minute-ia: ish software panic

Adding functions for software panic to ISH.  This includes
panic_set_reason, panic_get_reason and software_panic.

Added extra output when a software panic is detected.

Had to touch nds32/panic.c in order to make panic_sw_reasons
common.

BUG=b:134502392
BRANCH=none
TEST=Verified with crash assert, with CONFIG_DEBUG_ASSERT defined

Change-Id: Iebfe62a7dcd59b4bbed82b450dfd44cc8eaed1da
Signed-off-by: Denis Brockus <dbrockus@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1648958
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>

4 files changed, 96 insertions, 29 deletions

diff --git a/common/panic_output.c b/common/panic_output.c
index 8d34adaa38..1d85e0a9d8 100644
--- a/common/panic_output.c
+++ b/common/panic_output.c
@@ -10,6 +10,7 @@
 #include "host_command.h"
 #include "panic.h"
 #include "printf.h"
+#include "software_panic.h"
 #include "system.h"
 #include "task.h"
 #include "timer.h"
@@ -19,6 +20,31 @@
 /* Panic data goes at the end of RAM. */
 static struct panic_data * const pdata_ptr = PANIC_DATA_PTR;
 
+/* Common SW Panic reasons strings */
+const char * const panic_sw_reasons[] = {
+#ifdef CONFIG_SOFTWARE_PANIC
+	"PANIC_SW_DIV_ZERO",
+	"PANIC_SW_STACK_OVERFLOW",
+	"PANIC_SW_PD_CRASH",
+	"PANIC_SW_ASSERT",
+	"PANIC_SW_WATCHDOG",
+	"PANIC_SW_RNG",
+	"PANIC_SW_PMIC_FAULT",
+#endif
+};
+
+/**
+ * Check an interrupt vector as being a valid software panic
+ * @param reason	Reason for panic
+ * @return 0 if not a valid software panic reason, otherwise non-zero.
+ */
+int panic_sw_reason_is_valid(uint32_t reason)
+{
+	return (IS_ENABLED(CONFIG_SOFTWARE_PANIC) &&
+		reason >= PANIC_SW_BASE &&
+		(reason - PANIC_SW_BASE) < ARRAY_SIZE(panic_sw_reasons));
+}
+
 /**
  * Add a character directly to the UART buffer.
  *
diff --git a/core/minute-ia/panic.c b/core/minute-ia/panic.c
index 0898e4e717..442a69464a 100644
--- a/core/minute-ia/panic.c
+++ b/core/minute-ia/panic.c
@@ -9,6 +9,7 @@
 #include "host_command.h"
 #include "panic.h"
 #include "printf.h"
+#include "software_panic.h"
 #include "system.h"
 #include "task.h"
 #include "timer.h"
@@ -50,10 +51,17 @@ const static char *panic_reason[] = {
  */
 void panic_data_print(const struct panic_data *pdata)
 {
-	if (pdata->x86.vector == ISH_WDT_VEC)
+	if (pdata->x86.vector == PANIC_SW_WATCHDOG)
 		panic_printf("Reason: Watchdog Expiration\n");
 	else if (pdata->x86.vector <= 20)
 		panic_printf("Reason: %s\n", panic_reason[pdata->x86.vector]);
+	else if (panic_sw_reason_is_valid(pdata->x86.vector)) {
+		panic_printf("Software panic reason %s\n",
+			     panic_sw_reasons[pdata->x86.vector -
+					      PANIC_SW_BASE]);
+		panic_printf("Software panic info 0x%x\n",
+			     pdata->x86.error_code);
+	}
 	else
 		panic_printf("Interrupt vector number: 0x%08X (unknown)\n",
 			     pdata->x86.vector);
@@ -81,7 +89,7 @@ void panic_data_print(const struct panic_data *pdata)
  * order pushed to the stack by hardware: see "Intel 64 and IA-32
  * Architectures Software Developer's Manual", Volume 3A, Figure 6-4.
  */
-__attribute__ ((noreturn)) void __keep exception_panic(
+__attribute__((noreturn)) void __keep exception_panic(
 	uint32_t vector,
 	uint32_t error_code,
 	uint32_t eip,
@@ -111,6 +119,13 @@ __attribute__ ((noreturn)) void __keep exception_panic(
 	PANIC_DATA_PTR->x86.esi = esi;
 	PANIC_DATA_PTR->x86.edi = edi;
 
+	/*
+	 * Convert ISH_WDT_VEC to be a SW Watchdog. This is for
+	 * code that is in system_common_pre_init
+	 */
+	if (vector == ISH_WDT_VEC)
+		vector = PANIC_SW_WATCHDOG;
+
 	/* Save stack data to global panic structure */
 	PANIC_DATA_PTR->x86.vector = vector;
 	PANIC_DATA_PTR->x86.error_code = error_code;
@@ -134,32 +149,63 @@ __attribute__ ((noreturn)) void __keep exception_panic(
 	panic_printf("Resetting system...\n");
 	panic_printf("===========================\n");
 
-	if (panic_once) {
+	/*
+	 * Post increment panic_once to make sure we only go through
+	 * once before we resort to a hard reset
+	 */
+	if (panic_once++)
 		system_reset(SYSTEM_RESET_HARD);
-	} else if (vector == ISH_WDT_VEC) {
-		panic_once = 1;
+	else if (vector == PANIC_SW_WATCHDOG)
 		system_reset(SYSTEM_RESET_AP_WATCHDOG);
-	} else {
-		panic_once = 1;
+	else if (panic_sw_reason_is_valid(vector))
+		system_reset(SYSTEM_RESET_MANUALLY_TRIGGERED);
+	else
 		system_reset(0);
-	}
 
