, 0, &val) < 0) + return -EINVAL; + + if (val) { + mutex_lock(&pci_remove_rescan_mutex); + while ((b = pci_find_next_bus(b)) != NULL) + pci_rescan_bus(b); + mutex_unlock(&pci_remove_rescan_mutex); + } + return count; +} + +struct bus_attribute pci_bus_attrs[] = { + __ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, bus_rescan_store), + __ATTR_NULL +}; +#endif + struct device_attribute pci_dev_attrs[] = { __ATTR_RO(resource), __ATTR_RO(vendor), diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 2cd1cba..5b2eb30 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -136,6 +136,12 @@ extern int pcie_mch_quirk; extern struct device_attribute pci_dev_attrs[]; extern struct device_attribute dev_attr_cpuaffinity; extern struct device_attribute dev_attr_cpulistaffinity; +#ifdef CONFIG_HOTPLUG +extern struct bus_attribute pci_bus_attrs[]; +#else +#define pci_bus_attrs NULL +#endif + /** * pci_match_one_device - Tell if a PCI device structure has a matching diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 53edb7e..1541899 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1219,13 +1219,13 @@ unsigned int __devinit pci_rescan_bus(struct pci_bus *bus) max = pci_scan_child_bus(bus); - up_read(&pci_bus_sem); + down_read(&pci_bus_sem); list_for_each_entry(dev, &bus->devices, bus_list) if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE || dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) if (dev->subordinate) pci_bus_size_bridges(dev->subordinate); - down_read(&pci_bus_sem); + up_read(&pci_bus_sem); pci_bus_assign_resources(bus); pci_enable_bridges(bus);