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>
diff --git a/drivers/acpi/executer/exconfig.c b/drivers/acpi/executer/exconfig.c
index 25802f3..009aef5 100644
--- a/drivers/acpi/executer/exconfig.c
+++ b/drivers/acpi/executer/exconfig.c
@@ -234,6 +234,13 @@
 			   table->oem_table_id));
 	}
 
+	/* Invoke table handler if present */
+
+	if (acpi_gbl_table_handler) {
+		(void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_LOAD, table,
+					     acpi_gbl_table_handler_context);
+	}
+
 	*return_desc = ddb_handle;
 	return_ACPI_STATUS(status);
 }
@@ -352,6 +359,14 @@
 		return_ACPI_STATUS(status);
 	}
 
+	/* Invoke table handler if present */
+
+	if (acpi_gbl_table_handler) {
+		(void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_LOAD,
+					     table_desc.pointer,
+					     acpi_gbl_table_handler_context);
+	}
+
       cleanup:
 	if (ACPI_FAILURE(status)) {
 		acpi_tb_delete_table(&table_desc);
@@ -376,6 +391,7 @@
 	acpi_status status = AE_OK;
 	union acpi_operand_object *table_desc = ddb_handle;
 	acpi_native_uint table_index;
+	struct acpi_table_header *table;
 
 	ACPI_FUNCTION_TRACE(ex_unload_table);
 
@@ -395,6 +411,17 @@
 
 	table_index = (acpi_native_uint) table_desc->reference.object;
 
+	/* Invoke table handler if present */
+
+	if (acpi_gbl_table_handler) {
+		status = acpi_get_table_by_index(table_index, &table);
+		if (ACPI_SUCCESS(status)) {
+			(void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_UNLOAD,
+						     table,
+						     acpi_gbl_table_handler_context);
+		}
+	}
+
 	/*
 	 * Delete the entire namespace under this table Node
 	 * (Offset contains the table_id)
@@ -407,5 +434,5 @@
 	/* Delete the table descriptor (ddb_handle) */
 
 	acpi_ut_remove_reference(table_desc);
-	return_ACPI_STATUS(status);
+	return_ACPI_STATUS(AE_OK);
 }
diff --git a/drivers/acpi/tables/tbxface.c b/drivers/acpi/tables/tbxface.c
index a9e3331..5f22715 100644
--- a/drivers/acpi/tables/tbxface.c
+++ b/drivers/acpi/tables/tbxface.c
@@ -635,6 +635,95 @@
 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");
diff --git a/drivers/acpi/utilities/utglobal.c b/drivers/acpi/utilities/utglobal.c
index 630c9a2..4442543 100644
--- a/drivers/acpi/utilities/utglobal.c
+++ b/drivers/acpi/utilities/utglobal.c
@@ -675,12 +675,13 @@
 	acpi_gbl_gpe_fadt_blocks[0] = NULL;
 	acpi_gbl_gpe_fadt_blocks[1] = NULL;
 
-	/* Global notify handlers */
+	/* Global handlers */
 
 	acpi_gbl_system_notify.handler = NULL;
 	acpi_gbl_device_notify.handler = NULL;
 	acpi_gbl_exception_handler = NULL;
 	acpi_gbl_init_handler = NULL;
+	acpi_gbl_table_handler = NULL;
 
 	/* Global Lock support */