Messages in this thread | | | From | "Winkler, Tomas" <> | Subject | RE: [tpmdd-devel] [PATCH v2 3/3] tpm_crb: request and relinquish locality 0 | Date | Mon, 5 Dec 2016 21:51:42 +0000 |
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> > 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. > This has nothing to do with power management, please note, that this is run via runtime_pm handlers, which can be disabled via sysfs and actually on server platforms runtime pm is not relevant, while you cannot disable locality acquire/relinquish flow.
NACK > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@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); This is misleading this has nothing to do with go idle, what is the > > 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"); We are always in locality 0 here, right?
> > + 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; > > }
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