From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759982AbZCRWmf (ORCPT ); Wed, 18 Mar 2009 18:42:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755343AbZCRWkN (ORCPT ); Wed, 18 Mar 2009 18:40:13 -0400 Received: from g1t0028.austin.hp.com ([15.216.28.35]:2845 "EHLO g1t0028.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755865AbZCRWkL (ORCPT ); Wed, 18 Mar 2009 18:40:11 -0400 From: Alex Chiang Subject: [PATCH v4 07/12] 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: Wed, 18 Mar 2009 16:40:01 -0600 Message-ID: <20090318224001.887.63554.stgit@bob.kio> In-Reply-To: <20090318222426.887.1008.stgit@bob.kio> References: <20090318222426.887.1008.stgit@bob.kio> User-Agent: StGIT/0.14.3.215.gff3d MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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 | 29 +++++++++++++++++++++++++++++ drivers/pci/pci.h | 6 ++++++ 4 files changed, 45 insertions(+), 0 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index e638e15..ea4aee2 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -41,6 +41,15 @@ Description: for the device and attempt to bind to it. For example: # echo "8086 10f5" > /sys/bus/pci/drivers/foo/new_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 a5f11ad..62ed864 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -973,6 +973,7 @@ 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 1c89298..22dbc65 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -219,6 +219,35 @@ 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 (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + 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, 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 07c0aa5..6dea35f 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