From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933241AbcFJQnL (ORCPT ); Fri, 10 Jun 2016 12:43:11 -0400 Received: from mail.kernel.org ([198.145.29.136]:39626 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752250AbcFJQnJ (ORCPT ); Fri, 10 Jun 2016 12:43:09 -0400 Date: Fri, 10 Jun 2016 11:43:04 -0500 From: Bjorn Helgaas To: Rui Wang Cc: tglx@linutronix.de, rjw@rjwysocki.net, tony.luck@intel.com, bhelgaas@google.com, linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V3 1/3] x86/ioapic: Support hot-removal of IOAPICs present during boot Message-ID: <20160610164304.GJ19309@localhost> References: <1465369193-4816-2-git-send-email-rui.y.wang@intel.com> <1465378364-5982-1-git-send-email-rui.y.wang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1465378364-5982-1-git-send-email-rui.y.wang@intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 08, 2016 at 05:32:44PM +0800, Rui Wang wrote: > v3: Previous versions break mips. This version fixes it. > > IOAPICs present during system boot aren't added to ioapic_list, > thus are unable to be hot-removed. Fix it by calling > acpi_ioapic_add() during root bus enumeration. > > Signed-off-by: Rui Wang > --- > drivers/acpi/internal.h | 2 -- > drivers/acpi/ioapic.c | 7 ++++--- > drivers/acpi/pci_root.c | 2 +- > drivers/pci/setup-bus.c | 7 ++++++- > include/linux/acpi.h | 3 +++ > 5 files changed, 14 insertions(+), 7 deletions(-) > > diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h > index 9bb0773..bb567a7 100644 > --- a/drivers/acpi/internal.h > +++ b/drivers/acpi/internal.h > @@ -40,10 +40,8 @@ int acpi_sysfs_init(void); > void acpi_container_init(void); > void acpi_memory_hotplug_init(void); > #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC > -int acpi_ioapic_add(struct acpi_pci_root *root); > int acpi_ioapic_remove(struct acpi_pci_root *root); > #else > -static inline int acpi_ioapic_add(struct acpi_pci_root *root) { return 0; } > 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 ccdc8db..0f272e2 100644 > --- a/drivers/acpi/ioapic.c > +++ b/drivers/acpi/ioapic.c > @@ -189,16 +189,17 @@ exit: > return AE_OK; > } > > -int acpi_ioapic_add(struct acpi_pci_root *root) > +int acpi_ioapic_add(acpi_handle root_handle) > { > acpi_status status, retval = AE_OK; > > - status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root->device->handle, > + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root_handle, > UINT_MAX, handle_ioapic_add, NULL, > - root->device->handle, (void **)&retval); > + root_handle, (void **)&retval); > > return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV; > } > +EXPORT_SYMBOL_GPL(acpi_ioapic_add); > > int acpi_ioapic_remove(struct acpi_pci_root *root) > { > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > index ae3fe4e..53f5965 100644 > --- a/drivers/acpi/pci_root.c > +++ b/drivers/acpi/pci_root.c > @@ -614,7 +614,7 @@ static int acpi_pci_root_add(struct acpi_device *device, > if (hotadd) { > pcibios_resource_survey_bus(root->bus); > pci_assign_unassigned_root_bus_resources(root->bus); > - acpi_ioapic_add(root); > + acpi_ioapic_add(root->device->handle); > } > > pci_lock_rescan_remove(); > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index 55641a3..0658921 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -25,6 +25,7 @@ > #include > #include > #include > +#include > #include "pci.h" > > unsigned int pci_flags; > @@ -1779,8 +1780,12 @@ void __init pci_assign_unassigned_resources(void) > { > struct pci_bus *root_bus; > > - list_for_each_entry(root_bus, &pci_root_buses, node) > + list_for_each_entry(root_bus, &pci_root_buses, node) { > pci_assign_unassigned_root_bus_resources(root_bus); > +#ifdef CONFIG_X86 > + acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge)); > +#endif This seems like a strange place to call acpi_ioapic_add(). Your object is to call acpi_ioapic_add() during root bus enumeration. I assume we *can't* call acpi_ioapic_add() from acpi_pci_root_add() at boot time, for some reason you'll explain. But is there a reason we have to call it from pci_assign_unassigned_resources() (where it requires an ifdef) instead of from pcibios_assign_resources(), which is already x86-specific? In acpi_pci_root_add(), we have this: acpi_pci_root_add(...) { ... if (hotadd) acpi_ioapic_add(root); So the obvious question is why don't we just remove the "if (hotadd)" and call acpi_ioapic_add() always. I'm sure the reason is some ordering problem, but we need a comment in acpi_pci_root_add() about why the obvious solution doesn't work. > + } > } > > void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge) > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index 288fac5..3ed22df 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -262,6 +262,9 @@ int acpi_unmap_cpu(int cpu); > > #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC > int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr); > +int acpi_ioapic_add(acpi_handle root); > +#else > +static inline int acpi_ioapic_add(acpi_handle root) { return 0; } > #endif > > int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base); > -- > 1.8.3.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html