Now we have pci_root_buses list, and there is lots of iteration with list_of_each of it, that is not safe after we add pci root bus hotplug support after booting stage.
Also pci_find_next_bus is pretty misleading name, and it is only finding next root bus instead of regular pci bus.
Add pci_get_next_host_bridge and use bus_find_device in driver core to iterate host bridge and the same time get root bus.
In folllowing patches will replace searching root bus with searching host_bridge. after using with that host-bridge, will need to call put device to release reference if break early from the loop.
After those replacing, we even could kill pci_root_buses list.
-v2: fixes compiling error when CONFIG_PCI is not defined that Fengguang Wu found.
Signed-off-by: Yinghai Lu yinghai@kernel.org Cc: Mauro Carvalho Chehab mchehab@redhat.com Cc: Doug Thompson dougthompson@xmission.com Cc: linux-edac@vger.kernel.org Cc: x86@kernel.org Cc: David Airlie airlied@linux.ie Cc: dri-devel@lists.freedesktop.org Cc: "David S. Miller" davem@davemloft.net Cc: sparclinux@vger.kernel.org Cc: Tony Luck tony.luck@intel.com Cc: Fenghua Yu fenghua.yu@intel.com Cc: linux-ia64@vger.kernel.org Cc: linux-altix@sgi.com Cc: Richard Henderson rth@twiddle.net Cc: Ivan Kokshaysky ink@jurassic.park.msu.ru Cc: Matt Turner mattst88@gmail.com Cc: linux-alpha@vger.kernel.org Cc: Russell King linux@arm.linux.org.uk Cc: linux-arm-kernel@lists.infradead.org Cc: David Howells dhowells@redhat.com Cc: Michal Simek monstr@monstr.eu Cc: microblaze-uclinux@itee.uq.edu.au Cc: Koichi Yasutake yasutake.koichi@jp.panasonic.com Cc: linux-am33-list@redhat.com Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Paul Mackerras paulus@samba.org Cc: linuxppc-dev@lists.ozlabs.org --- drivers/pci/search.c | 24 ++++++++++++++++++++++++ include/linux/pci.h | 9 +++++++++ 2 files changed, 33 insertions(+)
diff --git a/drivers/pci/search.c b/drivers/pci/search.c index d0627fa..db0c3a9 100644 --- a/drivers/pci/search.c +++ b/drivers/pci/search.c @@ -178,6 +178,30 @@ struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus, } EXPORT_SYMBOL(pci_get_domain_bus_and_slot);
+static int match_pci_host_bridge(struct device *dev, void *data) +{ + return 1; +} + +struct pci_host_bridge *pci_get_next_host_bridge(struct pci_host_bridge *from) +{ + struct device *dev; + struct device *dev_start = NULL; + struct pci_host_bridge *bridge = NULL; + + WARN_ON(in_interrupt()); + if (from) + dev_start = &from->dev; + dev = bus_find_device(&pci_host_bridge_bus_type, dev_start, NULL, + match_pci_host_bridge); + if (dev) + bridge = to_pci_host_bridge(dev); + if (from) + put_device(&from->dev); + return bridge; +} +EXPORT_SYMBOL_GPL(pci_get_next_host_bridge); + static int match_pci_dev_by_id(struct device *dev, void *data) { struct pci_dev *pdev = to_pci_dev(dev); diff --git a/include/linux/pci.h b/include/linux/pci.h index 9da06ec..67879cb 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -375,6 +375,8 @@ struct pci_host_bridge { };
#define to_pci_host_bridge(n) container_of(n, struct pci_host_bridge, dev) +#define for_each_pci_host_bridge(d) while ((d = pci_get_next_host_bridge(d)) != NULL) + void pci_set_host_bridge_release(struct pci_host_bridge *bridge, void (*release_fn)(struct pci_host_bridge *), void *release_data); @@ -763,6 +765,7 @@ int pci_find_ht_capability(struct pci_dev *dev, int ht_cap); int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap); struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
+struct pci_host_bridge *pci_get_next_host_bridge(struct pci_host_bridge *from); struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from); struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device, @@ -1418,6 +1421,12 @@ static inline int pci_domain_nr(struct pci_bus *bus) static inline struct pci_dev *pci_dev_get(struct pci_dev *dev) { return NULL; }
+static inline struct pci_host_bridge *pci_get_next_host_bridge( + struct pci_host_bridge *host_bridge) +{ + return NULL; +} + #define dev_is_pci(d) (false) #define dev_is_pf(d) (false) #define dev_num_vf(d) (0)