ARC: Remove explicit passing around of ECR

With ECR now part of pt_regs

* No need to propagate from lowest asm handlers as arg
* No need to save it in tsk->thread.cause_code
* Avoid bit chopping to access the bit-fields

More code consolidation, cleanup

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/kernel/traps.c b/arch/arc/kernel/traps.c
index 0471d9c9..e21692d 100644
--- a/arch/arc/kernel/traps.c
+++ b/arch/arc/kernel/traps.c
@@ -28,10 +28,9 @@
 	return;
 }
 
-void die(const char *str, struct pt_regs *regs, unsigned long address,
-	 unsigned long cause_reg)
+void die(const char *str, struct pt_regs *regs, unsigned long address)
 {
-	show_kernel_fault_diag(str, regs, address, cause_reg);
+	show_kernel_fault_diag(str, regs, address);
 
 	/* DEAD END */
 	__asm__("flag 1");
@@ -42,14 +41,13 @@
  *  -for user faults enqueues requested signal
  *  -for kernel, chk if due to copy_(to|from)_user, otherwise die()
  */
-static noinline int handle_exception(unsigned long cause, char *str,
-				     struct pt_regs *regs, siginfo_t *info)
+static noinline int
+handle_exception(const char *str, struct pt_regs *regs, siginfo_t *info)
 {
 	if (user_mode(regs)) {
 		struct task_struct *tsk = current;
 
 		tsk->thread.fault_address = (__force unsigned int)info->si_addr;
-		tsk->thread.cause_code = cause;
 
 		force_sig_info(info->si_signo, info, tsk);
 
@@ -58,14 +56,14 @@
 		if (fixup_exception(regs))
 			return 0;
 
-		die(str, regs, (unsigned long)info->si_addr, cause);
+		die(str, regs, (unsigned long)info->si_addr);
 	}
 
 	return 1;
 }
 
 #define DO_ERROR_INFO(signr, str, name, sicode) \
-int name(unsigned long cause, unsigned long address, struct pt_regs *regs) \
+int name(unsigned long address, struct pt_regs *regs) \
 {						\
 	siginfo_t info = {			\
 		.si_signo = signr,		\
@@ -73,7 +71,7 @@
 		.si_code  = sicode,		\
 		.si_addr = (void __user *)address,	\
 	};					\
-	return handle_exception(cause, str, regs, &info);\
+	return handle_exception(str, regs, &info);\
 }
 
 /*
@@ -90,11 +88,11 @@
 /*
  * Entry Point for Misaligned Data access Exception, for emulating in software
  */
-int do_misaligned_access(unsigned long cause, unsigned long address,
-			 struct pt_regs *regs, struct callee_regs *cregs)
+int do_misaligned_access(unsigned long address, struct pt_regs *regs,
+			 struct callee_regs *cregs)
 {
-	if (misaligned_fixup(address, regs, cause, cregs) != 0)
-		return do_misaligned_error(cause, address, regs);
+	if (misaligned_fixup(address, regs, cregs) != 0)
+		return do_misaligned_error(address, regs);
 
 	return 0;
 }
@@ -104,10 +102,9 @@
  * Entry point for miscll errors such as Nested Exceptions
  *  -Duplicate TLB entry is handled seperately though
  */
-void do_machine_check_fault(unsigned long cause, unsigned long address,
-			    struct pt_regs *regs)
+void do_machine_check_fault(unsigned long address, struct pt_regs *regs)
 {
-	die("Machine Check Exception", regs, address, cause);
+	die("Machine Check Exception", regs, address);
 }
 
 
@@ -120,23 +117,22 @@
  *  -1 used for software breakpointing (gdb)
  *  -2 used by kprobes
  */
-void do_non_swi_trap(unsigned long cause, unsigned long address,
-			struct pt_regs *regs)
+void do_non_swi_trap(unsigned long address, struct pt_regs *regs)
 {
-	unsigned int param = cause & 0xff;
+	unsigned int param = regs->ecr_param;
 
 	switch (param) {
 	case 1:
-		trap_is_brkpt(cause, address, regs);
+		trap_is_brkpt(address, regs);
 		break;
 
 	case 2:
-		trap_is_kprobe(param, address, regs);
+		trap_is_kprobe(address, regs);
 		break;
 
 	case 3:
 	case 4:
-		kgdb_trap(regs, param);
+		kgdb_trap(regs);
 		break;
 
 	default:
@@ -149,14 +145,14 @@
  *  -For a corner case, ARC kprobes implementation resorts to using
  *   this exception, hence the check
  */
-void do_insterror_or_kprobe(unsigned long cause,
-				       unsigned long address,
-				       struct pt_regs *regs)
+void do_insterror_or_kprobe(unsigned long address, struct pt_regs *regs)
 {
+	int rc;
+
 	/* Check if this exception is caused by kprobes */
-	if (notify_die(DIE_IERR, "kprobe_ierr", regs, address,
-		       cause, SIGILL) == NOTIFY_STOP)
+	rc = notify_die(DIE_IERR, "kprobe_ierr", regs, address, 0, SIGILL);
+	if (rc == NOTIFY_STOP)
 		return;
 
-	insterror_is_error(cause, address, regs);
+	insterror_is_error(address, regs);
 }