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Message-ID: <8fff0ded33cf5b012eff398161a09af013b02d41.camel@linux.intel.com>
Date: Tue, 25 Sep 2018 17:31:07 +0300
From: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To: Tomas Winkler <tomas.winkler@...el.com>,
Jason Gunthorpe <jgg@...pe.ca>
Cc: Alexander Usyskin <alexander.usyskin@...el.com>,
Tadeusz Struk <tadeusz.struk@...el.com>,
linux-integrity@...r.kernel.org,
linux-security-module@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 10/21] tpm: factor out tpm 1.x pm suspend flow into
tpm1-cmd.c
On Fri, 2018-09-21 at 16:58 +0300, Tomas Winkler wrote:
> Factor out TPM 1.x suspend flow from tpm-interface.c into a new function
> tpm1_pm_suspend() in tpm1-cmd.c
>
> Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
> ---
> V2-V3: Rebase
> V4: 1. Add kdoc for tpm1_pm_suspend().
> 2. Fix commit message.
>
> drivers/char/tpm/tpm-interface.c | 55 ++++---------------------------------
> drivers/char/tpm/tpm.h | 1 +
> drivers/char/tpm/tpm1-cmd.c | 59
> ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 65 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-
> interface.c
> index 7239ccc16e2f..dfa972bbdd81 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -585,15 +585,6 @@ int tpm_send(struct tpm_chip *chip, void *cmd, size_t
> buflen)
> }
> EXPORT_SYMBOL_GPL(tpm_send);
>
> -#define TPM_ORD_SAVESTATE 152
> -#define SAVESTATE_RESULT_SIZE 10
> -
> -static const struct tpm_input_header savestate_header = {
> - .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
> - .length = cpu_to_be32(10),
> - .ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
> -};
> -
> /*
> * We are about to suspend. Save the TPM state
> * so that it can be restored.
> @@ -601,54 +592,18 @@ static const struct tpm_input_header savestate_header =
> {
> int tpm_pm_suspend(struct device *dev)
> {
> struct tpm_chip *chip = dev_get_drvdata(dev);
> - struct tpm_cmd_t cmd;
> - int rc, try;
> -
> - u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
> + int rc = 0;
>
> - if (chip == NULL)
> + if (!chip)
> return -ENODEV;
>
> if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
> return 0;
>
> - if (chip->flags & TPM_CHIP_FLAG_TPM2) {
> + if (chip->flags & TPM_CHIP_FLAG_TPM2)
> tpm2_shutdown(chip, TPM2_SU_STATE);
> - return 0;
> - }
> -
> - /* for buggy tpm, flush pcrs with extend to selected dummy */
> - if (tpm_suspend_pcr)
> - rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
> - "extending dummy pcr before suspend");
> -
> - /* now do the actual savestate */
> - for (try = 0; try < TPM_RETRY; try++) {
> - cmd.header.in = savestate_header;
> - rc = tpm_transmit_cmd(chip, NULL, &cmd,
> SAVESTATE_RESULT_SIZE,
> - 0, 0, NULL);
> -
> - /*
> - * If the TPM indicates that it is too busy to respond to
> - * this command then retry before giving up. It can take
> - * several seconds for this TPM to be ready.
> - *
> - * This can happen if the TPM has already been sent the
> - * SaveState command before the driver has loaded. TCG 1.2
> - * specification states that any communication after
> SaveState
> - * may cause the TPM to invalidate previously saved state.
> - */
> - if (rc != TPM_WARN_RETRY)
> - break;
> - tpm_msleep(TPM_TIMEOUT_RETRY);
> - }
> -
> - if (rc)
> - dev_err(&chip->dev,
> - "Error (%d) sending savestate before suspend\n", rc);
> - else if (try > 0)
> - dev_warn(&chip->dev, "TPM savestate took %dms\n",
> - try * TPM_TIMEOUT_RETRY);
> + else
> + rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
>
> return rc;
> }
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index fd945fc828b6..862c9262e037 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -543,6 +543,7 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct
> tpm_space *space,
> int tpm_startup(struct tpm_chip *chip);
> int tpm_get_timeouts(struct tpm_chip *);
>
> +int tpm1_pm_suspend(struct tpm_chip *chip, int tpm_suspend_pcr);
> int tpm1_do_selftest(struct tpm_chip *chip);
> int tpm1_auto_startup(struct tpm_chip *chip);
> int tpm1_get_timeouts(struct tpm_chip *chip);
> diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
> index 8ecda2cd3734..d118adbcd2a7 100644
> --- a/drivers/char/tpm/tpm1-cmd.c
> +++ b/drivers/char/tpm/tpm1-cmd.c
> @@ -667,3 +667,62 @@ int tpm1_auto_startup(struct tpm_chip *chip)
> rc = -ENODEV;
> return rc;
> }
> +
> +#define TPM_ORD_SAVESTATE 152
> +#define SAVESTATE_RESULT_SIZE 10
> +static const struct tpm_input_header savestate_header = {
> + .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
> + .length = cpu_to_be32(10),
> + .ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
> +};
> +
> +/**
> + * tpm1_pm_suspend() - pm suspend handler
> + * The functions saves the TPM state to be restored on resume.
> + *
> + * @chip: TPM chip to use.
> + * @tpm_suspend_pcr: flush pcr for buggy TPM chips.
> + *
> + * Return: 0 on success, < 0 on error.
> + */
> +int tpm1_pm_suspend(struct tpm_chip *chip, int tpm_suspend_pcr)
> +{
> + u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
> + struct tpm_cmd_t cmd;
> + int rc, try;
> +
> + /* for buggy tpm, flush pcrs with extend to selected dummy */
> + if (tpm_suspend_pcr)
> + rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
> + "extending dummy pcr before suspend");
> +
> + /* now do the actual savestate */
> + for (try = 0; try < TPM_RETRY; try++) {
> + cmd.header.in = savestate_header;
> + rc = tpm_transmit_cmd(chip, NULL, &cmd,
> SAVESTATE_RESULT_SIZE,
> + 0, 0, NULL);
> +
> + /*
> + * If the TPM indicates that it is too busy to respond to
> + * this command then retry before giving up. It can take
> + * several seconds for this TPM to be ready.
> + *
> + * This can happen if the TPM has already been sent the
> + * SaveState command before the driver has loaded. TCG 1.2
> + * specification states that any communication after
> SaveState
> + * may cause the TPM to invalidate previously saved state.
> + */
> + if (rc != TPM_WARN_RETRY)
> + break;
> + tpm_msleep(TPM_TIMEOUT_RETRY);
> + }
> +
> + if (rc)
> + dev_err(&chip->dev, "Error (%d) sending savestate before
> suspend\n",
> + rc);
> + else if (try > 0)
> + dev_warn(&chip->dev, "TPM savestate took %dms\n",
> + try * TPM_TIMEOUT_RETRY);
> +
> + return rc;
> +}
Again, looks otherwise good except for the heading comment.
/Jarkko
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