From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/char/tpm/tpm_ftpm_tee.c | 420 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 420 insertions(+) create mode 100644 drivers/char/tpm/tpm_ftpm_tee.c (limited to 'drivers/char/tpm/tpm_ftpm_tee.c') diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c new file mode 100644 index 000000000..deff23bb5 --- /dev/null +++ b/drivers/char/tpm/tpm_ftpm_tee.c @@ -0,0 +1,420 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) Microsoft Corporation + * + * Implements a firmware TPM as described here: + * https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/ + * + * A reference implementation is available here: + * https://github.com/microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM/optee_ta/fTPM + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "tpm.h" +#include "tpm_ftpm_tee.h" + +/* + * TA_FTPM_UUID: BC50D971-D4C9-42C4-82CB-343FB7F37896 + * + * Randomly generated, and must correspond to the GUID on the TA side. + * Defined here in the reference implementation: + * https://github.com/microsoft/ms-tpm-20-ref/blob/master/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/include/fTPM.h#L42 + */ +static const uuid_t ftpm_ta_uuid = + UUID_INIT(0xBC50D971, 0xD4C9, 0x42C4, + 0x82, 0xCB, 0x34, 0x3F, 0xB7, 0xF3, 0x78, 0x96); + +/** + * ftpm_tee_tpm_op_recv() - retrieve fTPM response. + * @chip: the tpm_chip description as specified in driver/char/tpm/tpm.h. + * @buf: the buffer to store data. + * @count: the number of bytes to read. + * + * Return: + * In case of success the number of bytes received. + * On failure, -errno. + */ +static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count) +{ + struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent); + size_t len; + + len = pvt_data->resp_len; + if (count < len) { + dev_err(&chip->dev, + "%s: Invalid size in recv: count=%zd, resp_len=%zd\n", + __func__, count, len); + return -EIO; + } + + memcpy(buf, pvt_data->resp_buf, len); + pvt_data->resp_len = 0; + + return len; +} + +/** + * ftpm_tee_tpm_op_send() - send TPM commands through the TEE shared memory. + * @chip: the tpm_chip description as specified in driver/char/tpm/tpm.h + * @buf: the buffer to send. + * @len: the number of bytes to send. + * + * Return: + * In case of success, returns 0. + * On failure, -errno + */ +static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t len) +{ + struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent); + size_t resp_len; + int rc; + u8 *temp_buf; + struct tpm_header *resp_header; + struct tee_ioctl_invoke_arg transceive_args; + struct tee_param command_params[4]; + struct tee_shm *shm = pvt_data->shm; + + if (len > MAX_COMMAND_SIZE) { + dev_err(&chip->dev, + "%s: len=%zd exceeds MAX_COMMAND_SIZE supported by fTPM TA\n", + __func__, len); + return -EIO; + } + + memset(&transceive_args, 0, sizeof(transceive_args)); + memset(command_params, 0, sizeof(command_params)); + pvt_data->resp_len = 0; + + /* Invoke FTPM_OPTEE_TA_SUBMIT_COMMAND function of fTPM TA */ + transceive_args = (struct tee_ioctl_invoke_arg) { + .func = FTPM_OPTEE_TA_SUBMIT_COMMAND, + .session = pvt_data->session, + .num_params = 4, + }; + + /* Fill FTPM_OPTEE_TA_SUBMIT_COMMAND parameters */ + command_params[0] = (struct tee_param) { + .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT, + .u.memref = { + .shm = shm, + .size = len, + .shm_offs = 0, + }, + }; + + temp_buf = tee_shm_get_va(shm, 0); + if (IS_ERR(temp_buf)) { + dev_err(&chip->dev, "%s: tee_shm_get_va failed for transmit\n", + __func__); + return PTR_ERR(temp_buf); + } + memset(temp_buf, 0, (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE)); + memcpy(temp_buf, buf, len); + + command_params[1] = (struct tee_param) { + .