From 4c6072130c0979095a6639af4c5c06937f785145 Mon Sep 17 00:00:00 2001
From: Subrata Banik <subratabanik@google.com>
Date: Thu, 14 Apr 2022 13:48:53 +0530
Subject: [PATCH] =?UTF-8?q?soc/intel/cmn/pch/lockdown:=20Implement=C2=A0LP?=
 =?UTF-8?q?C=20lock=20down=20configuration?=
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This patch implements a helper function to perform LPC registers lock
down configuration.

BUG=b:211954778
TEST=Able to build and boot google/redrix to OS. Verified LPC PCI
configuration register offset 0xDC bits BILD and LE are set.

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: I3e49b783e5db0ff40238e6e9259e48a4ecca66f8
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63630
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
---
 src/soc/intel/common/pch/lockdown/lockdown.c | 22 ++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/soc/intel/common/pch/lockdown/lockdown.c b/src/soc/intel/common/pch/lockdown/lockdown.c
index 8032b4ac3e..cd8b402b5d 100644
--- a/src/soc/intel/common/pch/lockdown/lockdown.c
+++ b/src/soc/intel/common/pch/lockdown/lockdown.c
@@ -3,6 +3,7 @@
 #include <bootstate.h>
 #include <intelblocks/cfg.h>
 #include <intelblocks/fast_spi.h>
+#include <intelblocks/lpc_lib.h>
 #include <intelblocks/pcr.h>
 #include <intelpch/lockdown.h>
 #include <intelblocks/gpmr.h>
@@ -88,6 +89,24 @@ static void fast_spi_lockdown_cfg(int chipset_lockdown)
 	}
 }
 
+static void lpc_lockdown_config(int chipset_lockdown)
+{
+	/* Set BIOS Interface Lock, BIOS Lock */
+	if (chipset_lockdown == CHIPSET_LOCKDOWN_COREBOOT) {
+		/* BIOS Interface Lock */
+		lpc_set_bios_interface_lock_down();
+
+		/* Only allow writes in SMM */
+		if (CONFIG(BOOTMEDIA_SMM_BWP)) {
+			lpc_set_eiss();
+			lpc_enable_wp();
+		}
+
+		/* BIOS Lock */
+		lpc_set_lock_enable();
+	}
+}
+
 /*
  * platform_lockdown_config has 2 major part.
  * 1. Common SoC lockdown configuration.
@@ -102,6 +121,9 @@ static void platform_lockdown_config(void *unused)
 	/* SPI lock down configuration */
 	fast_spi_lockdown_cfg(chipset_lockdown);
 
+	/* LPC/eSPI lock down configuration */
+	lpc_lockdown_config(chipset_lockdown);
+
 	/* DMI lock down configuration */
 	lockdown_cfg();