diff mbox

[V4,1/3] x86/ioapic: Support hot-removal of IOAPICs present during boot

Message ID 1466581219-20538-1-git-send-email-rui.y.wang@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wang, Rui Y June 22, 2016, 7:40 a.m. UTC
v4: Add comments explaining when to call acpi_ioapic_add().
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 <rui.y.wang@intel.com>
---
 drivers/acpi/internal.h |  2 --
 drivers/acpi/ioapic.c   |  7 ++++---
 drivers/acpi/pci_root.c | 13 ++++++++++++-
 drivers/pci/setup-bus.c |  7 ++++++-
 include/linux/acpi.h    |  3 +++
 5 files changed, 25 insertions(+), 7 deletions(-)

Comments

Bjorn Helgaas June 22, 2016, 3:14 p.m. UTC | #1
On Wed, Jun 22, 2016 at 03:40:19PM +0800, Rui Wang wrote:
> v4: Add comments explaining when to call acpi_ioapic_add().
> 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 <rui.y.wang@intel.com>
> ---
>  drivers/acpi/internal.h |  2 --
>  drivers/acpi/ioapic.c   |  7 ++++---
>  drivers/acpi/pci_root.c | 13 ++++++++++++-
>  drivers/pci/setup-bus.c |  7 ++++++-
>  include/linux/acpi.h    |  3 +++
>  5 files changed, 25 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
> index 27cc7fe..6d8e67e 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..31e4440 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -614,7 +614,18 @@ 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);
> +
> +		/*
> + 		 * This is only called for the hotadd case. For the boot-time
> + 		 * case, we need to wait until after PCI initialization in
> + 		 * order to deal with IOAPICs mapped in on a PCI BAR.
> + 		 *
> + 		 * This is currently x86-specific, because acpi_ioapic_add()
> + 		 * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
> + 		 * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
> + 		 * (see drivers/acpi/Kconfig).
> + 		 */
> +		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 <linux/ioport.h>
>  #include <linux/cache.h>
>  #include <linux/slab.h>
> +#include <linux/acpi.h>
>  #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

Doesn't this do the right thing even if you omit the #ifdefs, since you
define a stub function below?

> +	}
>  }
>  
>  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
> 
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<> June 23, 2016, 5:11 a.m. UTC | #2
From: Rui Wang <rui.y.wang@intel.com>

On Wed, June 22, 2016 11:15 PM Bjorn Helgaas wrote:
> [...]
> > @@ -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
> 
> Doesn't this do the right thing even if you omit the #ifdefs, since you
> define a stub function below?
> 

No. Without the '#ifdef CONFIG_X86' it breaks MIPS arch. The stub function is
within 'ifdef CONFIG_ACPI'. On archs without ACPI it doesn't compile due to
'undefined reference to acpi_ioapic_add'.

Thanks
Rui
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Bjorn Helgaas June 23, 2016, 5:34 p.m. UTC | #3
On Thu, Jun 23, 2016 at 01:11:41PM +0800,  wrote:
> From: Rui Wang <rui.y.wang@intel.com>
> 
> On Wed, June 22, 2016 11:15 PM Bjorn Helgaas wrote:
> > [...]
> > > @@ -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
> > 
> > Doesn't this do the right thing even if you omit the #ifdefs, since you
> > define a stub function below?
> > 
> 
> No. Without the '#ifdef CONFIG_X86' it breaks MIPS arch. The stub function is
> within 'ifdef CONFIG_ACPI'. On archs without ACPI it doesn't compile due to
> 'undefined reference to acpi_ioapic_add'.

But this *could* be made to work by defining a stub for the
non-CONFIG_ACPI case.  That's what we generally do to avoid ifdefs in
the code.

Bjorn
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Wang, Rui Y June 24, 2016, 3:30 p.m. UTC | #4
On Fri, Jun 24, 2016 1:35 AM Bjorn Helgaas wrote:
> On Thu, Jun 23, 2016 at 01:11:41PM +0800, Rui Wang wrote:
> > On Wed, June 22, 2016 11:15 PM Bjorn Helgaas wrote:
> > > [...]
> > > > @@ -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
> > >
> > > Doesn't this do the right thing even if you omit the #ifdefs, since
> > > you define a stub function below?
> > >
> >
> > No. Without the '#ifdef CONFIG_X86' it breaks MIPS arch. The stub
> > function is within 'ifdef CONFIG_ACPI'. On archs without ACPI it
> > doesn't compile due to 'undefined reference to acpi_ioapic_add'.
> 
> But this *could* be made to work by defining a stub for the non-
> CONFIG_ACPI case.  That's what we generally do to avoid ifdefs in the code.

That can be done. I'll make the change and do some cross-compiling tests first.

Thanks
Rui

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diff mbox

Patch

diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 27cc7fe..6d8e67e 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..31e4440 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -614,7 +614,18 @@  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);
+
+		/*
+ 		 * This is only called for the hotadd case. For the boot-time
+ 		 * case, we need to wait until after PCI initialization in
+ 		 * order to deal with IOAPICs mapped in on a PCI BAR.
+ 		 *
+ 		 * This is currently x86-specific, because acpi_ioapic_add()
+ 		 * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
+ 		 * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
+ 		 * (see drivers/acpi/Kconfig).
+ 		 */
+		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 <linux/ioport.h>
 #include <linux/cache.h>
 #include <linux/slab.h>
+#include <linux/acpi.h>
 #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
+	}
 }
 
 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);