123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251 |
- // SPDX-License-Identifier: GPL-2.0
- /*
- * Copyright (C) Microsoft Corporation
- *
- * Authors:
- * Thirupathaiah Annapureddy <thiruan@microsoft.com>
- *
- * Description:
- * Device Driver for 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 <common.h>
- #include <dm.h>
- #include <log.h>
- #include <tpm-v2.h>
- #include <tee.h>
- #include "tpm_tis.h"
- #include "tpm2_ftpm_tee.h"
- /**
- * ftpm_tee_transceive() - send fTPM commands and retrieve fTPM response.
- * @sendbuf - address of the data to send, byte by byte
- * @send_size - length of the data to send
- * @recvbuf - address where to read the response, byte by byte.
- * @recv_len - pointer to the size of buffer
- *
- * Return:
- * In case of success, returns 0.
- * On failure, -errno
- */
- static int ftpm_tee_transceive(struct udevice *dev, const u8 *sendbuf,
- size_t send_size, u8 *recvbuf,
- size_t *recv_len)
- {
- struct ftpm_tee_private *context = dev_get_priv(dev);
- int rc = 0;
- size_t resp_len;
- u8 *resp_buf;
- struct tpm_output_header *resp_header;
- struct tee_invoke_arg transceive_args;
- struct tee_param command_params[4];
- struct tee_shm *shm;
- if (send_size > MAX_COMMAND_SIZE) {
- debug("%s:send_size=%zd exceeds MAX_COMMAND_SIZE\n",
- __func__, send_size);
- return -EIO;
- }
- shm = context->shm;
- memset(&transceive_args, 0, sizeof(transceive_args));
- memset(command_params, 0, sizeof(command_params));
- /* Invoke FTPM_OPTEE_TA_SUBMIT_COMMAND function of fTPM TA */
- transceive_args = (struct tee_invoke_arg) {
- .func = FTPM_OPTEE_TA_SUBMIT_COMMAND,
- .session = context->session,
- };
- /* Fill FTPM_OPTEE_TA_SUBMIT_COMMAND parameters */
- /* request */
- command_params[0] = (struct tee_param) {
- .attr = TEE_PARAM_ATTR_TYPE_MEMREF_INPUT,
- .u.memref = {
- .shm = shm,
- .size = send_size,
- .shm_offs = 0,
- },
- };
- memset(command_params[0].u.memref.shm->addr, 0,
- (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE));
- memcpy(command_params[0].u.memref.shm->addr, sendbuf, send_size);
- /* response */
- command_params[1] = (struct tee_param) {
- .attr = TEE_PARAM_ATTR_TYPE_MEMREF_INOUT,
- .u.memref = {
- .shm = shm,
- .size = MAX_RESPONSE_SIZE,
- .shm_offs = MAX_COMMAND_SIZE,
- },
- };
- rc = tee_invoke_func(context->tee_dev, &transceive_args, 4,
- command_params);
- if ((rc < 0) || (transceive_args.ret != 0)) {
- debug("%s:SUBMIT_COMMAND invoke error: 0x%x\n",
- __func__, transceive_args.ret);
- return (rc < 0) ? rc : transceive_args.ret;
- }
- resp_buf = command_params[1].u.memref.shm->addr +
- command_params[1].u.memref.shm_offs;
- resp_header = (struct tpm_output_header *)resp_buf;
- resp_len = be32_to_cpu(resp_header->length);
- /* sanity check resp_len*/
- if (resp_len < TPM_HEADER_SIZE) {
- debug("%s:tpm response header too small\n", __func__);
- return -EIO;
- }
- if (resp_len > MAX_RESPONSE_SIZE) {
- debug("%s:resp_len=%zd exceeds MAX_RESPONSE_SIZE\n",
- __func__, resp_len);
- return -EIO;
- }
- if (resp_len > *recv_len) {
- debug("%s:response length is bigger than receive buffer\n",
- __func__);
- return -EIO;
- }
- /* sanity checks look good, copy the response */
