Update comments for the MD functions managing contexts for new

threads, to make it less confusing and using modern kernel terms.

Rename the functions to reflect current use of the functions, instead
of the historic KSE conventions:
  cpu_set_fork_handler -> cpu_fork_kthread_handler (for kthreads)
  cpu_set_upcall -> cpu_copy_thread (for forks)
  cpu_set_upcall_kse -> cpu_set_upcall (for new threads creation)

Reviewed by:	jhb (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Approved by:	re (hrs)
Differential revision:	https://reviews.freebsd.org/D6731

1 files changed, 13 insertions, 20 deletions

diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c
index 65f3a0a..a73b60d 100644
--- a/sys/i386/i386/vm_machdep.c
+++ b/sys/i386/i386/vm_machdep.c
@@ -324,10 +324,7 @@ cpu_fork(td1, p2, td2, flags)
  * This is needed to make kernel threads stay in kernel mode.
  */
 void
-cpu_set_fork_handler(td, func, arg)
-	struct thread *td;
-	void (*func)(void *);
-	void *arg;
+cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg)
 {
 	/*
 	 * Note that the trap frame follows the args, so the function
@@ -458,14 +455,14 @@ cpu_set_syscall_retval(struct thread *td, int error)
 }
 
 /*
- * Initialize machine state (pcb and trap frame) for a new thread about to
- * upcall. Put enough state in the new thread's PCB to get it to go back 
- * userret(), where we can intercept it again to set the return (upcall)
- * Address and stack, along with those from upcals that are from other sources
- * such as those generated in thread_userret() itself.
+ * Initialize machine state, mostly pcb and trap frame for a new
+ * thread, about to return to userspace.  Put enough state in the new
+ * thread's PCB to get it to go back to the fork_return(), which
+ * finalizes the thread state and handles peculiarities of the first
+ * return to userspace for the new thread.
  */
 void
-cpu_set_upcall(struct thread *td, struct thread *td0)
+cpu_copy_thread(struct thread *td, struct thread *td0)
 {
 	struct pcb *pcb2;
 
@@ -527,13 +524,12 @@ cpu_set_upcall(struct thread *td, struct thread *td0)
 }
 
 /*
- * Set that machine state for performing an upcall that has to
- * be done in thread_userret() so that those upcalls generated
- * in thread_userret() itself can be done as well.
+ * Set that machine state for performing an upcall that starts
+ * the entry function with the given argument.
  */
 void
-cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
-	stack_t *stack)
+cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg,
+    stack_t *stack)
 {
 
 	/* 
@@ -546,7 +542,7 @@ cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
 	cpu_thread_clean(td);
 
 	/*
-	 * Set the trap frame to point at the beginning of the uts
+	 * Set the trap frame to point at the beginning of the entry
 	 * function.
 	 */
 	td->td_frame->tf_ebp = 0; 
@@ -554,10 +550,7 @@ cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
 	    (((int)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
 	td->td_frame->tf_eip = (int)entry;
 
-	/*
-	 * Pass the address of the mailbox for this kse to the uts
-	 * function as a parameter on the stack.
-	 */
+	/* Pass the argument to the entry point. */
 	suword((void *)(td->td_frame->tf_esp + sizeof(void *)),
 	    (int)arg);
 }