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ACPI: Allow ACPI handles of devices to be initialized in advance

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Currently, the ACPI handles of devices are initialized from within
device_add(), by acpi_bind_one() called from acpi_platform_notify()
which first uses the .find_device() routine provided by the device's
bus type to find the matching device node in the ACPI namespace.
This is a source of some computational overhead and, moreover, the
correctness of the result depends on the implementation of
.find_device() which is known to fail occasionally for some bus types
(e.g. PCI).  In some cases, however, the corresponding ACPI device
node is known already before calling device_add() for the given
struct device object and the whole .find_device() dance in
acpi_platform_notify() is then simply unnecessary.

For this reason, make it possible to initialize the ACPI handles of
devices before calling device_add() for them.  Modify
acpi_platform_notify() to call acpi_bind_one() in advance to check
the device's existing ACPI handle and skip the .find_device()
search if that is successful.  Change acpi_bind_one() accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
This commit is contained in:
Rafael J. Wysocki 2012-11-21 00:21:39 +01:00
parent 8a66790b78
commit f3fd0c8a7f
1 changed files with 34 additions and 10 deletions
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44
drivers/acpi/glue.c
View File

@ -130,46 +130,59 @@ static int acpi_bind_one(struct device *dev, acpi_handle handle)
{
struct acpi_device *acpi_dev;
acpi_status status;
struct acpi_device_physical_node *physical_node;
struct acpi_device_physical_node *physical_node, *pn;
char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
int retval = -EINVAL;
if (dev->acpi_handle) {
dev_warn(dev, "Drivers changed 'acpi_handle'\n");
return -EINVAL;
if (handle) {
dev_warn(dev, "ACPI handle is already set\n");
return -EINVAL;
} else {
handle = dev->acpi_handle;
}
}
if (!handle)
return -EINVAL;
get_device(dev);
status = acpi_bus_get_device(handle, &acpi_dev);
if (ACPI_FAILURE(status))
goto err;
physical_node = kzalloc(sizeof(struct acpi_device_physical_node),
GFP_KERNEL);
physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
if (!physical_node) {
retval = -ENOMEM;
goto err;
}
mutex_lock(&acpi_dev->physical_node_lock);
/* Sanity check. */
list_for_each_entry(pn, &acpi_dev->physical_node_list, node)
if (pn->dev == dev) {
dev_warn(dev, "Already associated with ACPI node\n");
goto err_free;
}
/* allocate physical node id according to physical_node_id_bitmap */
physical_node->node_id =
find_first_zero_bit(acpi_dev->physical_node_id_bitmap,
ACPI_MAX_PHYSICAL_NODE);
if (physical_node->node_id >= ACPI_MAX_PHYSICAL_NODE) {
retval = -ENOSPC;
mutex_unlock(&acpi_dev->physical_node_lock);
kfree(physical_node);
goto err;
goto err_free;
}
set_bit(physical_node->node_id, acpi_dev->physical_node_id_bitmap);
physical_node->dev = dev;
list_add_tail(&physical_node->node, &acpi_dev->physical_node_list);
acpi_dev->physical_node_count++;
mutex_unlock(&acpi_dev->physical_node_lock);
dev->acpi_handle = handle;
if (!dev->acpi_handle)
dev->acpi_handle = handle;
if (!physical_node->node_id)
strcpy(physical_node_name, PHYSICAL_NODE_STRING);
@ -187,8 +200,14 @@ static int acpi_bind_one(struct device *dev, acpi_handle handle)
return 0;
err:
dev->acpi_handle = NULL;
put_device(dev);
return retval;
err_free:
mutex_unlock(&acpi_dev->physical_node_lock);
kfree(physical_node);
goto err;
}
static int acpi_unbind_one(struct device *dev)
@ -247,6 +266,10 @@ static int acpi_platform_notify(struct device *dev)
acpi_handle handle;
int ret = -EINVAL;
ret = acpi_bind_one(dev, NULL);
if (!ret)
goto out;
if (!dev->bus || !dev->parent) {
/* bridge devices genernally haven't bus or parent */
ret = acpi_find_bridge_device(dev, &handle);
@ -260,10 +283,11 @@ static int acpi_platform_notify(struct device *dev)
}
if ((ret = type->find_device(dev, &handle)) != 0)
DBG("Can't get handler for %s\n", dev_name(dev));
end:
end:
if (!ret)
acpi_bind_one(dev, handle);
out:
#if ACPI_GLUE_DEBUG
if (!ret) {
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };