diff options
Diffstat (limited to 'drivers/char/tpm/tpm-interface.c')
| -rw-r--r-- | drivers/char/tpm/tpm-interface.c | 1451 |
1 files changed, 1451 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c new file mode 100644 index 000000000..43c3f9b87 --- /dev/null +++ b/drivers/char/tpm/tpm-interface.c @@ -0,0 +1,1451 @@ +/* + * 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/tpm_eventlog.h> + +#include "tpm.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 facilitate 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); + +static int tpm_validate_command(struct tpm_chip *chip, + struct tpm_space *space, + const u8 *cmd, + size_t len) +{ + const struct tpm_input_header *header = (const void *)cmd; + int i; + u32 cc; + u32 attrs; + unsigned int nr_handles; + + if (len < TPM_HEADER_SIZE) + return -EINVAL; + + if (!space) + return 0; + + if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) { + cc = be32_to_cpu(header->ordinal); + + i = tpm2_find_cc(chip, cc); + if (i < 0) { + dev_dbg(&chip->dev, "0x%04X is an invalid command\n", + cc); + return -EOPNOTSUPP; + } + + attrs = chip->cc_attrs_tbl[i]; + nr_handles = + 4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0)); + if (len < TPM_HEADER_SIZE + 4 * nr_handles) + goto err_len; + } + + return 0; +err_len: + dev_dbg(&chip->dev, + "%s: insufficient command length %zu", __func__, len); + return -EINVAL; +} + +static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags) +{ + int rc; + + if (flags & TPM_TRANSMIT_NESTED) + return 0; + + if (!chip->ops->request_locality) + return 0; + + rc = chip->ops->request_locality(chip, 0); + if (rc < 0) + return rc; + + chip->locality = rc; + + return 0; +} + +static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags) +{ + int rc; + + if (flags & TPM_TRANSMIT_NESTED) + return; + + if (!chip->ops->relinquish_locality) + return; + + rc = chip->ops->relinquish_locality(chip, chip->locality); + if (rc) + dev_err(&chip->dev, "%s: : error %d\n", __func__, rc); + + chip->locality = -1; +} + +static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags) +{ + if (flags & TPM_TRANSMIT_NESTED) + return 0; + + if (!chip->ops->cmd_ready) + return 0; + + return chip->ops->cmd_ready(chip); +} + +static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags) +{ + if (flags & TPM_TRANSMIT_NESTED) + return 0; + + if (!chip->ops->go_idle) + return 0; + + return chip->ops->go_idle(chip); +} + +static ssize_t tpm_try_transmit(struct tpm_chip *chip, + struct tpm_space *space, + u8 *buf, size_t bufsiz, + unsigned int flags) +{ + struct tpm_output_header *header = (void *)buf; + int rc; + ssize_t len = 0; + u32 count, ordinal; + unsigned long stop; + bool need_locality; + + rc = tpm_validate_command(chip, space, buf, bufsiz); + if (rc == -EINVAL) + return rc; + /* + * If the command is not implemented by the TPM, synthesize a + * response with a TPM2_RC_COMMAND_CODE return for user-space. + */ + if (rc == -EOPNOTSUPP) { + header->length = cpu_to_be32(sizeof(*header)); + header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS); + header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE | + TSS2_RESMGR_TPM_RC_LAYER); + return sizeof(*header); + } + + 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) && !(flags & TPM_TRANSMIT_NESTED)) + mutex_lock(&chip->tpm_mutex); + + if (chip->ops->clk_enable != NULL) + chip->ops->clk_enable(chip, true); + + /* Store the decision as chip->locality will be changed. */ + need_locality = chip->locality == -1; + + if (need_locality) { + rc = tpm_request_locality(chip, flags); + if (rc < 0) { + need_locality = false; + goto out_locality; + } + } + + rc = tpm_cmd_ready(chip, flags); + if (rc) + goto out_locality; + + rc = tpm2_prepare_space(chip, space, ordinal, buf); + if (rc) + goto out; + + rc = chip->ops->send(chip, buf, count); + if (rc < 0) { + if (rc != -EPIPE) + dev_err(&chip->dev, + "%s: send(): error %d\n", __func__, rc); + goto out; + } + + /* A sanity check. send() should just return zero on success e.g. + * not the command length. + */ + if (rc > 0) { + dev_warn(&chip->dev, + "%s: send(): invalid value %d\n", __func__, rc); + rc = 0; + } + + 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; + } + + tpm_msleep(TPM_TIMEOUT_POLL); + rmb(); + } while (time_before(jiffies, stop)); + + chip->ops->cancel(chip); + dev_err(&chip->dev, "Operation Timed out\n"); + rc = -ETIME; + goto out; + +out_recv: + len = chip->ops->recv(chip, buf, bufsiz); + if (len < 0) { + rc = len; + dev_err(&chip->dev, + "tpm_transmit: tpm_recv: error %d\n", rc); + goto out; + } else if (len < TPM_HEADER_SIZE) { + rc = -EFAULT; + goto out; + } + + if (len != be32_to_cpu(header->length)) { + rc = -EFAULT; + goto out; + } + + rc = tpm2_commit_space(chip, space, ordinal, buf, &len); + if (rc) + dev_err(&chip->dev, "tpm2_commit_space: error %d\n", rc); + +out: + /* may fail but do not override previous error value in rc */ + tpm_go_idle(chip, flags); + +out_locality: + if (need_locality) + tpm_relinquish_locality(chip, flags); + + if (chip->ops->clk_enable != NULL) + chip->ops->clk_enable(chip, false); + + if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED)) + mutex_unlock(&chip->tpm_mutex); + return rc ? rc : len; +} + +/** + * tpm_transmit - Internal kernel interface to transmit