net: Add network task affinity config

This patch adds a default network tasks CPU affinity configuration
option. The network drivers have the option to create their own
daemon tasks with a custom CPU affinity set, or rely on the
default set.

cpukit/libnetworking/rtems/rtems_bsdnet.h

@@ -11,6 +11,7 @@ extern "C" {
 #endif
 
 #include <rtems.h>
+#include <sys/cpuset.h>
 
 /*
  *  If this file is included from inside the Network Stack proper or
@@ -181,6 +182,14 @@ struct rtems_bsdnet_config {
 	 */
 	unsigned long		tcp_tx_buf_size;
 	unsigned long		tcp_rx_buf_size;
+
+	/*
+	 * Default Network Tasks CPU Affinity
+	 */
+#ifdef RTEMS_SMP
+	const cpu_set_t		*network_task_cpuset;
+	size_t			network_task_cpuset_size;
+#endif
 };
 
 /*

cpukit/libnetworking/rtems/rtems_bsdnet_internal.h

@@ -157,6 +157,18 @@ rtems_id rtems_bsdnet_newproc (
   void  *arg
 );
 
+#ifdef RTEMS_SMP
+/* As rtems_bsdnet_newproc() but with ability to set CPU affinity too */
+rtems_id rtems_bsdnet_newproc_affinity (
+  char  *name,
+  int   stacksize,
+  void  (*entry)(void *),
+  void  *arg,
+  const cpu_set_t *set,
+  const size_t setsize
+);
+#endif
+
 rtems_status_code rtems_bsdnet_event_receive (
   rtems_event_set  event_in,
   rtems_option     option_set,

cpukit/libnetworking/rtems/rtems_glue.c

@@ -56,6 +56,10 @@ Semaphore_Control   *the_networkSemaphore;
 #endif
 static rtems_id networkDaemonTid;
 static uint32_t   networkDaemonPriority;
+#ifdef RTEMS_SMP
+static const cpu_set_t *networkDaemonCpuset = 0;
+static size_t          networkDaemonCpusetSize = 0;
+#endif
 static void networkDaemon (void *task_argument);
 
 /*
@@ -280,6 +284,14 @@ rtems_bsdnet_initialize (void)
 	else
 		networkDaemonPriority = rtems_bsdnet_config.network_task_priority;
 
+	/*
+	 * Default network task CPU affinity
+	 */
+#ifdef RTEMS_SMP
+	networkDaemonCpuset = rtems_bsdnet_config.network_task_cpuset;
+	networkDaemonCpusetSize = rtems_bsdnet_config.network_task_cpuset_size;
+#endif
+
 	/*
 	 * Set the memory allocation limits
 	 */
@@ -660,11 +672,25 @@ taskEntry (rtems_task_argument arg)
 	rtems_panic ("Network task returned!\n");
 }
 
+
 /*
  * Start a network task
  */
+#ifdef RTEMS_SMP
 rtems_id
 rtems_bsdnet_newproc (char *name, int stacksize, void(*entry)(void *), void *arg)
+{
+	return rtems_bsdnet_newproc_affinity( name, stacksize, entry, arg,
+		networkDaemonCpuset, networkDaemonCpusetSize );
+}
+
+rtems_id
+rtems_bsdnet_newproc_affinity (char *name, int stacksize, void(*entry)(void *),
+    void *arg, const cpu_set_t *set, const size_t setsize)
+#else
+rtems_id
+rtems_bsdnet_newproc (char *name, int stacksize, void(*entry)(void *), void *arg)
+#endif
 {
 	struct newtask *t;
 	char nm[4];
@@ -681,6 +707,14 @@ rtems_bsdnet_newproc (char *name, int stacksize, void(*entry)(void *), void *arg
 	if (sc != RTEMS_SUCCESSFUL)
 		rtems_panic ("Can't create network daemon `%s': `%s'\n", name, rtems_status_text (sc));
 
+#ifdef RTEMS_SMP
+	/*
+	 * Use the default affinity or use the user-provided CPU set
+	 */
+	if ( set != 0 )
+		rtems_task_set_affinity( tid, setsize, set );
+#endif
+
 	/*
 	 * Set up task arguments
 	 */