[IA64] Restore registers in the stack on INIT

Registers are not saved anywhere when INIT comes during fsys mode and
we cannot know what happened when we investigate vmcore captured by
kdump. This patch adds new function finish_pt_regs() so registers can
be saved in such a case.
Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/mca.c

@@ -887,6 +887,60 @@ ia64_mca_modify_comm(const struct task_struct *previous_current)
 	memcpy(current->comm, comm, sizeof(current->comm));
 }
 
+static void
+finish_pt_regs(struct pt_regs *regs, const pal_min_state_area_t *ms,
+		unsigned long *nat)
+{
+	const u64 *bank;
+
+	/* If ipsr.ic then use pmsa_{iip,ipsr,ifs}, else use
+	 * pmsa_{xip,xpsr,xfs}
+	 */
+	if (ia64_psr(regs)->ic) {
+		regs->cr_iip = ms->pmsa_iip;
+		regs->cr_ipsr = ms->pmsa_ipsr;
+		regs->cr_ifs = ms->pmsa_ifs;
+	} else {
+		regs->cr_iip = ms->pmsa_xip;
+		regs->cr_ipsr = ms->pmsa_xpsr;
+		regs->cr_ifs = ms->pmsa_xfs;
+	}
+	regs->pr = ms->pmsa_pr;
+	regs->b0 = ms->pmsa_br0;
+	regs->ar_rsc = ms->pmsa_rsc;
+	copy_reg(&ms->pmsa_gr[1-1], ms->pmsa_nat_bits, &regs->r1, nat);
+	copy_reg(&ms->pmsa_gr[2-1], ms->pmsa_nat_bits, &regs->r2, nat);
+	copy_reg(&ms->pmsa_gr[3-1], ms->pmsa_nat_bits, &regs->r3, nat);
+	copy_reg(&ms->pmsa_gr[8-1], ms->pmsa_nat_bits, &regs->r8, nat);
+	copy_reg(&ms->pmsa_gr[9-1], ms->pmsa_nat_bits, &regs->r9, nat);
+	copy_reg(&ms->pmsa_gr[10-1], ms->pmsa_nat_bits, &regs->r10, nat);
+	copy_reg(&ms->pmsa_gr[11-1], ms->pmsa_nat_bits, &regs->r11, nat);
+	copy_reg(&ms->pmsa_gr[12-1], ms->pmsa_nat_bits, &regs->r12, nat);
+	copy_reg(&ms->pmsa_gr[13-1], ms->pmsa_nat_bits, &regs->r13, nat);
+	copy_reg(&ms->pmsa_gr[14-1], ms->pmsa_nat_bits, &regs->r14, nat);
+	copy_reg(&ms->pmsa_gr[15-1], ms->pmsa_nat_bits, &regs->r15, nat);
+	if (ia64_psr(regs)->bn)
+		bank = ms->pmsa_bank1_gr;
+	else
+		bank = ms->pmsa_bank0_gr;
+	copy_reg(&bank[16-16], ms->pmsa_nat_bits, &regs->r16, nat);
+	copy_reg(&bank[17-16], ms->pmsa_nat_bits, &regs->r17, nat);
+	copy_reg(&bank[18-16], ms->pmsa_nat_bits, &regs->r18, nat);
+	copy_reg(&bank[19-16], ms->pmsa_nat_bits, &regs->r19, nat);
+	copy_reg(&bank[20-16], ms->pmsa_nat_bits, &regs->r20, nat);
+	copy_reg(&bank[21-16], ms->pmsa_nat_bits, &regs->r21, nat);
+	copy_reg(&bank[22-16], ms->pmsa_nat_bits, &regs->r22, nat);
+	copy_reg(&bank[23-16], ms->pmsa_nat_bits, &regs->r23, nat);
+	copy_reg(&bank[24-16], ms->pmsa_nat_bits, &regs->r24, nat);
+	copy_reg(&bank[25-16], ms->pmsa_nat_bits, &regs->r25, nat);
+	copy_reg(&bank[26-16], ms->pmsa_nat_bits, &regs->r26, nat);
+	copy_reg(&bank[27-16], ms->pmsa_nat_bits, &regs->r27, nat);
+	copy_reg(&bank[28-16], ms->pmsa_nat_bits, &regs->r28, nat);
+	copy_reg(&bank[29-16], ms->pmsa_nat_bits, &regs->r29, nat);
+	copy_reg(&bank[30-16], ms->pmsa_nat_bits, &regs->r30, nat);
+	copy_reg(&bank[31-16], ms->pmsa_nat_bits, &regs->r31, nat);
+}
+
 /* On entry to this routine, we are running on the per cpu stack, see
  * mca_asm.h.  The original stack has not been touched by this event.  Some of
  * the original stack's registers will be in the RBS on this stack.  This stack
@@ -921,7 +975,6 @@ ia64_mca_modify_original_stack(struct pt_regs *regs,
 	u64 r12 = ms->pmsa_gr[12-1], r13 = ms->pmsa_gr[13-1];
 	u64 ar_bspstore = regs->ar_bspstore;
 	u64 ar_bsp = regs->ar_bspstore + (loadrs >> 16);
-	const u64 *bank;
 	const char *msg;
 	int cpu = smp_processor_id();
 
