Initial import

1 files changed, 1056 insertions, 0 deletions

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
new file mode 100644
index 000000000..e85d3416d
--- /dev/null
+++ b/drivers/char/tpm/tpm-interface.c
@@ -0,0 +1,1056 @@
+/*
+ * Copyright (C) 2004 IBM Corporation
+ * Copyright (C) 2014 Intel Corporation
+ *
+ * Authors:
+ * Leendert van Doorn <leendert@watson.ibm.com>
+ * Dave Safford <safford@watson.ibm.com>
+ * Reiner Sailer <sailer@watson.ibm.com>
+ * Kylene Hall <kjhall@us.ibm.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * Device driver for TCG/TCPA TPM (trusted platform module).
+ * Specifications at www.trustedcomputinggroup.org
+ *
+ * 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.
+ *
+ * Note, the TPM chip is not interrupt driven (only polling)
+ * and can have very long timeouts (minutes!). Hence the unusual
+ * calls to msleep.
+ *
+ */
+
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/freezer.h>
+
+#include "tpm.h"
+#include "tpm_eventlog.h"
+
+#define TPM_MAX_ORDINAL 243
+#define TSC_MAX_ORDINAL 12
+#define TPM_PROTECTED_COMMAND 0x00
+#define TPM_CONNECTION_COMMAND 0x40
+
+/*
+ * Bug workaround - some TPM's don't flush the most
+ * recently changed pcr on suspend, so force the flush
+ * with an extend to the selected _unused_ non-volatile pcr.
+ */
+static int tpm_suspend_pcr;
+module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
+MODULE_PARM_DESC(suspend_pcr,
+		 "PCR to use for dummy writes to faciltate flush on suspend.");
+
+/*
+ * Array with one entry per ordinal defining the maximum amount
+ * of time the chip could take to return the result.  The ordinal
+ * designation of short, medium or long is defined in a table in
+ * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
+ * values of the SHORT, MEDIUM, and LONG durations are retrieved
+ * from the chip during initialization with a call to tpm_get_timeouts.
+ */
+static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
+	TPM_UNDEFINED,		/* 0 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,		/* 5 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,		/* 10 */
+	TPM_SHORT,
+	TPM_MEDIUM,
+	TPM_LONG,
+	TPM_LONG,
+	TPM_MEDIUM,		/* 15 */
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_MEDIUM,
+	TPM_LONG,
+	TPM_SHORT,		/* 20 */
+	TPM_SHORT,
+	TPM_MEDIUM,
+	TPM_MEDIUM,
+	TPM_MEDIUM,
+	TPM_SHORT,		/* 25 */
+	TPM_SHORT,
+	TPM_MEDIUM,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_MEDIUM,		/* 30 */
+	TPM_LONG,
+	TPM_MEDIUM,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,		/* 35 */
+	TPM_MEDIUM,
+	TPM_MEDIUM,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_MEDIUM,		/* 40 */
+	TPM_LONG,
+	TPM_MEDIUM,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,		/* 45 */
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_LONG,
+	TPM_MEDIUM,		/* 50 */
+	TPM_MEDIUM,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,		/* 55 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_MEDIUM,		/* 60 */
+	TPM_MEDIUM,
+	TPM_MEDIUM,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_MEDIUM,		/* 65 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,		/* 70 */
+	TPM_SHORT,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,		/* 75 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_LONG,		/* 80 */
+	TPM_UNDEFINED,
+	TPM_MEDIUM,
+	TPM_LONG,
+	TPM_SHORT,
+	TPM_UNDEFINED,		/* 85 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,		/* 90 */
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_UNDEFINED,		/* 95 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_MEDIUM,		/* 100 */
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,		/* 105 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,		/* 110 */
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,		/* 115 */
