| Message ID | 1358525267-14268-4-git-send-email-jiang.liu@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Saturday, January 19, 2013 12:07:41 AM Jiang Liu wrote: > When adding/removing a PCI bus, some other components want to be > notified so they could update their states. For example, the pci_slot > driver needs to create/destroy PCI slots attaching to the PCI bus. > So introduce a dedicate blocking notifier chain for PCI bus > addition/removal events. It could be extended to support PCI device > addition/removal events in the future when needed. > > Signed-off-by: Jiang Liu <jiang.liu@huawei.com> > --- > drivers/pci/bus.c | 24 ++++++++++++++++++++++++ > drivers/pci/pci.h | 1 + > drivers/pci/probe.c | 2 ++ > drivers/pci/remove.c | 1 + > include/linux/pci.h | 12 ++++++++++++ > 5 files changed, 40 insertions(+) > > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > index 4c843cd..8bbd3f2 100644 > --- a/drivers/pci/bus.c > +++ b/drivers/pci/bus.c > @@ -13,11 +13,33 @@ > #include <linux/errno.h> > #include <linux/ioport.h> > #include <linux/proc_fs.h> > +#include <linux/notifier.h> > #include <linux/init.h> > #include <linux/slab.h> > > #include "pci.h" > > +static BLOCKING_NOTIFIER_HEAD(pci_bus_notifier_chain); > + > +int pci_bus_register_notifier(struct notifier_block *nb) > +{ > + return blocking_notifier_chain_register(&pci_bus_notifier_chain, nb); > +} > + > +int pci_bus_unregister_notifier(struct notifier_block *nb) > +{ > + return blocking_notifier_chain_unregister(&pci_bus_notifier_chain, nb); > +} > + > +void pci_bus_call_notifier(struct pci_bus *bus, unsigned long code) > +{ > + int ret; > + > + ret = blocking_notifier_call_chain(&pci_bus_notifier_chain, > + code, bus); > + WARN_ON(ret != NOTIFY_DONE && ret != NOTIFY_OK); I'm not sure if this is a good idea. WARN_ON() is quite a heavy tool. > +} > + > void pci_add_resource_offset(struct list_head *resources, struct resource *res, > resource_size_t offset) > { > @@ -197,6 +219,8 @@ int pci_bus_add_child(struct pci_bus *bus) > if (retval) > return retval; > > + pci_bus_call_notifier(bus, PCI_NOTIFY_POST_BUS_ADD); > + > bus->is_added = 1; > > /* Create legacy_io and legacy_mem files for this bus */ > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 7414094..988e4b4 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -208,6 +208,7 @@ extern int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > extern int pci_resource_bar(struct pci_dev *dev, int resno, > enum pci_bar_type *type); > extern int pci_bus_add_child(struct pci_bus *bus); > +extern void pci_bus_call_notifier(struct pci_bus *bus, unsigned long code); > extern void pci_enable_ari(struct pci_dev *dev); > /** > * pci_ari_enabled - query ARI forwarding status > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index adb77c6..7db6528 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -1679,6 +1679,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, > if (error) > goto class_dev_reg_err; > > + pci_bus_call_notifier(b, PCI_NOTIFY_POST_BUS_ADD); > + > /* Create legacy_io and legacy_mem files for this bus */ > pci_create_legacy_files(b); > > diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c > index 0d03026..2d8fbc8 100644 > --- a/drivers/pci/remove.c > +++ b/drivers/pci/remove.c > @@ -50,6 +50,7 @@ void pci_remove_bus(struct pci_bus *bus) > up_write(&pci_bus_sem); > if (bus->is_added) { > pci_remove_legacy_files(bus); > + pci_bus_call_notifier(bus, PCI_NOTIFY_PRE_BUS_DEL); > device_del(&bus->dev); > } > put_device(&bus->dev); > diff --git a/include/linux/pci.h b/include/linux/pci.h > index ee21795..12e5447 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1033,6 +1033,18 @@ const struct pci_device_id *pci_match_id(const