[PATCH] riscv: pass system-failure to restart SBI call on emergency restart

[Jimmy Ho]

Let the restart SBI call pass the restart reason as system-failure
when an emergency restart occurs.

Signed-off-by: Jimmy Ho <jimmy.ho at sifive.com>
---
 arch/riscv/include/asm/emergency-restart.h | 13 +++++++++++++
 arch/riscv/include/asm/sbi.h               |  2 ++
 arch/riscv/kernel/sbi.c                    |  8 +++++++-
 3 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 arch/riscv/include/asm/emergency-restart.h

diff --git a/arch/riscv/include/asm/emergency-restart.h b/arch/riscv/include/asm/emergency-restart.h
new file mode 100644
index 000000000000..14c8da0f7ea2
--- /dev/null
+++ b/arch/riscv/include/asm/emergency-restart.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_RISCV_EMERGENCY_RESTART_H
+#define _ASM_RISCV_EMERGENCY_RESTART_H
+
+#include <asm/sbi.h>
+
+static inline void machine_emergency_restart(void)
+{
+	machine_restart(RISCV_EMERGENCY_RESTART_REASON);
+}
+
+#endif /* _ASM_RISCV_EMERGENCY_RESTART_H */
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 5725e0ca4dda..c8dceefa677d 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -121,6 +121,8 @@ enum sbi_srst_reset_reason {
 	SBI_SRST_RESET_REASON_SYS_FAILURE,
 };
 
+#define RISCV_EMERGENCY_RESTART_REASON "system-failure"
+
 enum sbi_ext_susp_fid {
 	SBI_EXT_SUSP_SYSTEM_SUSPEND = 0,
 };
diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
index c443337056ab..dae147420f1a 100644
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -10,6 +10,7 @@
 #include <linux/mm.h>
 #include <linux/pm.h>
 #include <linux/reboot.h>
+#include <linux/string.h>
 #include <asm/sbi.h>
 #include <asm/smp.h>
 #include <asm/tlbflush.h>
@@ -519,10 +520,15 @@ static void sbi_srst_reset(unsigned long type, unsigned long reason)
 static int sbi_srst_reboot(struct notifier_block *this,
 			   unsigned long mode, void *cmd)
 {
+	unsigned long reason = SBI_SRST_RESET_REASON_NONE;
+
+	if (cmd && !strcmp(cmd, RISCV_EMERGENCY_RESTART_REASON))
+		reason = SBI_SRST_RESET_REASON_SYS_FAILURE;
+
 	sbi_srst_reset((mode == REBOOT_WARM || mode == REBOOT_SOFT) ?
 		       SBI_SRST_RESET_TYPE_WARM_REBOOT :
 		       SBI_SRST_RESET_TYPE_COLD_REBOOT,
-		       SBI_SRST_RESET_REASON_NONE);
+		       reason);
 	return NOTIFY_DONE;
 }
 
-- 
2.43.7