// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2004 IBM Corporation * Copyright (C) 2014 Intel Corporation * * Authors: * Leendert van Doorn * Dave Safford * Reiner Sailer * Kylene Hall * * Device driver for TCG/TCPA TPM (trusted platform module). * Specifications at www.trustedcomputinggroup.org */ #include #include #include #include #include #include #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, NULL, buf.data, PAGE_SIZE, 0, 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->timeout_adjusted = 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, int 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, NULL, buf.data, PAGE_SIZE, TPM_DIGEST_SIZE, 0, 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, NULL, buf.data, PAGE_SIZE, min_cap_length, 0, 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 or a TPM return code otherwise */ 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, NULL, buf.data, PAGE_SIZE, sizeof(out->rng_data_len), 0, "attempting get random"); if (rc) 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_ORDINAL_PCRREAD 21 #define READ_PCR_RESULT_SIZE 30 #define READ_PCR_RESULT_BODY_SIZE 20 static const struct tpm_input_header pcrread_header = { .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND), .length = cpu_to_be32(14), .ordinal = cpu_to_be32(TPM_ORDINAL_PCRREAD) }; int tpm1_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, NULL, &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; } #define TPM_ORD_CONTINUE_SELFTEST 83 #define CONTINUE_SELFTEST_RESULT_SIZE 10 static const struct tpm_input_header continue_selftest_header = { .tag = cpu_to_be16(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 tpm1_continue_selftest(struct tpm_chip *chip) { int rc; struct tpm_cmd_t cmd; cmd.header.in = continue_selftest_header; rc = tpm_transmit_cmd(chip, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0, 0, "continue selftest"); 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_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"); 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; } return rc; out: if (rc > 0) rc = -ENODEV; return rc; } #define TPM_ORD_SAVESTATE 152 #define SAVESTATE_RESULT_SIZE 10 static const struct tpm_input_header savestate_header = { .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND), .length = cpu_to_be32(10), .ordinal = cpu_to_be32(TPM_ORD_SAVESTATE) }; /** * 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, int tpm_suspend_pcr) { u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 }; struct tpm_cmd_t cmd; int rc, try; /* 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"); /* now do the actual savestate */ for (try = 0; try < TPM_RETRY; try++) { cmd.header.in = savestate_header; rc = tpm_transmit_cmd(chip, NULL, &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; tpm_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; }