zephyr: Remove CONFIG_VBOOT_HASH_RELOAD_WATCHDOG

This reverts commit 0e5fa530e2f1eba6e16188be65ac39974a151a17.
After commit 97e22d467 it is no longer needed to reload
watchdog during hash calculation.

BUG=b:182499153
BRANCH=none
TEST=Flash EC and verify that hash calculation is correctly
     done without rebooting by watchdog. Reading watchdog value
     shows that there is enough remaining time.

Change-Id: Ia7bb6452a6ac42cda88d8b5e1203876cd0465b31
Signed-off-by: Michał Barnaś <mb@semihalf.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2897239
Reviewed-by: Keith Short <keithshort@chromium.org>
Commit-Queue: Keith Short <keithshort@chromium.org>

3 files changed, 4 insertions, 47 deletions

diff --git a/common/vboot_hash.c b/common/vboot_hash.c
index 1bb9298ced..04e3ae5f7f 100644
--- a/common/vboot_hash.c
+++ b/common/vboot_hash.c
@@ -127,28 +127,10 @@ static void hash_next_chunk(size_t size)
 
 static void vboot_hash_all_chunks(void)
 {
-#ifdef CONFIG_VBOOT_HASH_RELOAD_WATCHDOG
-	uint64_t prev_watchdog = get_time().val;
-
-	watchdog_reload();
-#endif
-
 	do {
 		size_t size = MIN(CHUNK_SIZE, data_size - curr_pos);
 		hash_next_chunk(size);
 		curr_pos += size;
-
-#ifdef CONFIG_VBOOT_HASH_RELOAD_WATCHDOG
-		{
-			uint64_t cur_time = get_time().val;
-
-			if ((cur_time - prev_watchdog) >
-			    (CONFIG_WATCHDOG_PERIOD_MS * 1000 / 2)) {
-				watchdog_reload();
-				prev_watchdog = cur_time;
-			}
-		}
-#endif
 	} while (curr_pos < data_size);
 
 	hash = SHA256_final(&ctx);
diff --git a/include/config.h b/include/config.h
index dfe458c5ad..c43ea3845a 100644
--- a/include/config.h
+++ b/include/config.h
@@ -5038,15 +5038,6 @@
 /* Support computing hash of code for verified boot */
 #undef CONFIG_VBOOT_HASH
 
-/*
- * Reload the watchdog at 1/2 the watchdog period during hash
- * calculation.  When CONFIG_SHA256_HW_ACCELERATE and
- * CONFIG_SHA256_UNROLLED are disabled, the hash calculation may trip
- * the watchdog.  This option becomes enabled by default when both
- * those options are disabled.
- */
-#undef CONFIG_VBOOT_HASH_RELOAD_WATCHDOG
-
 /* Support for secure temporary storage for verified boot */
 #undef CONFIG_VSTORE
 
@@ -6359,22 +6350,6 @@
 	"when CONFIG_SYSTEM_UNLOCK is also enabled."
 #endif /* CONFIG_BYPASS_CBI_EEPROM_WP_CHECK && !CONFIG_SYSTEM_UNLOCK */
 
-/*
- * Enable CONFIG_VBOOT_HASH_RELOAD_WATCHDOG by default when these
- * conditions are met:
- * - Watchdog enabled
- * - No hardware acceleration for SHA256 calculation
- * - Loops for SHA256 calculation are not unrolled
- *
- * See the CONFIG_VBOOT_HASH_RELOAD_WATCHDOG entry in this file for an
- * explanation as to why this is necessary.
- */
-#if defined(CONFIG_WATCHDOG) && !defined(CONFIG_SHA256_HW_ACCELERATE) && \
-	!defined(CONFIG_SHA256_UNROLLED) &&                              \
-	!defined(CONFIG_VBOOT_HASH_RELOAD_WATCHDOG)
-#define CONFIG_VBOOT_HASH_RELOAD_WATCHDOG
-#endif
-
 #if !defined(CONFIG_ZEPHYR) && !defined(CONFIG_ACCELGYRO_ICM_COMM_SPI) && \
 	!defined(CONFIG_ACCELGYRO_ICM_COMM_I2C)
 #ifdef I2C_PORT_ACCEL
diff --git a/zephyr/app/ec/ec_app_main.c b/zephyr/app/ec/ec_app_main.c
index c792a2892f..e0efb49475 100644
--- a/zephyr/app/ec/ec_app_main.c
+++ b/zephyr/app/ec/ec_app_main.c
@@ -62,10 +62,6 @@ void ec_app_main(void)
 		}
 	}
 
-	if (IS_ENABLED(CONFIG_PLATFORM_EC_WATCHDOG)) {
-		watchdog_init();
-	}
-
 	if (IS_ENABLED(CONFIG_PLATFORM_EC_VBOOT)) {
 		/*
 		 * For RO, it behaves as follows:
@@ -84,6 +80,10 @@ void ec_app_main(void)
 	 */
 	k_thread_priority_set(&k_sys_work_q.thread, LOWEST_THREAD_PRIORITY);
 
+	if (IS_ENABLED(CONFIG_PLATFORM_EC_WATCHDOG)) {
+		watchdog_init();
+	}
+
 	/* Call init hooks before main tasks start */
 	if (IS_ENABLED(CONFIG_PLATFORM_EC_HOOKS)) {
 		hook_notify(HOOK_INIT);