binaryPI: Disable CAR with empty stack

Calling disable_cache_as_ram() with valuables in stack is not
a stable solution, as per documentation AMD_DISABLE_STACK
should destroy stack in cache.

While we still preserve cache contents (there is wbinvd deep
inside AMD_DISABLE_STACK macro), we now actually do a stack
switch and much more closely meet the specification of CAR
teardown sequence in AGESA specifications.

We now somewhat incorrectly include files from agesa/ tree,
but the whole agesawrapper.c file removal will address the
issue of overall directory layout.

Change-Id: I2bac098099c1caffea181356c63924f4b5a93b54
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/18525
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 48 insertions, 0 deletions

diff --git a/src/cpu/amd/pi/romstage.c b/src/cpu/amd/pi/romstage.c
new file mode 100644
index 0000000000..393cbd4aeb
--- /dev/null
+++ b/src/cpu/amd/pi/romstage.c
@@ -0,0 +1,48 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2017 Kyösti Mälkki
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/cpu.h>
+#include <cpu/amd/car.h>
+#include <cpu/x86/mtrr.h>
+#include <console/console.h>
+#include <program_loading.h>
+#include <northbridge/amd/agesa/agesa_helper.h>
+#include <northbridge/amd/agesa/state_machine.h>
+
+void asmlinkage early_all_cores(void)
+{
+	amd_initmmio();
+}
+
+void * asmlinkage romstage_main(unsigned long bist)
+{
+	uintptr_t stack_top = CACHE_TMP_RAMTOP;
+	u8 initial_apic_id = cpuid_ebx(1) >> 24;
+
+	/* Only BSP returns from here. */
+	cache_as_ram_main(bist, initial_apic_id);
+
+	printk(BIOS_DEBUG, "Move CAR stack.\n");
+	return (void*)stack_top;
+}
+
+void asmlinkage romstage_after_car(void)
+{
+	printk(BIOS_DEBUG, "CAR disabled.\n");
+
+	agesa_postcar(NULL);
+
+	run_ramstage();
+}