[RFC][PATCH 1/30] ACPI / PCI: Make bus registration and unregistration symmetric

From: Rafael J. Wysocki
Date: Thu Jul 11 2013 - 19:59:38 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Since acpi_pci_slot_enumerate() and acpiphp_enumerate_slots() can get
the ACPI device handle they need from bus->bridge, it is not
necessary to pass that handle to them as an argument.

Drop the second argument of acpi_pci_slot_enumerate() and
acpiphp_enumerate_slots(), rework them to obtain the ACPI handle
from bus->bridge and make acpi_pci_add_bus() and
acpi_pci_remove_bus() entirely symmetrical.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/pci_slot.c | 14 +++++++++-----
drivers/pci/hotplug/acpiphp_glue.c | 7 ++++---
drivers/pci/pci-acpi.c | 16 ++++------------
include/linux/pci-acpi.h | 10 ++++------
4 files changed, 21 insertions(+), 26 deletions(-)

Index: linux-pm/drivers/acpi/pci_slot.c
===================================================================
--- linux-pm.orig/drivers/acpi/pci_slot.c
+++ linux-pm/drivers/acpi/pci_slot.c
@@ -159,12 +159,16 @@ register_slot(acpi_handle handle, u32 lv
return AE_OK;
}

-void acpi_pci_slot_enumerate(struct pci_bus *bus, acpi_handle handle)
+void acpi_pci_slot_enumerate(struct pci_bus *bus)
{
- mutex_lock(&slot_list_lock);
- acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
- register_slot, NULL, bus, NULL);
- mutex_unlock(&slot_list_lock);
+ acpi_handle handle = ACPI_HANDLE(bus->bridge);
+
+ if (handle) {
+ mutex_lock(&slot_list_lock);
+ acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+ register_slot, NULL, bus, NULL);
+ mutex_unlock(&slot_list_lock);
+ }
}

void acpi_pci_slot_remove(struct pci_bus *bus)
Index: linux-pm/drivers/pci/hotplug/acpiphp_glue.c
===================================================================
--- linux-pm.orig/drivers/pci/hotplug/acpiphp_glue.c
+++ linux-pm/drivers/pci/hotplug/acpiphp_glue.c
@@ -1169,15 +1169,16 @@ static void handle_hotplug_event_func(ac
* Create hotplug slots for the PCI bus.
* It should always return 0 to avoid skipping following notifiers.
*/
-void acpiphp_enumerate_slots(struct pci_bus *bus, acpi_handle handle)
+void acpiphp_enumerate_slots(struct pci_bus *bus)
{
- acpi_handle dummy_handle;
+ acpi_handle handle, dummy_handle;
struct acpiphp_bridge *bridge;

if (acpiphp_disabled)
return;

- if (detect_ejectable_slots(handle) <= 0)
+ handle = ACPI_HANDLE(bus->bridge);
+ if (!handle || detect_ejectable_slots(handle) <= 0)
return;

bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);
Index: linux-pm/drivers/pci/pci-acpi.c
===================================================================
--- linux-pm.orig/drivers/pci/pci-acpi.c
+++ linux-pm/drivers/pci/pci-acpi.c
@@ -290,24 +290,16 @@ static struct pci_platform_pm_ops acpi_p

void acpi_pci_add_bus(struct pci_bus *bus)
{
- acpi_handle handle = NULL;
-
- if (bus->bridge)
- handle = ACPI_HANDLE(bus->bridge);
- if (acpi_pci_disabled || handle == NULL)
+ if (acpi_pci_disabled || !bus->bridge)
return;

- acpi_pci_slot_enumerate(bus, handle);
- acpiphp_enumerate_slots(bus, handle);
+ acpi_pci_slot_enumerate(bus);
+ acpiphp_enumerate_slots(bus);
}

void acpi_pci_remove_bus(struct pci_bus *bus)
{
- /*
- * bus->bridge->acpi_node.handle has already been reset to NULL
- * when acpi_pci_remove_bus() is called, so don't check ACPI handle.
- */
- if (acpi_pci_disabled)
+ if (acpi_pci_disabled || !bus->bridge)
return;

acpiphp_remove_slots(bus);
Index: linux-pm/include/linux/pci-acpi.h
===================================================================
--- linux-pm.orig/include/linux/pci-acpi.h
+++ linux-pm/include/linux/pci-acpi.h
@@ -47,24 +47,22 @@ void acpi_pci_remove_bus(struct pci_bus

#ifdef CONFIG_ACPI_PCI_SLOT
void acpi_pci_slot_init(void);
-void acpi_pci_slot_enumerate(struct pci_bus *bus, acpi_handle handle);
+void acpi_pci_slot_enumerate(struct pci_bus *bus);
void acpi_pci_slot_remove(struct pci_bus *bus);
#else
static inline void acpi_pci_slot_init(void) { }
-static inline void acpi_pci_slot_enumerate(struct pci_bus *bus,
- acpi_handle handle) { }
+static inline void acpi_pci_slot_enumerate(struct pci_bus *bus) { }
static inline void acpi_pci_slot_remove(struct pci_bus *bus) { }
#endif

#ifdef CONFIG_HOTPLUG_PCI_ACPI
void acpiphp_init(void);
-void acpiphp_enumerate_slots(struct pci_bus *bus, acpi_handle handle);
+void acpiphp_enumerate_slots(struct pci_bus *bus);
void acpiphp_remove_slots(struct pci_bus *bus);
void acpiphp_check_host_bridge(acpi_handle handle);
#else
static inline void acpiphp_init(void) { }
-static inline void acpiphp_enumerate_slots(struct pci_bus *bus,
- acpi_handle handle) { }
+static inline void acpiphp_enumerate_slots(struct pci_bus *bus) { }
static inline void acpiphp_remove_slots(struct pci_bus *bus) { }
static inline void acpiphp_check_host_bridge(acpi_handle handle) { }
#endif

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