Support task_wait / task_wait_tid syscalls:

    - Add task_end2 syscall to allow pthread_exit-like retval.
    - Add/maintain task states.
    - Create task parent/child tracking tree.
    - Add task_detach function.
    - Implement wait syscalls.

Make task_exec caller the parent of spawned task:

    Previously the task_exec call caused a message to the
    VFS task, which called task_create and returned the tid
    in response to the message.  This causes the parent of
    the spawned task to appear to be the VFS task.

    Modify task_exec / VFS handling to instead return the
    entry point address on the message and have task_exec call
    task_create directly itself.

Change-Id: I6b6796f45875de37b1ab01e7596639b073820b95
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/443
Tested-by: Jenkins Server
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>
Reviewed-by: Andrew J. Geissler <andrewg@us.ibm.com>

1 files changed, 11 insertions, 5 deletions

diff --git a/src/kernel/kernel.C b/src/kernel/kernel.C
index 46ca11342..557a1c81c 100644
--- a/src/kernel/kernel.C
+++ b/src/kernel/kernel.C
@@ -43,7 +43,7 @@ extern uint64_t kernel_other_thread_spinlock;
 class Kernel
 {
     public:
-	void cppBootstrap();	
+	void cppBootstrap();
 	void memBootstrap();
 	void cpuBootstrap();
 	void inittaskBootstrap();
@@ -56,19 +56,22 @@ extern "C"
 int main()
 {
     printk("Booting %s kernel...\n\n", "Hostboot");
-    
+
+    // Erase task-pointer so that TaskManager::getCurrentTask() returns NULL.
+    setSPRG3(NULL);
+
     Kernel& kernel = Singleton<Kernel>::instance();
     kernel.cppBootstrap();
-    kernel.memBootstrap(); 
+    kernel.memBootstrap();
     kernel.cpuBootstrap();
 
     kernel.inittaskBootstrap();
-    
+
     // Ready to let the other CPUs go.
     lwsync();
     kernel_other_thread_spinlock = 1;
 
-    kernel_dispatch_task(); // no return.    
+    kernel_dispatch_task(); // no return.
     while(1);
     return 0;
 }
@@ -76,6 +79,9 @@ int main()
 extern "C"
 int smp_slave_main(cpu_t* cpu)
 {
+    // Erase task-pointer so that TaskManager::getCurrentTask() returns NULL.
+    setSPRG3(NULL);
+
     CpuManager::init_slave_smp(cpu);
     VmmManager::init_slb();
     cpu->scheduler->setNextRunnable();