From f5eebbe119a861b5e4f5c67c886eab0937c686ed Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Thu, 18 Jun 2009 14:46:52 -0600 Subject: [PATCH] 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 Signed-off-by: Len Brown --- drivers/acpi/pci_root.c | 100 +++++++++++++++------------------------- 1 file changed, 38 insertions(+), 62 deletions(-) diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index a8b250783937..0d69c0348c58 100644 --- 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; } -- 2.20.1