google/chromeos: disable platform hierarchy on resume for TPM2

On Chrome OS devices that use TPM2 parts the platform hierarchy
is disabled by the boot loader, depthcharge. Since the bootloader
isn't involved in resuming a suspended machine there's no equivalent
action in coreboot to disable the platform hierarchy. Therefore, to
ensure consistent state in resume the platform hierarchy in the TPM2
needs to be disabled as well. For systems that resume using the
firmware the platform hierarchy is disabled when utilizing
TPM2 devices.

BUG=chrome-os-partner:61097
BRANCH=reef
TEST=Suspend and resume. Confirmed 'stop trunksd; tpmc getvf; start
trunksd' shows that phEnable is 0.

Change-Id: I060252f338c8fd68389273224ee58caa99881de8
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/18096
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>

8 files changed, 122 insertions, 10 deletions

diff --git a/src/include/tpm_lite/tlcl.h b/src/include/tpm_lite/tlcl.h
index 8ea5564ecb..95bae77f42 100644
--- a/src/include/tpm_lite/tlcl.h
+++ b/src/include/tpm_lite/tlcl.h
@@ -151,4 +151,9 @@ uint32_t tlcl_extend(int pcr_num, const uint8_t *in_digest,
  */
 uint32_t tlcl_get_permanent_flags(TPM_PERMANENT_FLAGS *pflags);
 
+/**
+ * Disable platform hierarchy. Specific to TPM2. The TPM error code is returned.
+ */
+uint32_t tlcl_disable_platform_hierarchy(void);
+
 #endif  /* TPM_LITE_TLCL_H_ */
diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc
index 2d5aa57fe7..9a9ddc865e 100644
--- a/src/lib/Makefile.inc
+++ b/src/lib/Makefile.inc
@@ -144,6 +144,8 @@ ramstage-$(CONFIG_GENERIC_GPIO_LIB) += gpio.c
 ramstage-$(CONFIG_GENERIC_UDELAY) += timer.c
 ramstage-y += b64_decode.c
 ramstage-$(CONFIG_ACPI_NHLT) += nhlt.c
+ramstage-$(CONFIG_TPM2) += tpm2_marshaling.c
+ramstage-$(CONFIG_TPM2) += tpm2_tlcl.c
 
 romstage-y += cbmem_common.c
 romstage-y += imd_cbmem.c
diff --git a/src/lib/tpm2_marshaling.c b/src/lib/tpm2_marshaling.c
index 1edc69007a..38c8d2f05c 100644
--- a/src/lib/tpm2_marshaling.c
+++ b/src/lib/tpm2_marshaling.c
@@ -373,6 +373,23 @@ static void marshal_selftest(void **buffer,
 	marshal_u8(buffer, command_body->yes_no, buffer_space);
 }
 
+static void marshal_hierarchy_control(void **buffer,
+			struct tpm2_hierarchy_control_cmd *command_body,
+			size_t *buffer_space)
+{
+	struct tpm2_session_header session_header;
+
+	car_set_var(tpm_tag, TPM_ST_SESSIONS);
+
+	marshal_TPM_HANDLE(buffer, TPM_RH_PLATFORM, buffer_space);
+	memset(&session_header, 0, sizeof(session_header));
+	session_header.session_handle = TPM_RS_PW;
+	marshal_session_header(buffer, &session_header, buffer_space);
+
+	marshal_TPM_HANDLE(buffer, command_body->enable, buffer_space);
+	marshal_u8(buffer, command_body->state, buffer_space);
+}
+
 int tpm_marshal_command(TPM_CC command, void *tpm_command_body,
 			void *buffer, size_t buffer_size)
 {
@@ -414,6 +431,11 @@ int tpm_marshal_command(TPM_CC command, void *tpm_command_body,
 		marshal_selftest(&cmd_body, tpm_command_body, &body_size);
 		break;
 
