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path: root/drivers/char/tpm/tpm2-cmd.c
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Diffstat (limited to 'drivers/char/tpm/tpm2-cmd.c')
-rw-r--r--drivers/char/tpm/tpm2-cmd.c646
1 files changed, 646 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
new file mode 100644
index 000000000000..011909a9be96
--- /dev/null
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -0,0 +1,646 @@
+/*
+ * Copyright (C) 2014 Intel Corporation
+ *
+ * Authors:
+ * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * This file contains TPM2 protocol implementations of the commands
+ * used by the kernel internally.
+ *
+ * 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 "tpm.h"
+
+struct tpm2_startup_in {
+ __be16 startup_type;
+} __packed;
+
+struct tpm2_self_test_in {
+ u8 full_test;
+} __packed;
+
+struct tpm2_pcr_read_in {
+ __be32 pcr_selects_cnt;
+ __be16 hash_alg;
+ u8 pcr_select_size;
+ u8 pcr_select[TPM2_PCR_SELECT_MIN];
+} __packed;
+
+struct tpm2_pcr_read_out {
+ __be32 update_cnt;
+ __be32 pcr_selects_cnt;
+ __be16 hash_alg;
+ u8 pcr_select_size;
+ u8 pcr_select[TPM2_PCR_SELECT_MIN];
+ __be32 digests_cnt;
+ __be16 digest_size;
+ u8 digest[TPM_DIGEST_SIZE];
+} __packed;
+
+struct tpm2_null_auth_area {
+ __be32 handle;
+ __be16 nonce_size;
+ u8 attributes;
+ __be16 auth_size;
+} __packed;
+
+struct tpm2_pcr_extend_in {
+ __be32 pcr_idx;
+ __be32 auth_area_size;
+ struct tpm2_null_auth_area auth_area;
+ __be32 digest_cnt;
+ __be16 hash_alg;
+ u8 digest[TPM_DIGEST_SIZE];
+} __packed;
+
+struct tpm2_get_tpm_pt_in {
+ __be32 cap_id;
+ __be32 property_id;
+ __be32 property_cnt;
+} __packed;
+
+struct tpm2_get_tpm_pt_out {
+ u8 more_data;
+ __be32 subcap_id;
+ __be32 property_cnt;
+ __be32 property_id;
+ __be32 value;
+} __packed;
+
+struct tpm2_get_random_in {
+ __be16 size;
+} __packed;
+
+struct tpm2_get_random_out {
+ __be16 size;
+ u8 buffer[TPM_MAX_RNG_DATA];
+} __packed;
+
+union tpm2_cmd_params {
+ struct tpm2_startup_in startup_in;
+ struct tpm2_self_test_in selftest_in;
+ struct tpm2_pcr_read_in pcrread_in;
+ struct tpm2_pcr_read_out pcrread_out;
+ struct tpm2_pcr_extend_in pcrextend_in;
+ struct tpm2_get_tpm_pt_in get_tpm_pt_in;
+ struct tpm2_get_tpm_pt_out get_tpm_pt_out;
+ struct tpm2_get_random_in getrandom_in;
+ struct tpm2_get_random_out getrandom_out;
+};
+
+struct tpm2_cmd {
+ tpm_cmd_header header;
+ union tpm2_cmd_params params;
+} __packed;
+
+/*
+ * Array with one entry per ordinal defining the maximum amount
+ * of time the chip could take to return the result. The values
+ * of the SHORT, MEDIUM, and LONG durations are taken from the
+ * PC Client Profile (PTP) specification.
