On Fri, Sep 21, 2012 at 2:09 PM, Bjorn Helgaas [off-list ref] wrote:

On Tue, Sep 18, 2012 at 12:25 AM, Taku Izumi [off-list ref] wrote:

quoted

Currently there's no PCI-related clean-up code
in acpi_pci_root_remove() function.
This patch introduces function for hostbridge removal,
and brings back pci_stop_bus_devices() function.

Signed-off-by: Taku Izumi <redacted>
---
 drivers/acpi/pci_bind.c     |    7 +++++++
 drivers/acpi/pci_root.c     |    7 +++++++
 drivers/pci/remove.c        |   27 +++++++++++++++++++++++++++
 include/acpi/acpi_drivers.h |    1 +
 include/linux/pci.h         |    2 ++
 5 files changed, 44 insertions(+)

Index: Bjorn-next-0903/drivers/pci/remove.c
===================================================================

--- Bjorn-next-0903.orig/drivers/pci/remove.c
+++ Bjorn-next-0903/drivers/pci/remove.c

@@ -92,3 +92,30 @@ void pci_stop_and_remove_bus_device(stru
        pci_destroy_dev(dev);
 }
 EXPORT_SYMBOL(pci_stop_and_remove_bus_device);
+
+void pci_stop_bus_devices(struct pci_bus *bus)
+{
+       struct pci_dev *dev, *tmp;
+
+       list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
+               if (dev->subordinate)
+                       pci_stop_bus_devices(dev->subordinate);
+               pci_stop_dev(dev);
+       }
+
+}
+EXPORT_SYMBOL(pci_stop_bus_devices);
+
+void pci_remove_host_bridge(struct pci_host_bridge *bridge)
+{
+       struct pci_bus *root = bridge->bus;
+       struct pci_dev *dev, *tmp;
+
+       list_for_each_entry_safe_reverse(dev, tmp, &root->devices, bus_list)
+               pci_stop_and_remove_bus_device(dev);
+
+       pci_remove_bus(root);
+
+       device_unregister(&bridge->dev);
+}
+EXPORT_SYMBOL(pci_remove_host_bridge);

Index: Bjorn-next-0903/drivers/acpi/pci_root.c
===================================================================

--- Bjorn-next-0903.orig/drivers/acpi/pci_root.c
+++ Bjorn-next-0903/drivers/acpi/pci_root.c

@@ -652,8 +652,10 @@ static int acpi_pci_root_remove(struct a
 {
        struct acpi_pci_root *root = acpi_driver_data(device);
        struct acpi_pci_driver *driver;
+       struct pci_host_bridge *bridge = to_pci_host_bridge(root->bus->bridge);

        mutex_lock(&acpi_pci_root_lock);
+       pci_stop_bus_devices(root->bus);
        list_for_each_entry(driver, &acpi_pci_drivers, node)
                if (driver->remove)
                        driver->remove(root);

@@ -661,6 +663,11 @@ static int acpi_pci_root_remove(struct a
        device_set_run_wake(root->bus->bridge, false);
        pci_acpi_remove_bus_pm_notifier(device);

+       acpi_pci_irq_del_prt(root->bus);

acpi_pci_irq_del_prt() does not actually have a dependency on the
struct pci_bus, so I think its interface should be changed so it takes
a segment number and a bus number instead of the "struct pci_bus *".
The same applies to acpi_pci_irq_add_prt().

This basically boils down to reverting 859a3f86ca8 and d9efae3688a.  I
acked those changes at the time, but I think they were a mistake.  The
reason is that passing in the struct pci_bus * ties them into the host
bridge add/remove flow in a way that's not necessary.

If we get rid of the struct pci_bus * dependency, then we can easily
add the _PRT before doing PCI enumeration behind the bridge, and we
can remove the _PRT after removing the PCI devices.  I think this is
one small step toward getting rid of the add/start and stop/remove
split.

I'm going to work on doing this if nobody else is interested.

quoted

+       acpi_pci_unbind_root(device);
+
+       pci_remove_host_bridge(bridge);
+
        list_del(&root->node);
        mutex_unlock(&acpi_pci_root_lock);
        kfree(root);
Index: Bjorn-next-0903/include/linux/pci.h
===================================================================

--- Bjorn-next-0903.orig/include/linux/pci.h
+++ Bjorn-next-0903/include/linux/pci.h

@@ -734,6 +734,8 @@ extern struct pci_dev *pci_dev_get(struc
 extern void pci_dev_put(struct pci_dev *dev);
 extern void pci_remove_bus(struct pci_bus *b);
 extern void pci_stop_and_remove_bus_device(struct pci_dev *dev);
+extern void pci_stop_bus_devices(struct pci_bus *bus);
+extern void pci_remove_host_bridge(struct pci_host_bridge *bridge);
 void pci_setup_cardbus(struct pci_bus *bus);
 extern void pci_sort_breadthfirst(void);
 #define dev_is_pci(d) ((d)->bus == &pci_bus_type)

Index: Bjorn-next-0903/drivers/acpi/pci_bind.c
===================================================================

--- Bjorn-next-0903.orig/drivers/acpi/pci_bind.c
+++ Bjorn-next-0903/drivers/acpi/pci_bind.c

@@ -118,3 +118,10 @@ int acpi_pci_bind_root(struct acpi_devic

        return 0;
 }
+
+void  acpi_pci_unbind_root(struct acpi_device *device)
+{
+       device->ops.bind = NULL;
+       device->ops.unbind = NULL;
+}
+

Index: Bjorn-next-0903/include/acpi/acpi_drivers.h
===================================================================

--- Bjorn-next-0903.orig/include/acpi/acpi_drivers.h
+++ Bjorn-next-0903/include/acpi/acpi_drivers.h

@@ -101,6 +101,7 @@ struct pci_bus;

 struct pci_dev *acpi_get_pci_dev(acpi_handle);
 int acpi_pci_bind_root(struct acpi_device *device);
+void acpi_pci_unbind_root(struct acpi_device *device);

 /* Arch-defined function to add a bus to the system */