@@ -1024,54 +1077,9 @@ ia64_mca_modify_original_stack(struct pt_regs *regs,
 	p = (char *)r12 - sizeof(*regs);
 	old_regs = (struct pt_regs *)p;
 	memcpy(old_regs, regs, sizeof(*regs));
-	/* If ipsr.ic then use pmsa_{iip,ipsr,ifs}, else use
-	 * pmsa_{xip,xpsr,xfs}
-	 */
-	if (ia64_psr(regs)->ic) {
-		old_regs->cr_iip = ms->pmsa_iip;
-		old_regs->cr_ipsr = ms->pmsa_ipsr;
-		old_regs->cr_ifs = ms->pmsa_ifs;
-	} else {
-		old_regs->cr_iip = ms->pmsa_xip;
-		old_regs->cr_ipsr = ms->pmsa_xpsr;
-		old_regs->cr_ifs = ms->pmsa_xfs;
-	}
-	old_regs->pr = ms->pmsa_pr;
-	old_regs->b0 = ms->pmsa_br0;
 	old_regs->loadrs = loadrs;
-	old_regs->ar_rsc = ms->pmsa_rsc;
 	old_unat = old_regs->ar_unat;
-	copy_reg(&ms->pmsa_gr[1-1], ms->pmsa_nat_bits, &old_regs->r1, &old_unat);
-	copy_reg(&ms->pmsa_gr[2-1], ms->pmsa_nat_bits, &old_regs->r2, &old_unat);
-	copy_reg(&ms->pmsa_gr[3-1], ms->pmsa_nat_bits, &old_regs->r3, &old_unat);
-	copy_reg(&ms->pmsa_gr[8-1], ms->pmsa_nat_bits, &old_regs->r8, &old_unat);
-	copy_reg(&ms->pmsa_gr[9-1], ms->pmsa_nat_bits, &old_regs->r9, &old_unat);
-	copy_reg(&ms->pmsa_gr[10-1], ms->pmsa_nat_bits, &old_regs->r10, &old_unat);
-	copy_reg(&ms->pmsa_gr[11-1], ms->pmsa_nat_bits, &old_regs->r11, &old_unat);
-	copy_reg(&ms->pmsa_gr[12-1], ms->pmsa_nat_bits, &old_regs->r12, &old_unat);
-	copy_reg(&ms->pmsa_gr[13-1], ms->pmsa_nat_bits, &old_regs->r13, &old_unat);
-	copy_reg(&ms->pmsa_gr[14-1], ms->pmsa_nat_bits, &old_regs->r14, &old_unat);
-	copy_reg(&ms->pmsa_gr[15-1], ms->pmsa_nat_bits, &old_regs->r15, &old_unat);
-	if (ia64_psr(old_regs)->bn)
-		bank = ms->pmsa_bank1_gr;
-	else
-		bank = ms->pmsa_bank0_gr;
-	copy_reg(&bank[16-16], ms->pmsa_nat_bits, &old_regs->r16, &old_unat);
-	copy_reg(&bank[17-16], ms->pmsa_nat_bits, &old_regs->r17, &old_unat);
-	copy_reg(&bank[18-16], ms->pmsa_nat_bits, &old_regs->r18, &old_unat);
-	copy_reg(&bank[19-16], ms->pmsa_nat_bits, &old_regs->r19, &old_unat);
-	copy_reg(&bank[20-16], ms->pmsa_nat_bits, &old_regs->r20, &old_unat);
-	copy_reg(&bank[21-16], ms->pmsa_nat_bits, &old_regs->r21, &old_unat);
-	copy_reg(&bank[22-16], ms->pmsa_nat_bits, &old_regs->r22, &old_unat);
-	copy_reg(&bank[23-16], ms->pmsa_nat_bits, &old_regs->r23, &old_unat);
-	copy_reg(&bank[24-16], ms->pmsa_nat_bits, &old_regs->r24, &old_unat);
-	copy_reg(&bank[25-16], ms->pmsa_nat_bits, &old_regs->r25, &old_unat);
-	copy_reg(&bank[26-16], ms->pmsa_nat_bits, &old_regs->r26, &old_unat);
-	copy_reg(&bank[27-16], ms->pmsa_nat_bits, &old_regs->r27, &old_unat);
-	copy_reg(&bank[28-16], ms->pmsa_nat_bits, &old_regs->r28, &old_unat);
-	copy_reg(&bank[29-16], ms->pmsa_nat_bits, &old_regs->r29, &old_unat);
-	copy_reg(&bank[30-16], ms->pmsa_nat_bits, &old_regs->r30, &old_unat);
-	copy_reg(&bank[31-16], ms->pmsa_nat_bits, &old_regs->r31, &old_unat);
+	finish_pt_regs(old_regs, ms, &old_unat);
 
 	/* Next stack a struct switch_stack.  mca_asm.S built a partial
 	 * switch_stack, copy it and fill in the blanks using pt_regs and
@@ -1141,6 +1149,8 @@ ia64_mca_modify_original_stack(struct pt_regs *regs,
 no_mod:
 	mprintk(KERN_INFO "cpu %d, %s %s, original stack not modified\n",
 			smp_processor_id(), type, msg);
+	old_unat = regs->ar_unat;
+	finish_pt_regs(regs, ms, &old_unat);
 	return previous_current;
 }