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_LONG,		/* 120 */
+	TPM_LONG,
+	TPM_MEDIUM,
+	TPM_UNDEFINED,
+	TPM_SHORT,
+	TPM_SHORT,		/* 125 */
+	TPM_SHORT,
+	TPM_LONG,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,		/* 130 */
+	TPM_MEDIUM,
+	TPM_UNDEFINED,
+	TPM_SHORT,
+	TPM_MEDIUM,
+	TPM_UNDEFINED,		/* 135 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,		/* 140 */
+	TPM_SHORT,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,		/* 145 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,		/* 150 */
+	TPM_MEDIUM,
+	TPM_MEDIUM,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_UNDEFINED,		/* 155 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,		/* 160 */
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,		/* 165 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_LONG,		/* 170 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,		/* 175 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_MEDIUM,		/* 180 */
+	TPM_SHORT,
+	TPM_MEDIUM,
+	TPM_MEDIUM,
+	TPM_MEDIUM,
+	TPM_MEDIUM,		/* 185 */
+	TPM_SHORT,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,		/* 190 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,		/* 195 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,		/* 200 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,
+	TPM_SHORT,		/* 205 */
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_MEDIUM,		/* 210 */
+	TPM_UNDEFINED,
+	TPM_MEDIUM,
+	TPM_MEDIUM,
+	TPM_MEDIUM,
+	TPM_UNDEFINED,		/* 215 */
+	TPM_MEDIUM,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,
+	TPM_SHORT,		/* 220 */
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_SHORT,
+	TPM_UNDEFINED,		/* 225 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,		/* 230 */
+	TPM_LONG,
+	TPM_MEDIUM,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,		/* 235 */
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_UNDEFINED,
+	TPM_SHORT,		/* 240 */
+	TPM_UNDEFINED,
+	TPM_MEDIUM,
+};
+
+/*
+ * Returns max number of jiffies to wait
+ */
+unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
+					   u32 ordinal)
+{
+	int duration_idx = TPM_UNDEFINED;
+	int duration = 0;
+	u8 category = (ordinal >> 24) & 0xFF;
+
+	if ((category == TPM_PROTECTED_COMMAND && ordinal < TPM_MAX_ORDINAL) ||
+	    (category == TPM_CONNECTION_COMMAND && ordinal < TSC_MAX_ORDINAL))
+		duration_idx = tpm_ordinal_duration[ordinal];
+
+	if (duration_idx != TPM_UNDEFINED)
+		duration = chip->vendor.duration[duration_idx];
+	if (duration <= 0)
+		return 2 * 60 * HZ;
+	else
+		return duration;
+}
+EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
+
+/*
+ * Internal kernel interface to transmit TPM commands
+ */
+ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
+		     size_t bufsiz)
+{
+	ssize_t rc;
+	u32 count, ordinal;
+	unsigned long stop;
+
+	if (bufsiz > TPM_BUFSIZE)
+		bufsiz = TPM_BUFSIZE;
+
+	count = be32_to_cpu(*((__be32 *) (buf + 2)));
+	ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
+	if (count == 0)
+		return -ENODATA;
+	if (count > bufsiz) {
+		dev_err(chip->pdev,
+			"invalid count value %x %zx\n", count, bufsiz);
+		return -E2BIG;
+	}
+
+	mutex_lock(&chip->tpm_mutex);
+
+	rc = chip->ops->send(chip, (u8 *) buf, count);
+	if (rc < 0) {
+		dev_err(chip->pdev,
+			"tpm_transmit: tpm_send: error %zd\n", rc);
+		goto out;
+	}
+
+	if (chip->vendor.irq)
+		goto out_recv;
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
+	else
+		stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
+	do {
+		u8 status = chip->ops->status(chip);
+		if ((status & chip->ops->req_complete_mask) ==
+		    chip->ops->req_complete_val)
+			goto out_recv;
+
+		if (chip->ops->req_canceled(chip, status)) {
+			dev_err(chip->pdev, "Operation Canceled\n");
+			rc = -ECANCELED;
+			goto out;
