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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-11-25 00:52:21 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-11-25 00:52:21 +0100
commit2c22e6520ac87d8b12d4d9941e81d4119f2d903c (patch)
tree1c213ad56029c90ca38943ffdba091cff1aecded /drivers/acpi/scan.c
parent25db115b0bf72acfdf8a339fa8e37d8b895214d6 (diff)
ACPI / scan: Use direct recurrence for device hierarchy walks
Rework acpi_bus_trim() and acpi_bus_device_attach(), which is renamed as acpi_bus_attach(), to walk the list of each device object's children directly and call themselves recursively for each child instead of using acpi_walk_namespace(). This simplifies the code quite a bit and avoids the overhead of callbacks and the ACPICA's internal processing which are not really necessary for these two routines. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/scan.c')
-rw-r--r--drivers/acpi/scan.c120
1 files changed, 45 insertions, 75 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index cf773c91810..311904c720b 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1909,54 +1909,40 @@ static int acpi_scan_attach_handler(struct acpi_device *device)
return ret;
}
-static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
- void *not_used, void **ret_not_used)
+static void acpi_bus_attach(struct acpi_device *device)
{
- struct acpi_device *device;
- unsigned long long sta;
+ struct acpi_device *child;
int ret;
- /*
- * Ignore errors ignored by acpi_bus_check_add() to avoid terminating
- * namespace walks prematurely.
- */
- if (acpi_bus_type_and_status(handle, &ret, &sta))
- return AE_OK;
-
- if (acpi_bus_get_device(handle, &device))
- return AE_CTRL_DEPTH;
-
- acpi_set_device_status(device, sta);
+ acpi_bus_get_status(device);
/* Skip devices that are not present. */
- if (!acpi_device_is_present(device))
- goto err;
-
+ if (!acpi_device_is_present(device)) {
+ device->flags.visited = false;
+ return;
+ }
if (device->handler)
- return AE_OK;
+ goto ok;
if (!device->flags.initialized) {
acpi_bus_update_power(device, NULL);
device->flags.initialized = true;
}
+ device->flags.visited = false;
ret = acpi_scan_attach_handler(device);
if (ret < 0)
- goto err;
+ return;
device->flags.match_driver = true;
- if (ret > 0)
- goto ok;
-
- ret = device_attach(&device->dev);
- if (ret < 0)
- goto err;
-
- ok:
+ if (!ret) {
+ ret = device_attach(&device->dev);
+ if (ret < 0)
+ return;
+ }
device->flags.visited = true;
- return AE_OK;
- err:
- device->flags.visited = false;
- return AE_CTRL_DEPTH;
+ ok:
+ list_for_each_entry(child, &device->children, node)
+ acpi_bus_attach(child);
}
/**
@@ -1976,64 +1962,48 @@ static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
int acpi_bus_scan(acpi_handle handle)
{
void *device = NULL;
- int error = 0;
if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
acpi_bus_check_add, NULL, NULL, &device);
- if (!device)
- error = -ENODEV;
- else if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL)))
- acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
- acpi_bus_device_attach, NULL, NULL, NULL);
-
- return error;
-}
-EXPORT_SYMBOL(acpi_bus_scan);
-
-static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used,
- void *not_used, void **ret_not_used)
-{
- struct acpi_device *device = NULL;
-
- if (!acpi_bus_get_device(handle, &device)) {
- struct acpi_scan_handler *dev_handler = device->handler;
-
- if (dev_handler) {
- if (dev_handler->detach)
- dev_handler->detach(device);
-
- device->handler = NULL;
- } else {
- device_release_driver(&device->dev);
- }
- /*
- * Most likely, the device is going away, so put it into D3cold
- * before that.
- */
- acpi_device_set_power(device, ACPI_STATE_D3_COLD);
- device->flags.initialized = false;
- device->flags.visited = false;
+ if (device) {
+ acpi_bus_attach(device);
+ return 0;
}
- return AE_OK;
+ return -ENODEV;
}
+EXPORT_SYMBOL(acpi_bus_scan);
/**
- * acpi_bus_trim - Remove ACPI device node and all of its descendants
- * @start: Root of the ACPI device nodes subtree to remove.
+ * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
+ * @adev: Root of the ACPI namespace scope to walk.
*
* Must be called under acpi_scan_lock.
*/
-void acpi_bus_trim(struct acpi_device *start)
+void acpi_bus_trim(struct acpi_device *adev)
{
+ struct acpi_scan_handler *handler = adev->handler;
+ struct acpi_device *child;
+
+ list_for_each_entry_reverse(child, &adev->children, node)
+ acpi_bus_trim(child);
+
+ if (handler) {
+ if (handler->detach)
+ handler->detach(adev);
+
+ adev->handler = NULL;
+ } else {
+ device_release_driver(&adev->dev);
+ }
/*
- * Execute acpi_bus_device_detach() as a post-order callback to detach
- * all ACPI drivers from the device nodes being removed.
+ * Most likely, the device is going away, so put it into D3cold before
+ * that.
*/
- acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
- acpi_bus_device_detach, NULL, NULL);
- acpi_bus_device_detach(start->handle, 0, NULL, NULL);
+ acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
+ adev->flags.initialized = false;
+ adev->flags.visited = false;
}
EXPORT_SYMBOL_GPL(acpi_bus_trim);