struct pci_device_id *ids, > int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, > int pass); > > +/* > + * All notifiers below get called with the target struct pci_bus *bus as > + * an argument. > + * Note: all PCI bus notifier must return success. Currently there's no > + * error handling if any notifier returns error code. > + */ > +#define PCI_NOTIFY_POST_BUS_ADD 0x00000001 /* PCI bus has been added */ > +#define PCI_NOTIFY_PRE_BUS_DEL 0x00000002 /* PCI bus will be deleted */ I would call them PCI_EVENT_BUS_ADDED and PCI_EVENT_BUS_REMOVE, respectively. > + > +int pci_bus_register_notifier(struct notifier_block *nb); > +int pci_bus_unregister_notifier(struct notifier_block *nb); > + > void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), > void *userdata); > int pci_cfg_space_size_ext(struct pci_dev *dev); Apart from the nitpicks above, looks good. Thanks, Rafael
On 01/21/2013 07:54 AM, Rafael J. Wysocki wrote: > On Saturday, January 19, 2013 12:07:41 AM Jiang Liu wrote: >> When adding/removing a PCI bus, some other components want to be snip >> + >> +void pci_bus_call_notifier(struct pci_bus *bus, unsigned long code) >> +{ >> + int ret; >> + >> + ret = blocking_notifier_call_chain(&pci_bus_notifier_chain, >> + code, bus); >> + WARN_ON(ret != NOTIFY_DONE && ret != NOTIFY_OK); > > I'm not sure if this is a good idea. WARN_ON() is quite a heavy tool. Hi Rafael, How about WARN_ONCE() here? > >> +} >> + >> void pci_add_resource_offset(struct list_head *resources, struct resource *res, >> resource_size_t offset) >> { >> diff --git a/include/linux/pci.h b/include/linux/pci.h >> index ee21795..12e5447 100644 >> --- a/include/linux/pci.h >> +++ b/include/linux/pci.h >> @@ -1033,6 +1033,18 @@ const struct pci_device_id *pci_match_id(const struct pci_device_id *ids, >> int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, >> int pass); >> >> +/* >> + * All notifiers below get called with the target struct pci_bus *bus as >> + * an argument. >> + * Note: all PCI bus notifier must return success. Currently there's no >> + * error handling if any notifier returns error code. >> + */ >> +#define PCI_NOTIFY_POST_BUS_ADD 0x00000001 /* PCI bus has been added */ >> +#define PCI_NOTIFY_PRE_BUS_DEL 0x00000002 /* PCI bus will be deleted */ > > I would call them PCI_EVENT_BUS_ADDED and PCI_EVENT_BUS_REMOVE, respectively. Sure, will use them in next version. > >> + >> +int pci_bus_register_notifier(struct notifier_block *nb); >> +int pci_bus_unregister_notifier(struct notifier_block *nb); >> + >> void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), >> void *userdata); >> int pci_cfg_space_size_ext(struct pci_dev *dev); > > Apart from the nitpicks above, looks good. Thanks for review! Regards! Gerry > > Thanks, > Rafael > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tuesday, January 22, 2013 12:18:55 AM Jiang Liu wrote: > On 01/21/2013 07:54 AM, Rafael J. Wysocki wrote: > > On Saturday, January 19, 2013 12:07:41 AM Jiang Liu wrote: > >> When adding/removing a PCI bus, some other components want to be > snip > >> + > >> +void pci_bus_call_notifier(struct pci_bus *bus, unsigned long code) > >> +{ > >> + int ret; > >> + > >> + ret = blocking_notifier_call_chain(&pci_bus_notifier_chain, > >> + code, bus); > >> + WARN_ON(ret != NOTIFY_DONE && ret != NOTIFY_OK); > > > > I'm not sure if this is a good idea. WARN_ON() is quite a heavy tool. > Hi Rafael, > How about WARN_ONCE() here? Well, that depends on what you think it will be useful for. Thanks, Rafael