TPM commands. + * + * @chip: TPM chip to use + * @space: tpm space + * @buf: TPM command buffer + * @bufsiz: length of the TPM command buffer + * @flags: tpm transmit flags - bitmap + * + * A wrapper around tpm_try_transmit that handles TPM2_RC_RETRY + * returns from the TPM and retransmits the command after a delay up + * to a maximum wait of TPM2_DURATION_LONG. + * + * Note: TPM1 never returns TPM2_RC_RETRY so the retry logic is TPM2 + * only + * + * Return: + * the length of the return when the operation is successful. + * A negative number for system errors (errno). + */ +ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, + u8 *buf, size_t bufsiz, unsigned int flags) +{ + struct tpm_output_header *header = (struct tpm_output_header *)buf; + /* space for header and handles */ + u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)]; + unsigned int delay_msec = TPM2_DURATION_SHORT; + u32 rc = 0; + ssize_t ret; + const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE, + bufsiz); + /* the command code is where the return code will be */ + u32 cc = be32_to_cpu(header->return_code); + + /* + * Subtlety here: if we have a space, the handles will be + * transformed, so when we restore the header we also have to + * restore the handles. + */ + memcpy(save, buf, save_size); + + for (;;) { + ret = tpm_try_transmit(chip, space, buf, bufsiz, flags); + if (ret < 0) + break; + rc = be32_to_cpu(header->return_code); + if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING) + break; + /* + * return immediately if self test returns test + * still running to shorten boot time. + */ + if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST) + break; + + if (delay_msec > TPM2_DURATION_LONG) { + if (rc == TPM2_RC_RETRY) + dev_err(&chip->dev, "in retry loop\n"); + else + dev_err(&chip->dev, + "self test is still running\n"); + break; + } + tpm_msleep(delay_msec); + delay_msec *= 2; + memcpy(buf, save, save_size); + } + return ret; +} +/** + * tpm_transmit_cmd - send a tpm command to the device + * The function extracts tpm out header return code + * + * @chip: TPM chip to use + * @space: tpm space + * @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, struct tpm_space *space, + void *buf, size_t bufsiz, + size_t min_rsp_body_length, unsigned int flags, + const char *desc) +{ + const struct tpm_output_header *header = buf; + int err; + ssize_t len; + + len = tpm_transmit(chip, space, buf, bufsiz, flags); + if (len < 0) + return len; + + err = be32_to_cpu(header->return_code); + if (err != 0 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED + && 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; +} +EXPORT_SYMBOL_GPL(tpm_transmit_cmd); + +#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() + */ +int tpm_startup(struct tpm_chip *chip) +{ + struct tpm_buf buf; + int rc; + + dev_info(&chip->dev, "starting up the TPM manually\n"); + + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP); + if (rc < 0) + return rc; + + tpm_buf_append_u16(&buf, TPM2_SU_CLEAR); + } else { + 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; +} + +#define TPM_DIGEST_SIZE 20 +#define TPM_RET_CODE_IDX 6 +#define TPM_INTERNAL_RESULT_SIZE 200 +#define TPM_ORD_GET_CAP 101 +#define TPM_ORD_GET_RANDOM 70 + +static const struct tpm_input_header tpm_getcap_header = { + .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND), + .length = cpu_to_be32(22), + .ordinal = cpu_to_be32(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_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(tpm_getcap); + +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->duration[TPM_LONG_LONG] = + msecs_to_jiffies(TPM2_DURATION_LONG_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) { + if (tpm_startup(chip)) + 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)); + 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; +} +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 = 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 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, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, + 0, 0, "continue selftest"); + 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 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, 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; +} + +/** + * tpm_is_tpm2 - do we a have a TPM2 chip? + * @chip: a &struct tpm_chip instance, %NULL for the default chip + * + * Return: + * 1 if we have a TPM2 chip. + * 0 if we don't have a TPM2 chip. + * A negative number for system errors (errno). + */ +int tpm_is_tpm2(struct tpm_chip *chip) +{ + int rc; + + chip = tpm_find_get_ops(chip); + if (!chip) + 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 from SHA1 bank + * @chip: a &struct tpm_chip instance, %NULL for the default chip + * @pcr_idx: the PCR to be retrieved + * @res_buf: the value of the PCR + * + * Return: same as with tpm_transmit_cmd() + */ +int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) +{ + int rc; + + chip = tpm_find_get_ops(chip); + if (!chip) + 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 20 +#define EXTEND_PCR_RESULT_SIZE 34 +#define EXTEND_PCR_RESULT_BODY_SIZE 20 +static const struct tpm_input_header pcrextend_header = { + .