PCI/ACPI: Move _OSC stuff from acpi_pci_root_add() to negotiate_os_control()

This doesn't change any of the _OSC code; it just moves it out into
a new function so it doesn't clutter acpi_pci_root_add() so much.  This
also enables future simplifications.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index cc87cc4..3e57f10 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -360,6 +360,90 @@
 }
 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 
+static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
+				 int *clear_aspm)
+{
+	u32 flags, base_flags;
+	acpi_status status;
+	struct acpi_device *device = root->device;
+	acpi_handle handle = device->handle;
+
+	/*
+	 * All supported architectures that use ACPI have support for
+	 * PCI domains, so we indicate this in _OSC support capabilities.
+	 */
+	flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
+	acpi_pci_osc_support(root, flags);
+
+	if (pci_ext_cfg_avail())
+		flags |= OSC_PCI_EXT_CONFIG_SUPPORT;
+	if (pcie_aspm_support_enabled()) {
+		flags |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
+	}
+	if (pci_msi_enabled())
+		flags |= OSC_PCI_MSI_SUPPORT;
+	if (flags != base_flags) {
+		status = acpi_pci_osc_support(root, flags);
+		if (ACPI_FAILURE(status)) {
+			dev_info(&device->dev, "ACPI _OSC support "
+				"notification failed, disabling PCIe ASPM\n");
+			*no_aspm = 1;
+			flags = base_flags;
+		}
+	}
+
+	if (!pcie_ports_disabled
+	    && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
+		flags = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
+			| OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
+			| OSC_PCI_EXPRESS_PME_CONTROL;
+
+		if (pci_aer_available()) {
+			if (aer_acpi_firmware_first())
+				dev_dbg(&device->dev,
+					"PCIe errors handled by BIOS.\n");
+			else
+				flags |= OSC_PCI_EXPRESS_AER_CONTROL;
+		}
+
+		dev_info(&device->dev,
+			"Requesting ACPI _OSC control (0x%02x)\n", flags);
+
+		status = acpi_pci_osc_control_set(handle, &flags,
+				       OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
+		if (ACPI_SUCCESS(status)) {
+			dev_info(&device->dev,
+				"ACPI _OSC control (0x%02x) granted\n", flags);
+			if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
+				/*
+				 * We have ASPM control, but the FADT indicates
+				 * that it's unsupported. Clear it.
+				 */
+				*clear_aspm = 1;
+			}
+		} else {
+			dev_info(&device->dev,
+				"ACPI _OSC request failed (%s), "
+				"returned control mask: 0x%02x\n",
+				acpi_format_exception(status), flags);
+			dev_info(&device->dev,
+				 "ACPI _OSC control for PCIe not granted, disabling ASPM\n");
+			/*
+			 * We want to disable ASPM here, but aspm_disabled
+			 * needs to remain in its state from boot so that we
+			 * properly handle PCIe 1.1 devices.  So we set this
+			 * flag here, to defer the action until after the ACPI
+			 * root scan.
+			 */
+			*no_aspm = 1;
+		}
+	} else {
+		dev_info(&device->dev,
+			 "Unable to request _OSC control "
+			 "(_OSC support mask: 0x%02x)\n", flags);
+	}
+}
+
 static int acpi_pci_root_add(struct acpi_device *device,
 			     const struct acpi_device_id *not_used)
 {
@@ -367,9 +451,8 @@
 	acpi_status status;
 	int result;
 	struct acpi_pci_root *root;
-	u32 flags, base_flags;
 	acpi_handle handle = device->handle;
-	bool no_aspm = false, clear_aspm = false;
+	int no_aspm = 0, clear_aspm = 0;
 
 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 	if (!root)
@@ -422,80 +505,7 @@
 
 	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 
-	/*
-	 * All supported architectures that use ACPI have support for
-	 * PCI domains, so we indicate this in _OSC support capabilities.
-	 */
-	flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
-	acpi_pci_osc_support(root, flags);
-
-	if (pci_ext_cfg_avail())
-		flags |= OSC_PCI_EXT_CONFIG_SUPPORT;
-	if (pcie_aspm_support_enabled()) {
-		flags |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
-	}
-	if (pci_msi_enabled())
-		flags |= OSC_PCI_MSI_SUPPORT;
-	if (flags != base_flags) {
-		status = acpi_pci_osc_support(root, flags);
-		if (ACPI_FAILURE(status)) {
-			dev_info(&device->dev, "ACPI _OSC support "
-				"notification failed, disabling PCIe ASPM\n");
-			no_aspm = true;
-			flags = base_flags;
-		}
-	}
-
-	if (!pcie_ports_disabled
-	    && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
-		flags = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
-			| OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
-			| OSC_PCI_EXPRESS_PME_CONTROL;
-
-		if (pci_aer_available()) {
-			if (aer_acpi_firmware_first())
-				dev_dbg(&device->dev,
-					"PCIe errors handled by BIOS.\n");
-			else
-				flags |= OSC_PCI_EXPRESS_AER_CONTROL;
-		}
-
-		dev_info(&device->dev,
-			"Requesting ACPI _OSC control (0x%02x)\n", flags);
-
-		status = acpi_pci_osc_control_set(handle, &flags,
-				       OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
-		if (ACPI_SUCCESS(status)) {
-			dev_info(&device->dev,
-				"ACPI _OSC control (0x%02x) granted\n", flags);
-			if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
-				/*
-				 * We have ASPM control, but the FADT indicates
-				 * that it's unsupported. Clear it.
-				 */
-				clear_aspm = true;
-			}
-		} else {
-			dev_info(&device->dev,
-				"ACPI _OSC request failed (%s), "
-				"returned control mask: 0x%02x\n",
-				acpi_format_exception(status), flags);
-			dev_info(&device->dev,
-				 "ACPI _OSC control for PCIe not granted, disabling ASPM\n");
-			/*
-			 * We want to disable ASPM here, but aspm_disabled
-			 * needs to remain in its state from boot so that we
-			 * properly handle PCIe 1.1 devices.  So we set this
-			 * flag here, to defer the action until after the ACPI
-			 * root scan.
-			 */
-			no_aspm = true;
-		}
-	} else {
-		dev_info(&device->dev,
-			 "Unable to request _OSC control "
-			 "(_OSC support mask: 0x%02x)\n", flags);
-	}
+	negotiate_os_control(root, &no_aspm, &clear_aspm);
 
 	/*
 	 * TBD: Need PCI interface for enumeration/configuration of roots.