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OpenCloudOS-Kernel/drivers/char/tpm/tpm1-cmd.c

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// SPDX-License-Identifier: GPL-2.0
/*
* 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>
*
* Device driver for TCG/TCPA TPM (trusted platform module).
* Specifications at www.trustedcomputinggroup.org
*/
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/freezer.h>
#include <linux/tpm_eventlog.h>
#include "tpm.h"
#define TPM_MAX_ORDINAL 243
/*
* 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 tpm1_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,
};
/**
* tpm1_calc_ordinal_duration() - calculate the maximum command duration
* @chip: TPM chip to use.
* @ordinal: TPM command ordinal.
*
* The function returns the maximum amount of time the chip could take
* to return the result for a particular ordinal in jiffies.
*
* Return: A maximal duration time for an ordinal in jiffies.
*/
unsigned long tpm1_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 = tpm1_ordinal_duration[ordinal];
if (duration_idx != TPM_UNDEFINED)
duration = chip->duration[duration_idx];
if (duration <= 0)
return 2 * 60 * HZ;
else
return duration;
}
#define TPM_ORD_STARTUP 153
#define TPM_ST_CLEAR 1
/**
* tpm_startup() - turn on the TPM
* @chip: TPM chip to use
*
* Normally the firmware should start the TPM. This function is provided as a
* workaround if this does not happen. A legal case for this could be for
* example when a TPM emulator is used.
*
* Return: same as tpm_transmit_cmd()
*/
static int tpm1_startup(struct tpm_chip *chip)
{
struct tpm_buf buf;
int rc;
dev_info(&chip->dev, "starting up the TPM manually\n");
rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
if (rc < 0)
return rc;
tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
tpm_buf_destroy(&buf);
return rc;
}
int tpm1_get_timeouts(struct tpm_chip *chip)
{
cap_t cap;
unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
ssize_t rc;
rc = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
sizeof(cap.timeout));
if (rc == TPM_ERR_INVALID_POSTINIT) {
if (tpm1_startup(chip))
return rc;
rc = tpm1_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)
chip->ops->update_timeouts(chip, timeout_eff);
if (!chip->timeout_adjusted) {
/* Restore default if chip reported 0 */
unsigned 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 = tpm1_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));
chip->duration[TPM_LONG_LONG] = 0; /* not used under 1.2 */
/* 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;
}
#define TPM_ORD_PCR_EXTEND 20
int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash,
const char *log_msg)
{
struct tpm_buf buf;
int rc;
rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
if (rc)
return rc;
tpm_buf_append_u32(&buf, pcr_idx);
tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);
rc = tpm_transmit_cmd(chip, &buf, TPM_DIGEST_SIZE, log_msg);
tpm_buf_destroy(&buf);
return rc;
}
#define TPM_ORD_GET_CAP 101
ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
const char *desc, size_t min_cap_length)
{
struct tpm_buf buf;
int rc;
rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
if (rc)
return rc;
if (subcap_id == TPM_CAP_VERSION_1_1 ||
subcap_id == TPM_CAP_VERSION_1_2) {
tpm_buf_append_u32(&buf, subcap_id);
tpm_buf_append_u32(&buf, 0);
} else {
if (subcap_id == TPM_CAP_FLAG_PERM ||
subcap_id == TPM_CAP_FLAG_VOL)
tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
else
tpm_buf_append_u32(&buf, TPM_CAP_PROP);
tpm_buf_append_u32(&buf, 4);
tpm_buf_append_u32(&buf, subcap_id);
}
rc = tpm_transmit_cmd(chip, &buf, min_cap_length, desc);
if (!rc)
*cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
tpm_buf_destroy(&buf);
return rc;
}
EXPORT_SYMBOL_GPL(tpm1_getcap);
#define TPM_ORD_GET_RANDOM 70
struct tpm1_get_random_out {
__be32 rng_data_len;
u8 rng_data[TPM_MAX_RNG_DATA];
} __packed;
/**
* tpm1_get_random() - get random bytes from the TPM's RNG
* @chip: a &struct tpm_chip instance
* @dest: destination buffer for the random bytes
* @max: the maximum number of bytes to write to @dest
*
* Return:
* * number of bytes read
* * -errno (positive TPM return codes are masked to -EIO)
