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linux/drivers/char/tpm/tpm-interface.c

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/*
* 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 <linux/pm_runtime.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;
/*
* We only have a duration table for protected commands, where the upper
* 16 bits are 0. For the few other ordinals the fallback will be used.
*/
if (ordinal < TPM_MAX_ORDINAL)
duration_idx = tpm_ordinal_duration[ordinal];
if (duration_idx != TPM_UNDEFINED)
duration = chip->duration[duration_idx];
if (duration <= 0)
return 2 * 60 * HZ;
else
return duration;
}
EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
/**
* tmp_transmit - Internal kernel interface to transmit TPM commands.
*
* @chip: TPM chip to use
* @buf: TPM command buffer
* @bufsiz: length of the TPM command buffer
* @flags: tpm transmit flags - bitmap
*
* Return:
* 0 when the operation is successful.
* A negative number for system errors (errno).
*/
ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
unsigned int flags)
{
ssize_t rc;
u32 count, ordinal;
unsigned long stop;
if (bufsiz < TPM_HEADER_SIZE)
return -EINVAL;
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->dev,
"invalid count value %x %zx\n", count, bufsiz);
return -E2BIG;
}
if (!(flags & TPM_TRANSMIT_UNLOCKED))
mutex_lock(&chip->tpm_mutex);
if (chip->dev.parent)
pm_runtime_get_sync(chip->dev.parent);
rc = chip->ops->send(chip, (u8 *) buf, count);
if (rc < 0) {
dev_err(&chip->dev,
"tpm_transmit: tpm_send: error %zd\n", rc);
goto out;
}
if (chip->flags & TPM_CHIP_FLAG_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->dev, "Operation Canceled\n");
rc = -ECANCELED;
goto out;
}
msleep(TPM_TIMEOUT); /* CHECK */
rmb();
} while (time_before(jiffies, stop));
chip->ops->cancel(chip);
dev_err(&chip->dev, "Operation Timed out\n");
rc = -ETIME;
goto out;
out_recv:
rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
if (rc < 0)
dev_err(&chip->dev,
"tpm_transmit: tpm_recv: error %zd\n", rc);
out:
if (chip->dev.parent)
pm_runtime_put_sync(chip->dev.parent);
if (!(flags & TPM_TRANSMIT_UNLOCKED))
mutex_unlock(&chip->tpm_mutex);
return rc;
}
/**
* tmp_transmit_cmd - send a tpm command to the device
* The function extracts tpm out header return code
*
* @chip: TPM chip to use
* @buf: TPM command buffer
* @bufsiz: length of the buffer
* @min_rsp_body_length: minimum expected length of response body
* @flags: tpm transmit flags - bitmap
* @desc: command description used in the error message
*
* Return:
* 0 when the operation is successful.
* A negative number for system errors (errno).
* A positive number for a TPM error.
