Commit f5eebbe1 authored by Bjorn Helgaas's avatar Bjorn Helgaas Committed by Len Brown
Browse files

ACPI: pci_root: simplify acpi_pci_root_add() control flow 



By looking up the segment & bus number earlier, we don't have to
worry about cleaning up if it fails.

Signed-off-by: default avatarBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent fbe2b31b

drivers/acpi/pci_root.c

+38 −62
Original line number Diff line number Diff line
@@ -161,19 +161,22 @@ get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data) 
	return AE_OK;

}



static acpi_status try_get_root_bridge_busnr(acpi_handle handle, int *busnum)

static acpi_status try_get_root_bridge_busnr(acpi_handle handle,

					     unsigned long long *bus)

{

	acpi_status status;

	int busnum;



	*busnum = -1;

	busnum = -1;

	status =

	    acpi_walk_resources(handle, METHOD_NAME__CRS,

				get_root_bridge_busnr_callback, busnum);

				get_root_bridge_busnr_callback, &busnum);

	if (ACPI_FAILURE(status))

		return status;

	/* Check if we really get a bus number from _CRS */

	if (*busnum == -1)

	if (busnum == -1)

		return AE_ERROR;

	*bus = busnum;

	return AE_OK;

}
@@ -363,24 +366,39 @@ EXPORT_SYMBOL(acpi_pci_osc_control_set); 


static int __devinit acpi_pci_root_add(struct acpi_device *device)

{

	int result = 0;

	struct acpi_pci_root *root = NULL;

	acpi_status status = AE_OK;

	unsigned long long value = 0;

	acpi_handle handle = NULL;

	unsigned long long segment, bus;

	acpi_status status;

	int result;

	struct acpi_pci_root *root;

	acpi_handle handle;

	struct acpi_device *child;

	u32 flags, base_flags;

	int bus;



	segment = 0;

	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,

				       &segment);

	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {

		printk(KERN_ERR PREFIX "can't evaluate _SEG\n");

		return -ENODEV;

	}



	if (!device)

		return -EINVAL;

	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */

	bus = 0;

	status = try_get_root_bridge_busnr(device->handle, &bus);

	if (ACPI_FAILURE(status)) {

		status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,					       NULL, &bus);

		if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {

			printk(KERN_ERR PREFIX

			     "no bus number in _CRS and can't evaluate _BBN\n");

			return -ENODEV;

		}

	}



	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);

	if (!root)

		return -ENOMEM;

	INIT_LIST_HEAD(&root->node);



	INIT_LIST_HEAD(&root->node);

	root->device = device;

	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);

	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
@@ -395,54 +413,13 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device) 
	flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;

	acpi_pci_osc_support(root, flags);



	/* 

	 * Segment

	 * -------

	 * Obtained via _SEG, if exists, otherwise assumed to be zero (0).

	 */

	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,

				       &value);

	switch (status) {

	case AE_OK:

		root->id.segment = (u16) value;

		break;

	case AE_NOT_FOUND:

		ACPI_DEBUG_PRINT((ACPI_DB_INFO,

				  "Assuming segment 0 (no _SEG)\n"));

		root->id.segment = 0;

		break;

	default:

		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SEG"));

		result = -ENODEV;

		goto end;

	}



	/* 

	 * Bus

	 * ---

	 * Check _CRS first, then _BBN.  If no _BBN, default to zero.

	 */

	status = try_get_root_bridge_busnr(device->handle, &bus);

	if (ACPI_SUCCESS(status))

		root->id.bus = bus;

	else {

		status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,					       NULL, &value);

		if (ACPI_SUCCESS(status))

			root->id.bus = (u16) value;

		else if (status == AE_NOT_FOUND)

			root->id.bus = 0;

		else {

			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BBN"));

			result = -ENODEV;

			goto end;

		}

	}



	/*

	 * Device & Function

	 * -----------------

	 * Obtained from _ADR (which has already been evaluated for us).

	 */

	root->id.segment = segment & 0xFFFF;

	root->id.bus = bus & 0xFF;

	root->id.device = device->pnp.bus_address >> 16;

	root->id.function = device->pnp.bus_address & 0xFFFF;
@@ -509,13 +486,12 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device) 
	if (flags != base_flags)

		acpi_pci_osc_support(root, flags);



	return 0;



end:

	if (result) {

	if (!list_empty(&root->node))

		list_del(&root->node);

	kfree(root);

	}



	return result;

}