diff options
Diffstat (limited to 'drivers/char/tpm')
-rw-r--r-- | drivers/char/tpm/tpm2-cmd.c | 40 |
1 files changed, 23 insertions, 17 deletions
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 026fec4e1800..b82e2b141754 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -846,31 +846,37 @@ static int tpm2_do_selftest(struct tpm_chip *chip) } /** - * tpm2_probe() - probe TPM 2.0 - * @chip: TPM chip to use + * tpm2_probe() - probe for the TPM 2.0 protocol + * @chip: a &tpm_chip instance * - * Return: < 0 error and 0 on success. + * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the + * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by + * this function if this is the case. * - * Send idempotent TPM 2.0 command and see whether TPM 2.0 chip replied based on - * the reply tag. + * Return: + * 0 on success, + * -errno otherwise */ int tpm2_probe(struct tpm_chip *chip) { - struct tpm2_cmd cmd; + struct tpm_output_header *out; + struct tpm_buf buf; int rc; - cmd.header.in = tpm2_get_tpm_pt_header; - cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES); - cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100); - cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1); - - rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0, 0, NULL); - if (rc < 0) + rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY); + if (rc) return rc; - - if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS) - chip->flags |= TPM_CHIP_FLAG_TPM2; - + tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES); + tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS); + tpm_buf_append_u32(&buf, 1); + rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL); + /* We ignore TPM return codes on purpose. */ + if (rc >= 0) { + out = (struct tpm_output_header *)buf.data; + if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS) + chip->flags |= TPM_CHIP_FLAG_TPM2; + } + tpm_buf_destroy(&buf); return 0; } EXPORT_SYMBOL_GPL(tpm2_probe); |