[PATCH] powerpc/8xx: add system_reset_exception

When the watchdog is in NMI mode, the system reset interrupt is
generated when the watchdog counter expires.

Signed-off-by: Christophe Leroy <redacted>
---
 arch/powerpc/kernel/head_8xx.S | 2 +-
 arch/powerpc/kernel/traps.c    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 43ddaae..f7b8007 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S

@@ -227,7 +227,7 @@ i##n:								\
 			  ret_from_except)
 
 /* System reset */
-	EXCEPTION(0x100, Reset, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x100, Reset, system_reset_exception, EXC_XFER_STD)
 
 /* Machine check */
 	. = 0x200

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 2cb5892..f8fa11b 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c

@@ -269,7 +269,6 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
 	force_sig_info(signr, &info, current);
 }
 
-#ifdef CONFIG_PPC64
 void system_reset_exception(struct pt_regs *regs)
 {
 	/* See if any machine dependent calls */

@@ -287,6 +286,7 @@ void system_reset_exception(struct pt_regs *regs)
 	/* What should we do here? We could issue a shutdown or hard reset. */
 }
 
+#ifdef CONFIG_PPC64
 /*
  * This function is called in real mode. Strictly no printk's please.
  *

-- 
2.1.0

On Mon, 2016-09-05 at 08:42 +0200, Christophe Leroy wrote:

Does this do anything useful beyond what unknown_exception does?  Do you plan
to have a ppc_md.system_reset_exception callback?

-Scott

Le 07/09/2016 à 00:40, Scott Wood a écrit :

On Mon, 2016-09-05 at 08:42 +0200, Christophe Leroy wrote:

quoted

When the watchdog is in NMI mode, the system reset interrupt is
generated when the watchdog counter expires.

Signed-off-by: Christophe Leroy <redacted>
---
 arch/powerpc/kernel/head_8xx.S | 2 +-
 arch/powerpc/kernel/traps.c    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 43ddaae..f7b8007 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S

@@ -227,7 +227,7 @@ i##n:							

	\
 			  ret_from_except)

 /* System reset */
-	EXCEPTION(0x100, Reset, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x100, Reset, system_reset_exception, EXC_XFER_STD)

Does this do anything useful beyond what unknown_exception does?  Do you plan
to have a ppc_md.system_reset_exception callback?

Yes that's the plan, having a platform specific callback to take 
emergency actions in order to speed up systemwise recovery, then restart 
the board.

In addition, unknown_exception doesn't show you that the exception comes 
from the NMI watchdog.

Christophe