- memcpy(recvbuf, resp_buf, resp_len);
- *recv_len = resp_len;
- return 0;
- }
- static int ftpm_tee_open(struct udevice *dev)
- {
- struct ftpm_tee_private *context = dev_get_priv(dev);
- if (context->is_open)
- return -EBUSY;
- context->is_open = 1;
- return 0;
- }
- static int ftpm_tee_close(struct udevice *dev)
- {
- struct ftpm_tee_private *context = dev_get_priv(dev);
- if (context->is_open)
- context->is_open = 0;
- return 0;
- }
- static int ftpm_tee_desc(struct udevice *dev, char *buf, int size)
- {
- if (size < 32)
- return -ENOSPC;
- return snprintf(buf, size, "Microsoft OP-TEE fTPM");
- }
- static int ftpm_tee_match(struct tee_version_data *vers, const void *data)
- {
- debug("%s:vers->gen_caps =0x%x\n", __func__, vers->gen_caps);
- /*
- * Currently this driver only support GP Complaint OPTEE based fTPM TA
- */
- return vers->gen_caps & TEE_GEN_CAP_GP;
- }
- static int ftpm_tee_probe(struct udevice *dev)
- {
- int rc;
- struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
- struct ftpm_tee_private *context = dev_get_priv(dev);
- struct tee_open_session_arg sess_arg;
- const struct tee_optee_ta_uuid uuid = TA_FTPM_UUID;
- memset(context, 0, sizeof(*context));
- /* Use the TPM v2 stack */
- priv->version = TPM_V2;
- priv->pcr_count = 24;
- priv->pcr_select_min = 3;
- /* Find TEE device */
- context->tee_dev = tee_find_device(NULL, ftpm_tee_match, NULL, NULL);
- if (!context->tee_dev) {
- debug("%s:tee_find_device failed\n", __func__);
- return -ENODEV;
- }
- /* Open a session with the fTPM TA */
- memset(&sess_arg, 0, sizeof(sess_arg));
- tee_optee_ta_uuid_to_octets(sess_arg.uuid, &uuid);
- rc = tee_open_session(context->tee_dev, &sess_arg, 0, NULL);
- if ((rc < 0) || (sess_arg.ret != 0)) {
- debug("%s:tee_open_session failed, err=%x\n",
- __func__, sess_arg.ret);
- return -EIO;
- }
- context->session = sess_arg.session;
- /* Allocate dynamic shared memory with fTPM TA */
- rc = tee_shm_alloc(context->tee_dev,
- MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE,
- 0, &context->shm);
- if (rc) {
- debug("%s:tee_shm_alloc failed with rc = %d\n", __func__, rc);
- goto out_shm_alloc;
- }
- return 0;
- out_shm_alloc:
- tee_close_session(context->tee_dev, context->session);
- return rc;
- }
- static int ftpm_tee_remove(struct udevice *dev)
- {
- struct ftpm_tee_private *context = dev_get_priv(dev);
- int rc;
- /* tee_pre_remove frees any leftover TEE shared memory */
- /* close the existing session with fTPM TA*/
- rc = tee_close_session(context->tee_dev, context->session);
- debug("%s: tee_close_session - rc =%d\n", __func__, rc);
- return 0;
- }
- static const struct tpm_ops ftpm_tee_ops = {
- .open = ftpm_tee_open,
- .close = ftpm_tee_close,
- .get_desc = ftpm_tee_desc,
- .xfer = ftpm_tee_transceive,
- };
- static const struct udevice_id ftpm_tee_ids[] = {
- { .compatible = "microsoft,ftpm" },
- { }
- };
- U_BOOT_DRIVER(ftpm_tee) = {
- .name = "ftpm_tee",
- .id = UCLASS_TPM,
- .of_match = ftpm_tee_ids,
- .ops = &ftpm_tee_ops,
- .probe = ftpm_tee_probe,
- .remove = ftpm_tee_remove,
- .flags = DM_FLAG_OS_PREPARE,
- .priv_auto_alloc_size = sizeof(struct ftpm_tee_private),
- };
|