On Wed, Sep 25, 2019 at 11:16:55AM +1000, Benjamin Herrenschmidt wrote:
> pci_reassign_bridge_resources() can be called by pci_resize_resource()
> at runtime.
>
> It will walk the PCI tree up and down, and isn't currently protected
> against any changes or hotplug operation.
>
> Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Applied to pci/resource for v5.5, thanks!
> ---
>
> v2: Fix a missing exit case
> Reported by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>
> ---
> drivers/pci/setup-bus.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 79b1fa6519be..871dad7d02ea 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -2066,6 +2066,8 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
> unsigned int i;
> int ret;
>
> + down_read(&pci_bus_sem);
> +
> /* Walk to the root hub, releasing bridge BARs when possible */
> next = bridge;
> do {
> @@ -2100,8 +2102,10 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
> next = bridge->bus ? bridge->bus->self : NULL;
> } while (next);
>
> - if (list_empty(&saved))
> + if (list_empty(&saved)) {
> + up_read(&pci_bus_sem);
> return -ENOENT;
> + }
>
> __pci_bus_size_bridges(bridge->subordinate, &added);
> __pci_bridge_assign_resources(bridge, &added, &failed);
> @@ -2122,6 +2126,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
> }
>
> free_list(&saved);
> + up_read(&pci_bus_sem);
> return 0;
>
> cleanup:
> @@ -2150,6 +2155,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
> pci_setup_bridge(bridge->subordinate);
> }
> free_list(&saved);
> + up_read(&pci_bus_sem);
>
> return ret;
> }
>
>
