diff options
Diffstat (limited to 'src/drivers/spi/tpm')
| -rw-r--r-- | src/drivers/spi/tpm/tpm.c | 162 | ||||
| -rw-r--r-- | src/drivers/spi/tpm/tpm.h | 3 |
2 files changed, 140 insertions, 25 deletions
diff --git a/src/drivers/spi/tpm/tpm.c b/src/drivers/spi/tpm/tpm.c index 4263dce523..bc40e852a2 100644 --- a/src/drivers/spi/tpm/tpm.c +++ b/src/drivers/spi/tpm/tpm.c @@ -31,6 +31,15 @@ #define TPM_DID_VID_REG (TPM_LOCALITY_0_SPI_BASE + 0xf00) #define TPM_RID_REG (TPM_LOCALITY_0_SPI_BASE + 0xf04) #define TPM_FW_VER (TPM_LOCALITY_0_SPI_BASE + 0xf90) +#define CR50_BOARD_CFG (TPM_LOCALITY_0_SPI_BASE + 0xfe0) + +#define CR50_BOARD_CFG_LOCKBIT_MASK 0x80000000U +#define CR50_BOARD_CFG_FEATUREBITS_MASK 0x3FFFFFFFU + +#define CR50_BOARD_CFG_100US_READY_PULSE 0x00000001U +#define CR50_BOARD_CFG_VALUE \ + (CONFIG(CR50_USE_LONG_INTERRUPT_PULSES) \ + ? CR50_BOARD_CFG_100US_READY_PULSE : 0) #define CR50_TIMEOUT_INIT_MS 30000 /* Very long timeout for TPM init */ @@ -39,6 +48,12 @@ static struct spi_slave spi_slave; /* Cached TPM device identification. */ static struct tpm2_info tpm_info; +struct cr50_firmware_version { + int epoch; + int major; + int minor; +}; +static struct cr50_firmware_version cr50_firmware_version; /* * TODO(vbendeb): make CONFIG(DEBUG_TPM) an int to allow different level of @@ -421,12 +436,109 @@ static int tpm2_claim_locality(void) return 0; } +static int cr50_parse_fw_version(const char *version_str, struct cr50_firmware_version *ver) +{ + int epoch, major, minor; + + char *number = strstr(version_str, " RW_A:"); + if (!number) + number = strstr(version_str, " RW_B:"); + if (!number) + return -1; + number += 6; /* Skip past the colon. */ + + epoch = skip_atoi(&number); + if (*number++ != '.') + return -2; + major = skip_atoi(&number); + if (*number++ != '.') + return -2; + minor = skip_atoi(&number); + + ver->epoch = epoch; + ver->major = major; + ver->minor = minor; + return 0; +} + +static int cr50_fw_supports_board_cfg(struct cr50_firmware_version *version) +{ + /* Cr50 supports the CR50_BOARD_CFG register from version 0.5.5 / 0.6.5 + * and onwards. */ + if (version->epoch > 0 || version->major >= 7 + || (version->major >= 5 && version->minor >= 5)) + return 1; + printk(BIOS_INFO, "Cr50 firmware does not support CR50_BOARD_CFG, version: %d.%d.%d\n", + version->epoch, version->major, version->minor); + return 0; +} + +/** + * Set the BOARD_CFG register on the TPM chip to a particular compile-time constant value. + */ +static void cr50_set_board_cfg(void) +{ + uint32_t board_cfg_value; + if (!cr50_fw_supports_board_cfg(&cr50_firmware_version)) + return; + /* Set the CR50_BOARD_CFG register, for e.g. asking cr50 to use longer ready pulses. */ + if (!tpm2_read_reg(CR50_BOARD_CFG, &board_cfg_value, sizeof(board_cfg_value))) { + printk(BIOS_INFO, "Error reading from cr50\n"); + return; + } + if ((board_cfg_value & CR50_BOARD_CFG_FEATUREBITS_MASK) == CR50_BOARD_CFG_VALUE) { + printk(BIOS_INFO, + "Current CR50_BOARD_CFG = 0x%08x, matches desired = 0x%08x\n", + board_cfg_value, CR50_BOARD_CFG_VALUE); + return; + } + if (board_cfg_value & CR50_BOARD_CFG_LOCKBIT_MASK) { + /* The high bit is set, meaning that the Cr50 is already locked on a particular + * value for the register, but not the one we wanted. */ + printk(BIOS_ERR, + "ERROR: Current CR50_BOARD_CFG = 0x%08x, does not match desired = 0x%08x\n", + board_cfg_value, CR50_BOARD_CFG_VALUE); + return; + } + printk(BIOS_INFO, "Current CR50_BOARD_CFG = 0x%08x, setting to 0x%08x\n", + board_cfg_value, CR50_BOARD_CFG_VALUE); + board_cfg_value = CR50_BOARD_CFG_VALUE; + if (!tpm2_write_reg(CR50_BOARD_CFG, &board_cfg_value, sizeof(board_cfg_value))) + printk(BIOS_INFO, "Error