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: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index a8b2507..0d69c03 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -161,19 +161,22 @@
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 @@
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 @@
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 @@
if (flags != base_flags)
acpi_pci_osc_support(root, flags);
- end:
- if (result) {
- if (!list_empty(&root->node))
- list_del(&root->node);
- kfree(root);
- }
+ return 0;
+end:
+ if (!list_empty(&root->node))
+ list_del(&root->node);
+ kfree(root);
return result;
}