Allocate a stack for thread0 and switch to it before calling

mi_startup(). This frees up kstack for static PAL/SAL calls
and double-fault handling.

3 files changed, 34 insertions, 21 deletions

diff --git a/sys/ia64/ia64/locore.S b/sys/ia64/ia64/locore.S
index e52c76a..6b1d8f1 100644
--- a/sys/ia64/ia64/locore.S
+++ b/sys/ia64/ia64/locore.S
@@ -110,6 +110,28 @@ ENTRY_NOPROFILE(__start, 1)
 	br.call.sptk.many rp=ia64_init
 	;;
 }
+	// We have the new bspstore in r8 and the new sp in r9.
+	// Switch onto the new stack and call mi_startup().
+{
+	mov	ar.rsc = 0
+	;;
+	mov	ar.bspstore = r8
+	mov	sp = r9
+	;;
+}
+{
+	loadrs
+	;;
+	mov	ar.rsc = 3
+	nop	0
+	;;
+}
+{
+	nop	0
+	nop	0
+	br.call.sptk.many rp=mi_startup
+	;;
+}
 	/* NOTREACHED */
 1:	br.cond.sptk.few 1b
 END(__start)
diff --git a/sys/ia64/ia64/machdep.c b/sys/ia64/ia64/machdep.c
index e6e5d7f..0c28f2b 100644
--- a/sys/ia64/ia64/machdep.c
+++ b/sys/ia64/ia64/machdep.c
@@ -109,8 +109,6 @@ u_int64_t pa_bootinfo;
 struct bootinfo bootinfo;
 
 struct pcpu pcpu0;
-extern char kstack[]; 
-vm_offset_t proc0kstack;
 
 extern u_int64_t kernel_text[], _end[];
 
@@ -153,8 +151,6 @@ vm_paddr_t phys_avail[PHYSMAP_SIZE + 2];
 /* must be 2 less so 0 0 can signal end of chunks */
 #define PHYS_AVAIL_ARRAY_END ((sizeof(phys_avail) / sizeof(vm_offset_t)) - 2)
 
-void mi_startup(void);		/* XXX should be in a MI header */
-
 struct kva_md_info kmi;
 
 #define	Mhz	1000000L
@@ -550,9 +546,10 @@ calculate_frequencies(void)
 	}
 }
 
-void
+struct ia64_init_return
 ia64_init(void)
 {
+	struct ia64_init_return ret;
 	int phys_avail_cnt;
 	vm_offset_t kernstart, kernend;
 	vm_offset_t kernstartpfn, kernendpfn, pfn0, pfn1;
@@ -793,8 +790,7 @@ ia64_init(void)
 	/*
 	 * Init mapping for kernel stack for proc 0
 	 */
-	proc0kstack = (vm_offset_t)kstack;
-	thread0.td_kstack = proc0kstack;
+	thread0.td_kstack = pmap_steal_memory(KSTACK_PAGES * PAGE_SIZE);
 	thread0.td_kstack_pages = KSTACK_PAGES;
 
 	mutex_init();
@@ -831,19 +827,9 @@ ia64_init(void)
 	ia64_set_tpr(0);
 	ia64_srlz_d();
 
-	/*
-	 * Save our current context so that we have a known (maybe even
-	 * sane) context as the initial context for new threads that are
-	 * forked from us. If any of those threads (including thread0)
-	 * does something wrong, we may be lucky and return here where
-	 * we're ready for them with a nice panic.
-	 */
-	if (!savectx(thread0.td_pcb))
-		mi_startup();
-
-	/* We should not get here. */
-	panic("ia64_init: Whooaa there!");
-	/* NOTREACHED */
+	ret.bspstore = thread0.td_pcb->pcb_special.bspstore;
+	ret.sp = thread0.td_pcb->pcb_special.sp;
+	return (ret);
 }
 
 __volatile void *
diff --git a/sys/ia64/include/md_var.h b/sys/ia64/include/md_var.h
index 738fefa..0520e57 100644
--- a/sys/ia64/include/md_var.h
+++ b/sys/ia64/include/md_var.h
@@ -71,6 +71,11 @@ struct reg;
 struct thread;
 struct trapframe;
 
+struct ia64_init_return {
+	uint64_t	bspstore;
+	uint64_t	sp;
+};
+
 void	busdma_swi(void);
 int	copyout_regstack(struct thread *, uint64_t *, uint64_t *);
 void	cpu_mp_add(u_int, u_int, u_int);
@@ -82,7 +87,7 @@ int	ia64_flush_dirty(struct thread *, struct _special *);
 uint64_t ia64_get_hcdp(void);
 int	ia64_highfp_drop(struct thread *);
 int	ia64_highfp_save(struct thread *);
-void	ia64_init(void);
+struct ia64_init_return ia64_init(void);
 void	ia64_probe_sapics(void);
 void	interrupt(struct trapframe *);
 void	map_gateway_page(void);