+		}
+
+		msleep(TPM_TIMEOUT);	/* CHECK */
+		rmb();
+	} while (time_before(jiffies, stop));
+
+	chip->ops->cancel(chip);
+	dev_err(chip->pdev, "Operation Timed out\n");
+	rc = -ETIME;
+	goto out;
+
+out_recv:
+	rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
+	if (rc < 0)
+		dev_err(chip->pdev,
+			"tpm_transmit: tpm_recv: error %zd\n", rc);
+out:
+	mutex_unlock(&chip->tpm_mutex);
+	return rc;
+}
+
+#define TPM_DIGEST_SIZE 20
+#define TPM_RET_CODE_IDX 6
+
+ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd,
+			 int len, const char *desc)
+{
+	struct tpm_output_header *header;
+	int err;
+
+	len = tpm_transmit(chip, (u8 *) cmd, len);
+	if (len <  0)
+		return len;
+	else if (len < TPM_HEADER_SIZE)
+		return -EFAULT;
+
+	header = cmd;
+
+	err = be32_to_cpu(header->return_code);
+	if (err != 0 && desc)
+		dev_err(chip->pdev, "A TPM error (%d) occurred %s\n", err,
+			desc);
+
+	return err;
+}
+
+#define TPM_INTERNAL_RESULT_SIZE 200
+#define TPM_ORD_GET_CAP cpu_to_be32(101)
+#define TPM_ORD_GET_RANDOM cpu_to_be32(70)
+
+static const struct tpm_input_header tpm_getcap_header = {
+	.tag = TPM_TAG_RQU_COMMAND,
+	.length = cpu_to_be32(22),
+	.ordinal = TPM_ORD_GET_CAP
+};
+
+ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
+		   const char *desc)
+{
+	struct tpm_cmd_t tpm_cmd;
+	int rc;
+	struct tpm_chip *chip = dev_get_drvdata(dev);
+
+	tpm_cmd.header.in = tpm_getcap_header;
+	if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
+		tpm_cmd.params.getcap_in.cap = subcap_id;
+		/*subcap field not necessary */
+		tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
+		tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
+	} else {
+		if (subcap_id == TPM_CAP_FLAG_PERM ||
+		    subcap_id == TPM_CAP_FLAG_VOL)
+			tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
+		else
+			tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
+		tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
+		tpm_cmd.params.getcap_in.subcap = subcap_id;
+	}
+	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
+	if (!rc)
+		*cap = tpm_cmd.params.getcap_out.cap;
+	return rc;
+}
+
+void tpm_gen_interrupt(struct tpm_chip *chip)
+{
+	struct	tpm_cmd_t tpm_cmd;
+	ssize_t rc;
+
+	tpm_cmd.header.in = tpm_getcap_header;
+	tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
+	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
+	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
+
+	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
+			      "attempting to determine the timeouts");
+}
+EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
+
+#define TPM_ORD_STARTUP cpu_to_be32(153)
+#define TPM_ST_CLEAR cpu_to_be16(1)
+#define TPM_ST_STATE cpu_to_be16(2)
+#define TPM_ST_DEACTIVATED cpu_to_be16(3)
+static const struct tpm_input_header tpm_startup_header = {
+	.tag = TPM_TAG_RQU_COMMAND,
+	.length = cpu_to_be32(12),
+	.ordinal = TPM_ORD_STARTUP
+};
+
+static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
+{
+	struct tpm_cmd_t start_cmd;
+	start_cmd.header.in = tpm_startup_header;
+
+	start_cmd.params.startup_in.startup_type = startup_type;
+	return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
+				"attempting to start the TPM");
+}
+
+int tpm_get_timeouts(struct tpm_chip *chip)
+{
+	struct tpm_cmd_t tpm_cmd;
+	unsigned long new_timeout[4];
+	unsigned long old_timeout[4];
+	struct duration_t *duration_cap;
+	ssize_t rc;
+
+	tpm_cmd.header.in = tpm_getcap_header;
+	tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
+	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
+	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
+	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
+
+	if (rc == TPM_ERR_INVALID_POSTINIT) {
+		/* The TPM is not started, we are the first to talk to it.
