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-rw-r--r--drivers/char/tpm/tpm-interface.c530
1 files changed, 530 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
new file mode 100644
index 0000000000..66b16d26ee
--- /dev/null
+++ b/drivers/char/tpm/tpm-interface.c
@@ -0,0 +1,530 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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
+ *
+ * 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/suspend.h>
+#include <linux/freezer.h>
+#include <linux/tpm_eventlog.h>
+
+#include "tpm.h"
+
+/*
+ * 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 u32 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.");
+
+/**
+ * tpm_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 tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
+{
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
+ return tpm2_calc_ordinal_duration(chip, ordinal);
+ else
+ return tpm1_calc_ordinal_duration(chip, ordinal);
+}
+EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
+
+static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
+{
+ struct tpm_header *header = buf;
+ int rc;
+ ssize_t len = 0;
+ u32 count, ordinal;
+ unsigned long stop;
+
+ if (bufsiz < TPM_HEADER_SIZE)
+ return -EINVAL;
+
+ if (bufsiz > TPM_BUFSIZE)
+ bufsiz = TPM_BUFSIZE;
+
+ count = be32_to_cpu(header->length);
+ ordinal = be32_to_cpu(header->ordinal);
+ if (count == 0)
+ return -ENODATA;
+ if (count > bufsiz) {
+ dev_err(&chip->dev,
+ "invalid count value %x %zx\n", count, bufsiz);
+ return -E2BIG;
+ }
+
+ rc = chip->ops->send(chip, buf, count);
+ if (rc < 0) {
+ if (rc != -EPIPE)
+ dev_err(&chip->dev,
+ "%s: send(): error %d\n", __func__, rc);
+ return rc;
+ }
+
+ /* 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;
+
+ 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");
+ return -ECANCELED;
+ }
+
+ tpm_msleep(TPM_TIMEOUT_POLL);
+ rmb();
+ } while (time_before(jiffies, stop));
+
+ chip->ops->cancel(chip);
+ dev_err(&chip->dev, "Operation Timed out\n");
+ return -ETIME;
+
+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);
+ } else if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
+ rc = -EFAULT;
+
+ return rc ? rc : len;
+}
+
+/**
+ * tpm_transmit - Internal kernel interface to transmit TPM commands.
+ * @chip: a TPM chip to use
+ * @buf: a TPM command buffer
+ * @bufsiz: length of the TPM command buffer
+ *
+ * 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 that TPM 1.x never returns TPM2_RC_RETRY so the retry logic is TPM 2.0
+ * only.
+ *
+ * Return:
+ * * The response length - OK
+ * * -errno - A system error
+ */
+ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz)
+{
+ struct tpm_header *header = (struct tpm_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(sizeof(save), 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, buf, bufsiz);
+ 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
+ * @chip: a TPM chip to use
+ * @buf: a TPM command buffer
+ * @min_rsp_body_length: minimum expected length of response body
+ * @desc: command description used in the error message
+ *
+ * Return:
+ * * 0 - OK
+ * * -errno - A system error
+ * * TPM_RC - A TPM error
+ */
+ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf,
+ size_t min_rsp_body_length, const char *desc)
+{
+ const struct tpm_header *header = (struct tpm_header *)buf->data;
+ int err;
+ ssize_t len;
+
+ len = tpm_transmit(chip, buf->data, PAGE_SIZE);
+ if (len < 0)
+ return len;
+
+ err = be32_to_cpu(header->return_code);
+ if (err != 0 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED
+ && err != TPM2_RC_TESTING && 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);
+
+int tpm_get_timeouts(struct tpm_chip *chip)
+{
+ if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
+ return 0;
+
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
+ return tpm2_get_timeouts(chip);
+ else
+ return tpm1_get_timeouts(chip);
+}
+EXPORT_SYMBOL_GPL(tpm_get_timeouts);
+
+/**
+ * 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
+ * @digest: the PCR bank and buffer current PCR value is written to
+ *
+ * Return: same as with tpm_transmit_cmd()
+ */
+int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
+ struct tpm_digest *digest)
+{
+ 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, digest, NULL);
+ else
+ rc = tpm1_pcr_read(chip, pcr_idx, digest->digest);
+
+ tpm_put_ops(chip);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_pcr_read);
+
+/**
+ * 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
+ * @digests: array of tpm_digest structures used to extend PCRs
+ *
+ * Note: callers must pass a digest for every allocated PCR bank, in the same
+ * order of the banks in chip->allocated_banks.
