soc/amd/stoneyridge: Create a HALT_THIS_AP callout

It was required for all cores use the same CAR teardown function
(exit_car.S and gcccar.inc). AGESA has already been modified to do the
AP to do the call out. Create assembly code to call chipset_teardown_car
and then enter an endless loop with halt instruction. Then create the
call out that will call this new assembly code.

BUG=b:70338633
AGESA COMMIT=3313d277
TEST=Created a debug version of AGESA that would print the returned
status of HALT_THIS_AP. Build code without the fix, see the return.
Build code with the fix, see that there's no return.

Change-Id: I05ee405812211d93dfdbdc5ee7d9978c2eb585e1
Signed-off-by: Richard Spiegel <richard.spiegel@silverbackltd.com>
Reviewed-on: https://review.coreboot.org/24999
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/src/soc/amd/common/block/cpu/car/ap_exit_car.S b/src/soc/amd/common/block/cpu/car/ap_exit_car.S
new file mode 100644
index 0000000000..5d3e13b1a2
--- /dev/null
+++ b/src/soc/amd/common/block/cpu/car/ap_exit_car.S
@@ -0,0 +1,61 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2018 Advanced Micro Devices, Inc.
+ *
+ * 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.
+ */
+
+.code32
+
+#include <cpu/x86/cr.h>
+
+.globl ap_teardown_car
+ap_teardown_car:
+	pop	%esi		/* return address, don't care */
+	pop	%esi		/* flags */
+
+	/* chipset_teardown_car() is expected to disable cache-as-ram. */
+	call	chipset_teardown_car
+
+	/*
+	 * Check flags requirements (0 = FALSE, 1 = TRUE) :
+	 * bit 0 = ExecWbinvd
+	 * bit 1 = CacheEn
+	 */
+
+	/*
+	 * TODO: Either use or remove this code - we'll node if the code
+	 * is needed when 3 conditions happens:
+	 * 1) This code is in place
+	 * 2) AGESA code that calls HALT_THIS_AP is in place
+	 * 3) We boot to OS, go to S3 and resume.
+	 * If S3 resume fails, this code might be needed, if S3 resume
+	 * is successful then the code can be removed.
+	 */
+
+	/*
+	 * Commented out until defined if needed or not.
+	 * test	%esi, 1
+	 * jz	1f
+	 * wbinvd
+	 * 1:
+	 */
+
+	test	%esi, 2
+	jz	2f
+	/* Enable cache */
+	mov	%cr0, %eax
+	and	$(~(CR0_CD | CR0_NW)), %eax
+	mov	%eax, %cr0
+2:
+	cli
+	hlt
+	jmp	2b