*/
int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
{
struct tpm1_get_random_out *out;
u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
struct tpm_buf buf;
u32 total = 0;
int retries = 5;
u32 recd;
int rc;
rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
if (rc)
return rc;
do {
tpm_buf_append_u32(&buf, num_bytes);
rc = tpm_transmit_cmd(chip, &buf, sizeof(out->rng_data_len),
"attempting get random");
if (rc) {
if (rc > 0)
rc = -EIO;
goto out;
}
out = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE];
recd = be32_to_cpu(out->rng_data_len);
if (recd > num_bytes) {
rc = -EFAULT;
goto out;
}
if (tpm_buf_length(&buf) < TPM_HEADER_SIZE +
sizeof(out->rng_data_len) + recd) {
rc = -EFAULT;
goto out;
}
memcpy(dest, out->rng_data, recd);
dest += recd;
total += recd;
num_bytes -= recd;
tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
} while (retries-- && total < max);
rc = total ? (int)total : -EIO;
out:
tpm_buf_destroy(&buf);
return rc;
}
#define TPM_ORD_PCRREAD 21
int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
{
struct tpm_buf buf;
int rc;
rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCRREAD);
if (rc)
return rc;
tpm_buf_append_u32(&buf, pcr_idx);
rc = tpm_transmit_cmd(chip, &buf, TPM_DIGEST_SIZE,
"attempting to read a pcr value");
if (rc)
goto out;
if (tpm_buf_length(&buf) < TPM_DIGEST_SIZE) {
rc = -EFAULT;
goto out;
}
memcpy(res_buf, &buf.data[TPM_HEADER_SIZE], TPM_DIGEST_SIZE);
out:
tpm_buf_destroy(&buf);
return rc;
}
#define TPM_ORD_CONTINUE_SELFTEST 83
/**
* 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 tpm1_continue_selftest(struct tpm_chip *chip)
{
struct tpm_buf buf;
int rc;
rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_CONTINUE_SELFTEST);
if (rc)
return rc;
rc = tpm_transmit_cmd(chip, &buf, 0, "continue selftest");
tpm_buf_destroy(&buf);
return rc;
}
/**
* tpm1_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 tpm1_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 = tpm1_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
loops = jiffies_to_msecs(duration) / delay_msec;
rc = tpm1_continue_selftest(chip);
if (rc == TPM_ERR_INVALID_POSTINIT) {
chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
}
/* 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 = tpm1_pcr_read(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");
tpm_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;
tpm_msleep(delay_msec);
} while (--loops > 0);
return rc;
}
EXPORT_SYMBOL_GPL(tpm1_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 = tpm1_get_timeouts(chip);
if (rc)
goto out;
rc = tpm1_do_selftest(chip);
if (rc) {
dev_err(&chip->dev, "TPM self test failed\n");
goto out;
}
chip->allocated_banks = kcalloc(1, sizeof(*chip->allocated_banks),
GFP_KERNEL);
if (!chip->allocated_banks) {
rc = -ENOMEM;
goto out;
}
chip->allocated_banks[0].alg_id = TPM_ALG_SHA1;
chip->allocated_banks[0].digest_size = hash_digest_size[HASH_ALGO_SHA1];
chip->allocated_banks[0].crypto_id = HASH_ALGO_SHA1;
chip->nr_allocated_banks = 1;
return rc;
out:
if (rc > 0)
rc = -ENODEV;
return rc;
}
#define TPM_ORD_SAVESTATE 152
/**
* tpm1_pm_suspend() - pm suspend handler
* @chip: TPM chip to use.
* @tpm_suspend_pcr: flush pcr for buggy TPM chips.
*
* The functions saves the TPM state to be restored on resume.
*
* Return:
* * 0 on success,
* * < 0 on error.
*/
int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr)
{
u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
struct tpm_buf buf;
unsigned int try;
int rc;
/* for buggy tpm, flush pcrs with extend to selected dummy */
if (tpm_suspend_pcr)
rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
"extending dummy pcr before suspend");
rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_SAVESTATE);
if (rc)
return rc;
/* now do the actual savestate */
for (try = 0; try < TPM_RETRY; try++) {
rc = tpm_transmit_cmd(chip, &buf, 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;
tpm_msleep(TPM_TIMEOUT_RETRY);
tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_SAVESTATE);
}
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);
tpm_buf_destroy(&buf);
return rc;
}
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