*/
ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *buf,
size_t bufsiz, size_t min_rsp_body_length,
unsigned int flags, const char *desc)
{
const struct tpm_output_header *header;
int err;
ssize_t len;
len = tpm_transmit(chip, (const u8 *)buf, bufsiz, flags);
if (len < 0)
return len;
else if (len < TPM_HEADER_SIZE)
return -EFAULT;
header = buf;
if (len != be32_to_cpu(header->length))
return -EFAULT;
err = be32_to_cpu(header->return_code);
if (err != 0 && desc)
dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
desc);
if (err)
return err;
if (len < min_rsp_body_length + TPM_HEADER_SIZE)
return -EFAULT;
return 0;
}
#define TPM_DIGEST_SIZE 20
#define TPM_RET_CODE_IDX 6
#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 tpm_chip *chip, u32 subcap_id, cap_t *cap,
const char *desc, size_t min_cap_length)
{
struct tpm_cmd_t tpm_cmd;
int rc;
tpm_cmd.header.in = tpm_getcap_header;
if (subcap_id == TPM_CAP_VERSION_1_1 ||
subcap_id == TPM_CAP_VERSION_1_2) {
tpm_cmd.params.getcap_in.cap = cpu_to_be32(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 =
cpu_to_be32(TPM_CAP_FLAG);
else
tpm_cmd.params.getcap_in.cap =
cpu_to_be32(TPM_CAP_PROP);
tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
tpm_cmd.params.getcap_in.subcap = cpu_to_be32(subcap_id);
}
rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
min_cap_length, 0, desc);
if (!rc)
*cap = tpm_cmd.params.getcap_out.cap;
return rc;
}
EXPORT_SYMBOL_GPL(tpm_getcap);
#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, 0,
0, "attempting to start the TPM");
}
int tpm_get_timeouts(struct tpm_chip *chip)
{
cap_t cap;
unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
ssize_t rc;
if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
return 0;
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
/* Fixed timeouts for TPM2 */
chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
chip->duration[TPM_SHORT] =
msecs_to_jiffies(TPM2_DURATION_SHORT);
chip->duration[TPM_MEDIUM] =
msecs_to_jiffies(TPM2_DURATION_MEDIUM);
chip->duration[TPM_LONG] =
msecs_to_jiffies(TPM2_DURATION_LONG);
chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
return 0;
}
rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
sizeof(cap.timeout));
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->dev, "Issuing TPM_STARTUP\n");
if (tpm_startup(chip, TPM_ST_CLEAR))
return rc;
rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
"attempting to determine the timeouts",
sizeof(cap.timeout));
}
if (rc) {
dev_err(&chip->dev,
"A TPM error (%zd) occurred attempting to determine the timeouts\n",
rc);
return rc;
}
timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
timeout_chip[0] = be32_to_cpu(cap.timeout.a);
timeout_chip[1] = be32_to_cpu(cap.timeout.b);
timeout_chip[2] = be32_to_cpu(cap.timeout.c);
timeout_chip[3] = be32_to_cpu(cap.timeout.d);
memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
/*
* Provide ability for vendor overrides of timeout values in case
* of misreporting.
*/
if (chip->ops->update_timeouts != NULL)
chip->timeout_adjusted =
chip->ops->update_timeouts(chip, timeout_eff);
if (!chip->timeout_adjusted) {
/* Restore default if chip reported 0 */
int i;
for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
if (timeout_eff[i])
continue;
timeout_eff[i] = timeout_old[i];
chip->timeout_adjusted = true;
}
if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
/* timeouts in msec rather usec */
for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
timeout_eff[i] *= 1000;
chip->timeout_adjusted = true;
}
}
/* Report adjusted timeouts */
if (chip->timeout_adjusted) {
dev_info(&chip->dev,
HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
timeout_chip[0], timeout_eff[0],
timeout_chip[1], timeout_eff[1],
timeout_chip[2], timeout_eff[2],
timeout_chip[3], timeout_eff[3]);
}
chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
"attempting to determine the durations",
sizeof(cap.duration));
if (rc)
return rc;
chip->duration[TPM_SHORT] =
usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
chip->duration[TPM_MEDIUM] =
usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
chip->duration[TPM_LONG] =
usecs_to_jiffies(be32_to_cpu(cap.duration.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->duration[TPM_SHORT] < (HZ / 100)) {
chip->duration[TPM_SHORT] = HZ;
chip->duration[TPM_MEDIUM] *= 1000;
chip->duration[TPM_LONG] *= 1000;
chip->duration_adjusted = true;
dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
}
chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
return 0;
}
EXPORT_SYMBOL_GPL(tpm_get_timeouts);
#define TPM_ORD_CONTINUE_SELFTEST 83
#define CONTINUE_SELFTEST_RESULT_SIZE 10
static const 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, 0, 0,
"continue selftest");
return rc;
}
#define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
#define READ_PCR_RESULT_SIZE 30
#define READ_PCR_RESULT_BODY_SIZE 20
static const 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,
READ_PCR_RESULT_BODY_SIZE, 0,
"attempting to read a pcr value");
if (rc == 0)
memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
TPM_DIGEST_SIZE);
return rc;
}
/**
* tpm_is_tpm2 - is the chip a TPM2 chip?
