sh: Add a few missing irqflags tracing markers.

save_regs contains an SR modification without an irqflags annotation,
which resulted in a missing TRACE_IRQS_OFF in the interrupt exception
path on SH-3/SH4.

I've also moved the TRACE_IRQS_OFF/ON annotation when returning from the
interrupt to just before we call __restore_all. This seems like the most
logical place to put this because the annotation is for when we restore
the SR register so we should delay the annotation until as last as
possible.

We were also missing a TRACE_IRQS_OFF in resume_kernel when
CONFIG_PREEMPT is enabled.

The end result is that this fixes up the lockdep engine debugging support
with CONFIG_PREEMPT enabled on all SH-3/4 parts.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/cpu/sh3/entry.S

@@ -508,6 +508,14 @@ ENTRY(handle_interrupt)
 	bsr	save_regs	! needs original pr value in k3
 	 mov	#-1, k2		! default vector kept in k2
 
+	stc	sr, r0	! get status register
+	shlr2	r0
+	and	#0x3c, r0
+	cmp/eq	#0x3c, r0
+	bf	9f
+	TRACE_IRQS_OFF
+9:
+
 	! Setup return address and jump to do_IRQ
 	mov.l	4f, r9		! fetch return address
 	lds	r9, pr		! put return address in pr

arch/sh/kernel/entry-common.S

@@ -77,15 +77,6 @@ ENTRY(ret_from_irq)
 	!
 	mov	#OFF_SR, r0
 	mov.l	@(r0,r15), r0	! get status register
-
-	shlr2	r0
-	and	#0x3c, r0
-	cmp/eq	#0x3c, r0
-	bt	9f
-	TRACE_IRQS_ON
-9:
-	mov	#OFF_SR, r0
-	mov.l	@(r0,r15), r0	! get status register
 	shll	r0
 	shll	r0		! kernel space?
 	get_current_thread_info r8, r0
@@ -96,6 +87,7 @@ ENTRY(ret_from_irq)
 	 nop
 ENTRY(resume_kernel)
 	cli
+	TRACE_IRQS_OFF
 	mov.l	@(TI_PRE_COUNT,r8), r0	! current_thread_info->preempt_count
 	tst	r0, r0
 	bf	noresched
@@ -213,12 +205,25 @@ syscall_trace_entry:
 	 mov.l	r0, @(OFF_R0,r15)	! Return value
 
 __restore_all:
-	mov.l	1f, r0
+	mov	#OFF_SR, r0
+	mov.l	@(r0,r15), r0	! get status register
+
+	shlr2	r0
+	and	#0x3c, r0
+	cmp/eq	#0x3c, r0
+	bt	1f
+	TRACE_IRQS_ON
+	bra	2f
+	 nop
+1:
+	TRACE_IRQS_OFF
+2:
+	mov.l	3f, r0
 	jmp	@r0
 	 nop
 
 	.align	2
-1:	.long	restore_all
+3:	.long	restore_all
 
 	.align	2
 syscall_badsys:			! Bad syscall number