ish: combine watchdog expiration and panic handler

watchdog_warning implements similar functionality to exception_panic,
but worse, as the value it prints for EIP is wrong, and it does not
have the no-double-panic logic of the panic handler. This commit
removes watchdog_warning and integrates the relevant functionality
into exception_panic.

BUG=b:129983997
BRANCH=none
TEST=observed watchdog reset with 'waitms 10500'

Change-Id: I78375337aa85be5424850e29a8204c409384d019
Signed-off-by: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1599732
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Reviewed-by: Jett Rink <jettrink@chromium.org>

3 files changed, 30 insertions, 37 deletions

diff --git a/chip/ish/watchdog.c b/chip/ish/watchdog.c
index fd0ebcf247..79f6e788df 100644
--- a/chip/ish/watchdog.c
+++ b/chip/ish/watchdog.c
@@ -20,7 +20,6 @@
  */
 
 #include "common.h"
-#include "console.h"
 #include "hooks.h"
 #include "task.h"
 #include "registers.h"
@@ -46,32 +45,6 @@ int watchdog_init(void)
 	return EC_SUCCESS;
 }
 
-/* Parameters are pushed by hardware, we only care about %EIP */
-__attribute__ ((noreturn))
-void watchdog_warning(uint32_t errorcode,
-		      uint32_t eip,
-		      uint32_t cs,
-		      uint32_t eflags)
-{
-	ccprintf("\nWDT Expired. EIP was 0x%08X. Resetting...\n", eip);
-	cflush();
-
-	system_reset(SYSTEM_RESET_AP_WATCHDOG);
-	__builtin_unreachable();
-}
-
-__attribute__ ((noreturn))
-void watchdog_warning_irq(void)
-{
-	/*
-	 * Parameters to watchdog_warning were pushed by hardware, use
-	 * asm here to re-use these parameters in the call.
-	 */
-	__asm__ ("call watchdog_warning\n");
-	__builtin_unreachable();
-}
-DECLARE_IRQ(ISH_WDT_IRQ, watchdog_warning_irq);
-
 void watchdog_reload(void)
 {
 	/*
diff --git a/core/minute-ia/interrupts.c b/core/minute-ia/interrupts.c
index efa07ef062..5e69b9c199 100644
--- a/core/minute-ia/interrupts.c
+++ b/core/minute-ia/interrupts.c
@@ -169,15 +169,19 @@ static const irq_desc_t system_irqs[] = {
  * and go directly to the CPU core, so get_current_interrupt_vector
  * cannot be used.
  */
-#define DEFINE_EXN_HANDLER(vector)					\
-	void __keep exception_panic_##vector(void);			\
-	__attribute__ ((noreturn)) void exception_panic_##vector(void)	\
-	{								\
-		__asm__ (						\
-			"push $" #vector "\n"				\
-			"call exception_panic\n");			\
-		while (1)						\
-			continue;					\
+#define DEFINE_EXN_HANDLER(vector)				\
+	_DEFINE_EXN_HANDLER(vector, exception_panic_##vector)
+#define _DEFINE_EXN_HANDLER(vector, name)	\
+	__DEFINE_EXN_HANDLER(vector, name)
+#define __DEFINE_EXN_HANDLER(vector, name)		\
+	void __keep name(void);			\
+	__attribute__ ((noreturn)) void name(void)	\
+	{						\
+		__asm__ (				\
+			"push $" #vector "\n"		\
+			"call exception_panic\n");	\
+		while (1)				\
+			continue;			\
 	}
 
 DEFINE_EXN_HANDLER(0);
@@ -200,6 +204,7 @@ DEFINE_EXN_HANDLER(17);
 DEFINE_EXN_HANDLER(18);
 DEFINE_EXN_HANDLER(19);
 DEFINE_EXN_HANDLER(20);
+_DEFINE_EXN_HANDLER(ISH_WDT_VEC, exception_panic_wdt);
 
 void set_interrupt_gate(uint8_t num, isr_handler_t func, uint8_t flags)
 {
@@ -457,6 +462,16 @@ void init_interrupts(void)
 	set_interrupt_gate(19, exception_panic_19, IDT_DESC_FLAGS);
 	set_interrupt_gate(20, exception_panic_20, IDT_DESC_FLAGS);
 
+	/*
+	 * Set up watchdog expiration like a panic, that way we can
+	 * use the common panic handling code, and also properly
+	 * retrieve EIP.
+	 */
+	if (IS_ENABLED(CONFIG_WATCHDOG))
+		set_interrupt_gate(ISH_WDT_VEC,
+				   exception_panic_wdt,
+				   IDT_DESC_FLAGS);
+
 	/* Note: At reset, ID field is already set to 0 in APIC ID register */
 
 	/* Enable the APIC, mapping the spurious interrupt at the same time. */
diff --git a/core/minute-ia/panic.c b/core/minute-ia/panic.c
index 40e8ee1cf0..0898e4e717 100644
--- a/core/minute-ia/panic.c
+++ b/core/minute-ia/panic.c
@@ -50,7 +50,9 @@ const static char *panic_reason[] = {
  */
 void panic_data_print(const struct panic_data *pdata)
 {
-	if (pdata->x86.vector <= 20)
+	if (pdata->x86.vector == ISH_WDT_VEC)
+		panic_printf("Reason: Watchdog Expiration\n");
+	else if (pdata->x86.vector <= 20)
 		panic_printf("Reason: %s\n", panic_reason[pdata->x86.vector]);
 	else
 		panic_printf("Interrupt vector number: 0x%08X (unknown)\n",
@@ -134,6 +136,9 @@ __attribute__ ((noreturn)) void __keep exception_panic(
 
 	if (panic_once) {
 		system_reset(SYSTEM_RESET_HARD);
+	} else if (vector == ISH_WDT_VEC) {
+		panic_once = 1;
+		system_reset(SYSTEM_RESET_AP_WATCHDOG);
 	} else {
 		panic_once = 1;
 		system_reset(0);