Merge branch 'pci/acpi'

- Simplify _OSC negotiation with platform for control of PCIe features
  (Joerg Roedel)

* pci/acpi:
  PCI/ACPI: Check for _OSC support in acpi_pci_osc_control_set()
  PCI/ACPI: Move _OSC query checks to separate function
  PCI/ACPI: Move supported and control calculations to separate functions
  PCI/ACPI: Remove OSC_PCI_SUPPORT_MASKS and OSC_PCI_CONTROL_MASKS

drivers/acpi/pci_root.c

@@ -199,33 +199,20 @@ static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 	acpi_status status;
 	u32 result, capbuf[3];
 
-	support &= OSC_PCI_SUPPORT_MASKS;
 	support |= root->osc_support_set;
 
 	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
 	capbuf[OSC_SUPPORT_DWORD] = support;
-	if (control) {
-		*control &= OSC_PCI_CONTROL_MASKS;
-		capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
-	} else {
-		/* Run _OSC query only with existing controls. */
-		capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
-	}
+	capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
 
 	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 	if (ACPI_SUCCESS(status)) {
 		root->osc_support_set = support;
-		if (control)
-			*control = result;
+		*control = result;
 	}
 	return status;
 }
 
-static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
-{
-	return acpi_pci_query_osc(root, flags, NULL);
-}
-
 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 {
 	struct acpi_pci_root *root;
@@ -348,8 +335,9 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
  * _OSC bits the BIOS has granted control of, but its contents are meaningless
  * on failure.
  **/
-static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
+static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 support)
 {
+	u32 req = OSC_PCI_EXPRESS_CAPABILITY_CONTROL;
 	struct acpi_pci_root *root;
 	acpi_status status;
 	u32 ctrl, capbuf[3];
@@ -357,22 +345,16 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 r
 	if (!mask)
 		return AE_BAD_PARAMETER;
 
-	ctrl = *mask & OSC_PCI_CONTROL_MASKS;
-	if ((ctrl & req) != req)
-		return AE_TYPE;
-
 	root = acpi_pci_find_root(handle);
 	if (!root)
 		return AE_NOT_EXIST;
 
-	*mask = ctrl | root->osc_control_set;
-	/* No need to evaluate _OSC if the control was already granted. */
-	if ((root->osc_control_set & ctrl) == ctrl)
-		return AE_OK;
+	ctrl   = *mask;
+	*mask |= root->osc_control_set;
 
 	/* Need to check the available controls bits before requesting them. */
-	while (*mask) {
-		status = acpi_pci_query_osc(root, root->osc_support_set, mask);
+	do {
+		status = acpi_pci_query_osc(root, support, mask);
 		if (ACPI_FAILURE(status))
 			return status;
 		if (ctrl == *mask)
@@ -380,7 +362,11 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 r
 		decode_osc_control(root, "platform does not support",
 				   ctrl & ~(*mask));
 		ctrl = *mask;
-	}
+	} while (*mask);
+
+	/* No need to request _OSC if the control was already granted. */
+	if ((root->osc_control_set & ctrl) == ctrl)
+		return AE_OK;
 
 	if ((ctrl & req) != req) {
 		decode_osc_control(root, "not requesting control; platform does not support",
@@ -399,25 +385,9 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 r
 	return AE_OK;
 }
 
-static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
-				 bool is_pcie)
+static u32 calculate_support(void)
 {
-	u32 support, control, requested;
-	acpi_status status;
-	struct acpi_device *device = root->device;
-	acpi_handle handle = device->handle;
-
-	/*
-	 * Apple always return failure on _OSC calls when _OSI("Darwin") has
-	 * been called successfully. We know the feature set supported by the
-	 * platform, so avoid calling _OSC at all
-	 */
-	if (x86_apple_machine) {
-		root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
-		decode_osc_control(root, "OS assumes control of",
-				   root->osc_control_set);
-		return;
-	}
+	u32 support;
 
 	/*
 	 * All supported architectures that use ACPI have support for
@@ -434,30 +404,12 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
 	if (IS_ENABLED(CONFIG_PCIE_EDR))
 		support |= OSC_PCI_EDR_SUPPORT;
 
-	decode_osc_support(root, "OS supports", support);
-	status = acpi_pci_osc_support(root, support);
-	if (ACPI_FAILURE(status)) {
-		*no_aspm = 1;
-
-		/* _OSC is optional for PCI host bridges */
-		if ((status == AE_NOT_FOUND) && !is_pcie)
-			return;
-
-		dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
-			 acpi_format_exception(status));
-		return;
-	}
-
-	if (pcie_ports_disabled) {
-		dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
-		return;
-	}
+	return support;
+}
 