+ */
+static const u8 tpm2_ordinal_duration[TPM2_CC_LAST - TPM2_CC_FIRST + 1] = {
+ TPM_UNDEFINED, /* 11F */
+ TPM_UNDEFINED, /* 120 */
+ TPM_LONG, /* 121 */
+ TPM_UNDEFINED, /* 122 */
+ TPM_UNDEFINED, /* 123 */
+ TPM_UNDEFINED, /* 124 */
+ TPM_UNDEFINED, /* 125 */
+ TPM_UNDEFINED, /* 126 */
+ TPM_UNDEFINED, /* 127 */
+ TPM_UNDEFINED, /* 128 */
+ TPM_LONG, /* 129 */
+ TPM_UNDEFINED, /* 12a */
+ TPM_UNDEFINED, /* 12b */
+ TPM_UNDEFINED, /* 12c */
+ TPM_UNDEFINED, /* 12d */
+ TPM_UNDEFINED, /* 12e */
+ TPM_UNDEFINED, /* 12f */
+ TPM_UNDEFINED, /* 130 */
+ TPM_UNDEFINED, /* 131 */
+ TPM_UNDEFINED, /* 132 */
+ TPM_UNDEFINED, /* 133 */
+ TPM_UNDEFINED, /* 134 */
+ TPM_UNDEFINED, /* 135 */
+ TPM_UNDEFINED, /* 136 */
+ TPM_UNDEFINED, /* 137 */
+ TPM_UNDEFINED, /* 138 */
+ TPM_UNDEFINED, /* 139 */
+ TPM_UNDEFINED, /* 13a */
+ TPM_UNDEFINED, /* 13b */
+ TPM_UNDEFINED, /* 13c */
+ TPM_UNDEFINED, /* 13d */
+ TPM_MEDIUM, /* 13e */
+ TPM_UNDEFINED, /* 13f */
+ TPM_UNDEFINED, /* 140 */
+ TPM_UNDEFINED, /* 141 */
+ TPM_UNDEFINED, /* 142 */
+ TPM_LONG, /* 143 */
+ TPM_MEDIUM, /* 144 */
+ TPM_UNDEFINED, /* 145 */
+ TPM_UNDEFINED, /* 146 */
+ TPM_UNDEFINED, /* 147 */
+ TPM_UNDEFINED, /* 148 */
+ TPM_UNDEFINED, /* 149 */
+ TPM_UNDEFINED, /* 14a */
+ TPM_UNDEFINED, /* 14b */
+ TPM_UNDEFINED, /* 14c */
+ TPM_UNDEFINED, /* 14d */
+ TPM_LONG, /* 14e */
+ TPM_UNDEFINED, /* 14f */
+ TPM_UNDEFINED, /* 150 */
+ TPM_UNDEFINED, /* 151 */
+ TPM_UNDEFINED, /* 152 */
+ TPM_UNDEFINED, /* 153 */
+ TPM_UNDEFINED, /* 154 */
+ TPM_UNDEFINED, /* 155 */
+ TPM_UNDEFINED, /* 156 */
+ TPM_UNDEFINED, /* 157 */
+ TPM_UNDEFINED, /* 158 */
+ TPM_UNDEFINED, /* 159 */
+ TPM_UNDEFINED, /* 15a */
+ TPM_UNDEFINED, /* 15b */
+ TPM_MEDIUM, /* 15c */
+ TPM_UNDEFINED, /* 15d */
+ TPM_UNDEFINED, /* 15e */
+ TPM_UNDEFINED, /* 15f */
+ TPM_UNDEFINED, /* 160 */
+ TPM_UNDEFINED, /* 161 */
+ TPM_UNDEFINED, /* 162 */
+ TPM_UNDEFINED, /* 163 */
+ TPM_UNDEFINED, /* 164 */
+ TPM_UNDEFINED, /* 165 */
+ TPM_UNDEFINED, /* 166 */
+ TPM_UNDEFINED, /* 167 */
+ TPM_UNDEFINED, /* 168 */
+ TPM_UNDEFINED, /* 169 */
+ TPM_UNDEFINED, /* 16a */
+ TPM_UNDEFINED, /* 16b */
+ TPM_UNDEFINED, /* 16c */
+ TPM_UNDEFINED, /* 16d */
+ TPM_UNDEFINED, /* 16e */
+ TPM_UNDEFINED, /* 16f */
+ TPM_UNDEFINED, /* 170 */
+ TPM_UNDEFINED, /* 171 */
+ TPM_UNDEFINED, /* 172 */
+ TPM_UNDEFINED, /* 173 */
+ TPM_UNDEFINED, /* 174 */
+ TPM_UNDEFINED, /* 175 */
+ TPM_UNDEFINED, /* 176 */
+ TPM_LONG, /* 177 */
+ TPM_UNDEFINED, /* 178 */
+ TPM_UNDEFINED, /* 179 */
