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Diffstat (limited to 'include/tpm-common.h')
-rw-r--r-- | include/tpm-common.h | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/include/tpm-common.h b/include/tpm-common.h new file mode 100644 index 0000000..f9c2ca2 --- /dev/null +++ b/include/tpm-common.h @@ -0,0 +1,296 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (c) 2013 The Chromium OS Authors. + * Coypright (c) 2013 Guntermann & Drunck GmbH + */ + +#ifndef __TPM_COMMON_H +#define __TPM_COMMON_H + +enum tpm_duration { + TPM_SHORT = 0, + TPM_MEDIUM = 1, + TPM_LONG = 2, + TPM_UNDEFINED, + + TPM_DURATION_COUNT, +}; + +/* + * Here is a partial implementation of TPM commands. Please consult TCG Main + * Specification for definitions of TPM commands. + */ + +#define TPM_HEADER_SIZE 10 + +/* Max buffer size supported by our tpm */ +#define TPM_DEV_BUFSIZE 1260 + +#define TPM_PCR_MINIMUM_DIGEST_SIZE 20 + +/** + * enum tpm_version - The version of the TPM stack to be used + * @TPM_V1: Use TPM v1.x stack + * @TPM_V2: Use TPM v2.x stack + */ +enum tpm_version { + TPM_V1 = 0, + TPM_V2, +}; + +/** + * struct tpm_chip_priv - Information about a TPM, stored by the uclass + * + * These values must be set up by the device's probe() method before + * communcation is attempted. If the device has an xfer() method, this is + * not needed. There is no need to set up @buf. + * + * @version: TPM stack to be used + * @duration_ms: Length of each duration type in milliseconds + * @retry_time_ms: Time to wait before retrying receive + * @buf: Buffer used during the exchanges with the chip + * @pcr_count: Number of PCR per bank + * @pcr_select_min: Minimum size in bytes of the pcrSelect array + */ +struct tpm_chip_priv { + enum tpm_version version; + + uint duration_ms[TPM_DURATION_COUNT]; + uint retry_time_ms; + u8 buf[TPM_DEV_BUFSIZE + sizeof(u8)]; /* Max buffer size + addr */ + + /* TPM v2 specific data */ + uint pcr_count; + uint pcr_select_min; +}; + +/** + * struct tpm_ops - low-level TPM operations + * + * These are designed to avoid loops and delays in the driver itself. These + * should be handled in the uclass. + * + * In gneral you should implement everything except xfer(). Where you need + * complete control of the transfer, then xfer() can be provided and will + * override the other methods. + * + * This interface is for low-level TPM access. It does not understand the + * concept of localities or the various TPM messages. That interface is + * defined in the functions later on in this file, but they all translate + * to bytes which are sent and received. + */ +struct tpm_ops { + /** + * open() - Request access to locality 0 for the caller + * + * After all commands have been completed the caller should call + * close(). + * + * @dev: Device to open + * @return 0 ok OK, -ve on error + */ + int (*open)(struct udevice *dev); + + /** + * close() - Close the current session + * + * Releasing the locked locality. Returns 0 on success, -ve 1 on + * failure (in case lock removal did not succeed). + * + * @dev: Device to close + * @return 0 ok OK, -ve on error + */ + int (*close)(struct udevice *dev); + + /** + * get_desc() - Get a text description of the TPM + * + * @dev: Device to check + * @buf: Buffer to put the string + * @size: Maximum size of buffer + * @return length of string, or -ENOSPC it no space + */ + int (*get_desc)(struct udevice *dev, char *buf, int size); + + /** + * send() - send data to the TPM + * + * @dev: Device to talk to + * @sendbuf: Buffer of the data to send + * @send_size: Size of the data to send + * + * Returns 0 on success or -ve on failure. + */ + int (*send)(struct udevice *dev, const u8 *sendbuf, size_t send_size); + + /** + * recv() - receive a response from the TPM + * + * @dev: Device to talk to + * @recvbuf: Buffer to save the response to + * @max_size: Maximum number of bytes to receive + * + * Returns number of bytes received on success, -EAGAIN if the TPM + * response is not ready, -EINTR if cancelled, or other -ve value on + * failure. + */ + int (*recv)(struct udevice *dev, u8 *recvbuf, size_t max_size); + + /** + * cleanup() - clean up after an operation in progress + * + * This is called if receiving times out. The TPM may need to abort + * the