-	if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
-		decode_osc_support(root, "not requesting OS control; OS requires",
-				   ACPI_PCIE_REQ_SUPPORT);
-		return;
-	}
+static u32 calculate_control(void)
+{
+	u32 control;
 
 	control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
 		| OSC_PCI_EXPRESS_PME_CONTROL;
@@ -483,11 +435,59 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
 	if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
 		control |= OSC_PCI_EXPRESS_DPC_CONTROL;
 
-	requested = control;
-	status = acpi_pci_osc_control_set(handle, &control,
-					  OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
+	return control;
+}
+
+static bool os_control_query_checks(struct acpi_pci_root *root, u32 support)
+{
+	struct acpi_device *device = root->device;
+
+	if (pcie_ports_disabled) {
+		dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
+		return false;
+	}
+
+	if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
+		decode_osc_support(root, "not requesting OS control; OS requires",
+				   ACPI_PCIE_REQ_SUPPORT);
+		return false;
+	}
+
+	return true;
+}
+
+static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
+				 bool is_pcie)
+{
+	u32 support, control = 0, requested = 0;
+	acpi_status status;
+	struct acpi_device *device = root->device;
+	acpi_handle handle = device->handle;
+
+	/*
+	 * Apple always return failure on _OSC calls when _OSI("Darwin") has
+	 * been called successfully. We know the feature set supported by the
+	 * platform, so avoid calling _OSC at all
+	 */
+	if (x86_apple_machine) {
+		root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
+		decode_osc_control(root, "OS assumes control of",
+				   root->osc_control_set);
+		return;
+	}
+
+	support = calculate_support();
+
+	decode_osc_support(root, "OS supports", support);
+
+	if (os_control_query_checks(root, support))
+		requested = control = calculate_control();
+
+	status = acpi_pci_osc_control_set(handle, &control, support);
 	if (ACPI_SUCCESS(status)) {
-		decode_osc_control(root, "OS now controls", control);
+		if (control)
+			decode_osc_control(root, "OS now controls", control);
+
 		if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 			/*
 			 * We have ASPM control, but the FADT indicates that
@@ -498,11 +498,6 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
 			*no_aspm = 1;
 		}
 	} else {
-		decode_osc_control(root, "OS requested", requested);
-		decode_osc_control(root, "platform willing to grant", control);
-		dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
-			acpi_format_exception(status));
-
 		/*
 		 * We want to disable ASPM here, but aspm_disabled
 		 * needs to remain in its state from boot so that we
@@ -511,6 +506,18 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
 		 * root scan.
 		 */
 		*no_aspm = 1;
+
+		/* _OSC is optional for PCI host bridges */
+		if ((status == AE_NOT_FOUND) && !is_pcie)
+			return;
+
+		if (control) {
+			decode_osc_control(root, "OS requested", requested);
+			decode_osc_control(root, "platform willing to grant", control);
+		}
+
+		dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
+			 acpi_format_exception(status));
 	}
 }
 

include/linux/acpi.h

@@ -577,7 +577,6 @@ extern u32 osc_sb_native_usb4_control;
 #define OSC_PCI_MSI_SUPPORT			0x00000010
 #define OSC_PCI_EDR_SUPPORT			0x00000080
 #define OSC_PCI_HPX_TYPE_3_SUPPORT		0x00000100
-#define OSC_PCI_SUPPORT_MASKS			0x0000019f
 
 /* PCI Host Bridge _OSC: Capabilities DWORD 3: Control Field */
 #define OSC_PCI_EXPRESS_NATIVE_HP_CONTROL	0x00000001
@@ -587,7 +586,6 @@ extern u32 osc_sb_native_usb4_control;
 #define OSC_PCI_EXPRESS_CAPABILITY_CONTROL	0x00000010
 #define OSC_PCI_EXPRESS_LTR_CONTROL		0x00000020
 #define OSC_PCI_EXPRESS_DPC_CONTROL		0x00000080
-#define OSC_PCI_CONTROL_MASKS			0x000000bf
 
 #define ACPI_GSB_ACCESS_ATTRIB_QUICK		0x00000002
 #define ACPI_GSB_ACCESS_ATTRIB_SEND_RCV         0x00000004