writing to cr50\n"); +} + +/* + * Expose method to read the CR50_BOARD_CFG register, will return zero if + * register not supported by Cr50 firmware. + */ +static uint32_t cr50_get_board_cfg(void) +{ + uint32_t board_cfg_value; + if (!cr50_fw_supports_board_cfg(&cr50_firmware_version)) + return 0; + if (!tpm2_read_reg(CR50_BOARD_CFG, &board_cfg_value, sizeof(board_cfg_value))) { + printk(BIOS_INFO, "Error reading from cr50\n"); + return 0; + } + return board_cfg_value & CR50_BOARD_CFG_FEATUREBITS_MASK; +} + +bool cr50_is_long_interrupt_pulse_enabled(void) +{ + return cr50_get_board_cfg() & CR50_BOARD_CFG_100US_READY_PULSE; +} + /* Device/vendor ID values of the TPM devices this driver supports. */ static const uint32_t supported_did_vids[] = { 0x00281ae0, /* H1 based Cr50 security chip. */ 0x0000104a /* ST33HTPH2E32 */ }; +static int first_access_this_boot(void) +{ + return ENV_SEPARATE_VERSTAGE || ENV_BOOTBLOCK || !CONFIG(VBOOT); +} + int tpm2_init(struct spi_slave *spi_if) { uint32_t did_vid, status; @@ -471,7 +583,7 @@ int tpm2_init(struct spi_slave *spi_if) printk(BIOS_INFO, " done!\n"); // FIXME: Move this to tpm_setup() - if (ENV_SEPARATE_VERSTAGE || ENV_BOOTBLOCK || !CONFIG(VBOOT)) + if (first_access_this_boot()) /* * Claim locality 0, do it only during the first * initialization after reset. @@ -502,18 +614,10 @@ int tpm2_init(struct spi_slave *spi_if) tpm_info.vendor_id, tpm_info.device_id, tpm_info.revision); /* Let's report device FW version if available. */ - if (tpm_info.vendor_id == 0x1ae0) { + if (CONFIG(TPM_CR50) && tpm_info.vendor_id == 0x1ae0) { int chunk_count = 0; - size_t chunk_size; - /* - * let's read 50 bytes at a time; leave room for the trailing - * zero. - */ - char vstr[51]; - - chunk_size = sizeof(vstr) - 1; - - printk(BIOS_INFO, "Firmware version: "); + size_t chunk_size = 50; + char version_str[301]; /* * Does not really matter what's written, this just makes sure @@ -521,20 +625,28 @@ int tpm2_init(struct spi_slave *spi_if) */ tpm2_write_reg(TPM_FW_VER, &chunk_size, 1); - /* Print it out in sizeof(vstr) - 1 byte chunks. */ - vstr[chunk_size] = 0; + /* + * Read chunk_size bytes at a time, last chunk will be zero padded. + */ do { - tpm2_read_reg(TPM_FW_VER, vstr, chunk_size); - printk(BIOS_INFO, "%s", vstr); - - /* - * While string is not over, and is no longer than 300 - * characters. - */ - } while (vstr[chunk_size - 1] && - (chunk_count++ < (300 / chunk_size))); - - printk(BIOS_INFO, "\n"); + tpm2_read_reg(TPM_FW_VER, + version_str + chunk_count * chunk_size, + chunk_size); + if (!version_str[++chunk_count * chunk_size - 1]) + /* Zero padding detected: end of string. */ + break; + /* Check if there is enough room for reading one more chunk. */ + } while (chunk_count * chunk_size < sizeof(version_str) - chunk_size); + version_str[chunk_count * chunk_size] = '\0'; + printk(BIOS_INFO, "Firmware version: %s\n", version_str); + if (cr50_parse_fw_version(version_str, &cr50_firmware_version)) { + printk(BIOS_ERR, "Did not recognize Cr50 version format\n"); + return -1; + } + if (CR50_BOARD_CFG_VALUE) { + if (first_access_this_boot()) + cr50_set_board_cfg(); + } } return 0; } diff --git a/src/drivers/spi/tpm/tpm.h b/src/drivers/spi/tpm/tpm.h index be98ed05df..b3e3f45ee9 100644 --- a/src/drivers/spi/tpm/tpm.h +++ b/src/drivers/spi/tpm/tpm.h @@ -41,4 +41,7 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size, /* Get information about previously initialized TPM device. */ void tpm2_get_info(struct tpm2_info *info); +/* Indicates whether Cr50 ready pulses are guaranteed to be at least 100us. */ +bool cr50_is_long_interrupt_pulse_enabled(void); + #endif /* ! __COREBOOT_SRC_DRIVERS_SPI_TPM_TPM_H */ |