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 4c843cd..8bbd3f2 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -13,11 +13,33 @@ #include <linux/errno.h> #include <linux/ioport.h> #include <linux/proc_fs.h> +#include <linux/notifier.h> #include <linux/init.h> #include <linux/slab.h> #include "pci.h" +static BLOCKING_NOTIFIER_HEAD(pci_bus_notifier_chain); + +int pci_bus_register_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&pci_bus_notifier_chain, nb); +} + +int pci_bus_unregister_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&pci_bus_notifier_chain, nb); +} + +void pci_bus_call_notifier(struct pci_bus *bus, unsigned long code) +{ + int ret; + + ret = blocking_notifier_call_chain(&pci_bus_notifier_chain, + code, bus); + WARN_ON(ret != NOTIFY_DONE && ret != NOTIFY_OK); +} + void pci_add_resource_offset(struct list_head *resources, struct resource *res, resource_size_t offset) { @@ -197,6 +219,8 @@ int pci_bus_add_child(struct pci_bus *bus) if (retval) return retval; + pci_bus_call_notifier(bus, PCI_NOTIFY_POST_BUS_ADD); + bus->is_added = 1; /* Create legacy_io and legacy_mem files for this bus */ diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 7414094..988e4b4 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -208,6 +208,7 @@ extern int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, extern int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); extern int pci_bus_add_child(struct pci_bus *bus); +extern void pci_bus_call_notifier(struct pci_bus *bus, unsigned long code); extern void pci_enable_ari(struct pci_dev *dev); /** * pci_ari_enabled - query ARI forwarding status diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index adb77c6..7db6528 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1679,6 +1679,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, if (error) goto class_dev_reg_err; + pci_bus_call_notifier(b, PCI_NOTIFY_POST_BUS_ADD); + /* Create legacy_io and legacy_mem files for this bus */ pci_create_legacy_files(b); diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index 0d03026..2d8fbc8 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -50,6 +50,7 @@ void pci_remove_bus(struct pci_bus *bus) up_write(&pci_bus_sem); if (bus->is_added) { pci_remove_legacy_files(bus); + pci_bus_call_notifier(bus, PCI_NOTIFY_PRE_BUS_DEL); device_del(&bus->dev); } put_device(&bus->dev); diff --git a/include/linux/pci.h b/include/linux/pci.h index ee21795..12e5447 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1033,6 +1033,18 @@ const struct pci_device_id *pci_match_id(const struct pci_device_id *ids, int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass); +/* + * All notifiers below get called with the target struct pci_bus *bus as + * an argument. + * Note: all PCI bus notifier must return success. Currently there's no + * error handling if any notifier returns error code. + */ +#define PCI_NOTIFY_POST_BUS_ADD 0x00000001 /* PCI bus has been added */ +#define PCI_NOTIFY_PRE_BUS_DEL 0x00000002 /* PCI bus will be deleted */ + +int pci_bus_register_notifier(struct notifier_block *nb); +int pci_bus_unregister_notifier(struct notifier_block *nb); + void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), void *userdata); int pci_cfg_space_size_ext(struct pci_dev *dev);
When adding/removing a PCI bus, some other components want to be notified so they could update their states. For example, the pci_slot driver needs to create/destroy PCI slots attaching to the PCI bus. So introduce a dedicate blocking notifier chain for PCI bus addition/removal events. It could be extended to support PCI device addition/removal events in the future when needed. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> --- drivers/pci/bus.c | 24 ++++++++++++++++++++++++ drivers/pci/pci.h | 1 + drivers/pci/probe.c | 2 ++ drivers/pci/remove.c | 1 + include/linux/pci.h | 12 ++++++++++++ 5 files changed, 40 insertions(+)