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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/char/tpm/tpm-interface.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/char/tpm/tpm-interface.c')
| -rw-r--r-- | drivers/char/tpm/tpm-interface.c | 576 |
1 files changed, 576 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..f745a0989 --- /dev/null +++ b/drivers/char/tpm/tpm-interface.c @@ -0,0 +1,576 @@ +// 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(ordinal); + else + return tpm1_calc_ordinal_duration(chip, ordinal); +} +EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration); + +static void tpm_chip_cancel(struct tpm_chip *chip) +{ + if (!chip->ops->cancel) + return; + + chip->ops->cancel(chip); +} + +static u8 tpm_chip_status(struct tpm_chip *chip) +{ + if (!chip->ops->status) + return 0; + + return chip->ops->status(chip); +} + +static bool tpm_chip_req_canceled(struct tpm_chip *chip, u8 status) +{ + if (!chip->ops->req_canceled) + return false; + + return chip->ops->req_canceled(chip, status); +} + +static bool tpm_transmit_completed(u8 status, struct tpm_chip *chip) +{ + u8 status_masked = status & chip->ops->req_complete_mask; + + return status_masked == chip->ops->req_complete_val; +} + +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, bufsiz, count); + if (rc < 0) { + if (rc != -EPIPE) + dev_err(&chip->dev, + "%s: send(): error %d\n", __func__, rc); + return rc; + } + + /* + * Synchronous devices return the response directly during the send() + * call in the same buffer. + */ + if (chip->flags & TPM_CHIP_FLAG_SYNC) { + len = rc; + rc = 0; + goto out_sync; + } + + /* + * A sanity check. send() of asynchronous devices 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 = tpm_chip_status(chip); + if (tpm_transmit_completed(status, chip)) + goto out_recv; + + if (tpm_chip_req_canceled(chip, status)) { + dev_err(&chip->dev, "Operation Canceled\n"); + return -ECANCELED; + } + + tpm_msleep(TPM_TIMEOUT_POLL); + rmb(); + } while (time_before(jiffies, stop)); + + /* + * Check for completion one more time, just in case the device reported + * it while the driver was sleeping in the busy loop above. + */ + if (tpm_transmit_completed(tpm_chip_status(chip), chip)) + goto out_recv; + + tpm_chip_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); + return rc; + } +out_sync: + 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; + + buf->length = len; + 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; + + if (!chip) + return -ENODEV; + + rc = tpm_try_get_ops(chip); + if (rc) + return rc; + + 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; + + if (!chip) + return -ENODEV; + + rc = tpm_try_get_ops(chip); + if (rc) + return rc; + + 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; + + if (!chip) + return -ENODEV; + + rc = tpm_try_get_ops(chip); + if (rc) + return rc; + + 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); + +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; + + rc = tpm_try_get_ops(chip); + if (rc) { + /* Can be safely set out of locks, as no action cannot race: */ + chip->flags |= TPM_CHIP_FLAG_SUSPENDED; + goto out; + } + + 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; + + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + tpm2_end_auth_session(chip); + tpm2_shutdown(chip, TPM2_SU_STATE); + goto suspended; + } + + rc = tpm1_pm_suspend(chip, tpm_suspend_pcr); + +suspended: + chip->flags |= TPM_CHIP_FLAG_SUSPENDED; + tpm_put_ops(chip); + +out: + 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; + + if (!chip) + return -ENODEV; + + rc = tpm_try_get_ops(chip); + if (rc) + return rc; + + 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"); |
