diff options
Diffstat (limited to 'drivers/pci/bus.c')
| -rw-r--r-- | drivers/pci/bus.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 9daf13ed3714..4383a36fd6ca 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -8,6 +8,7 @@ */ #include <linux/module.h> #include <linux/kernel.h> +#include <linux/cleanup.h> #include <linux/pci.h> #include <linux/errno.h> #include <linux/ioport.h> @@ -435,6 +436,27 @@ static int __pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void return ret; } +static int __pci_walk_bus_reverse(struct pci_bus *top, + int (*cb)(struct pci_dev *, void *), + void *userdata) +{ + struct pci_dev *dev; + int ret = 0; + + list_for_each_entry_reverse(dev, &top->devices, bus_list) { + if (dev->subordinate) { + ret = __pci_walk_bus_reverse(dev->subordinate, cb, + userdata); + if (ret) + break; + } + ret = cb(dev, userdata); + if (ret) + break; + } + return ret; +} + /** * pci_walk_bus - walk devices on/under bus, calling callback. * @top: bus whose devices should be walked @@ -456,6 +478,23 @@ void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), void } EXPORT_SYMBOL_GPL(pci_walk_bus); +/** + * pci_walk_bus_reverse - walk devices on/under bus, calling callback. + * @top: bus whose devices should be walked + * @cb: callback to be called for each device found + * @userdata: arbitrary pointer to be passed to callback + * + * Same semantics as pci_walk_bus(), but walks the bus in reverse order. + */ +void pci_walk_bus_reverse(struct pci_bus *top, + int (*cb)(struct pci_dev *, void *), void *userdata) +{ + down_read(&pci_bus_sem); + __pci_walk_bus_reverse(top, cb, userdata); + up_read(&pci_bus_sem); +} +EXPORT_SYMBOL_GPL(pci_walk_bus_reverse); + void pci_walk_bus_locked(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), void *userdata) { lockdep_assert_held(&pci_bus_sem); |