Commit 51a85faf authored by Bjorn Helgaas's avatar Bjorn Helgaas Committed by Len Brown
Browse files

ACPI: use acpi_walk_namespace() to enumerate devices 



acpi_bus_scan() currently walks the namespace manually.  This patch changes
it to use acpi_walk_namespace() instead.

Besides removing some complicated code, this means we take advantage of the
namespace locking done by acpi_walk_namespace().  The locking isn't so
important at boot-time, but I hope to eventually use this same path to
handle hot-addition of devices, when it will be important.

Note that acpi_walk_namespace() does not actually visit the starting node
first, so we need to do that by hand first.

Signed-off-by: default avatarBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 859ac9a4

drivers/acpi/scan.c

+74 −122
Original line number Diff line number Diff line
@@ -1393,65 +1393,23 @@ end: 
	return result;

}



static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops)

static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,

				      void *context, void **return_value)

{

	acpi_status status = AE_OK;

	struct acpi_device *parent = NULL;

	struct acpi_device *child = NULL;

	acpi_handle phandle = NULL;

	acpi_handle chandle = NULL;

	struct acpi_device *device = NULL;

	acpi_object_type type = 0;

	u32 level = 1;

	int ret;



	/*

	 * We must have an acpi_device for the starting node already, and

	 * we scan its children.

	 */

	phandle = handle;

	ret = acpi_bus_get_device(phandle, &parent);

	if (ret)

		return ret;



	/*

	 * Parse through the ACPI namespace, identify all 'devices', and

	 * create a new 'struct acpi_device' for each.

	 */

	while ((level > 0) && parent) {

	struct acpi_bus_ops *ops = context;



		status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,

					      chandle, &chandle);



		/*

		 * If this scope is exhausted then move our way back up.

		 */

		if (ACPI_FAILURE(status)) {

			level--;

			chandle = phandle;

			acpi_get_parent(phandle, &phandle);

			if (parent->parent)

				parent = parent->parent;

			continue;

		}



		status = acpi_get_type(chandle, &type);

	status = acpi_get_type(handle, &type);

	if (ACPI_FAILURE(status))

			continue;



		/*

		 * If this is a scope object then parse it (depth-first).

		 */

		if (type == ACPI_TYPE_LOCAL_SCOPE) {

			level++;

			phandle = chandle;

			chandle = NULL;

			continue;

		}

		return AE_OK;



	/*

	 * We're only interested in objects that we consider 'devices'.

	 */

	switch (type) {

	case ACPI_TYPE_ANY:		/* for ACPI_ROOT_OBJECT */

	case ACPI_TYPE_DEVICE:

		type = ACPI_BUS_TYPE_DEVICE;

		break;
@@ -1465,22 +1423,21 @@ static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops) 
		type = ACPI_BUS_TYPE_POWER;

		break;

	default:

			continue;

		return AE_OK;

	}



	if (ops->acpi_op_add)

			status = acpi_add_single_object(&child, chandle, type,

							ops);

		status = acpi_add_single_object(&device, handle, type, ops);

	else

			status = acpi_bus_get_device(chandle, &child);

		status = acpi_bus_get_device(handle, &device);



	if (ACPI_FAILURE(status))

			continue;

		return AE_CTRL_DEPTH;



	if (ops->acpi_op_start && !(ops->acpi_op_add)) {

			status = acpi_start_single_object(child);

		status = acpi_start_single_object(device);

		if (ACPI_FAILURE(status))

				continue;

			return AE_CTRL_DEPTH;

	}



	/*
@@ -1492,24 +1449,36 @@ static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops) 
	 *

	 * TBD: Need notifications and other detection mechanisms

	 *      in place before we can fully implement this.

		 */

		 /*

	 *

	 * When the device is not present but functional, it is also

	 * necessary to scan the children of this device.

	 */

		if (child->status.present || (!child->status.present &&

					child->status.functional)) {

			status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,

						      NULL, NULL);

			if (ACPI_SUCCESS(status)) {

				level++;

				phandle = chandle;

				chandle = NULL;

				parent = child;

			}

		}

	if (!device->status.present && !device->status.functional)

		return AE_CTRL_DEPTH;



	if (!*return_value)

		*return_value = device;

	return AE_OK;

}



static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops,

			 struct acpi_device **child)

{

	acpi_status status;

	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	void *device = NULL;



	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);

	printk(KERN_INFO PREFIX "Enumerating devices from [%s]\n",

	       (char *) buffer.pointer);



	status = acpi_bus_check_add(handle, 0, ops, &device);

	if (ACPI_SUCCESS(status))

		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,

				    acpi_bus_check_add, ops, &device);



	if (child)

		*child = device;

	return 0;

}
@@ -1517,33 +1486,25 @@ int 
acpi_bus_add(struct acpi_device **child,

	     struct acpi_device *parent, acpi_handle handle, int type)

{

	int result;

	struct acpi_bus_ops ops;



	memset(&ops, 0, sizeof(ops));

	ops.acpi_op_add = 1;



	result = acpi_add_single_object(child, handle, type, &ops);

	if (!result)

		result = acpi_bus_scan((*child)->handle, &ops);



	return result;

	acpi_bus_scan(handle, &ops, child);

	return 0;

}

EXPORT_SYMBOL(acpi_bus_add);



int acpi_bus_start(struct acpi_device *device)

{

	int result;

	struct acpi_bus_ops ops;



	memset(&ops, 0, sizeof(ops));

	ops.acpi_op_start = 1;



	result = acpi_start_single_object(device);

	if (!result)

		result = acpi_bus_scan(device->handle, &ops);



	return result;

	acpi_bus_scan(device->handle, &ops, NULL);

	return 0;

}

EXPORT_SYMBOL(acpi_bus_start);
@@ -1645,18 +1606,10 @@ int __init acpi_scan_init(void) 
		printk(KERN_ERR PREFIX "Could not register bus type\n");

	}



	/*

	 * Create the root device in the bus's device tree

	 */

	result = acpi_add_single_object(&acpi_root, ACPI_ROOT_OBJECT,

					ACPI_BUS_TYPE_DEVICE, &ops);

	if (result)

		goto Done;



	/*

	 * Enumerate devices in the ACPI namespace.

	 */

	result = acpi_bus_scan(acpi_root->handle, &ops);

	result = acpi_bus_scan(ACPI_ROOT_OBJECT, &ops, &acpi_root);



	if (!result)

		result = acpi_bus_scan_fixed();
@@ -1664,6 +1617,5 @@ int __init acpi_scan_init(void) 
	if (result)

		acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);



Done:

	return result;

}

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