PCI/ACPI: move _OSC code to pci_root.c

Move PCI _OSC management code from drivers/pci/pci-acpi.c to
drivers/acpi/pci_root.c. The benefits are

- We no longer need struct osc_data and its management code (contents
  are moved to struct acpi_pci_root). This simplify the code, and we
  no longer care about kmalloc() failure.

- We can make pci_acpi_osc_support() be a static function, which is
  called only from drivers/acpi/pci_root.c.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reviewed-by: Andrew Patterson <andrew.patterson@hp.com>
Tested-by: Andrew Patterson <andrew.patterson@hp.com>
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/acpi/pci_root.c

@@ -66,11 +66,18 @@ struct acpi_pci_root {
 	struct acpi_device * device;
 	struct acpi_pci_id id;
 	struct pci_bus *bus;
+
+	u32 osc_support_set;	/* _OSC state of support bits */
+	u32 osc_control_set;	/* _OSC state of control bits */
+	u32 osc_control_qry;	/* the latest _OSC query result */
+
+	u32 osc_queried:1;	/* has _OSC control been queried? */
 };
 
 static LIST_HEAD(acpi_pci_roots);
 
 static struct acpi_pci_driver *sub_driver;
+static DEFINE_MUTEX(osc_lock);
 
 int acpi_pci_register_driver(struct acpi_pci_driver *driver)
 {
@@ -185,6 +192,175 @@ static void acpi_pci_bridge_scan(struct acpi_device *device)
 		}
 }
 