+ TPM_MEDIUM, /* 17a */
+ TPM_LONG, /* 17b */
+ TPM_UNDEFINED, /* 17c */
+ TPM_UNDEFINED, /* 17d */
+ TPM_UNDEFINED, /* 17e */
+ TPM_UNDEFINED, /* 17f */
+ TPM_UNDEFINED, /* 180 */
+ TPM_UNDEFINED, /* 181 */
+ TPM_MEDIUM, /* 182 */
+ TPM_UNDEFINED, /* 183 */
+ TPM_UNDEFINED, /* 184 */
+ TPM_MEDIUM, /* 185 */
+ TPM_MEDIUM, /* 186 */
+ TPM_UNDEFINED, /* 187 */
+ TPM_UNDEFINED, /* 188 */
+ TPM_UNDEFINED, /* 189 */
+ TPM_UNDEFINED, /* 18a */
+ TPM_UNDEFINED, /* 18b */
+ TPM_UNDEFINED, /* 18c */
+ TPM_UNDEFINED, /* 18d */
+ TPM_UNDEFINED, /* 18e */
+ TPM_UNDEFINED /* 18f */
+};
+
+#define TPM2_PCR_READ_IN_SIZE \
+ (sizeof(struct tpm_input_header) + \
+ sizeof(struct tpm2_pcr_read_in))
+
+static const struct tpm_input_header tpm2_pcrread_header = {
+ .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+ .length = cpu_to_be32(TPM2_PCR_READ_IN_SIZE),
+ .ordinal = cpu_to_be32(TPM2_CC_PCR_READ)
+};
+
+/**
+ * tpm2_pcr_read() - read a PCR value
+ * @chip: TPM chip to use.
+ * @pcr_idx: index of the PCR to read.
+ * @ref_buf: buffer to store the resulting hash,
+ *
+ * 0 is returned when the operation is successful. If a negative number is
+ * returned it remarks a POSIX error code. If a positive number is returned
+ * it remarks a TPM error.
+ */
+int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
+{
+ int rc;
+ struct tpm2_cmd cmd;
+ u8 *buf;
+
+ if (pcr_idx >= TPM2_PLATFORM_PCR)
+ return -EINVAL;
+
+ cmd.header.in = tpm2_pcrread_header;
+ cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
+ cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
+ cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
+
+ memset(cmd.params.pcrread_in.pcr_select, 0,
+ sizeof(cmd.params.pcrread_in.pcr_select));
+ cmd.params.pcrread_in.pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
+
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ "attempting to read a pcr value");
+ if (rc == 0) {
+ buf = cmd.params.pcrread_out.digest;
+ memcpy(res_buf, buf, TPM_DIGEST_SIZE);
+ }
+
+ return rc;
+}
+
+#define TPM2_GET_PCREXTEND_IN_SIZE \
+ (sizeof(struct tpm_input_header) + \
+ sizeof(struct tpm2_pcr_extend_in))
+
+static const struct tpm_input_header tpm2_pcrextend_header = {
+ .tag = cpu_to_be16(TPM2_ST_SESSIONS),
+ .length = cpu_to_be32(TPM2_GET_PCREXTEND_IN_SIZE),
+ .ordinal = cpu_to_be32(TPM2_CC_PCR_EXTEND)
+};
+
+/**
+ * tpm2_pcr_extend() - extend a PCR value
+ * @chip: TPM chip to use.
+ * @pcr_idx: index of the PCR.
+ * @hash: hash value to use for the extend operation.
