/*
* Finish a fork operation, with process p2 nearly set up.
* Copy and update the pcb and trap frame, making the child ready to run.
*
* Rig the child's kernel stack so that it will start out in
* proc_trampoline() and call child_return() with p2 as an
* argument. This causes the newly-created child process to go
* directly to user level with an apparent return value of 0 from
* fork(), while the parent process returns normally.
*
* p1 is the process being forked; if p1 == &proc0, we are creating
* a kernel thread, and the return path and argument are specified with
* `func' and `arg'.
*
* If an alternate user-level stack is requested (with non-zero values
* in both the stack and stacksize args), set up the user stack pointer
* accordingly.
*/
void
cpu_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize,
void (*func)(void *), void *arg)
{
struct pcb *pcb1, *pcb2;
struct trapframe *tf;
pcb1 = lwp_getpcb(l1);
pcb2 = lwp_getpcb(l2);
/* Copy pcb from lwp l1 to l2. */
if (l1 == curlwp) {
/* Sync the PCB before we copy it. */
savectx(pcb1);
#if 0
/* ia64_highfp_save(???); */
#endif
} else {
KASSERT(l1 == &lwp0);
}
*pcb2 = *pcb1;
l2->l_md.md_flags = l1->l_md.md_flags;
l2->l_md.md_tf = (struct trapframe *)(uvm_lwp_getuarea(l2) + USPACE) - 1;
l2->l_md.md_astpending = 0;
/*
* Copy the trapframe.
*/
tf = l2->l_md.md_tf;
*tf = *l1->l_md.md_tf;
/*
* If specified, give the child a different stack.
*/
if (stack != NULL)
tf->tf_special.sp = (unsigned long)stack + stacksize;
/* Set-up the return values as expected by the fork() libc stub. */
if (tf->tf_special.psr & IA64_PSR_IS) {
tf->tf_scratch.gr8 = 0;
tf->tf_scratch.gr10 = 1;
} else {
tf->tf_scratch.gr8 = 0;
tf->tf_scratch.gr9 = 1;
tf->tf_scratch.gr10 = 0;
}
tf->tf_scratch.gr2 = (unsigned long)FDESC_FUNC(func);
tf->tf_scratch.gr3 = (unsigned long)arg;
pcb2->pcb_special.sp = (unsigned long)tf - 16;
pcb2->pcb_special.rp = (unsigned long)FDESC_FUNC(lwp_trampoline);
pcb2->pcb_special.pfs = 0;
return;
}
void
cpu_set_upcall(struct thread *td, struct thread *td0)
{
struct pcb *pcb;
struct trapframe *tf;
ia64_highfp_save(td0);
tf = td->td_frame;
KASSERT(tf != NULL, ("foo"));
bcopy(td0->td_frame, tf, sizeof(*tf));
tf->tf_length = sizeof(struct trapframe);
tf->tf_flags = FRAME_SYSCALL;
tf->tf_special.ndirty = 0;
tf->tf_special.bspstore &= ~0x1ffUL;
tf->tf_scratch.gr8 = 0;
tf->tf_scratch.gr9 = 1;
tf->tf_scratch.gr10 = 0;
pcb = td->td_pcb;
KASSERT(pcb != NULL, ("foo"));
bcopy(td0->td_pcb, pcb, sizeof(*pcb));
pcb->pcb_special.bspstore = td->td_kstack;
pcb->pcb_special.pfs = 0;
pcb->pcb_current_pmap = vmspace_pmap(td->td_proc->p_vmspace);
pcb->pcb_special.sp = (uintptr_t)tf - 16;
pcb->pcb_special.rp = FDESC_FUNC(fork_trampoline);
cpu_set_fork_handler(td, (void (*)(void*))fork_return, td);
/* Setup to release the spin count in fork_exit(). */
td->td_md.md_spinlock_count = 1;
td->td_md.md_saved_intr = 1;
}
