build algorithms into the mac80211 module

The old infrastructure was:
- the default algorithm is built into mac80211
- other algorithms get into their own modules

The implementation of this complicated scheme was horrible
(just look at net/mac80211/Makefile), and anyone adding a new
algorithm would most likely not get it right at his first attempt.

This patch therefore builds all enabled algorithms into the mac80211
module.

The user interface for the rate control algorithms changes as follows:
- first the user can choose which algorithms to enable (currently only
  MAC80211_RC_PID is available)
- if more than one algorithm is enabled (currently not possible since
  only one algorithm is present) the user then chooses the default one

Note:
- MAC80211_RC_PID is always enables for CONFIG_EMBEDDED=n

Technical changes:
- all selected algorithms get into the mac80211 module
- net/mac80211/Makefile can now become much less complicated
- support for rc80211_pid_algo.c being modular is no longer required
- this includes unexporting mesh_plink_broken

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/Kconfig

@@ -27,6 +27,14 @@ comment "QoS/HT support needs CONFIG_NETDEVICES_MULTIQUEUE"
 menu "Rate control algorithm selection"
 	depends on MAC80211 != n
 
+config MAC80211_RC_PID
+	bool "PID controller based rate control algorithm" if EMBEDDED
+	default y
+	---help---
+	  This option enables a TX rate control algorithm for
+	  mac80211 that uses a PID controller to select the TX
+	  rate.
+
 choice
 	prompt "Default rate control algorithm"
 	default MAC80211_RC_DEFAULT_PID
@@ -38,40 +46,19 @@ choice
 
 config MAC80211_RC_DEFAULT_PID
 	bool "PID controller based rate control algorithm"
-	select MAC80211_RC_PID
+	depends on MAC80211_RC_PID
 	---help---
 	  Select the PID controller based rate control as the
 	  default rate control algorithm. You should choose
 	  this unless you know what you are doing.
 
-config MAC80211_RC_DEFAULT_NONE
-	bool "No default algorithm"
-	depends on EMBEDDED
-	help
-	  Selecting this option will select no default algorithm
-	  and allow you to not build any. Do not choose this
-	  option unless you know your driver comes with another
-	  suitable algorithm.
 endchoice
 
-comment "Selecting 'y' for an algorithm will"
-comment "build the algorithm into mac80211."
-
 config MAC80211_RC_DEFAULT
 	string
 	default "pid" if MAC80211_RC_DEFAULT_PID
 	default ""
 
-config MAC80211_RC_PID
-	tristate "PID controller based rate control algorithm"
-	---help---
-	  This option enables a TX rate control algorithm for
-	  mac80211 that uses a PID controller to select the TX
-	  rate.
-
-	  Say Y or M unless you're sure you want to use a
-	  different rate control algorithm.
-
 endmenu
 
 config MAC80211_MESH

net/mac80211/Makefile

@@ -1,13 +1,5 @@
 obj-$(CONFIG_MAC80211) += mac80211.o
 
-# objects for PID algorithm
-rc80211_pid-y := rc80211_pid_algo.o
-rc80211_pid-$(CONFIG_MAC80211_DEBUGFS) += rc80211_pid_debugfs.o
-
-# build helper for PID algorithm
-rc-pid-y := $(rc80211_pid-y)
-rc-pid-m := rc80211_pid.o
-
 # mac80211 objects
 mac80211-y := \
 	main.o \
@@ -42,10 +34,8 @@ mac80211-$(CONFIG_MAC80211_MESH) += \
 	mesh_plink.o \
 	mesh_hwmp.o
 
+# objects for PID algorithm
+rc80211_pid-y := rc80211_pid_algo.o
+rc80211_pid-$(CONFIG_MAC80211_DEBUGFS) += rc80211_pid_debugfs.o
 
-# Build rate control algorithm(s)
-CFLAGS_rc80211_pid_algo.o += -DRC80211_PID_COMPILE
-mac80211-$(CONFIG_MAC80211_RC_PID) += $(rc-pid-$(CONFIG_MAC80211_RC_PID))
-
-# Modular rate algorithms are assigned to mac80211-m - make separate modules
-obj-m += $(mac80211-m)
+mac80211-$(CONFIG_MAC80211_RC_PID) += $(rc80211_pid-y)

net/mac80211/mesh_pathtbl.c

@@ -262,7 +262,6 @@ void mesh_plink_broken(struct sta_info *sta)
 	}
 	rcu_read_unlock();
 }
-EXPORT_SYMBOL(mesh_plink_broken);
 
 /**
  * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches

net/mac80211/rate.h

@@ -162,9 +162,7 @@ void rate_control_deinitialize(struct ieee80211_local *local);
 
 
 /* Rate control algorithms */
-#if defined(RC80211_PID_COMPILE) || \
-	(defined(CONFIG_MAC80211_RC_PID) && \
-	 !defined(CONFIG_MAC80211_RC_PID_MODULE))
+#ifdef CONFIG_MAC80211_RC_PID
 extern int rc80211_pid_init(void);
 extern void rc80211_pid_exit(void);
 #else

net/mac80211/rc80211_pid_algo.c

@@ -540,11 +540,6 @@ static struct rate_control_ops mac80211_rcpid = {
 #endif
 };
 
-MODULE_DESCRIPTION("PID controller based rate control algorithm");
-MODULE_AUTHOR("Stefano Brivio");
-MODULE_AUTHOR("Mattias Nissler");
-MODULE_LICENSE("GPL");
-
 int __init rc80211_pid_init(void)
 {
 	return ieee80211_rate_control_register(&mac80211_rcpid);
@@ -554,8 +549,3 @@ void rc80211_pid_exit(void)
 {
 	ieee80211_rate_control_unregister(&mac80211_rcpid);
 }
-
-#ifdef CONFIG_MAC80211_RC_PID_MODULE
-module_init(rc80211_pid_init);
-module_exit(rc80211_pid_exit);
-#endif