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND), + .length = cpu_to_be32(34), + .ordinal = cpu_to_be32(TPM_ORD_PCR_EXTEND) +}; + +static int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash, + 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, EXTEND_PCR_RESULT_SIZE, + EXTEND_PCR_RESULT_BODY_SIZE, 0, log_msg); + tpm_buf_destroy(&buf); + return rc; +} + +/** + * tpm_pcr_extend - extend a PCR value in SHA1 bank. + * @chip: a &struct tpm_chip instance, %NULL for the default chip + * @pcr_idx: the PCR to be retrieved + * @hash: the hash value used to extend the PCR value + * + * Note: with TPM 2.0 extends also those banks with a known digest size to the + * cryto subsystem in order to prevent malicious use of those PCR banks. In the + * future we should dynamically determine digest sizes. + * + * Return: same as with tpm_transmit_cmd() + */ +int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash) +{ + int rc; + struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)]; + u32 count = 0; + int i; + + chip = tpm_find_get_ops(chip); + if (!chip) + return -ENODEV; + + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + memset(digest_list, 0, sizeof(digest_list)); + + for (i = 0; i < ARRAY_SIZE(chip->active_banks) && + chip->active_banks[i] != TPM2_ALG_ERROR; i++) { + digest_list[i].alg_id = chip->active_banks[i]; + memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE); + count++; + } + + rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list); + tpm_put_ops(chip); + return rc; + } + + rc = tpm1_pcr_extend(chip, pcr_idx, hash, + "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); + 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 = 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"); + 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(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; +} + +/** + * tpm_send - send a TPM command + * @chip: a &struct tpm_chip instance, %NULL for the default chip + * @cmd: a TPM command buffer + * @buflen: the length of the TPM command buffer + * + * Return: same as with tpm_transmit_cmd() + */ +int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen) +{ + int rc; + + chip = tpm_find_get_ops(chip); + if (!chip) + return -ENODEV; + + rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0, + "attempting to a send a command"); + tpm_put_ops(chip); + return rc; +} +EXPORT_SYMBOL_GPL(tpm_send); + +#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) +}; + +/* + * 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_ALWAYS_POWERED) + return 0; + + 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) + 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; +} +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 = cpu_to_be16(TPM_TAG_RQU_COMMAND), + .length = cpu_to_be32(14), + .ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM) +}; + +/** + * tpm_get_random() - get random bytes from the TPM's RNG + * @chip: a &struct tpm_chip instance, %NULL for the default chip + * @out: destination buffer for the random bytes + * @max: the max number of bytes to write to @out + * + * Return: same as with tpm_transmit_cmd() + */ +int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max) +{ + 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_find_get_ops(chip); + if (!chip) + 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, NULL, &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); + if (recd > num_bytes) { + total = -EFAULT; + break; + } + + rlength = be32_to_cpu(tpm_cmd.header.out.length); + if (rlength < TPM_HEADER_SIZE + + 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 payload + * @chip: a &struct tpm_chip instance, %NULL for the default chip + * @options: authentication values and other options + * @payload: the key data in clear and encrypted form + * + * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in + * the keyring subsystem. + * + * Return: same as with tpm_transmit_cmd() + */ +int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload, + struct trusted_key_options *options) +{ + int rc; + + chip = tpm_find_get_ops(chip); + if (!chip || !(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: a &struct tpm_chip instance, %NULL for the default chip + * @options: authentication values and other options + * @payload: the key data in clear and encrypted form + * + * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in + * the keyring subsystem. + * + * Return: same as with tpm_transmit_cmd() + */ +int tpm_unseal_trusted(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options) +{ + int rc; + + chip = tpm_find_get_ops(chip); + if (!chip || !(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); + } + + tpmrm_class = class_create(THIS_MODULE, "tpmrm"); + if (IS_ERR(tpmrm_class)) { + pr_err("couldn't create tpmrm class\n"); + class_destroy(tpm_class); + return PTR_ERR(tpmrm_class); + } + + rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm"); + if (rc < 0) { + pr_err("tpm: failed to allocate char dev region\n"); + class_destroy(tpmrm_class); + class_destroy(tpm_class); + return rc; + } + + return 0; +} + +static void __exit tpm_exit(void) +{ + idr_destroy(&dev_nums_idr); + class_destroy(tpm_class); + class_destroy(tpmrm_class); + unregister_chrdev_region(tpm_devt, 2*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"); |