ACPICA: New interfaces for table event handlers

Designed and implemented new external interfaces to install and
remove handlers for ACPI table-related events. Current events that
are defined are LOAD and UNLOAD. These interfaces allow the host to
track ACPI tables as they are dynamically loaded and unloaded. See
AcpiInstallTableHandler and AcpiRemoveTableHandler.

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

drivers/acpi/tables/tbxface.c

@@ -635,6 +635,95 @@ acpi_status acpi_load_tables(void)
 ACPI_EXPORT_SYMBOL(acpi_load_tables)
 
 
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_install_table_handler
+ *
+ * PARAMETERS:  Handler         - Table event handler
+ *              Context         - Value passed to the handler on each event
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Install table event handler
+ *
+ ******************************************************************************/
+acpi_status
+acpi_install_table_handler(acpi_tbl_handler handler, void *context)
+{
+	acpi_status status;
+
+	ACPI_FUNCTION_TRACE(acpi_install_table_handler);
+
+	if (!handler) {
+		return_ACPI_STATUS(AE_BAD_PARAMETER);
+	}
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	/* Don't allow more than one handler */
+
+	if (acpi_gbl_table_handler) {
+		status = AE_ALREADY_EXISTS;
+		goto cleanup;
+	}
+
+	/* Install the handler */
+
+	acpi_gbl_table_handler = handler;
+	acpi_gbl_table_handler_context = context;
+
+      cleanup:
+	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
+	return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_install_table_handler)
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_remove_table_handler
+ *
+ * PARAMETERS:  Handler         - Table event handler that was installed
+ *                                previously.
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Remove table event handler
+ *
+ ******************************************************************************/
+acpi_status acpi_remove_table_handler(acpi_tbl_handler handler)
+{
+	acpi_status status;
+
+	ACPI_FUNCTION_TRACE(acpi_remove_table_handler);
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	/* Make sure that the installed handler is the same */
+
+	if (!handler || handler != acpi_gbl_table_handler) {
+		status = AE_BAD_PARAMETER;
+		goto cleanup;
+	}
+
+	/* Remove the handler */
+
+	acpi_gbl_table_handler = NULL;
+
+      cleanup:
+	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
+	return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_remove_table_handler)
+
+
 static int __init acpi_no_auto_ssdt_setup(char *s) {
 
         printk(KERN_NOTICE "ACPI: SSDT auto-load disabled\n");