+static u8 OSC_UUID[16] = {0x5B, 0x4D, 0xDB, 0x33, 0xF7, 0x1F, 0x1C, 0x40,
+			  0x96, 0x57, 0x74, 0x41, 0xC0, 0x3D, 0xD7, 0x66};
+
+static acpi_status acpi_pci_run_osc(acpi_handle handle,
+				    const u32 *capbuf, u32 *retval)
+{
+	acpi_status status;
+	struct acpi_object_list input;
+	union acpi_object in_params[4];
+	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+	union acpi_object *out_obj;
+	u32 errors;
+
+	/* Setting up input parameters */
+	input.count = 4;
+	input.pointer = in_params;
+	in_params[0].type 		= ACPI_TYPE_BUFFER;
+	in_params[0].buffer.length 	= 16;
+	in_params[0].buffer.pointer	= OSC_UUID;
+	in_params[1].type 		= ACPI_TYPE_INTEGER;
+	in_params[1].integer.value 	= 1;
+	in_params[2].type 		= ACPI_TYPE_INTEGER;
+	in_params[2].integer.value	= 3;
+	in_params[3].type		= ACPI_TYPE_BUFFER;
+	in_params[3].buffer.length 	= 12;
+	in_params[3].buffer.pointer 	= (u8 *)capbuf;
+
+	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	if (!output.length)
+		return AE_NULL_OBJECT;
+
+	out_obj = output.pointer;
+	if (out_obj->type != ACPI_TYPE_BUFFER) {
+		printk(KERN_DEBUG "_OSC evaluation returned wrong type\n");
+		status = AE_TYPE;
+		goto out_kfree;
+	}
+	/* Need to ignore the bit0 in result code */
+	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
+	if (errors) {
+		if (errors & OSC_REQUEST_ERROR)
+			printk(KERN_DEBUG "_OSC request failed\n");
+		if (errors & OSC_INVALID_UUID_ERROR)
+			printk(KERN_DEBUG "_OSC invalid UUID\n");
+		if (errors & OSC_INVALID_REVISION_ERROR)
+			printk(KERN_DEBUG "_OSC invalid revision\n");
+		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
+			if (capbuf[OSC_QUERY_TYPE] & OSC_QUERY_ENABLE)
+				goto out_success;
+			printk(KERN_DEBUG
+			       "Firmware did not grant requested _OSC control\n");
+			status = AE_SUPPORT;
+			goto out_kfree;
+		}
+		status = AE_ERROR;
+		goto out_kfree;
+	}
+out_success:
+	*retval = *((u32 *)(out_obj->buffer.pointer + 8));
+	status = AE_OK;
+
+out_kfree:
+	kfree(output.pointer);
+	return status;
+}
+
+static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 flags)
+{
+	acpi_status status;
+	u32 support_set, result, capbuf[3];
+
+	/* do _OSC query for all possible controls */
+	support_set = root->osc_support_set | (flags & OSC_SUPPORT_MASKS);
+	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
+	capbuf[OSC_SUPPORT_TYPE] = support_set;
+	capbuf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;
+
+	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
+	if (ACPI_SUCCESS(status)) {
+		root->osc_support_set = support_set;
+		root->osc_control_qry = result;
+		root->osc_queried = 1;
+	}
+	return status;
+}
+
+static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
+{
+	acpi_status status;
+	acpi_handle tmp;
+
+	status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
+	if (ACPI_FAILURE(status))
+		return status;
+	mutex_lock(&osc_lock);
+	status = acpi_pci_query_osc(root, flags);
+	mutex_unlock(&osc_lock);
+	return status;
+}
+
+static struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
+{
+	struct acpi_pci_root *root;
+	list_for_each_entry(root, &acpi_pci_roots, node) {
+		if (root->device->handle == handle)
+			return root;
+	}
+	return NULL;
+}
+
+/**
+ * pci_osc_control_set - commit requested control to Firmware
+ * @handle: acpi_handle for the target ACPI object
+ * @flags: driver's requested control bits
+ *
+ * Attempt to take control from Firmware on requested control bits.
+ **/
+acpi_status pci_osc_control_set(acpi_handle handle, u32 flags)
+{
+	acpi_status status;
+	u32 control_req, result, capbuf[3];
+	acpi_handle tmp;
+	struct acpi_pci_root *root;
+
+	status = acpi_get_handle(handle, "_OSC", &tmp);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	control_req = (flags & OSC_CONTROL_MASKS);
+	if (!control_req)
+		return AE_TYPE;
+
+	root = acpi_pci_find_root(handle);
+	if (!root)
+		return AE_NOT_EXIST;
+
+	mutex_lock(&osc_lock);
+	/* No need to evaluate _OSC if the control was already granted. */
+	if ((root->osc_control_set & control_req) == control_req)
+		goto out;
+
+	/* Need to query controls first before requesting them */
+	if (!root->osc_queried) {
+		status = acpi_pci_query_osc(root, root->osc_support_set);
+		if (ACPI_FAILURE(status))
+			goto out;
+	}
+	if ((root->osc_control_qry & control_req) != control_req) {
+		printk(KERN_DEBUG
+		       "Firmware did not grant requested _OSC control\n");
+		status = AE_SUPPORT;
+		goto out;
+	}
+
+	capbuf[OSC_QUERY_TYPE] = 0;
+	capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
+	capbuf[OSC_CONTROL_TYPE] = root->osc_control_set | control_req;
+	status = acpi_pci_run_osc(handle, capbuf, &result);
+	if (ACPI_SUCCESS(status))
+		root->osc_control_set = result;
+out:
+	mutex_unlock(&osc_lock);
+	return status;
+}
+EXPORT_SYMBOL(pci_osc_control_set);
+
 static int __devinit acpi_pci_root_add(struct acpi_device *device)
 {
 	int result = 0;
@@ -217,7 +393,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 	 * PCI domains, so we indicate this in _OSC support capabilities.
 	 */
 	flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
-	pci_acpi_osc_support(device->handle, flags);
+	acpi_pci_osc_support(root, flags);
 
 	/* 
 	 * Segment
@@ -353,7 +529,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 	if (pci_msi_enabled())
 		flags |= OSC_MSI_SUPPORT;
 	if (flags != base_flags)
-		pci_acpi_osc_support(device->handle, flags);
+		acpi_pci_osc_support(root, flags);
 
       end:
 	if (result) {