This adds a bus attribute named "scan" to the PCI bus, which will appear in sysfs at "/sys/bus/pci/scan". Writing to this file will trigger a rescan of all PCI busses. To do this pci_scan_single_device() is modified to first check if the device to be scanned is already known to Linux. In which case it just returns the existing device. The old behavior was to create a new device anyway that would conflict with the existing one, causing all manner of Bad Things to happen. pci_scan_slot() has been rewritten to be less complex and will now return the number of *new* devices found. It didn't used to work to call pci_scan_slot() on a previously scanned slot, so returning all devices found was effectivly the same as returning new devices. --- drivers/pci/pci-driver.c | 1 + drivers/pci/pci-sysfs.c | 14 +++++++++++ drivers/pci/pci.h | 6 +++++ drivers/pci/probe.c | 55 +++++++++++++++++++++++++++------------------ 4 files changed, 54 insertions(+), 22 deletions(-) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 2bec651..fcfd445 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -847,6 +847,7 @@ 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 d422f37..0781ab7 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -266,6 +266,20 @@ struct device_attribute pci_dev_attrs[] = { __ATTR_NULL, }; +#ifdef CONFIG_HOTPLUG +static ssize_t __ref scan(struct bus_type *type, const char *buf, size_t count) +{ + pci_rescan_busses(); + + return count; +} + +struct bus_attribute pci_bus_attrs[] = { + __ATTR(scan, S_IWUSR, NULL, scan), + __ATTR_NULL +}; +#endif + static ssize_t pci_read_config(struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 65deed8..49d7bb4 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -87,6 +87,7 @@ static inline int pci_proc_detach_bus(struct pci_bus *bus) { return 0; } /* Functions for PCI Hotplug drivers to use */ extern unsigned int pci_do_scan_bus(struct pci_bus *bus); +extern void pci_rescan_busses(void) __devinit; #ifdef HAVE_PCI_LEGACY extern void pci_create_legacy_files(struct pci_bus *bus); @@ -128,6 +129,11 @@ 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 251c2b1..6e6172d 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1006,6 +1006,13 @@ struct pci_dev *__ref pci_scan_single_device(struct pci_bus *bus, int devfn) { struct pci_dev *dev; + /* Check to see if the device is already known */ + dev = pci_get_slot(bus, devfn); + if (dev) { + pci_dev_put(dev); + return dev; + } + dev = pci_scan_device(bus, devfn); if (!dev) return NULL; @@ -1024,35 +1031,26 @@ EXPORT_SYMBOL(pci_scan_single_device); * Scan a PCI slot on the specified PCI bus for devices, adding * discovered devices to the @bus->devices list. New devices * will not have is_added set. + * + * Returns the number of new devices found. */ int pci_scan_slot(struct pci_bus *bus, int devfn) { - int func, nr = 0; - int scan_all_fns; - - scan_all_fns = pcibios_scan_all_fns(bus, devfn); - - for (func = 0; func < 8; func++, devfn++) { - struct pci_dev *dev; + int fn, nr = 0; + struct pci_dev *dev; - dev = pci_scan_single_device(bus, devfn); - if (dev) { + if ((dev = pci_scan_single_device(bus, devfn))) + if (!dev->is_added) /* new device? */ nr++; - /* - * If this is a single function device, - * don't scan past the first function. - */ - if (!dev->multifunction) { - if (func > 0) { - dev->multifunction = 1; - } else { - break; - } + if ((dev && dev->multifunction) || + (!dev && pcibios_scan_all_fns(bus, devfn))) { + for (fn = 1; fn < 8; fn++) { + if ((dev = pci_scan_single_device(bus, devfn + fn))) { + if (!dev->is_added) + nr++; + dev->multifunction = 1; } - } else { - if (func == 0 && !scan_all_fns) - break; } } @@ -1192,11 +1190,24 @@ struct pci_bus * __devinit pci_scan_bus_parented(struct device *parent, } EXPORT_SYMBOL(pci_scan_bus_parented); +/* Does a recursive rescan of all PCI busses. */ +void __devinit pci_rescan_busses(void) +{ + struct pci_bus *bus = NULL; + + while ((bus = pci_find_next_bus(bus)) != NULL) { + pci_scan_child_bus(bus); + pci_bus_assign_resources(bus); + pci_bus_add_devices(bus); + } +} + #ifdef CONFIG_HOTPLUG EXPORT_SYMBOL(pci_add_new_bus); EXPORT_SYMBOL(pci_scan_slot); EXPORT_SYMBOL(pci_scan_bridge); EXPORT_SYMBOL_GPL(pci_scan_child_bus); +EXPORT_SYMBOL_GPL(pci_rescan_busses); #endif static int __init pci_sort_bf_cmp(const struct device *d_a, const struct device *d_b) -- 1.5.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html