1 files changed, 178 insertions, 2 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 5b38a026d122..979eccc82c5b 100644
--- a/drivers/acpi/pci_root.c
+++ b/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) {