+	case TPM2_Hierarchy_Control:
+		marshal_hierarchy_control(&cmd_body, tpm_command_body,
+						&body_size);
+		break;
+
 	case TPM2_Clear:
 		marshal_clear(&cmd_body, &body_size);
 		break;
@@ -583,6 +605,7 @@ struct tpm2_response *tpm_unmarshal_response(TPM_CC command,
 				  &tpm2_resp->nvr);
 		break;
 
+	case TPM2_Hierarchy_Control:
 	case TPM2_Clear:
 	case TPM2_NV_DefineSpace:
 	case TPM2_NV_Write:
diff --git a/src/lib/tpm2_tlcl.c b/src/lib/tpm2_tlcl.c
index 6f5243e160..6c0cd6e2b2 100644
--- a/src/lib/tpm2_tlcl.c
+++ b/src/lib/tpm2_tlcl.c
@@ -369,3 +369,19 @@ uint32_t tlcl_define_space(uint32_t space_index, size_t space_size)
 		return TPM_E_INTERNAL_INCONSISTENCY;
 	}
 }
+
+uint32_t tlcl_disable_platform_hierarchy(void)
+{
+	struct tpm2_response *response;
+	struct tpm2_hierarchy_control_cmd hc = {
+		.enable = TPM_RH_PLATFORM,
+		.state = 0,
+	};
+
+	response = tpm_process_command(TPM2_Hierarchy_Control, &hc);
+
+	if (!response || response->hdr.tpm_code)
+		return TPM_E_INTERNAL_INCONSISTENCY;
+
+	return TPM_SUCCESS;
+}
diff --git a/src/lib/tpm2_tlcl_structures.h b/src/lib/tpm2_tlcl_structures.h
index 36a3e8b253..c5c6d87985 100644
--- a/src/lib/tpm2_tlcl_structures.h
+++ b/src/lib/tpm2_tlcl_structures.h
@@ -28,7 +28,7 @@ typedef uint8_t TPMI_YES_NO;
 typedef TPM_ALG_ID TPMI_ALG_HASH;
 typedef TPM_HANDLE TPMI_DH_PCR;
 typedef TPM_HANDLE TPMI_RH_NV_INDEX;
-typedef TPM_HANDLE TPMI_RH_PROVISION;
+typedef TPM_HANDLE TPMI_RH_ENABLES;
 typedef TPM_HANDLE TPMI_SH_AUTH_SESSION;
 typedef TPM_HANDLE TPM_RH;
 
@@ -59,15 +59,16 @@ struct tpm_header {
 } __attribute__((packed));
 
 /* TPM command codes. */
-#define TPM2_Clear          ((TPM_CC)0x00000126)
-#define TPM2_NV_DefineSpace ((TPM_CC)0x0000012A)
-#define TPM2_NV_Write       ((TPM_CC)0x00000137)
-#define TPM2_NV_WriteLock   ((TPM_CC)0x00000138)
-#define TPM2_SelfTest       ((TPM_CC)0x00000143)
-#define TPM2_Startup        ((TPM_CC)0x00000144)
-#define TPM2_NV_Read        ((TPM_CC)0x0000014E)
-#define TPM2_GetCapability  ((TPM_CC)0x0000017A)
-#define TPM2_PCR_Extend     ((TPM_CC)0x00000182)
+#define TPM2_Hierarchy_Control ((TPM_CC)0x00000121)
+#define TPM2_Clear             ((TPM_CC)0x00000126)
+#define TPM2_NV_DefineSpace    ((TPM_CC)0x0000012A)
+#define TPM2_NV_Write          ((TPM_CC)0x00000137)
+#define TPM2_NV_WriteLock      ((TPM_CC)0x00000138)
+#define TPM2_SelfTest          ((TPM_CC)0x00000143)
+#define TPM2_Startup           ((TPM_CC)0x00000144)
+#define TPM2_NV_Read           ((TPM_CC)0x0000014E)
+#define TPM2_GetCapability     ((TPM_CC)0x0000017A)
+#define TPM2_PCR_Extend        ((TPM_CC)0x00000182)
 
 /* Startup values. */
 #define TPM_SU_CLEAR 0
@@ -334,4 +335,9 @@ struct tpm2_pcr_extend_cmd {
 	TPML_DIGEST_VALUES digests;
 };
 