+		   Execute a startup command. */
+		dev_info(chip->pdev, "Issuing TPM_STARTUP");
+		if (tpm_startup(chip, TPM_ST_CLEAR))
+			return rc;
+
+		tpm_cmd.header.in = tpm_getcap_header;
+		tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
+		tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
+		tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
+		rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
+				  NULL);
+	}
+	if (rc) {
+		dev_err(chip->pdev,
+			"A TPM error (%zd) occurred attempting to determine the timeouts\n",
+			rc);
+		goto duration;
+	}
+
+	if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
+	    be32_to_cpu(tpm_cmd.header.out.length)
+	    != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
+		return -EINVAL;
+
+	old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
+	old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
+	old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
+	old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
+	memcpy(new_timeout, old_timeout, sizeof(new_timeout));
+
+	/*
+	 * Provide ability for vendor overrides of timeout values in case
+	 * of misreporting.
+	 */
+	if (chip->ops->update_timeouts != NULL)
+		chip->vendor.timeout_adjusted =
+			chip->ops->update_timeouts(chip, new_timeout);
+
+	if (!chip->vendor.timeout_adjusted) {
+		/* Don't overwrite default if value is 0 */
+		if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
+			int i;
+
+			/* timeouts in msec rather usec */
+			for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
+				new_timeout[i] *= 1000;
+			chip->vendor.timeout_adjusted = true;
+		}
+	}
+
+	/* Report adjusted timeouts */
+	if (chip->vendor.timeout_adjusted) {
+		dev_info(chip->pdev,
+			 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
+			 old_timeout[0], new_timeout[0],
+			 old_timeout[1], new_timeout[1],
+			 old_timeout[2], new_timeout[2],
+			 old_timeout[3], new_timeout[3]);
+	}
+
+	chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
+	chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
+	chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
+	chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
+
+duration:
+	tpm_cmd.header.in = tpm_getcap_header;
+	tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
+	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
+	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
+
+	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
+			      "attempting to determine the durations");
+	if (rc)
+		return rc;
+
+	if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
+	    be32_to_cpu(tpm_cmd.header.out.length)
+	    != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
+		return -EINVAL;
+
+	duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
+	chip->vendor.duration[TPM_SHORT] =
+	    usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
+	chip->vendor.duration[TPM_MEDIUM] =
+	    usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
+	chip->vendor.duration[TPM_LONG] =
+	    usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
+
+	/* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
+	 * value wrong and apparently reports msecs rather than usecs. So we
+	 * fix up the resulting too-small TPM_SHORT value to make things work.
+	 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
+	 */
+	if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
+		chip->vendor.duration[TPM_SHORT] = HZ;
+		chip->vendor.duration[TPM_MEDIUM] *= 1000;
+		chip->vendor.duration[TPM_LONG] *= 1000;
+		chip->vendor.duration_adjusted = true;
+		dev_info(chip->pdev, "Adjusting TPM timeout parameters.");
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tpm_get_timeouts);
+
+#define TPM_ORD_CONTINUE_SELFTEST 83
+#define CONTINUE_SELFTEST_RESULT_SIZE 10
+
+static struct tpm_input_header continue_selftest_header = {
+	.tag = TPM_TAG_RQU_COMMAND,
+	.length = cpu_to_be32(10),
+	.ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
+};
+
+/**
+ * tpm_continue_selftest -- run TPM's selftest
+ * @chip: TPM chip to use
+ *
+ * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
+ * a TPM error code.
