Re: [PATCH v2 6/6] ACPI, PCI: add resoruce-assign code for devices under hot-added hostbridge

[Yinghai Lu <yinghai@kernel.org>]

On Mon, Sep 3, 2012 at 1:07 AM, Taku Izumi <izumi.taku@jp.fujitsu.com> wrote:
>
> Devices under hot-added hostbridge have no chance to assign resources
> and to configure them, so this patch adds such code for hot-added
> hostbridges at acpi_pci_root_start().
>
> Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
> ---
>  drivers/acpi/pci_root.c |   17 +++++++++++++++++
>  include/acpi/acpi_bus.h |    1 +
>  2 files changed, 18 insertions(+)
>
> 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
> @@ -39,6 +39,7 @@
>  #include <acpi/acpi_bus.h>
>  #include <acpi/acpi_drivers.h>
>  #include <acpi/apei.h>
> +#include <linux/pci_hotplug.h>
>
>  #define PREFIX "ACPI: "
>
> @@ -461,6 +462,9 @@ static int __devinit acpi_pci_root_add(s
>         if (!root)
>                 return -ENOMEM;
>
> +       if (system_state != SYSTEM_BOOTING)
> +               root->hot_added = true;
> +
>         segment = 0;
>         status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
>                                        &segment);
> @@ -639,6 +643,7 @@ static int acpi_pci_root_start(struct ac
>  {
>         struct acpi_pci_root *root = acpi_driver_data(device);
>         struct acpi_pci_driver *driver;
> +       struct pci_dev *pdev;
>
>         mutex_lock(&acpi_pci_root_lock);
>         list_for_each_entry(driver, &acpi_pci_drivers, node)
> @@ -646,6 +651,18 @@ static int acpi_pci_root_start(struct ac
>                         driver->add(device->handle);
>         mutex_unlock(&acpi_pci_root_lock);
>
> +       /*
> +        * Devices under hot-added hostbridge have no chance to assign
> +        * resources and to configure them, so do that here
> +        */
> +       if (root->hot_added) {
> +               pci_bus_size_bridges(root->bus);
> +               pci_bus_assign_resources(root->bus);
> +               list_for_each_entry(pdev, &root->bus->devices, bus_list)
> +                       pci_configure_slot(pdev);
> +               pci_enable_bridges(root->bus);
> +       }
> +
>         pci_bus_add_devices(root->bus);

after looking at your simplified version in patch5 and patch6
found that you do not understand my patchset correctly.

in my patchset there is change on:
acpi_pci_root_add
acpi_pci_root_start
acpi_pci_root_remove

and
handle_root_bridge_insertion/acpi_root_configure_bridge
handle_root_bridge_removal

for hot add path:
handle_root_bridge_insertion will call
      acpi_pci_root_add: it will scan the root bus and find all pci device
      acpi_root_configure_bridge: it will survey fw set pci resource,
and assigned unsigned resource
      acpi_pci_root_start: it will start acpi_pci driver for ioapic
controller and dmar iommu
                                    then call pci_bus_add_devices to
load other pci device drivers.

for hot remove path:
      acpi_pci_root_remove: will call pci_stop_bus_devices() to stop
drivers for all normal pci devices.
                                        then stop acpi_pci driver for
dmar and ioapic driver
                                        then call
pci_stop_and_remove_bus to remove the root bus.

the point is : keep the driver of ioapic and dmar  driver loading
before normal pci drivers, and later
stop driver for dmar/iommu, after unloading pci drivers.

Thanks

Yinghai