+struct tpm2_hierarchy_control_cmd {
+	TPMI_RH_ENABLES enable;
+	TPMI_YES_NO state;
+};
+
 #endif // __SRC_LIB_TPM2_TLCL_STRUCTURES_H
diff --git a/src/vendorcode/google/chromeos/Kconfig b/src/vendorcode/google/chromeos/Kconfig
index 238b4e51b1..97dfc60c22 100644
--- a/src/vendorcode/google/chromeos/Kconfig
+++ b/src/vendorcode/google/chromeos/Kconfig
@@ -127,6 +127,20 @@ config CHROMEOS_FWID_VERSION
 	  This is the second part of the FWID written to various regions of a
 	  Chrome OS firmware image to identify its version.
 
+config CHROMEOS_DISABLE_PLATFORM_HIERARCHY_ON_RESUME
+	bool
+	default y
+	depends on TPM2 && RESUME_PATH_SAME_AS_BOOT
+	help
+	  Disable the platform heirarchy on resume path if the firmware
+	  is involved in resume. The hierarchy is disabled prior to jumping
+	  to the OS.  Note that this option is sepcific to TPM2 boards.
+	  This option is auto selected if CHROMEOS because it matches with
+	  vboot_reference model which disables the platform hierarchy in
+	  the boot loader. However, those operations need to be symmetric
+	  on normal boot as well as resume and coreboot is only involved
+	  in the resume piece w.r.t. the platform hierarchy.
+
 menu "GBB configuration"
 
 config GBB_HWID
diff --git a/src/vendorcode/google/chromeos/Makefile.inc b/src/vendorcode/google/chromeos/Makefile.inc
index 878b0684c0..f0762bcb55 100644
--- a/src/vendorcode/google/chromeos/Makefile.inc
+++ b/src/vendorcode/google/chromeos/Makefile.inc
@@ -24,6 +24,7 @@ ramstage-$(CONFIG_HAVE_ACPI_TABLES) += acpi.c
 ramstage-$(CONFIG_CHROMEOS_RAMOOPS) += ramoops.c
 romstage-y += vpd_decode.c
 ramstage-y += vpd_decode.c cros_vpd.c vpd_mac.c vpd_serialno.c vpd_calibration.c
+ramstage-$(CONFIG_CHROMEOS_DISABLE_PLATFORM_HIERARCHY_ON_RESUME) += tpm2.c
 ramstage-$(CONFIG_HAVE_REGULATORY_DOMAIN) += wrdd.c
 ramstage-$(CONFIG_USE_SAR) += sar.c
 ifeq ($(CONFIG_ARCH_MIPS),)
diff --git a/src/vendorcode/google/chromeos/tpm2.c b/src/vendorcode/google/chromeos/tpm2.c
new file mode 100644
index 0000000000..fd1dac9a35
--- /dev/null
+++ b/src/vendorcode/google/chromeos/tpm2.c
@@ -0,0 +1,45 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2017 Google 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.
+ */
+
+#include <bootstate.h>
+#include <console/console.h>
+#include <tpm_lite/tlcl.h>
+#include <vb2_api.h>
+
+static void disable_platform_hierarchy(void *unused)
+{
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_TPM2))
+		return;
+
+	if (!IS_ENABLED(CONFIG_RESUME_PATH_SAME_AS_BOOT))
+		return;
+
+	ret = tlcl_lib_init();
+
+	if (ret != VB2_SUCCESS) {
+		printk(BIOS_ERR, "tlcl_lib_init() failed: %x\n", ret);
+		return;
+	}
+
+	ret = tlcl_disable_platform_hierarchy();
+	if (ret != TPM_SUCCESS)
+		printk(BIOS_ERR, "Platform hierarchy disablement failed: %x\n",
+			ret);
+}
+
+BOOT_STATE_INIT_ENTRY(BS_OS_RESUME, BS_ON_ENTRY, disable_platform_hierarchy,
+			NULL);