* @chip_num: tpm idx # or ANY
*
* Returns < 0 on error, and 1 or 0 on success depending whether the chip
* is a TPM2 chip.
*/
int tpm_is_tpm2(u32 chip_num)
{
struct tpm_chip *chip;
int rc;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL)
return -ENODEV;
rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
tpm_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_is_tpm2);
/**
* 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_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_pcr_read);
#define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
#define EXTEND_PCR_RESULT_SIZE 34
#define EXTEND_PCR_RESULT_BODY_SIZE 24
static const struct tpm_input_header pcrextend_header = {
.tag = TPM_TAG_RQU_COMMAND,
.length = cpu_to_be32(34),
.ordinal = TPM_ORD_PCR_EXTEND
};
/**
* 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.
*/
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_put_ops(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,
EXTEND_PCR_RESULT_BODY_SIZE, 0,
"attempting extend a PCR value");
tpm_put_ops(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;
u8 dummy[TPM_DIGEST_SIZE];
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 */
rc = tpm_pcr_read_dev(chip, 0, dummy);
/* 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->dev, HW_ERR
"TPM command timed out during continue self test");
msleep(delay_msec);
continue;
}
if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
dev_info(&chip->dev,
"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);
/**
* tpm1_auto_startup - Perform the standard automatic TPM initialization
* sequence
* @chip: TPM chip to use
*
* Returns 0 on success, < 0 in case of fatal error.
*/
int tpm1_auto_startup(struct tpm_chip *chip)
{
int rc;
rc = tpm_get_timeouts(chip);
if (rc)
goto out;
rc = tpm_do_selftest(chip);
if (rc) {
dev_err(&chip->dev, "TPM self test failed\n");
goto out;
}
return rc;
out:
if (rc > 0)
rc = -ENODEV;
return rc;
}
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, 0, 0, "attempting tpm_cmd");
tpm_put_ops(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->flags & TPM_CHIP_FLAG_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 const 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,
EXTEND_PCR_RESULT_BODY_SIZE, 0,
"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, 0,
0, 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->dev,
"Error (%d) sending savestate before suspend\n", rc);
else if (try > 0)
dev_warn(&chip->dev, "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 const 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), rlength;
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_put_ops(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,
offsetof(struct tpm_getrandom_out,
rng_data),
0, "attempting get random");
if (err)
break;
recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
rlength = be32_to_cpu(tpm_cmd.header.out.length);
if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
recd) {
total = -EFAULT;
break;
}
memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
dest += recd;
total += recd;
num_bytes -= recd;
} while (retries-- && total < max);
tpm_put_ops(chip);
return total ? total : -EIO;
}
EXPORT_SYMBOL_GPL(tpm_get_random);
/**
* tpm_seal_trusted() - seal a trusted key
* @chip_num: A specific chip number for the request or TPM_ANY_NUM
* @options: authentication values and other options
* @payload: the key data in clear and encrypted form
*
* Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
* are supported.
*/
int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
struct tpm_chip *chip;
int rc;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
return -ENODEV;
rc = tpm2_seal_trusted(chip, payload, options);
tpm_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_seal_trusted);
/**
* tpm_unseal_trusted() - unseal a trusted key
* @chip_num: A specific chip number for the request or TPM_ANY_NUM
* @options: authentication values and other options
* @payload: the key data in clear and encrypted form
*
* Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
* are supported.
*/
int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
struct tpm_chip *chip;
int rc;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
return -ENODEV;
rc = tpm2_unseal_trusted(chip, payload, options);
tpm_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
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)
{
idr_destroy(&dev_nums_idr);
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");
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