diff options
Diffstat (limited to 'drivers/char/tpm/tpm1-cmd.c')
| -rw-r--r-- | drivers/char/tpm/tpm1-cmd.c | 813 |
1 files changed, 813 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c new file mode 100644 index 000000000..cf64c7385 --- /dev/null +++ b/drivers/char/tpm/tpm1-cmd.c @@ -0,0 +1,813 @@ +// 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 + +/** + * tpm1_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]; + unsigned long durations[3]; + 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 */ + + /* + * Provide the ability for vendor overrides of duration values in case + * of misreporting. + */ + if (chip->ops->update_durations) + chip->ops->update_durations(chip, durations); + + if (chip->duration_adjusted) { + dev_info(&chip->dev, HW_ERR "Adjusting reported durations."); + chip->duration[TPM_SHORT] = durations[0]; + chip->duration[TPM_MEDIUM] = durations[1]; + chip->duration[TPM_LONG] = durations[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 +/** + * tpm1_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 == TPM_ERR_FAILEDSELFTEST) { + dev_warn(&chip->dev, "TPM self test failed, switching to the firmware upgrade mode\n"); + /* A TPM in this state possibly allows or needs a firmware upgrade */ + chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE; + return 0; + } else if (rc) { + dev_err(&chip->dev, "TPM self test failed\n"); + goto out; + } + + 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; +} + +/** + * tpm1_get_pcr_allocation() - initialize the allocated bank + * @chip: TPM chip to use. + * + * The function initializes the SHA1 allocated bank to extend PCR + * + * Return: + * * 0 on success, + * * < 0 on error. + */ +int tpm1_get_pcr_allocation(struct tpm_chip *chip) +{ + chip->allocated_banks = kcalloc(1, sizeof(*chip->allocated_banks), + GFP_KERNEL); + if (!chip->allocated_banks) + return -ENOMEM; + + 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 0; +} |