pci-acpi: use local buffer for _OSC

Current pci-acpi implementation uses array in osc_data directly to
evaluate _OSC. It needs to save the old data and restore it if _OSC
evaluation fails. To make it more robust, we should use local array to
evaluate _OSC.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 39 insertions, 34 deletions

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 032b3268018b..b1bd6e6155a3 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -21,12 +21,18 @@
 
 struct acpi_osc_data {
         acpi_handle handle;
-        u32 ctrlset_buf[3];
-        u32 global_ctrlsets;
+        u32 support_set;
+        u32 control_set;
+        u32 query_result;
         struct list_head sibiling;
 };
 static LIST_HEAD(acpi_osc_data_list);
 
+struct acpi_osc_args {
+        u32 capbuf[3];
+        u32 query_result;
+};
+
 static struct acpi_osc_data *acpi_get_osc_data(acpi_handle handle)
 {
         struct acpi_osc_data *data;
@@ -47,14 +53,14 @@ static struct acpi_osc_data *acpi_get_osc_data(acpi_handle handle)
 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_run_osc(acpi_handle handle,
-                                struct acpi_osc_data *osc_data)
+                                struct acpi_osc_args *osc_args)
 {
         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 osc_dw0, flags = osc_data->ctrlset_buf[OSC_QUERY_TYPE];
+        u32 osc_dw0, flags = osc_args->capbuf[OSC_QUERY_TYPE];
 
         /* Setting up input parameters */
         input.count = 4;
@@ -68,7 +74,7 @@ static acpi_status acpi_run_osc(acpi_handle handle,
         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 *)osc_data->ctrlset_buf;
+        in_params[3].buffer.pointer     = (u8 *)osc_args->capbuf;
 
         status = acpi_evaluate_object(handle, "_OSC", &input, &output);
         if (ACPI_FAILURE(status))
@@ -99,11 +105,9 @@ static acpi_status acpi_run_osc(acpi_handle handle,
                 goto out_kfree;
         }
 out_success:
-        if (flags & OSC_QUERY_ENABLE) {
-                /* Update Global Control Set */
-                osc_data->global_ctrlsets =
+        if (flags & OSC_QUERY_ENABLE)
+                osc_args->query_result =
                         *((u32 *)(out_obj->buffer.pointer + 8));
-        }
         status = AE_OK;
 
 out_kfree:
@@ -117,8 +121,9 @@ static acpi_status acpi_query_osc(acpi_handle handle,
         acpi_status status;
         acpi_status *ret_status = (acpi_status *)retval;
         struct acpi_osc_data *osc_data;
-        u32 flags = (unsigned long)context, temp;
+        u32 flags = (unsigned long)context, support_set;
         acpi_handle tmp;
+        struct acpi_osc_args osc_args;
 
         status = acpi_get_handle(handle, "_OSC", &tmp);
         if (ACPI_FAILURE(status))
@@ -130,21 +135,18 @@ static acpi_status acpi_query_osc(acpi_handle handle,
                 return AE_ERROR;
         }
 
-        osc_data->ctrlset_buf[OSC_SUPPORT_TYPE] |= (flags & OSC_SUPPORT_MASKS);
-
         /* do _OSC query for all possible controls */
-        temp = osc_data->ctrlset_buf[OSC_CONTROL_TYPE];
-        osc_data->ctrlset_buf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
-        osc_data->ctrlset_buf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;
+        support_set = osc_data->support_set | (flags & OSC_SUPPORT_MASKS);
+        osc_args.capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
+        osc_args.capbuf[OSC_SUPPORT_TYPE] = support_set;
+        osc_args.capbuf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;
 
-        status = acpi_run_osc(handle, osc_data);
+        status = acpi_run_osc(handle, &osc_args);
         *ret_status = status;
 
-        osc_data->ctrlset_buf[OSC_QUERY_TYPE] = !OSC_QUERY_ENABLE;
-        osc_data->ctrlset_buf[OSC_CONTROL_TYPE] = temp;
-        if (ACPI_FAILURE(status)) {
-                /* no osc support at all */
-                osc_data->ctrlset_buf[OSC_SUPPORT_TYPE] = 0;
+        if (ACPI_SUCCESS(status)) {
+                osc_data->support_set = support_set;
+                osc_data->query_result = osc_args.query_result;
         }
 
         return status;
@@ -181,10 +183,11 @@ acpi_status __pci_osc_support_set(u32 flags, const char *hid)
  **/
 acpi_status pci_osc_control_set(acpi_handle handle, u32 flags)
 {
-        acpi_status     status;
-        u32             ctrlset;
+        acpi_status status;
+        u32 ctrlset, control_set;
         acpi_handle tmp;
         struct acpi_osc_data *osc_data;
+        struct acpi_osc_args osc_args;
 
         status = acpi_get_handle(handle, "_OSC", &tmp);
         if (ACPI_FAILURE(status))
@@ -197,19 +200,21 @@ acpi_status pci_osc_control_set(acpi_handle handle, u32 flags)
         }
 
         ctrlset = (flags & OSC_CONTROL_MASKS);
-        if (!ctrlset) {
+        if (!ctrlset)
                 return AE_TYPE;
-        }
-        if (osc_data->ctrlset_buf[OSC_SUPPORT_TYPE] &&
-                ((osc_data->global_ctrlsets & ctrlset) != ctrlset)) {
+
+        if (osc_data->support_set &&
+            ((osc_data->query_result & ctrlset) != ctrlset))
                 return AE_SUPPORT;
-        }
-        osc_data->ctrlset_buf[OSC_CONTROL_TYPE] |= ctrlset;
-        status = acpi_run_osc(handle, osc_data);
-        if (ACPI_FAILURE (status)) {
-                osc_data->ctrlset_buf[OSC_CONTROL_TYPE] &= ~ctrlset;
-        }
-        
+
+        control_set = osc_data->control_set | ctrlset;
+        osc_args.capbuf[OSC_QUERY_TYPE] = 0;
+        osc_args.capbuf[OSC_SUPPORT_TYPE] = osc_data->support_set;
+        osc_args.capbuf[OSC_CONTROL_TYPE] = control_set;
+        status = acpi_run_osc(handle, &osc_args);
+        if (ACPI_SUCCESS(status))
+                osc_data->control_set = control_set;
+
         return status;
 }
 EXPORT_SYMBOL(pci_osc_control_set);