+ *
+ * 0 is returned when the operation is successful. If a negative number is
+ * returned it remarks a POSIX error code. If a positive number is returned
+ * it remarks a TPM error.
+ */
+int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
+{
+ struct tpm2_cmd cmd;
+ int rc;
+
+ cmd.header.in = tpm2_pcrextend_header;
+ cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
+ cmd.params.pcrextend_in.auth_area_size =
+ cpu_to_be32(sizeof(struct tpm2_null_auth_area));
+ cmd.params.pcrextend_in.auth_area.handle =
+ cpu_to_be32(TPM2_RS_PW);
+ cmd.params.pcrextend_in.auth_area.nonce_size = 0;
+ cmd.params.pcrextend_in.auth_area.attributes = 0;
+ cmd.params.pcrextend_in.auth_area.auth_size = 0;
+ cmd.params.pcrextend_in.digest_cnt = cpu_to_be32(1);
+ cmd.params.pcrextend_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
+ memcpy(cmd.params.pcrextend_in.digest, hash, TPM_DIGEST_SIZE);
+
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ "attempting extend a PCR value");
+
+ return rc;
+}
+
+#define TPM2_GETRANDOM_IN_SIZE \
+ (sizeof(struct tpm_input_header) + \
+ sizeof(struct tpm2_get_random_in))
+
+static const struct tpm_input_header tpm2_getrandom_header = {
+ .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+ .length = cpu_to_be32(TPM2_GETRANDOM_IN_SIZE),
+ .ordinal = cpu_to_be32(TPM2_CC_GET_RANDOM)
+};
+
+/**
+ * tpm2_get_random() - get random bytes from the TPM RNG
+ * @chip: TPM chip to use
+ * @out: destination buffer for the random bytes
+ * @max: the max number of bytes to write to @out
+ *
+ * 0 is returned when the operation is successful. If a negative number is
+ * returned it remarks a POSIX error code. If a positive number is returned
+ * it remarks a TPM error.
+ */
+int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
+{
+ struct tpm2_cmd cmd;
+ u32 recd;
+ u32 num_bytes;
+ int err;
+ int total = 0;
+ int retries = 5;
+ u8 *dest = out;
+
+ num_bytes = min_t(u32, max, sizeof(cmd.params.getrandom_out.buffer));
+
+ if (!out || !num_bytes ||
+ max > sizeof(cmd.params.getrandom_out.buffer))
+ return -EINVAL;
+
+ do {
+ cmd.header.in = tpm2_getrandom_header;
+ cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);
+
+ err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ "attempting get random");
+ if (err)
+ break;
+
+ recd = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size),
+ num_bytes);
+ memcpy(dest, cmd.params.getrandom_out.buffer, recd);
+
+ dest += recd;
+ total += recd;
+ num_bytes -= recd;
+ } while (retries-- && total < max);
+
+ return total ? total : -EIO;
+}
+
+#define TPM2_GET_TPM_PT_IN_SIZE \
+ (sizeof(struct tpm_input_header) + \
+ sizeof(struct tpm2_get_tpm_pt_in))
+
+static const struct tpm_input_header tpm2_get_tpm_pt_header = {
+ .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+ .length = cpu_to_be32(TPM2_GET_TPM_PT_IN_SIZE),
+ .ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY)
+};
+
+/**
+ * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
+ * @chip: TPM chip to use.
+ * @property_id: property ID.
+ * @value: output variable.
+ * @desc: passed to tpm_transmit_cmd()
+ *
+ * 0 is returned when the operation is successful. If a negative number is
+ * returned it remarks a POSIX error code. If a positive number is returned
+ * it remarks a TPM error.
