u-boot/include/tpm-common.h
Simon Glass 3bb4db4c38 tpm: Allow reporting the internal state
It is useful to read information about the current TPM state, where
supported, e.g. for debugging purposes when verified boot fails.

Add support for this to the TPM interface as well as Cr50. Add a simple
sandbox test.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2022-09-03 16:59:05 +03:00

326 lines
8.7 KiB
C

/* 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
#include <command.h>
struct udevice;
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
* @plat_hier_disabled: Platform hierarchy has been disabled (TPM is locked
* down until next reboot)
*/
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;
bool plat_hier_disabled;
};
/**
* 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);
/**
* report_state() - Collect information about the current TPM state
*
* @dev: Device to check
* @buf: Buffer to put the string
* @size: Maximum size of buffer
* Return: return code of the operation (0 = success)
*/
int (*report_state)(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(struct cmd_tbl *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_report_state() - Collect information about the current TPM state
*
* @dev: Device to check
* @buf: Buffer to put the string
* @size: Maximum size of buffer
* Return: return code of the operation (0 = success)
*/
int tpm_report_state(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 struct cmd_tbl array.
*/
#if defined(CONFIG_TPM_V1)
struct cmd_tbl *get_tpm1_commands(unsigned int *size);
#else
static inline struct cmd_tbl *get_tpm1_commands(unsigned int *size)
{
return NULL;
}
#endif
#if defined(CONFIG_TPM_V2)
struct cmd_tbl *get_tpm2_commands(unsigned int *size);
#else
static inline struct cmd_tbl *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);
/* Iterate on all TPM devices */
#define for_each_tpm_device(dev) uclass_foreach_dev_probe(UCLASS_TPM, (dev))
#endif /* __TPM_COMMON_H */