+ *
+ * Return: same as with tpm_transmit_cmd()
+ */
+int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
+ struct tpm_digest *digests)
+{
+ int rc;
+ int i;
+
+ chip = tpm_find_get_ops(chip);
+ if (!chip)
+ return -ENODEV;
+
+ for (i = 0; i < chip->nr_allocated_banks; i++) {
+ if (digests[i].alg_id != chip->allocated_banks[i].alg_id) {
+ rc = -EINVAL;
+ goto out;
+ }
+ }
+
+ if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+ rc = tpm2_pcr_extend(chip, pcr_idx, digests);
+ goto out;
+ }
+
+ rc = tpm1_pcr_extend(chip, pcr_idx, digests[0].digest,
+ "attempting extend a PCR value");
+
+out:
+ tpm_put_ops(chip);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_pcr_extend);
+
+/**
+ * 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)
+{
+ struct tpm_buf buf;
+ int rc;
+
+ chip = tpm_find_get_ops(chip);
+ if (!chip)
+ return -ENODEV;
+
+ buf.data = cmd;
+ rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to a send a command");
+
+ tpm_put_ops(chip);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_send);
+
+int tpm_auto_startup(struct tpm_chip *chip)
+{
+ int rc;
+
+ if (!(chip->ops->flags & TPM_OPS_AUTO_STARTUP))
+ return 0;
+
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
+ rc = tpm2_auto_startup(chip);
+ else
+ rc = tpm1_auto_startup(chip);
+
+ return rc;
+}
+
+/*
+ * 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);
+ int rc = 0;
+
+ if (!chip)
+ return -ENODEV;
+
+ if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
+ goto suspended;
+
+ if ((chip->flags & TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED) &&
+ !pm_suspend_via_firmware())
+ goto suspended;
+
+ rc = tpm_try_get_ops(chip);
+ if (!rc) {
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
+ tpm2_shutdown(chip, TPM2_SU_STATE);
+ else
+ rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
+
+ tpm_put_ops(chip);
+ }
+
+suspended:
+ chip->flags |= TPM_CHIP_FLAG_SUSPENDED;
+
+ if (rc)
+ dev_err(dev, "Ignoring error %d while suspending\n", rc);
+ return 0;
+}
+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;
+
+ chip->flags &= ~TPM_CHIP_FLAG_SUSPENDED;
+
+ /*
+ * Guarantee that SUSPENDED is written last, so that hwrng does not
+ * activate before the chip has been fully resumed.
+ */
+ wmb();
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tpm_pm_resume);
+
+/**
+ * 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: number of random bytes read or a negative error value.
+ */
+int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
+{
+ int rc;
+
+ if (!out || max > TPM_MAX_RNG_DATA)
+ return -EINVAL;
+
+ chip = tpm_find_get_ops(chip);
+ if (!chip)
+ return -ENODEV;
+
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
+ rc = tpm2_get_random(chip, out, max);
+ else
+ rc = tpm1_get_random(chip, out, max);
+
+ tpm_put_ops(chip);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_get_random);
+
+static int __init tpm_init(void)
+{
+ int rc;
+
+ rc = class_register(&tpm_class);
+ if (rc) {
+ pr_err("couldn't create tpm class\n");
+ return rc;
+ }
+
+ rc = class_register(&tpmrm_class);
+ if (rc) {
+ pr_err("couldn't create tpmrm class\n");
+ goto out_destroy_tpm_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");
+ goto out_destroy_tpmrm_class;
+ }
+
+ rc = tpm_dev_common_init();
+ if (rc) {
+ pr_err("tpm: failed to allocate char dev region\n");
+ goto out_unreg_chrdev;
+ }
+
+ return 0;
+
+out_unreg_chrdev:
+ unregister_chrdev_region(tpm_devt, 2 * TPM_NUM_DEVICES);
+out_destroy_tpmrm_class:
+ class_unregister(&tpmrm_class);
+out_destroy_tpm_class:
+ class_unregister(&tpm_class);
+
+ return rc;
+}
+
+static void __exit tpm_exit(void)
+{
+ idr_destroy(&dev_nums_idr);
+ class_unregister(&tpm_class);
+ class_unregister(&tpmrm_class);
+ unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
+ tpm_dev_common_exit();
+}
+
+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");