rapidio: add modular build option for the subsystem core

Add a configuration option to build RapidIO subsystem core code as a
loadable kernel module. Currently this option is available only for
x86-based platforms, with the additional patch for PowerPC planned to be
provided later.

This patch replaces kernel command line parameter "riohdid=" with its
module-specific analog "rapidio.hdid=".

Signed-off-by: Alexandre Bounine <[e-mail]>
Cc: Matt Porter <[e-mail]>
Cc: Li Yang <[e-mail]>
Cc: Kumar Gala <[e-mail]>
Cc: Andre van Herk <[e-mail]>
Cc: Micha Nelissen <[e-mail]>
Cc: Stef van Os <[e-mail]>
Cc: Jean Delvare <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/x86/Kconfig

···
 source "drivers/pci/hotplug/Kconfig"
 
 config RAPIDIO
-	bool "RapidIO support"
+	tristate "RapidIO support"
 	depends on PCI
 	default n
 	help
-	  If you say Y here, the kernel will include drivers and
+	  If enabled this option will include drivers and the core
 	  infrastructure code to support RapidIO interconnect devices.
 
 source "drivers/rapidio/Kconfig"

drivers/rapidio/Makefile

···
 #
 # Makefile for RapidIO interconnect services
 #
-obj-y += rio.o rio-access.o rio-driver.o rio-sysfs.o
+obj-$(CONFIG_RAPIDIO) += rapidio.o
+rapidio-y := rio.o rio-access.o rio-driver.o rio-sysfs.o
+
 obj-$(CONFIG_RAPIDIO_ENUM_BASIC) += rio-scan.o
 
 obj-$(CONFIG_RAPIDIO)		+= switches/

drivers/rapidio/rio.c

···
  * Copyright 2005 MontaVista Software, Inc.
  * Matt Porter <[e-mail]>
  *
- * Copyright 2009 Integrated Device Technology, Inc.
+ * Copyright 2009 - 2013 Integrated Device Technology, Inc.
  * Alex Bounine <[e-mail]>
  *
  * This program is free software; you can redistribute  it and/or modify it
···
 #include <linux/interrupt.h>
 
 #include "rio.h"
+
+MODULE_DESCRIPTION("RapidIO Subsystem Core");
+MODULE_AUTHOR("Matt Porter <[e-mail]>");
+MODULE_AUTHOR("Alexandre Bounine <[e-mail]>");
+MODULE_LICENSE("GPL");
+
+static int hdid[RIO_MAX_MPORTS];
+static int ids_num;
+module_param_array(hdid, int, &ids_num, 0);
+MODULE_PARM_DESC(hdid,
+	"Destination ID assignment to local RapidIO controllers");
 
 static LIST_HEAD(rio_devices);
 static DEFINE_SPINLOCK(rio_global_list_lock);
···
 	return 0;
 }
 
-static int hdids[RIO_MAX_MPORTS + 1];
-
 static int rio_get_hdid(int index)
 {
-	if (!hdids[0] || hdids[0] <= index || index >= RIO_MAX_MPORTS)
+	if (ids_num == 0 || ids_num <= index || index >= RIO_MAX_MPORTS)
 		return -1;
 
-	return hdids[index + 1];
+	return hdid[index];
 }
-
-static int rio_hdid_setup(char *str)
-{
-	(void)get_options(str, ARRAY_SIZE(hdids), hdids);
-	return 1;
-}
-
-__setup("riohdid=", rio_hdid_setup);
 
 int rio_register_mport(struct rio_mport *port)
 {