ACPICA: New: AcpiInstallMethod - install a single control method

This interface enables the override or creation of a single
control method. Useful to repair a bug or install a missing method.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 150 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/nsxfname.c b/drivers/acpi/acpica/nsxfname.c
index 9589fea24997..f23593d6add4 100644
--- a/drivers/acpi/acpica/nsxfname.c
+++ b/drivers/acpi/acpica/nsxfname.c
@@ -45,6 +45,8 @@
 #include <acpi/acpi.h>
 #include "accommon.h"
 #include "acnamesp.h"
+#include "acparser.h"
+#include "amlcode.h"
 
 #define _COMPONENT          ACPI_NAMESPACE
 ACPI_MODULE_NAME("nsxfname")
@@ -358,3 +360,151 @@ acpi_get_object_info(acpi_handle handle, struct acpi_buffer * buffer)
 }
 
 ACPI_EXPORT_SYMBOL(acpi_get_object_info)
+
+/******************************************************************************
+ *
+ * FUNCTION:    acpi_install_method
+ *
+ * PARAMETERS:  Buffer         - An ACPI table containing one control method
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Install a control method into the namespace. If the method
+ *              name already exists in the namespace, it is overwritten. The
+ *              input buffer must contain a valid DSDT or SSDT containing a
+ *              single control method.
+ *
+ ******************************************************************************/
+acpi_status acpi_install_method(u8 *buffer)
+{
+        struct acpi_table_header *table =
+            ACPI_CAST_PTR(struct acpi_table_header, buffer);
+        u8 *aml_buffer;
+        u8 *aml_start;
+        char *path;
+        struct acpi_namespace_node *node;
+        union acpi_operand_object *method_obj;
+        struct acpi_parse_state parser_state;
+        u32 aml_length;
+        u16 opcode;
+        u8 method_flags;
+        acpi_status status;
+
+        /* Parameter validation */
+
+        if (!buffer) {
+                return AE_BAD_PARAMETER;
+        }
+
+        /* Table must be a DSDT or SSDT */
+
+        if (!ACPI_COMPARE_NAME(table->signature, ACPI_SIG_DSDT) &&
+            !ACPI_COMPARE_NAME(table->signature, ACPI_SIG_SSDT)) {
+                return AE_BAD_HEADER;
+        }
+
+        /* First AML opcode in the table must be a control method */
+
+        parser_state.aml = buffer + sizeof(struct acpi_table_header);
+        opcode = acpi_ps_peek_opcode(&parser_state);
+        if (opcode != AML_METHOD_OP) {
+                return AE_BAD_PARAMETER;
+        }
+
+        /* Extract method information from the raw AML */
+
+        parser_state.aml += acpi_ps_get_opcode_size(opcode);
+        parser_state.pkg_end = acpi_ps_get_next_package_end(&parser_state);
+        path = acpi_ps_get_next_namestring(&parser_state);
+        method_flags = *parser_state.aml++;
+        aml_start = parser_state.aml;
+        aml_length = ACPI_PTR_DIFF(parser_state.pkg_end, aml_start);
+
+        /*
+         * Allocate resources up-front. We don't want to have to delete a new
+         * node from the namespace if we cannot allocate memory.
+         */
+        aml_buffer = ACPI_ALLOCATE(aml_length);
+        if (!aml_buffer) {
+                return AE_NO_MEMORY;
+        }
+
+        method_obj = acpi_ut_create_internal_object(ACPI_TYPE_METHOD);
+        if (!method_obj) {
+                ACPI_FREE(aml_buffer);
+                return AE_NO_MEMORY;
+        }
+
+        /* Lock namespace for acpi_ns_lookup, we may be creating a new node */
+
+        status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+        if (ACPI_FAILURE(status)) {
+                goto error_exit;
+        }
+
+        /* The lookup either returns an existing node or creates a new one */
+
+        status =
+            acpi_ns_lookup(NULL, path, ACPI_TYPE_METHOD, ACPI_IMODE_LOAD_PASS1,
+                           ACPI_NS_DONT_OPEN_SCOPE | ACPI_NS_ERROR_IF_FOUND,
+                           NULL, &node);
+
+        (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+
+        if (ACPI_FAILURE(status)) {     /* ns_lookup */
+                if (status != AE_ALREADY_EXISTS) {
+                        goto error_exit;
+                }
+
+                /* Node existed previously, make sure it is a method node */
+
+                if (node->type != ACPI_TYPE_METHOD) {
+                        status = AE_TYPE;
+                        goto error_exit;
+                }
+        }
+
+        /* Copy the method AML to the local buffer */
+
+        ACPI_MEMCPY(aml_buffer, aml_start, aml_length);
+
+        /* Initialize the method object with the new method's information */
+
+        method_obj->method.aml_start = aml_buffer;
+        method_obj->method.aml_length = aml_length;
+
+        method_obj->method.param_count = (u8)
+            (method_flags & AML_METHOD_ARG_COUNT);
+
+        method_obj->method.method_flags = (u8)
+            (method_flags & ~AML_METHOD_ARG_COUNT);
+
+        if (method_flags & AML_METHOD_SERIALIZED) {
+                method_obj->method.sync_level = (u8)
+                    ((method_flags & AML_METHOD_SYNC_LEVEL) >> 4);
+        }
+
+        /*
+         * Now that it is complete, we can attach the new method object to
+         * the method Node (detaches/deletes any existing object)
+         */
+        status = acpi_ns_attach_object(node, method_obj, ACPI_TYPE_METHOD);
+
+        /*
+         * Flag indicates AML buffer is dynamic, must be deleted later.
+         * Must be set only after attach above.
+         */
+        node->flags |= ANOBJ_ALLOCATED_BUFFER;
+
+        /* Remove local reference to the method object */
+
+        acpi_ut_remove_reference(method_obj);
+        return status;
+
+error_exit:
+
+        ACPI_FREE(aml_buffer);
+        ACPI_FREE(method_obj);
+        return status;
+}
+ACPI_EXPORT_SYMBOL(acpi_install_method)