+ */
+ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
+ const char *desc)
+{
+ struct tpm2_cmd cmd;
+ int rc;
+
+ cmd.header.in = tpm2_get_tpm_pt_header;
+ cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
+ cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);
+ cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
+
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), desc);
+ if (!rc)
+ *value = cmd.params.get_tpm_pt_out.value;
+
+ return rc;
+}
+
+#define TPM2_STARTUP_IN_SIZE \
+ (sizeof(struct tpm_input_header) + \
+ sizeof(struct tpm2_startup_in))
+
+static const struct tpm_input_header tpm2_startup_header = {
+ .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+ .length = cpu_to_be32(TPM2_STARTUP_IN_SIZE),
+ .ordinal = cpu_to_be32(TPM2_CC_STARTUP)
+};
+
+/**
+ * tpm2_startup() - send startup command to the TPM chip
+ * @chip: TPM chip to use.
+ * @startup_type startup type. The value is either
+ * TPM_SU_CLEAR or TPM_SU_STATE.
+ *
+ * 0 is returned when the operation is successful. If a negative number is
+ * returned it remarks a POSIX error code. If a positive number is returned
+ * it remarks a TPM error.
+ */
+int tpm2_startup(struct tpm_chip *chip, u16 startup_type)
+{
+ struct tpm2_cmd cmd;
+
+ cmd.header.in = tpm2_startup_header;
+
+ cmd.params.startup_in.startup_type = cpu_to_be16(startup_type);
+ return tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ "attempting to start the TPM");
+}
+EXPORT_SYMBOL_GPL(tpm2_startup);
+
+#define TPM2_SHUTDOWN_IN_SIZE \
+ (sizeof(struct tpm_input_header) + \
+ sizeof(struct tpm2_startup_in))
+
+static const struct tpm_input_header tpm2_shutdown_header = {
+ .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+ .length = cpu_to_be32(TPM2_SHUTDOWN_IN_SIZE),
+ .ordinal = cpu_to_be32(TPM2_CC_SHUTDOWN)
+};
+
+/**
+ * tpm2_shutdown() - send shutdown command to the TPM chip
+ * @chip: TPM chip to use.
+ * @shutdown_type shutdown type. The value is either
+ * TPM_SU_CLEAR or TPM_SU_STATE.
+ */
+void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
+{
+ struct tpm2_cmd cmd;
+ int rc;
+
+ cmd.header.in = tpm2_shutdown_header;
+ cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);
+
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), "stopping the TPM");
+
+ /* In places where shutdown command is sent there's no much we can do
+ * except print the error code on a system failure.
+ */
+ if (rc < 0)
+ dev_warn(chip->pdev, "transmit returned %d while stopping the TPM",
+ rc);
+}
+EXPORT_SYMBOL_GPL(tpm2_shutdown);
+
+/*
+ * tpm2_calc_ordinal_duration() - maximum duration for a command
+ * @chip: TPM chip to use.
+ * @ordinal: command code number.
+ *
+ * 0 is returned when the operation is successful. If a negative number is
+ * returned it remarks a POSIX error code. If a positive number is returned
+ * it remarks a TPM error.
+ */
+unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
+{
+ int index = TPM_UNDEFINED;
+ int duration = 0;
+
+ if (ordinal >= TPM2_CC_FIRST && ordinal <= TPM2_CC_LAST)
+ index = tpm2_ordinal_duration[ordinal - TPM2_CC_FIRST];
+
+ if (index != TPM_UNDEFINED)
+ duration = chip->vendor.duration[index];
+
+ if (duration <= 0)
+ duration = 2 * 60 * HZ;
+
+ return duration;
+}
+EXPORT_SYMBOL_GPL(tpm2_calc_ordinal_duration);
+
+#define TPM2_SELF_TEST_IN_SIZE \
+ (sizeof(struct tpm_input_header) + \
+ sizeof(struct tpm2_self_test_in))
+
+static const struct tpm_input_header tpm2_selftest_header = {
+ .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+ .length = cpu_to_be32(TPM2_SELF_TEST_IN_SIZE),
+ .ordinal = cpu_to_be32(TPM2_CC_SELF_TEST)
+};
+
+/**
+ * tpm2_continue_selftest() - start a self test
+ * @chip: TPM chip to use
+ * @full: test all commands instead of testing only those that were not
+ * previously tested.
