[RFC PATCH v1 5/6] PCI, ACPI: update ACPI hotplug slot informationwhen PCI hotplug event happens

From: Jiang Liu
Date: Mon Jun 04 2012 - 01:18:55 EST


From: Jiang Liu <liuj97@xxxxxxxxx>

Currently the acpiphp driver fails to update hotplug slot information under
several conditions, such as:
1) The bridge device is removed through /sys/bus/pci/devices/.../remove
2) The bridge device is added/removed by PCI hotplug driver other than the
acpiphp driver itself. For example, if an IO expansion box with ACPI
hotplug slots available is hot-added by the pciehp driver, all ACPI
hotplug slots won't be discovered by the acpiphp driver.

So hook the BUS_NOTIFY_ADD_DEVICE/BUS_NOTIFY_DEL_DEVICE events to
update ACPI hotplug slot information when PCI hotplug event happens.

Signed-off-by: Jiang Liu <liuj97@xxxxxxxxx>
---
drivers/pci/hotplug/acpiphp_glue.c | 64 ++++++++++++++++++++++++++++++++++--
1 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 73af337..44d055c 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -61,6 +61,7 @@ static void handle_hotplug_event_bridge (acpi_handle, u32, void *);
static void acpiphp_sanitize_bus(struct pci_bus *bus);
static void acpiphp_set_hpp_values(struct pci_bus *bus);
static void handle_hotplug_event_func(acpi_handle handle, u32 type, void *context);
+static struct acpiphp_bridge *acpiphp_handle_to_bridge(acpi_handle handle);

/* callback routine to check for the existence of a pci dock device */
static acpi_status
@@ -377,7 +378,7 @@ static inline void config_p2p_bridge_flags(struct acpiphp_bridge *bridge)


/* allocate and initialize host bridge data structure */
-static void add_host_bridge(acpi_handle *handle)
+static void add_host_bridge(acpi_handle handle)
{
struct acpiphp_bridge *bridge;
struct acpi_pci_root *root = acpi_pci_find_root(handle);
@@ -396,12 +397,14 @@ static void add_host_bridge(acpi_handle *handle)
init_bridge_misc(bridge);
}

-
/* allocate and initialize PCI-to-PCI bridge data structure */
-static void add_p2p_bridge(acpi_handle *handle)
+static void add_p2p_bridge(acpi_handle handle)
{
struct acpiphp_bridge *bridge;

+ if (acpiphp_handle_to_bridge(handle))
+ return;
+
bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);
if (bridge == NULL) {
err("out of memory\n");
@@ -1419,6 +1422,58 @@ find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
return AE_OK ;
}

+static void acpiphp_hp_notify_add(struct pci_dev *dev)
+{
+ acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
+
+ if (!dev->subordinate || !handle)
+ return;
+
+ /* check if this bridge has ejectable slots */
+ if (detect_ejectable_slots(handle) > 0) {
+ dbg("found PCI-to-PCI bridge at PCI %s\n", pci_name(dev));
+ add_p2p_bridge(handle);
+ }
+}
+
+static void acpiphp_hp_notify_del(struct pci_dev *dev)
+{
+ struct acpiphp_bridge *bridge, *tmp;
+ struct pci_bus *bus = dev->subordinate;
+
+ if (!bus)
+ return;
+
+ list_for_each_entry_safe(bridge, tmp, &bridge_list, list)
+ if (bridge->pci_bus == bus) {
+ cleanup_bridge(bridge);
+ break;
+ }
+}
+
+static int acpi_pci_hp_notify_fn(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct device *dev = data;
+
+ switch (event) {
+ case BUS_NOTIFY_ADD_DEVICE:
+ acpiphp_hp_notify_add(to_pci_dev(dev));
+ break;
+ case BUS_NOTIFY_DEL_DEVICE:
+ acpiphp_hp_notify_del(to_pci_dev(dev));
+ break;
+ default:
+ return NOTIFY_DONE;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block acpi_pci_hp_notifier = {
+ .notifier_call = &acpi_pci_hp_notify_fn,
+};
+
static struct acpi_pci_driver acpi_pci_hp_driver = {
.add = add_bridge,
.remove = remove_bridge,
@@ -1439,6 +1494,8 @@ int __init acpiphp_glue_init(void)
else
acpi_pci_register_driver(&acpi_pci_hp_driver);

+ bus_register_notifier(&pci_bus_type, &acpi_pci_hp_notifier);
+
return 0;
}

@@ -1450,6 +1507,7 @@ int __init acpiphp_glue_init(void)
*/
void acpiphp_glue_exit(void)
{
+ bus_unregister_notifier(&pci_bus_type, &acpi_pci_hp_notifier);
acpi_pci_unregister_driver(&acpi_pci_hp_driver);
}

--
1.7.1


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