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 (file)
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -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);
 
-      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;
 }