CC linux-security-module
On Sat, Dec 03, 2016 at 07:52:13PM +0200, Jarkko Sakkinen wrote:
> Request and relinquish locality for the driver use in order to be
> a better citizen in a multi locality environment like TXT. The
> locality is requested and relinquished as part of going into and
> waking up from idle.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
> ---
> drivers/char/tpm/tpm_crb.c | 36 ++++++++++++++++++++++++------------
> 1 file changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> index f986d02..f6e0beb 100644
> --- a/drivers/char/tpm/tpm_crb.c
> +++ b/drivers/char/tpm/tpm_crb.c
> @@ -34,6 +34,15 @@ enum crb_defaults {
> CRB_ACPI_START_INDEX = 1,
> };
>
> +enum crb_loc_ctrl {
> + CRB_LOC_CTRL_REQUEST_ACCESS = BIT(0),
> + CRB_LOC_CTRL_RELINQUISH = BIT(1),
> +};
> +
> +enum crb_loc_state {
> + CRB_LOC_STATE_LOC_ASSIGNED = BIT(1),
> +};
> +
> enum crb_ctrl_req {
> CRB_CTRL_REQ_CMD_READY = BIT(0),
> CRB_CTRL_REQ_GO_IDLE = BIT(1),
> @@ -101,12 +110,8 @@ struct crb_priv {
> * @dev: crb device
> * @priv: crb private data
> *
> - * Write CRB_CTRL_REQ_GO_IDLE to TPM_CRB_CTRL_REQ
> - * The device should respond within TIMEOUT_C by clearing the bit.
> - * Anyhow, we do not wait here as a consequent CMD_READY request
> - * will be handled correctly even if idle was not completed.
> - *
> - * The function does nothing for devices with ACPI-start method.
> + * Put device to the idle state and relinquish locality. The function does
> + * nothing for devices with the ACPI-start method.
> *
> * Return: 0 always
> */
> @@ -115,6 +120,7 @@ static int __maybe_unused crb_go_idle(struct device *dev,
> struct crb_priv *priv)
> if (priv->flags & CRB_FL_ACPI_START)
> return 0;
>
> + iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl);
> iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
> /* we don't really care when this settles */
>
> @@ -146,11 +152,8 @@ static bool crb_wait_for_reg_32(u32 __iomem *reg, u32
> mask, u32 value,
> * @dev: crb device
> * @priv: crb private data
> *
> - * Write CRB_CTRL_REQ_CMD_READY to TPM_CRB_CTRL_REQ
> - * and poll till the device acknowledge it by clearing the bit.
> - * The device should respond within TIMEOUT_C.
> - *
> - * The function does nothing for devices with ACPI-start method
> + * Try to wake up the device and request locality. The function does nothing
> + * for devices with the ACPI-start method.
> *
> * Return: 0 on success -ETIME on timeout;
> */
> @@ -165,7 +168,16 @@ static int __maybe_unused crb_cmd_ready(struct device
> *dev,
> CRB_CTRL_REQ_CMD_READY /* mask */,
> 0, /* value */
> TPM2_TIMEOUT_C)) {
> - dev_warn(dev, "cmdReady timed out\n");
> + dev_warn(dev, "TPM_CRB_CTRL_REQ_x.cmdReady timed out\n");
> + return -ETIME;
> + }
> +
> + iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl);
> + if (!crb_wait_for_reg_32(&priv->regs_h->loc_state,
> + CRB_LOC_STATE_LOC_ASSIGNED, /* mask */
> + CRB_LOC_STATE_LOC_ASSIGNED, /* value */
> + TPM2_TIMEOUT_C)) {
> + dev_warn(dev, "TPM_LOC_STATE_x.requestAccess timed out\n");
> return -ETIME;
> }
>
> --
> 2.9.3
>
