ux500: Start crash dump through SW reset

When using kexec/kdump without an crash kernel image loaded:

* clean the caches and write the crash_notes

* perform a restart

ST-Ericsson ID: 340331

Change-Id: I1ae34ed2b5e43da4849650a8a7d2f1e453dcbe93
Signed-off-by: Per Fransson <per.xx.fransson@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/32678
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
Reviewed-by: Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com>

5 files changed, 36 insertions, 4 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index d40d2599269..3b1c685136f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1859,6 +1859,13 @@ config KEXEC
 	  initially work for you.  It may help to enable device hotplugging
 	  support.
 
+config CRASH_SWRESET
+	bool "Perform a software reset at a panic (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
+	depends on KEXEC
+	help
+	  If no crash kernel has been loaded, perform a SW reset as plan B.
+
 config ATAGS_PROC
 	bool "Export atags in procfs"
 	depends on KEXEC
diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c
index ae1d73a15d3..2a9c3430115 100644
--- a/arch/arm/kernel/machine_kexec.c
+++ b/arch/arm/kernel/machine_kexec.c
@@ -123,3 +123,13 @@ void machine_kexec(struct kimage *image)
 	flush_cache_all();
 	cpu_reset(reboot_code_buffer_phys);
 }
+
+void machine_crash_swreset(void)
+{
+	printk(KERN_INFO "Software reset on panic!\n");
+
+	flush_cache_all();
+	outer_flush_all();
+	outer_disable();
+	arm_pm_restart(0, NULL);
+}
diff --git a/arch/arm/mach-ux500/reboot_reasons.c b/arch/arm/mach-ux500/reboot_reasons.c
index c78a11c21ea..93afab59537 100644
--- a/arch/arm/mach-ux500/reboot_reasons.c
+++ b/arch/arm/mach-ux500/reboot_reasons.c
@@ -35,9 +35,15 @@ u16 reboot_reason_code(const char *cmd)
 {
 	int i;
 
-	if (cmd == NULL)
-		/* normal reboot w/o argument */
-		return SW_RESET_NO_ARGUMENT;
+	if (cmd == NULL) {
+		if (oops_in_progress) {
+			/* if we're in an oops assume it's a crash */
+			return SW_RESET_CRASH;
+		} else {
+			/* normal reboot w/o argument */
+			return SW_RESET_NO_ARGUMENT;
+		}
+	}
 
 	/* Search through reboot reason list */
 	for (i = 0; i < reboot_reasons_size; i++) {
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 76b4db78ec1..f36d95a8223 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -110,6 +110,7 @@ struct kimage {
 
 /* kexec interface functions */
 extern void machine_kexec(struct kimage *image);
+extern void machine_crash_swreset(void);
 extern int machine_kexec_prepare(struct kimage *image);
 extern void machine_kexec_cleanup(struct kimage *image);
 extern asmlinkage long sys_kexec_load(unsigned long entry,
diff --git a/kernel/kexec.c b/kernel/kexec.c
index cf5f9ad2b91..e3ae2e75e78 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1069,6 +1069,7 @@ asmlinkage long compat_sys_kexec_load(unsigned long entry,
 
 void crash_kexec(struct pt_regs *regs)
 {
+	struct pt_regs fixed_regs;
 	/* Take the kexec_mutex here to prevent sys_kexec_load
 	 * running on one cpu from replacing the crash kernel
 	 * we are using after a panic on a different cpu.
@@ -1079,7 +1080,6 @@ void crash_kexec(struct pt_regs *regs)
 	 */
 	if (mutex_trylock(&kexec_mutex)) {
 		if (kexec_crash_image) {
-			struct pt_regs fixed_regs;
 
 			kmsg_dump(KMSG_DUMP_KEXEC);
 
@@ -1088,6 +1088,14 @@ void crash_kexec(struct pt_regs *regs)
 			machine_crash_shutdown(&fixed_regs);
 			machine_kexec(kexec_crash_image);
 		}
+#ifdef CONFIG_CRASH_SWRESET
+		else {
+			crash_setup_regs(&fixed_regs, regs);
+			crash_save_vmcoreinfo();
+			machine_crash_shutdown(&fixed_regs);
+			machine_crash_swreset();
+		}
+#endif
 		mutex_unlock(&kexec_mutex);
 	}
 }