Hi Jason,
On Sun, Sep 30, 2012 at 05:30:12PM -0600, Jason Gunthorpe wrote:
> The TPM will respond to TPM_GET_CAP with TPM_ERR_INVALID_POSTINIT if
> TPM_STARTUP has not been issued. This will result in the TPM driver
> failing to load and no way to recover. Detect this and automatically
> issue TPM_STARTUP.
>
> This is for embedded applications where the kernel is the first thing
> to touch the TPM.
>
> Signed-off-by: Jason Gunthorpe <jguntho...@obsidianresearch.com>
> ---
> drivers/char/tpm/tpm.c | 41 ++++++++++++++++++++++++++++++++++++-----
> drivers/char/tpm/tpm.h | 6 ++++++
> 2 files changed, 42 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
> index 817f0ee..60e8442 100644
> --- a/drivers/char/tpm/tpm.c
> +++ b/drivers/char/tpm/tpm.c
> @@ -473,7 +473,7 @@ static ssize_t transmit_cmd(struct tpm_chip *chip, struct
> tpm_cmd_t *cmd,
> return -EFAULT;
>
> err = be32_to_cpu(cmd->header.out.return_code);
> - if (err != 0)
> + if (err != 0 && desc)
> dev_err(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
>
> return err;
> @@ -489,6 +489,15 @@ static const struct tpm_input_header tpm_getcap_header =
> {
> .ordinal = TPM_ORD_GET_CAP
> };
>
> +
> +#define TPM_ORD_STARTUP cpu_to_be32(153)
> +#define TPM_ST_CLEAR cpu_to_be32(1)
> +static const struct tpm_input_header tpm_startup_header = {
> + .tag = TPM_TAG_RQU_COMMAND,
> + .length = cpu_to_be32(12),
> + .ordinal = TPM_ORD_STARTUP
> +};
> +
> ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
> const char *desc)
> {
> @@ -545,11 +554,33 @@ int tpm_get_timeouts(struct tpm_chip *chip)
> tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
> tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
> + rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0);
> +
> + if (rc == TPM_ERR_INVALID_POSTINIT) {
> + struct tpm_cmd_t start_cmd;
> + /* The TPM is not started, we are the first to talk to it.
> + Execute a startup command. */
> + start_cmd.header.in = tpm_startup_header;
> + start_cmd.params.startup_in.startup_type = TPM_ST_CLEAR;
Please make this its own function instead of putting it inside
tpm_get_timeouts.
Kent
> +
> + dev_info(chip->dev, "Issuing TPM_STARTUP");
> + rc = transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
> + "attempting to start the TPM");
> + if (rc)
> + return -EINVAL;
>
> - rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> - "attempting to determine the timeouts");
> - if (rc)
> + tpm_cmd.header.in = tpm_getcap_header;
> + tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
> + tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> + tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
> + rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0);
> + }
> + if (rc) {
> + dev_err(chip->dev,
> + "A TPM error (%d) occurred attempting to determine the
> timeouts\n",
> + rc);
> goto duration;
> + }
>
> if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
> be32_to_cpu(tpm_cmd.header.out.length)
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 917f727..2d583ef 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -41,6 +41,7 @@ enum tpm_addr {
> #define TPM_WARN_DOING_SELFTEST 0x802
> #define TPM_ERR_DEACTIVATED 0x6
> #define TPM_ERR_DISABLED 0x7
> +#define TPM_ERR_INVALID_POSTINIT 38
>
> #define TPM_HEADER_SIZE 10
> extern ssize_t tpm_show_pubek(struct device *, struct device_attribute *attr,
> @@ -269,6 +270,10 @@ struct tpm_pcrextend_in {
> u8 hash[TPM_DIGEST_SIZE];
> }__attribute__((packed));
>
> +struct tpm_startup_in {
> + __be16 startup_type;
> +} __packed;
> +
> typedef union {
> struct tpm_getcap_params_out getcap_out;
> struct tpm_readpubek_params_out readpubek_out;
> @@ -277,6 +282,7 @@ typedef union {
> struct tpm_pcrread_in pcrread_in;
> struct tpm_pcrread_out pcrread_out;
> struct tpm_pcrextend_in pcrextend_in;
> + struct tpm_startup_in startup_in;
> } tpm_cmd_params;
>
> struct tpm_cmd_t {
> --
> 1.7.4.1
>
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