current transaction if it did not complete, and make itself + * ready for another. + * + * @dev: Device to talk to + */ + int (*cleanup)(struct udevice *dev); + + /** + * xfer() - send data to the TPM and get response + * + * This method is optional. If it exists it is used in preference + * to send(), recv() and cleanup(). It should handle all aspects of + * TPM communication for a single transfer. + * + * @dev: Device to talk to + * @sendbuf: Buffer of the data to send + * @send_size: Size of the data to send + * @recvbuf: Buffer to save the response to + * @recv_size: Pointer to the size of the response buffer + * + * Returns 0 on success (and places the number of response bytes at + * recv_size) or -ve on failure. + */ + int (*xfer)(struct udevice *dev, const u8 *sendbuf, size_t send_size, + u8 *recvbuf, size_t *recv_size); +}; + +#define tpm_get_ops(dev) ((struct tpm_ops *)device_get_ops(dev)) + +#define MAKE_TPM_CMD_ENTRY(cmd) \ + U_BOOT_CMD_MKENT(cmd, 0, 1, do_tpm_ ## cmd, "", "") + +#define TPM_COMMAND_NO_ARG(cmd) \ +int do_##cmd(cmd_tbl_t *cmdtp, int flag, \ + int argc, char * const argv[]) \ +{ \ + struct udevice *dev; \ + int rc; \ + \ + rc = get_tpm(&dev); \ + if (rc) \ + return rc; \ + if (argc != 1) \ + return CMD_RET_USAGE; \ + return report_return_code(cmd(dev)); \ +} + +/** + * tpm_open() - Request access to locality 0 for the caller + * + * After all commands have been completed the caller is supposed to + * call tpm_close(). + * + * @dev - TPM device + * Returns 0 on success, -ve on failure. + */ +int tpm_open(struct udevice *dev); + +/** + * tpm_close() - Close the current session + * + * Releasing the locked locality. Returns 0 on success, -ve 1 on + * failure (in case lock removal did not succeed). + * + * @dev - TPM device + * Returns 0 on success, -ve on failure. + */ +int tpm_close(struct udevice *dev); + +/** + * tpm_clear_and_reenable() - Force clear the TPM and reenable it + * + * @dev: TPM device + * @return 0 on success, -ve on failure + */ +u32 tpm_clear_and_reenable(struct udevice *dev); + +/** + * tpm_get_desc() - Get a text description of the TPM + * + * @dev: Device to check + * @buf: Buffer to put the string + * @size: Maximum size of buffer + * @return length of string, or -ENOSPC it no space + */ +int tpm_get_desc(struct udevice *dev, char *buf, int size); + +/** + * tpm_xfer() - send data to the TPM and get response + * + * This first uses the device's send() method to send the bytes. Then it calls + * recv() to get the reply. If recv() returns -EAGAIN then it will delay a + * short time and then call recv() again. + * + * Regardless of whether recv() completes successfully, it will then call + * cleanup() to finish the transaction. + * + * Note that the outgoing data is inspected to determine command type + * (ordinal) and a timeout is used for that command type. + * + * @dev - TPM device + * @sendbuf - buffer of the data to send + * @send_size size of the data to send + * @recvbuf - memory to save the response to + * @recv_len - pointer to the size of the response buffer + * + * Returns 0 on success (and places the number of response bytes at + * recv_len) or -ve on failure. + */ +int tpm_xfer(struct udevice *dev, const u8 *sendbuf, size_t send_size, + u8 *recvbuf, size_t *recv_size); + +/** + * Initialize TPM device. It must be called before any TPM commands. + * + * @dev - TPM device + * @return 0 on success, non-0 on error. + */ +int tpm_init(struct udevice *dev); + +/** + * Retrieve the array containing all the v1 (resp. v2) commands. + * + * @return a cmd_tbl_t array. + */ +#if defined(CONFIG_TPM_V1) +cmd_tbl_t *get_tpm1_commands(unsigned int *size); +#else +static inline cmd_tbl_t *get_tpm1_commands(unsigned int *size) +{ + return NULL; +} +#endif +#if defined(CONFIG_TPM_V2) +cmd_tbl_t *get_tpm2_commands(unsigned int *size); +#else +static inline cmd_tbl_t *get_tpm2_commands(unsigned int *size) +{ + return NULL; +} +#endif + +/** + * tpm_get_version() - Find the version of a TPM + * + * This checks the uclass data for a TPM device and returns the version number + * it supports. + * + * @dev: TPM device + * @return version number (TPM_V1 or TPMV2) + */ +enum tpm_version tpm_get_version(struct udevice *dev); + +#endif /* __TPM_COMMON_H */ |