lkml.org 
[lkml]   [2013]   [Jan]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[RFC PATCH v5 3/8] PCI: add a blocking notifier chain for PCI bus addition/removal
    Date
    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);
    +}
    +
    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);
    --
    1.7.9.5


    \
     
     \ /
      Last update: 2013-01-18 17:41    [W:3.726 / U:0.400 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site