+ */
+static int tpm_continue_selftest(struct tpm_chip *chip)
+{
+	int rc;
+	struct tpm_cmd_t cmd;
+
+	cmd.header.in = continue_selftest_header;
+	rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
+			      "continue selftest");
+	return rc;
+}
+
+#define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
+#define READ_PCR_RESULT_SIZE 30
+static struct tpm_input_header pcrread_header = {
+	.tag = TPM_TAG_RQU_COMMAND,
+	.length = cpu_to_be32(14),
+	.ordinal = TPM_ORDINAL_PCRREAD
+};
+
+int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
+{
+	int rc;
+	struct tpm_cmd_t cmd;
+
+	cmd.header.in = pcrread_header;
+	cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
+	rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
+			      "attempting to read a pcr value");
+
+	if (rc == 0)
+		memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
+		       TPM_DIGEST_SIZE);
+	return rc;
+}
+
+/**
+ * tpm_pcr_read - read a pcr value
+ * @chip_num:	tpm idx # or ANY
+ * @pcr_idx:	pcr idx to retrieve
+ * @res_buf:	TPM_PCR value
+ *		size of res_buf is 20 bytes (or NULL if you don't care)
+ *
+ * The TPM driver should be built-in, but for whatever reason it
+ * isn't, protect against the chip disappearing, by incrementing
+ * the module usage count.
+ */
+int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
+{
+	struct tpm_chip *chip;
+	int rc;
+
+	chip = tpm_chip_find_get(chip_num);
+	if (chip == NULL)
+		return -ENODEV;
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
+	else
+		rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
+	tpm_chip_put(chip);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_pcr_read);
+
+/**
+ * tpm_pcr_extend - extend pcr value with hash
+ * @chip_num:	tpm idx # or AN&
+ * @pcr_idx:	pcr idx to extend
+ * @hash:	hash value used to extend pcr value
+ *
+ * The TPM driver should be built-in, but for whatever reason it
+ * isn't, protect against the chip disappearing, by incrementing
+ * the module usage count.
+ */
+#define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
+#define EXTEND_PCR_RESULT_SIZE 34
+static struct tpm_input_header pcrextend_header = {
+	.tag = TPM_TAG_RQU_COMMAND,
+	.length = cpu_to_be32(34),
+	.ordinal = TPM_ORD_PCR_EXTEND
+};
+
+int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
+{
+	struct tpm_cmd_t cmd;
+	int rc;
+	struct tpm_chip *chip;
+
+	chip = tpm_chip_find_get(chip_num);
+	if (chip == NULL)
+		return -ENODEV;
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+		rc = tpm2_pcr_extend(chip, pcr_idx, hash);
+		tpm_chip_put(chip);
+		return rc;
+	}
+
+	cmd.header.in = pcrextend_header;
+	cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
+	memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
+	rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
+			      "attempting extend a PCR value");
+
+	tpm_chip_put(chip);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_pcr_extend);
+
+/**
+ * tpm_do_selftest - have the TPM continue its selftest and wait until it
+ *                   can receive further commands
+ * @chip: TPM chip to use
+ *
+ * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
+ * a TPM error code.
