1 files changed, 104 insertions, 46 deletions

diff --git a/drivers/acpi/utilities/utresrc.c b/drivers/acpi/utilities/utresrc.c
index 27158dd0f877..4c24e6d5400a 100644
--- a/drivers/acpi/utilities/utresrc.c
+++ b/drivers/acpi/utilities/utresrc.c
@@ -240,6 +240,104 @@ static const u8 acpi_gbl_resource_types[] = {
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_ut_walk_aml_resources
+ *
+ * PARAMETERS:  Aml             - Pointer to the raw AML resource template
+ *              aml_length      - Length of the entire template
+ *              user_function   - Called once for each descriptor found. If
+ *                                NULL, a pointer to the end_tag is returned
+ *              Context         - Passed to user_function
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Walk a raw AML resource list(buffer). User function called
+ *              once for each resource found.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ut_walk_aml_resources(u8 * aml,
+                           acpi_size aml_length,
+                           acpi_walk_aml_callback user_function, void *context)
+{
+        acpi_status status;
+        u8 *end_aml;
+        u8 resource_index;
+        u32 length;
+        u32 offset = 0;
+
+        ACPI_FUNCTION_TRACE("ut_walk_aml_resources");
+
+        /* The absolute minimum resource template is one end_tag descriptor */
+
+        if (aml_length < sizeof(struct aml_resource_end_tag)) {
+                return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
+        }
+
+        /* Point to the end of the resource template buffer */
+
+        end_aml = aml + aml_length;
+
+        /* Walk the byte list, abort on any invalid descriptor type or length */
+
+        while (aml < end_aml) {
+
+                /* Validate the Resource Type and Resource Length */
+
+                status = acpi_ut_validate_resource(aml, &resource_index);
+                if (ACPI_FAILURE(status)) {
+                        return_ACPI_STATUS(status);
+                }
+
+                /* Get the length of this descriptor */
+
+                length = acpi_ut_get_descriptor_length(aml);
+
+                /* Invoke the user function */
+
+                if (user_function) {
+                        status =
+                            user_function(aml, length, offset, resource_index,
+                                          context);
+                        if (ACPI_FAILURE(status)) {
+                                return (status);
+                        }
+                }
+
+                /* An end_tag descriptor terminates this resource template */
+
+                if (acpi_ut_get_resource_type(aml) ==
+                    ACPI_RESOURCE_NAME_END_TAG) {
+                        /*
+                         * There must be at least one more byte in the buffer for
+                         * the 2nd byte of the end_tag
+                         */
+                        if ((aml + 1) >= end_aml) {
+                                return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
+                        }
+
+                        /* Return the pointer to the end_tag if requested */
+
+                        if (!user_function) {
+                                *(void **)context = aml;
+                        }
+
+                        /* Normal exit */
+
+                        return_ACPI_STATUS(AE_OK);
+                }
+
+                aml += length;
+                offset += length;
+        }
+
+        /* Did not find an end_tag descriptor */
+
+        return (AE_AML_NO_RESOURCE_END_TAG);
+}
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_ut_validate_resource
  *
  * PARAMETERS:  Aml             - Pointer to the raw AML resource descriptor
@@ -498,61 +596,21 @@ acpi_ut_get_resource_end_tag(union acpi_operand_object * obj_desc,
                              u8 ** end_tag)
 {
         acpi_status status;
-        u8 *aml;
-        u8 *end_aml;
 
         ACPI_FUNCTION_TRACE("ut_get_resource_end_tag");
 
-        /* Get start and end pointers */
-
-        aml = obj_desc->buffer.pointer;
-        end_aml = aml + obj_desc->buffer.length;
-
         /* Allow a buffer length of zero */
 
         if (!obj_desc->buffer.length) {
-                *end_tag = aml;
+                *end_tag = obj_desc->buffer.pointer;
                 return_ACPI_STATUS(AE_OK);
         }
 
-        /* Walk the resource template, one descriptor per iteration */
-
-        while (aml < end_aml) {
-
-                /* Validate the Resource Type and Resource Length */
-
-                status = acpi_ut_validate_resource(aml, NULL);
-                if (ACPI_FAILURE(status)) {
-                        return_ACPI_STATUS(status);
-                }
-
-                /* end_tag resource indicates the end of the resource template */
-
-                if (acpi_ut_get_resource_type(aml) ==
-                    ACPI_RESOURCE_NAME_END_TAG) {
-                        /*
-                         * There must be at least one more byte in the buffer for
-                         * the 2nd byte of the end_tag
-                         */
-                        if ((aml + 1) >= end_aml) {
-                                return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
-                        }
-
-                        /* Return the pointer to the end_tag */
-
-                        *end_tag = aml;
-                        return_ACPI_STATUS(AE_OK);
-                }
-
-                /*
-                 * Point to the next resource descriptor in the AML buffer. The
-                 * descriptor length is guaranteed to be non-zero by resource
-                 * validation above.
-                 */
-                aml += acpi_ut_get_descriptor_length(aml);
-        }
+        /* Validate the template and get a pointer to the end_tag */
 
-        /* Did not find an end_tag resource descriptor */
+        status = acpi_ut_walk_aml_resources(obj_desc->buffer.pointer,
+                                            obj_desc->buffer.length, NULL,
+                                            end_tag);
 
-        return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
+        return_ACPI_STATUS(status);
 }