From 705b1aaa823e800490f157cd9366ad8cff385f5f Mon Sep 17 00:00:00 2001 From: Alex Chiang Date: Fri, 20 Mar 2009 14:56:31 -0600 Subject: PCI: Introduce /sys/bus/pci/rescan 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 Signed-off-by: Jesse Barnes --- drivers/pci/pci-driver.c | 1 + drivers/pci/pci-sysfs.c | 26 ++++++++++++++++++++++++++ drivers/pci/pci.h | 6 ++++++ drivers/pci/probe.c | 4 ++-- 4 files changed, 35 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 87a5ddbb324..95d19857029 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 ec7a175dcba..be7468a5eb7 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 22dcfdb75d9..45833a5bca6 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -138,6 +138,12 @@ 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 60a8e5fec6c..56c71e585f3 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1228,13 +1228,13 @@ 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); -- cgit v1.2.3