clear-pkgs-linux-iot-lts2018/0689-Debug-Add-register-dump.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: "Duan, YayongX" <yayongx.duan@intel.com>
Date: Wed, 27 Dec 2017 12:26:06 +0800
Subject: [PATCH] Debug: Add register dump

Store CPU registers during cpu stop in order to get them with ramdump.

Signed-off-by: Emmanuel Berthier <emmanuel.berthier@intel.com>
Signed-off-by: Duan, YayongX
---
 arch/x86/kernel/smp.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index b2b87b91f336..5e8ebdfd4456 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -117,6 +117,19 @@
 static atomic_t stopping_cpu = ATOMIC_INIT(-1);
 static bool smp_no_nmi_ipi = false;
 
+static DEFINE_PER_CPU(struct pt_regs, cpu_regs);
+
+/* Store regs of this CPU for RAM dump decoding help */
+static inline void store_regs(struct pt_regs *regs)
+{
+        struct pt_regs *print_regs;
+       print_regs = &get_cpu_var(cpu_regs);
+       crash_setup_regs(print_regs, regs);
+
+       /* Flush CPU cache */
+       wbinvd();
+}
+
 /*
  * this function sends a 'reschedule' IPI to another CPU.
  * it goes straight through and wastes no time serializing
@@ -163,6 +176,7 @@ static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs)
 	if (raw_smp_processor_id() == atomic_read(&stopping_cpu))
 		return NMI_HANDLED;
 
+	store_regs(regs);
 	cpu_emergency_vmxoff();
 	stop_this_cpu(NULL);
 
@@ -173,9 +187,10 @@ static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs)
  * this function calls the 'stop' function on all other CPUs in the system.
  */
 
-asmlinkage __visible void smp_reboot_interrupt(void)
+__visible void smp_reboot_interrupt(struct pt_regs *regs)
 {
 	ipi_entering_ack_irq();
+	store_regs(regs);
 	cpu_emergency_vmxoff();
 	stop_this_cpu(NULL);
 	irq_exit();
@@ -255,6 +270,7 @@ static void native_stop_other_cpus(int wait)
 			udelay(1);
 	}
 
+	store_regs(NULL);
 	local_irq_save(flags);
 	disable_local_APIC();
 	mcheck_cpu_clear(this_cpu_ptr(&cpu_info));
-- 
https://clearlinux.org