Fix handling of external interrupts: we weren't calling ast() when

interrupting user mode. The net effect of this bug is that a clock
interrupt does not cause rescheduling and processes are not
preempted. It only takes a "while (1);" to render the machine
useless.

This bug was introduced by the context changes and EPC syscall code.
Handling of ASTs was moved to C for clarity and ease of maintenance,
but was not added for the external interrupt case.

This needs to be revisited. We now have calls to do_ast() in trap(),
break_syscall() and ivt_External_Interrupt(). A single call in
exception_restore covers these 3 places without duplication. This
is where we handled ASTs prior to the overhaul, except that the
meat has been moved to do_ast(), a C function. This was the goal
to begin with.

Pointy hat: marcel

2 files changed, 51 insertions, 14 deletions

diff --git a/sys/ia64/ia64/exception.S b/sys/ia64/ia64/exception.S
index 795ec93..feffb65 100644
--- a/sys/ia64/ia64/exception.S
+++ b/sys/ia64/ia64/exception.S
@@ -1150,28 +1150,65 @@ IVT_ENTRY(External_Interrupt, 0x3000)
 	br.sptk		exception_save
 	;;
 }
-{	.mmb
-2:	alloc	r14=ar.pfs,0,0,2,0	// make a frame for calling with
-	add	out1=16,sp
-	nop	0
-}
-
-3:	mov	out0=cr.ivr		// find interrupt vector
+	alloc		r14=ar.pfs,0,0,2,0
 	;;
-	cmp.eq	p15,p0=15,out0		// check for spurious vector number
-(p15)	br.dpnt.few exception_restore	// if spurious, we are done
+1:
+{	.mii
+	mov		out0=cr.ivr	// Get interrupt vector
+	add		out1=16,sp
 	;;
-	ssm	psr.i			// re-enable interrupts
+	cmp.eq		p15,p0=15,out0	// check for spurious vector number
+}
+{	.mbb
+	ssm		psr.i		// re-enable interrupts
+(p15)	br.dpnt.few 2f			// if spurious, we are done
 	br.call.sptk.many rp=interrupt	// call high-level handler
 	;;
-	rsm	psr.i			// disable interrupts
+}
+{	.mmi
+	rsm		psr.i		// disable interrupts
 	;;
 	srlz.d
-	mov	cr.eoi=r0		// and ack the interrupt
+	nop		0
+}
+{	.mmi
+	mov		cr.eoi=r0	// ack the interrupt
 	;;
 	srlz.d
-	br.sptk.few 3b			// loop for more
+	nop		0
+}
+{	.mfb
+	nop		0
+	nop		0
+	br.sptk		1b		// loop for more
 	;;
+}
+2:
+{	.mmi
+	add		r14=16+TF_SPECIAL_IIP,sp
+	;;
+	ld8		r14=[r14]
+	add		out0=16,sp
+	;;
+}
+{	.mii
+	nop		0
+	extr.u		r14=r14,61,3
+	;;
+	cmp.ge		p15,p0=5,r14
+}
+{	.mfb
+	nop		0
+	nop		0
+(p15)	br.call.sptk	rp=do_ast
+	;;
+}
+{	.mfb
+	nop		0
+	nop		0
+	br.sptk		exception_restore
+	;;
+}
 IVT_END(External_Interrupt)
 
 IVT_ENTRY(Reserved_3400, 0x3400)
diff --git a/sys/ia64/ia64/genassym.c b/sys/ia64/ia64/genassym.c
index 302c441..0c0ec81 100644
--- a/sys/ia64/ia64/genassym.c
+++ b/sys/ia64/ia64/genassym.c
@@ -112,7 +112,7 @@ ASSYM(TD_PCB,		offsetof(struct thread, td_pcb));
 ASSYM(TDF_ASTPENDING,	TDF_ASTPENDING);
 ASSYM(TDF_NEEDRESCHED,	TDF_NEEDRESCHED);
 
-ASSYM(TF_SPECIAL_NDIRTY, offsetof(struct trapframe, tf_special.ndirty));
+ASSYM(TF_SPECIAL_IIP, offsetof(struct trapframe, tf_special.iip));
 
 ASSYM(UC_MCONTEXT,	offsetof(ucontext_t, uc_mcontext));