 	__builtin_unreachable();
 }
 
 #ifdef CONFIG_SOFTWARE_PANIC
-void software_panic(uint32_t reason, uint32_t info)
+__attribute__((noreturn)) void software_panic(uint32_t reason, uint32_t info)
 {
-	/* TODO: store panic log */
-	while (1)
-		continue;
+	uint16_t code_segment;
+
+	/* Get the current code segment */
+	__asm__ volatile ("movw  %%cs, %0":"=m" (code_segment));
+
+	exception_panic(reason,
+			info,
+			(uint32_t)__builtin_return_address(0),
+			code_segment,
+			0);
+
+	__builtin_unreachable();
 }
 
 void panic_set_reason(uint32_t reason, uint32_t info, uint8_t exception)
 {
+	/* Setup panic data structure */
+	memset(PANIC_DATA_PTR, 0, sizeof(struct panic_data));
+	PANIC_DATA_PTR->magic = PANIC_DATA_MAGIC;
+	PANIC_DATA_PTR->struct_size = sizeof(struct panic_data);
+	PANIC_DATA_PTR->struct_version = 2;
+	PANIC_DATA_PTR->arch = PANIC_ARCH_X86;
+
+	/* Log panic cause */
+	PANIC_DATA_PTR->x86.vector = reason;
+	PANIC_DATA_PTR->x86.error_code = info;
+	PANIC_DATA_PTR->x86.eflags = exception;
 }
 
 void panic_get_reason(uint32_t *reason, uint32_t *info, uint8_t *exception)
 {
+	if (PANIC_DATA_PTR->magic == PANIC_DATA_MAGIC &&
+	    PANIC_DATA_PTR->struct_version == 2) {
+		*reason = PANIC_DATA_PTR->x86.vector;
+		*info = PANIC_DATA_PTR->x86.error_code;
+		*exception = PANIC_DATA_PTR->x86.eflags;
+	} else {
+		*reason = *info = *exception = 0;
+	}
 }
 #endif
diff --git a/core/nds32/panic.c b/core/nds32/panic.c
index 3dabc1d2f0..9bc06fc409 100644
--- a/core/nds32/panic.c
+++ b/core/nds32/panic.c
@@ -8,6 +8,7 @@
 #include "cpu.h"
 #include "panic.h"
 #include "printf.h"
+#include "software_panic.h"
 #include "system.h"
 #include "task.h"
 #include "timer.h"
@@ -78,18 +79,6 @@ static const char * const itype_exc_type[16] = {
 #endif /* CONFIG_DEBUG_EXCEPTIONS */
 
 #ifdef CONFIG_SOFTWARE_PANIC
-/* Software panic reasons */
-static const char * const panic_sw_reasons[8] = {
-	"PANIC_SW_DIV_ZERO",
-	"PANIC_SW_STACK_OVERFLOW",
-	"PANIC_SW_PD_CRASH",
-	"PANIC_SW_ASSERT",
-	"PANIC_SW_WATCHDOG",
-	NULL,
-	NULL,
-	NULL,
-};
-
 void software_panic(uint32_t reason, uint32_t info)
 {
 	asm volatile ("mov55  $r6, %0" : : "r"(reason));
@@ -163,10 +152,11 @@ static void print_panic_information(uint32_t *regs, uint32_t itype,
 
 #ifdef CONFIG_DEBUG_EXCEPTIONS
 	panic_printf("SWID of ITYPE: %x\n", ((itype >> 16) & 0x7fff));
-	if ((regs[SOFT_PANIC_GPR_REASON] & 0xfffffff0) == PANIC_SW_BASE) {
+	if (panic_sw_reason_is_valid(regs[SOFT_PANIC_GPR_REASON])) {
 #ifdef CONFIG_SOFTWARE_PANIC
 		panic_printf("Software panic reason %s\n",
-			panic_sw_reasons[(regs[SOFT_PANIC_GPR_REASON] & 0x7)]);
+			panic_sw_reasons[(regs[SOFT_PANIC_GPR_REASON] -
+					  PANIC_SW_BASE)]);
 		panic_printf("Software panic info 0x%x\n",
 			regs[SOFT_PANIC_GPR_INFO]);
 #endif
diff --git a/include/software_panic.h b/include/software_panic.h
index 99205f02c3..2702c6dc92 100644
--- a/include/software_panic.h
+++ b/include/software_panic.h
@@ -1,10 +1,10 @@
-/* Copyright (c) 2015 The Chromium OS Authors. All rights reserved.
+/* Copyright 2019 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
- *
- * Software panic constants. This file must be parsable by the assembler.
  */
 
+/* Software panic constants. This file must be parsable by the assembler. */
+
 #ifndef __CROS_EC_SOFTWARE_PANIC_H
 #define __CROS_EC_SOFTWARE_PANIC_H
 
@@ -23,4 +23,9 @@
 #define PANIC_SW_BAD_RNG		(PANIC_SW_BASE + 5)
 #define PANIC_SW_PMIC_FAULT		(PANIC_SW_BASE + 6)
 
+#ifndef __ASSEMBLER__
+extern const char * const panic_sw_reasons[];
+extern int panic_sw_reason_is_valid(uint32_t vec);
+#endif
+
 #endif  /* __CROS_EC_SOFTWARE_PANIC_H */