Re: [PATCH v9 7/8] tpm: TPM 2.0 CRB Interface

tpm_crb is a driver for TPM 2.0 Command Response Buffer (CRB) Interface
as defined in PC Client Platform TPM Profile (PTP) Specification.

Only polling and single locality is supported as these are the limitations
of the available hardware, Platform Trust Techonlogy (PTT) in Haswell
CPUs.

The driver always applies CRB with ACPI start because PTT reports using
only ACPI start as start method but as a result of my testing it requires
also CRB start.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/char/tpm/Kconfig   |   9 ++
 drivers/char/tpm/Makefile  |   1 +
 drivers/char/tpm/tpm_crb.c | 356
+++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 366
insertions(+)
 create mode 100644 drivers/char/tpm/tpm_crb.c

diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index 3d0873b..9d4e375 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig

@@ -122,4 +122,13 @@ config TCG_XEN
 	  To compile this driver as a module, choose M here; the module
 	  will be called xen-tpmfront.

+config TCG_CRB
+	tristate "TPM 2.0 CRB Interface"
+	depends on X86 && ACPI
+	---help---
+	  If you have a TPM security chip that is compliant with the
+	  TCG CRB 2.0 TPM specification say Yes and it will be accessible
+	  from within Linux.  To compile this driver as a module, choose
+	  M here; the module will be called tpm_crb.
+
 endif # TCG_TPM

diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 88848ed..990cf18 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile

@@ -22,3 +22,4 @@ obj-$(CONFIG_TCG_INFINEON) += tpm_infineon.o
 obj-$(CONFIG_TCG_IBMVTPM) += tpm_ibmvtpm.o
 obj-$(CONFIG_TCG_TIS_I2C_ST33) += tpm_i2c_stm_st33.o
 obj-$(CONFIG_TCG_XEN) += xen-tpmfront.o
+obj-$(CONFIG_TCG_CRB) += tpm_crb.o

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
new file mode 100644
index 0000000..eb78f93
--- /dev/null
+++ b/drivers/char/tpm/tpm_crb.c

@@ -0,0 +1,356 @@
+/*
+ * Copyright (C) 2014 Intel Corporation
+ *
+ * Authors:
+ * Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
+ *
+ * Maintained by: <tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
+ *
+ * This device driver implements the TPM interface as defined in
+ * the TCG CRB 2.0 TPM specification.
+ *
+ * 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.
+ */
+
+#include <linux/acpi.h>
+#include <linux/highmem.h>
+#include <linux/rculist.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include "tpm.h"
+
+#define ACPI_SIG_TPM2 "TPM2"
+
+static const u8 CRB_ACPI_START_UUID[] = {
+	/* 0000 */ 0xAB, 0x6C, 0xBF, 0x6B, 0x63, 0x54, 0x14, 0x47,
+	/* 0008 */ 0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4
+};
+
+enum crb_defaults {
+	CRB_ACPI_START_REVISION_ID = 1,
+	CRB_ACPI_START_INDEX = 1,
+};
+
+enum crb_start_method {
+	CRB_SM_ACPI_START = 2,
+	CRB_SM_CRB = 7,
+	CRB_SM_CRB_WITH_ACPI_START = 8,
+};
+
+struct acpi_tpm2 {
+	struct acpi_table_header hdr;
+	u16 platform_class;
+	u16 reserved;
+	u64 control_area_pa;
+	u32 start_method;
+} __packed;
+
+enum crb_ca_request {
+	CRB_CA_REQ_GO_IDLE	= BIT(0),
+	CRB_CA_REQ_CMD_READY	= BIT(1),
+};
+
+enum crb_ca_status {
+	CRB_CA_STS_ERROR	= BIT(0),
+	CRB_CA_STS_TPM_IDLE	= BIT(1),
+};
+
+enum crb_start {
+	CRB_START_INVOKE	= BIT(0),
+};
+
+enum crb_cancel {
+	CRB_CANCEL_INVOKE	= BIT(0),
+};
+
+struct crb_control_area {
+	u32 req;
+	u32 sts;
+	u32 cancel;
+	u32 start;
+	u32 int_enable;
+	u32 int_sts;
+	u32 cmd_size;
+	u64 cmd_pa;
+	u32 rsp_size;
+	u64 rsp_pa;
+} __packed;
+
+enum crb_status {
+	CRB_STS_COMPLETE	= BIT(0),
+};
+
+enum crb_flags {
+	CRB_FL_ACPI_START	= BIT(0),
+	CRB_FL_CRB_START	= BIT(1),
+};
+
+struct crb_priv {
+	unsigned int flags;
+	struct crb_control_area *cca;
+	u8 *cmd;
+	u8 *rsp;
+};
+
+#ifdef CONFIG_PM_SLEEP
+int crb_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int crb_resume(struct device *dev)
+{
+	struct tpm_chip *chip = dev_get_drvdata(dev);
+
+	(void) tpm2_do_selftest(chip);