+ */
+int tpm_do_selftest(struct tpm_chip *chip)
+{
+	int rc;
+	unsigned int loops;
+	unsigned int delay_msec = 100;
+	unsigned long duration;
+	struct tpm_cmd_t cmd;
+
+	duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
+
+	loops = jiffies_to_msecs(duration) / delay_msec;
+
+	rc = tpm_continue_selftest(chip);
+	/* This may fail if there was no TPM driver during a suspend/resume
+	 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
+	 */
+	if (rc)
+		return rc;
+
+	do {
+		/* Attempt to read a PCR value */
+		cmd.header.in = pcrread_header;
+		cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
+		rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
+		/* Some buggy TPMs will not respond to tpm_tis_ready() for
+		 * around 300ms while the self test is ongoing, keep trying
+		 * until the self test duration expires. */
+		if (rc == -ETIME) {
+			dev_info(chip->pdev, HW_ERR "TPM command timed out during continue self test");
+			msleep(delay_msec);
+			continue;
+		}
+
+		if (rc < TPM_HEADER_SIZE)
+			return -EFAULT;
+
+		rc = be32_to_cpu(cmd.header.out.return_code);
+		if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
+			dev_info(chip->pdev,
+				 "TPM is disabled/deactivated (0x%X)\n", rc);
+			/* TPM is disabled and/or deactivated; driver can
+			 * proceed and TPM does handle commands for
+			 * suspend/resume correctly
+			 */
+			return 0;
+		}
+		if (rc != TPM_WARN_DOING_SELFTEST)
+			return rc;
+		msleep(delay_msec);
+	} while (--loops > 0);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_do_selftest);
+
+int tpm_send(u32 chip_num, void *cmd, size_t buflen)
+{
+	struct tpm_chip *chip;
+	int rc;
+
+	chip = tpm_chip_find_get(chip_num);
+	if (chip == NULL)
+		return -ENODEV;
+
+	rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
+
+	tpm_chip_put(chip);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_send);
+
+static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
+					bool check_cancel, bool *canceled)
+{
+	u8 status = chip->ops->status(chip);
+
+	*canceled = false;
+	if ((status & mask) == mask)
+		return true;
+	if (check_cancel && chip->ops->req_canceled(chip, status)) {
+		*canceled = true;
+		return true;
+	}
+	return false;
+}
+
+int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
+		      wait_queue_head_t *queue, bool check_cancel)
+{
+	unsigned long stop;
+	long rc;
+	u8 status;
+	bool canceled = false;
+
+	/* check current status */
+	status = chip->ops->status(chip);
+	if ((status & mask) == mask)
+		return 0;
+
+	stop = jiffies + timeout;
+
+	if (chip->vendor.irq) {
+again:
+		timeout = stop - jiffies;
+		if ((long)timeout <= 0)
+			return -ETIME;
+		rc = wait_event_interruptible_timeout(*queue,
+			wait_for_tpm_stat_cond(chip, mask, check_cancel,
+					       &canceled),
+			timeout);
+		if (rc > 0) {
+			if (canceled)
+				return -ECANCELED;
+			return 0;
+		}
+		if (rc == -ERESTARTSYS && freezing(current)) {
+			clear_thread_flag(TIF_SIGPENDING);
+			goto again;
+		}
+	} else {
+		do {
+			msleep(TPM_TIMEOUT);
+			status = chip->ops->status(chip);
+			if ((status & mask) == mask)
+				return 0;
+		} while (time_before(jiffies, stop));
+	}
+	return -ETIME;
+}
+EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
+
+#define TPM_ORD_SAVESTATE cpu_to_be32(152)
+#define SAVESTATE_RESULT_SIZE 10
+
+static struct tpm_input_header savestate_header = {
+	.tag = TPM_TAG_RQU_COMMAND,
+	.length = cpu_to_be32(10),
+	.ordinal = TPM_ORD_SAVESTATE
+};
+
+/*
+ * We are about to suspend. Save the TPM state
+ * so that it can be restored.
+ */
+int tpm_pm_suspend(struct device *dev)
+{
+	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_cmd_t cmd;
+	int rc, try;
+
+	u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
+
+	if (chip == NULL)
+		return -ENODEV;
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+		tpm2_shutdown(chip, TPM2_SU_STATE);
+		return 0;
+	}
+
+	/* for buggy tpm, flush pcrs with extend to selected dummy */
+	if (tpm_suspend_pcr) {
+		cmd.header.in = pcrextend_header;
+		cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
+		memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
+		       TPM_DIGEST_SIZE);
+		rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
+				      "extending dummy pcr before suspend");
+	}
+
+	/* now do the actual savestate */
+	for (try = 0; try < TPM_RETRY; try++) {
+		cmd.header.in = savestate_header;
+		rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
+
+		/*
+		 * If the TPM indicates that it is too busy to respond to
+		 * this command then retry before giving up.  It can take
+		 * several seconds for this TPM to be ready.
