linux/drivers/char/tpm/tpm-interface.c
Jarkko Sakkinen 313d21eeab tpm: device class for tpm
Added own device class for TPM. Uses MISC_MAJOR:TPM_MINOR for the
first character device in order to retain backwards compatibility.
Added tpm_dev_release() back attached to the character device.

I've been running this code now for a while on my laptop (Lenovo
T430S) TrouSerS works perfectly without modifications. I don't
believe it breaks anything significantly.

The sysfs attributes that have been placed under the wrong place
and are against sysfs-rules.txt should be probably left to
stagnate under platform device directory and start defining
new sysfs attributes to the char device directory.

Guidelines for future TPM sysfs attributes should be probably
along the lines of

- Single flat set of mandatory sysfs attributes. For example,
  current PPI interface is way way too rich when you only want
  to use it to clear and activate the TPM.

- Define sysfs attribute if and only if there's no way to get
  the value from ring-3. No attributes for TPM properties. It's
  just unnecessary maintenance hurdle that we don't want.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jasob Gunthorpe <jason.gunthorpe@obsidianresearch.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: Scot Doyle <lkml14@scotdoyle.com>
Tested-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
2015-01-17 14:00:10 +01:00

1033 lines
25 KiB
C

/*
* 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;
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;
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;
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;
/* 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;
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");