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT, + .u.memref = { + .shm = shm, + .size = MAX_RESPONSE_SIZE, + .shm_offs = MAX_COMMAND_SIZE, + }, + }; + + rc = tee_client_invoke_func(pvt_data->ctx, &transceive_args, + command_params); + if ((rc < 0) || (transceive_args.ret != 0)) { + dev_err(&chip->dev, "%s: SUBMIT_COMMAND invoke error: 0x%x\n", + __func__, transceive_args.ret); + return (rc < 0) ? rc : transceive_args.ret; + } + + temp_buf = tee_shm_get_va(shm, command_params[1].u.memref.shm_offs); + if (IS_ERR(temp_buf)) { + dev_err(&chip->dev, "%s: tee_shm_get_va failed for receive\n", + __func__); + return PTR_ERR(temp_buf); + } + + resp_header = (struct tpm_header *)temp_buf; + resp_len = be32_to_cpu(resp_header->length); + + /* sanity check resp_len */ + if (resp_len < TPM_HEADER_SIZE) { + dev_err(&chip->dev, "%s: tpm response header too small\n", + __func__); + return -EIO; + } + if (resp_len > MAX_RESPONSE_SIZE) { + dev_err(&chip->dev, + "%s: resp_len=%zd exceeds MAX_RESPONSE_SIZE\n", + __func__, resp_len); + return -EIO; + } + + /* sanity checks look good, cache the response */ + memcpy(pvt_data->resp_buf, temp_buf, resp_len); + pvt_data->resp_len = resp_len; + + return 0; +} + +static void ftpm_tee_tpm_op_cancel(struct tpm_chip *chip) +{ + /* not supported */ +} + +static u8 ftpm_tee_tpm_op_status(struct tpm_chip *chip) +{ + return 0; +} + +static bool ftpm_tee_tpm_req_canceled(struct tpm_chip *chip, u8 status) +{ + return false; +} + +static const struct tpm_class_ops ftpm_tee_tpm_ops = { + .flags = TPM_OPS_AUTO_STARTUP, + .recv = ftpm_tee_tpm_op_recv, + .send = ftpm_tee_tpm_op_send, + .cancel = ftpm_tee_tpm_op_cancel, + .status = ftpm_tee_tpm_op_status, + .req_complete_mask = 0, + .req_complete_val = 0, + .req_canceled = ftpm_tee_tpm_req_canceled, +}; + +/* + * Check whether this driver supports the fTPM TA in the TEE instance + * represented by the params (ver/data) to this function. + */ +static int ftpm_tee_match(struct tee_ioctl_version_data *ver, const void *data) +{ + /* + * Currently this driver only support GP Complaint OPTEE based fTPM TA + */ + if ((ver->impl_id == TEE_IMPL_ID_OPTEE) && + (ver->gen_caps & TEE_GEN_CAP_GP)) + return 1; + else + return 0; +} + +/** + * ftpm_tee_probe() - initialize the fTPM + * @pdev: the platform_device description. + * + * Return: + * On success, 0. On failure, -errno. + */ +static int ftpm_tee_probe(struct device *dev) +{ + int rc; + struct tpm_chip *chip; + struct ftpm_tee_private *pvt_data = NULL; + struct tee_ioctl_open_session_arg sess_arg; + + pvt_data = devm_kzalloc(dev, sizeof(struct ftpm_tee_private), + GFP_KERNEL); + if (!pvt_data) + return -ENOMEM; + + dev_set_drvdata(dev, pvt_data); + + /* Open context with TEE driver */ + pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL, + NULL); + if (IS_ERR(pvt_data->ctx)) { + if (PTR_ERR(pvt_data->ctx) == -ENOENT) + return -EPROBE_DEFER; + dev_err(dev, "%s: tee_client_open_context failed\n", __func__); + return PTR_ERR(pvt_data->ctx); + } + + /* Open a session with fTPM TA */ + memset(&sess_arg, 0, sizeof(sess_arg)); + export_uuid(sess_arg.uuid, &ftpm_ta_uuid); + sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC; + sess_arg.num_params = 0; + + rc = tee_client_open_session(pvt_data->ctx, &sess_arg, NULL); + if ((rc < 0) || (sess_arg.ret != 0)) { + dev_err(dev, "%s: tee_client_open_session failed, err=%x\n", + __func__, sess_arg.ret); + rc = -EINVAL; + goto out_tee_session; + } + pvt_data->session = sess_arg.session; + + /* Allocate dynamic shared memory with fTPM TA */ + pvt_data->shm = tee_shm_alloc_kernel_buf(pvt_data->ctx, + MAX_COMMAND_SIZE + + MAX_RESPONSE_SIZE); + if (IS_ERR(pvt_data->shm)) { + dev_err(dev, "%s: tee_shm_alloc_kernel_buf failed\n", __func__); + rc = -ENOMEM; + goto out_shm_alloc; + } + + /* Allocate new struct tpm_chip instance */ + chip = tpm_chip_alloc(dev, &ftpm_tee_tpm_ops); + if (IS_ERR(chip)) { + dev_err(dev, "%s: tpm_chip_alloc failed\n", __func__); + rc = PTR_ERR(chip); + goto out_chip_alloc; + } + + pvt_data->chip = chip; + pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2; + + /* Create a character device for the fTPM */ + rc = tpm_chip_register(pvt_data->chip); + if (rc) { + dev_err(dev, "%s: tpm_chip_register failed with rc=%d\n", + __func__, rc); + goto out_chip; + } + + return 0; + +out_chip: + put_device(&pvt_data->chip->dev); +out_chip_alloc: + tee_shm_free(pvt_data->shm); +out_shm_alloc: + tee_client_close_session(pvt_data->ctx, pvt_data->session); +out_tee_session: + tee_client_close_context(pvt_data->ctx); + + return rc; +} + +static int ftpm_plat_tee_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + + return ftpm_tee_probe(dev); +} + +/** + * ftpm_tee_remove() - remove the TPM device + * @pdev: the platform_device description. + * + * Return: + * 0 always. + */ +static int ftpm_tee_remove(struct device *dev) +{ + struct ftpm_tee_private *pvt_data = dev_get_drvdata(dev); + + /* Release the chip */ + tpm_chip_unregister(pvt_data->chip); + + /* frees chip */ + put_device(&pvt_data->chip->dev); + + /* Free the shared memory pool */ + tee_shm_free(pvt_data->shm); + + /* close the existing session with fTPM TA*/ + tee_client_close_session(pvt_data->ctx, pvt_data->session); + + /* close the context with TEE driver */ + tee_client_close_context(pvt_data->ctx); + + /* memory allocated with devm_kzalloc() is freed automatically */ + + return 0; +} + +static int ftpm_plat_tee_remove(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + + return ftpm_tee_remove(dev); +} + +/** + * ftpm_tee_shutdown() - shutdown the TPM device + * @pdev: the platform_device description. + */ +static void ftpm_plat_tee_shutdown(struct platform_device *pdev) +{ + struct ftpm_tee_private *pvt_data = dev_get_drvdata(&pdev->dev); + + tee_shm_free(pvt_data->shm); + tee_client_close_session(pvt_data->ctx, pvt_data->session); + tee_client_close_context(pvt_data->ctx); +} + +static const struct of_device_id of_ftpm_tee_ids[] = { + { .compatible = "microsoft,ftpm" }, + { } +}; +MODULE_DEVICE_TABLE(of, of_ftpm_tee_ids); + +static struct platform_driver ftpm_tee_plat_driver = { + .driver = { + .name = "ftpm-tee", + .of_match_table = of_match_ptr(of_ftpm_tee_ids), + }, + .shutdown = ftpm_plat_tee_shutdown, + .probe = ftpm_plat_tee_probe, + .remove = ftpm_plat_tee_remove, +}; + +/* UUID of the fTPM TA */ +static const struct tee_client_device_id optee_ftpm_id_table[] = { + {UUID_INIT(0xbc50d971, 0xd4c9, 0x42c4, + 0x82, 0xcb, 0x34, 0x3f, 0xb7, 0xf3, 0x78, 0x96)}, + {} +}; + +MODULE_DEVICE_TABLE(tee, optee_ftpm_id_table); + +static struct tee_client_driver ftpm_tee_driver = { + .id_table = optee_ftpm_id_table, + .driver = { + .name = "optee-ftpm", + .bus = &tee_bus_type, + .probe = ftpm_tee_probe, + .remove = ftpm_tee_remove, + }, +}; + +static int __init ftpm_mod_init(void) +{ + int rc; + + rc = platform_driver_register(&ftpm_tee_plat_driver); + if (rc) + return rc; + + rc = driver_register(&ftpm_tee_driver.driver); + if (rc) { + platform_driver_unregister(&ftpm_tee_plat_driver); + return rc; + } + + return 0; +} + +static void __exit ftpm_mod_exit(void) +{ + platform_driver_unregister(&ftpm_tee_plat_driver); + driver_unregister(&ftpm_tee_driver.driver); +} + +module_init(ftpm_mod_init); +module_exit(ftpm_mod_exit); + +MODULE_AUTHOR("Thirupathaiah Annapureddy "); +MODULE_DESCRIPTION("TPM Driver for fTPM TA in TEE"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3