+ *
+ * 0 is returned when the operation is successful. If a negative number is
+ * returned it remarks a POSIX error code. If a positive number is returned
+ * it remarks a TPM error.
+ */
+static int tpm2_start_selftest(struct tpm_chip *chip, bool full)
+{
+ int rc;
+ struct tpm2_cmd cmd;
+
+ cmd.header.in = tpm2_selftest_header;
+ cmd.params.selftest_in.full_test = full;
+
+ rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE,
+ "continue selftest");
+
+ /* At least some prototype chips seem to give RC_TESTING error
+ * immediately. This is a workaround for that.
+ */
+ if (rc == TPM2_RC_TESTING) {
+ dev_warn(chip->pdev, "Got RC_TESTING, ignoring\n");
+ rc = 0;
+ }
+
+ return rc;
+}
+
+/**
+ * tpm2_do_selftest() - run a full self test
+ * @chip: TPM chip to use
+ *
+ * During the self test TPM2 commands return with the error code RC_TESTING.
+ * Waiting is done by issuing PCR read until it executes successfully.
+ *
+ * 0 is returned when the operation is successful. If a negative number is
+ * returned it remarks a POSIX error code. If a positive number is returned
+ * it remarks a TPM error.
+ */
+int tpm2_do_selftest(struct tpm_chip *chip)
+{
+ int rc;
+ unsigned int loops;
+ unsigned int delay_msec = 100;
+ unsigned long duration;
+ struct tpm2_cmd cmd;
+ int i;
+
+ duration = tpm2_calc_ordinal_duration(chip, TPM2_CC_SELF_TEST);
+
+ loops = jiffies_to_msecs(duration) / delay_msec;
+
+ rc = tpm2_start_selftest(chip, true);
+ if (rc)
+ return rc;
+
+ for (i = 0; i < loops; i++) {
+ /* Attempt to read a PCR value */
+ cmd.header.in = tpm2_pcrread_header;
+ cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
+ cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
+ cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
+ cmd.params.pcrread_in.pcr_select[0] = 0x01;
+ cmd.params.pcrread_in.pcr_select[1] = 0x00;
+ cmd.params.pcrread_in.pcr_select[2] = 0x00;
+
+ rc = tpm_transmit_cmd(chip, (u8 *) &cmd, sizeof(cmd), NULL);
+ if (rc < 0)
+ break;
+
+ rc = be32_to_cpu(cmd.header.out.return_code);
+ if (rc != TPM2_RC_TESTING)
+ break;
+
+ msleep(delay_msec);
+ }
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm2_do_selftest);
+
+/**
+ * tpm2_gen_interrupt() - generate an interrupt
+ * @chip: TPM chip to use
+ *
+ * 0 is returned when the operation is successful. If a negative number is
+ * returned it remarks a POSIX error code. If a positive number is returned
+ * it remarks a TPM error.
+ */
+int tpm2_gen_interrupt(struct tpm_chip *chip)
+{
+ u32 dummy;
+
+ return tpm2_get_tpm_pt(chip, 0x100, &dummy,
+ "attempting to generate an interrupt");
+}
+EXPORT_SYMBOL_GPL(tpm2_gen_interrupt);
+
+/**
+ * tpm2_probe() - probe TPM 2.0
+ * @chip: TPM chip to use
+ *
+ * Send idempotent TPM 2.0 command and see whether TPM 2.0 chip replied based on
+ * the reply tag.
+ */
+int tpm2_probe(struct tpm_chip *chip)
+{
+ struct tpm2_cmd cmd;
+ int rc;
+
+ cmd.header.in = tpm2_get_tpm_pt_header;
+ cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
+ cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);
+ cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
+
+ rc = tpm_transmit(chip, (const char *) &cmd, sizeof(cmd));
+ if (rc < 0)
+ return rc;
+ else if (rc < TPM_HEADER_SIZE)
+ return -EFAULT;
+
+ if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS)
+ chip->flags |= TPM_CHIP_FLAG_TPM2;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tpm2_probe);