reset: Provide new single-function reset API

board_reset() replaces the existing common reset API. There is no common
distinction between reset types across platforms, hence, common code
could never decide which one to call.

Currently only hard_reset() is used by common code. We replace these
calls and provide a fall-back to the current hard_reset() implemen-
tation. The fall-back will be removed along with hard_reset() after the
transition of all boards.

Change-Id: I274a8cee9cb38226b5a0bdff6a847c74ef0b3128
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/29047
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/lib/reset.c

@@ -18,6 +18,30 @@
 #include <halt.h>
 #include <reset.h>
 
+__noreturn void board_reset(void)
+{
+	printk(BIOS_INFO, "%s() called!\n", __func__);
+	dcache_clean_all();
+	do_board_reset();
+	halt();
+}
+
+#if IS_ENABLED(CONFIG_MISSING_BOARD_RESET)
+void do_board_reset(void)
+{
+	printk(BIOS_CRIT, "No board_reset implementation, hanging...\n");
+}
+#else
+/*
+ * Fall back to hard_reset() for a regression free transition.
+ * FIXME: Remove after everything is converted to board_reset().
+ */
+__weak void do_board_reset(void)
+{
+	hard_reset();
+}
+#endif
+
 __noreturn static void __hard_reset(void) {
 	if (IS_ENABLED(CONFIG_HAVE_HARD_RESET))
 		do_hard_reset();