On Tue, Feb 28, 2017 at 09:34:29PM +0800, Rui Wang wrote:
> The hot-removal of IOAPIC is broken into two parts: the PCI part and
> the ACPI part. The PCI part releases PCI resources before the PCI bus
> is gone, and the ACPI part is moved to a stage later than the hot-removal
> of the PCI root bus, so that the IOAPIC driver is able to hook the
> pcibios_release_device() of every PCI device under the same parent root
> bus, before the IOAPIC is hot-removed. This makes it possible for the
> IOAPIC to free any IRQ resource previously unable to get freed.
>
> v2: Fixed compiling error on i386 (missing stub of pci_ioapic_remove())
>
> Signed-off-by: Rui Wang <rui.y.wang@xxxxxxxxx>
Minor comments below, but
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
> drivers/acpi/internal.h | 2 ++
> drivers/acpi/ioapic.c | 22 ++++++++++++++++------
> drivers/acpi/pci_root.c | 4 ++--
> 3 files changed, 20 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
> index 219b90b..f159001 100644
> --- a/drivers/acpi/internal.h
> +++ b/drivers/acpi/internal.h
> @@ -41,8 +41,10 @@ static inline void acpi_amba_init(void) {}
> void acpi_container_init(void);
> void acpi_memory_hotplug_init(void);
> #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
> +void pci_ioapic_remove(struct acpi_pci_root *root);
> int acpi_ioapic_remove(struct acpi_pci_root *root);
> #else
> +static inline void pci_ioapic_remove(struct acpi_pci_root *root) { return; }
Superfluous "return;" here.
> static inline int acpi_ioapic_remove(struct acpi_pci_root *root) { return 0; }
> #endif
> #ifdef CONFIG_ACPI_DOCK
> diff --git a/drivers/acpi/ioapic.c b/drivers/acpi/ioapic.c
> index 6d7ce6e..1120dfd6 100644
> --- a/drivers/acpi/ioapic.c
> +++ b/drivers/acpi/ioapic.c
> @@ -206,24 +206,34 @@ int acpi_ioapic_add(acpi_handle root_handle)
> return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV;
> }
>
> -int acpi_ioapic_remove(struct acpi_pci_root *root)
> +void pci_ioapic_remove(struct acpi_pci_root *root)
> {
> - int retval = 0;
> struct acpi_pci_ioapic *ioapic, *tmp;
>
> mutex_lock(&ioapic_list_lock);
> list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
I don't think it's necessary to use the "safe" iterator here, since
you're not modifying ioapic_list in the loop any more.
> if (root->device->handle != ioapic->root_handle)
> continue;
> -
> - if (acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base))
> - retval = -EBUSY;
> -
> if (ioapic->pdev) {
> pci_release_region(ioapic->pdev, 0);
> pci_disable_device(ioapic->pdev);
> pci_dev_put(ioapic->pdev);
> }
> + }
> + mutex_unlock(&ioapic_list_lock);
> +}
> +
> +int acpi_ioapic_remove(struct acpi_pci_root *root)
> +{
> + int retval = 0;
> + struct acpi_pci_ioapic *ioapic, *tmp;
> +
> + mutex_lock(&ioapic_list_lock);
> + list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
> + if (root->device->handle != ioapic->root_handle)
> + continue;
> + if (acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base))
> + retval = -EBUSY;
> if (ioapic->res.flags && ioapic->res.parent)
> release_resource(&ioapic->res);
> list_del(&ioapic->list);
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index bf601d4..919be0a 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -648,12 +648,12 @@ static void acpi_pci_root_remove(struct acpi_device *device)
>
> pci_stop_root_bus(root->bus);
>
> - WARN_ON(acpi_ioapic_remove(root));
> -
> + pci_ioapic_remove(root);
> device_set_run_wake(root->bus->bridge, false);
> pci_acpi_remove_bus_pm_notifier(device);
>
> pci_remove_root_bus(root->bus);
> + WARN_ON(acpi_ioapic_remove(root));
You didn't change this, but my personal preference is not to call
functions with side-effects inside a WARN_ON() or BUG_ON(). The
acpi_ioapic_remove() call is essential here, and I think it gets
obscured a bit by being inside WARN_ON().
> dmar_device_remove(device->handle);
>
> --
> 1.8.3.1
>