+		 *
+		 * This can happen if the TPM has already been sent the
+		 * SaveState command before the driver has loaded.  TCG 1.2
+		 * specification states that any communication after SaveState
+		 * may cause the TPM to invalidate previously saved state.
+		 */
+		if (rc != TPM_WARN_RETRY)
+			break;
+		msleep(TPM_TIMEOUT_RETRY);
+	}
+
+	if (rc)
+		dev_err(chip->pdev,
+			"Error (%d) sending savestate before suspend\n", rc);
+	else if (try > 0)
+		dev_warn(chip->pdev, "TPM savestate took %dms\n",
+			 try * TPM_TIMEOUT_RETRY);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_pm_suspend);
+
+/*
+ * Resume from a power safe. The BIOS already restored
+ * the TPM state.
+ */
+int tpm_pm_resume(struct device *dev)
+{
+	struct tpm_chip *chip = dev_get_drvdata(dev);
+
+	if (chip == NULL)
+		return -ENODEV;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tpm_pm_resume);
+
+#define TPM_GETRANDOM_RESULT_SIZE	18
+static struct tpm_input_header tpm_getrandom_header = {
+	.tag = TPM_TAG_RQU_COMMAND,
+	.length = cpu_to_be32(14),
+	.ordinal = TPM_ORD_GET_RANDOM
+};
+
+/**
+ * tpm_get_random() - Get random bytes from the tpm's RNG
+ * @chip_num: A specific chip number for the request or TPM_ANY_NUM
+ * @out: destination buffer for the random bytes
+ * @max: the max number of bytes to write to @out
+ *
+ * Returns < 0 on error and the number of bytes read on success
+ */
+int tpm_get_random(u32 chip_num, u8 *out, size_t max)
+{
+	struct tpm_chip *chip;
+	struct tpm_cmd_t tpm_cmd;
+	u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
+	int err, total = 0, retries = 5;
+	u8 *dest = out;
+
+	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
+		return -EINVAL;
+
+	chip = tpm_chip_find_get(chip_num);
+	if (chip == NULL)
+		return -ENODEV;
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+		err = tpm2_get_random(chip, out, max);
+		tpm_chip_put(chip);
+		return err;
+	}
+
+	do {
+		tpm_cmd.header.in = tpm_getrandom_header;
+		tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
+
+		err = tpm_transmit_cmd(chip, &tpm_cmd,
+				   TPM_GETRANDOM_RESULT_SIZE + num_bytes,
+				   "attempting get random");
+		if (err)
+			break;
+
+		recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
+		memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
+
+		dest += recd;
+		total += recd;
+		num_bytes -= recd;
+	} while (retries-- && total < max);
+
+	tpm_chip_put(chip);
+	return total ? total : -EIO;
+}
+EXPORT_SYMBOL_GPL(tpm_get_random);
+
+static int __init tpm_init(void)
+{
+	int rc;
+
+	tpm_class = class_create(THIS_MODULE, "tpm");
+	if (IS_ERR(tpm_class)) {
+		pr_err("couldn't create tpm class\n");
+		return PTR_ERR(tpm_class);
+	}
+
+	rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
+	if (rc < 0) {
+		pr_err("tpm: failed to allocate char dev region\n");
+		class_destroy(tpm_class);
+		return rc;
+	}
+
+	return 0;
+}
+
+static void __exit tpm_exit(void)
+{
+	class_destroy(tpm_class);
+	unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
+}
+
+subsys_initcall(tpm_init);
+module_exit(tpm_exit);
+
+MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
+MODULE_DESCRIPTION("TPM Driver");
+MODULE_VERSION("2.0");
+MODULE_LICENSE("GPL");