On Mon, Oct 19, 2020 at 05:14:26PM -0700, Jerry Snitselaar wrote:
>
> James Bottomley @ 2020-10-01 11:09 MST:
>
> > If a TIS TPM doesn't have legacy cycles, any write to the interrupt
> > registers is ignored unless a locality is active. This means even to
> > set up the interrupt vectors a locality must first be activated. Fix
> > this by activating the 0 locality in the interrupt probe setup.
> >
> > Since the TPM_EOI signalling also requires an active locality, the
> > interrupt routine cannot end an interrupt if the locality is released.
> > This can lead to a situation where the TPM goes command ready after
> > locality release and since the interrupt cannot be ended it refires
> > continuously. Fix this by disabling all interrupts except locality
> > change when a locality is released (this only fires when a locality
> > becomes active, meaning the TPM_EOI should work).
> >
> > Finally, since we now disable all status based interrupts in the
> > locality release, they must be re-enabled before waiting to check the
> > condition, so add interrupt enabling to the status wait.
> >
> > Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
> >
> > ---
> >
> > v2: renamed functions
> > ---
> > drivers/char/tpm/tpm_tis_core.c | 125 ++++++++++++++++++++++++++------
> > 1 file changed, 101 insertions(+), 24 deletions(-)
> >
> > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> > index 431919d5f48a..0c07da8cd680 100644
> > --- a/drivers/char/tpm/tpm_tis_core.c
> > +++ b/drivers/char/tpm/tpm_tis_core.c
> > @@ -29,6 +29,46 @@
> >
> > static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value);
> >
> > +static void tpm_tis_enable_interrupt(struct tpm_chip *chip, u8 mask)
> > +{
> > + struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> > + u32 intmask;
> > +
> > + /* Take control of the TPM's interrupt hardware and shut it off */
>
> s/shut it off/turn it on/ ?
>
> > + tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
> > +
> > + intmask |= mask | TPM_GLOBAL_INT_ENABLE;
> > +
> > + tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
> > +}
> > +
> > +static void tpm_tis_disable_interrupt(struct tpm_chip *chip, u8 mask)
> > +{
> > + struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> > + u32 intmask;
> > +
> > + /* Take control of the TPM's interrupt hardware and shut it off */
> > + tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
> > +
> > + intmask &= ~mask;
> > +
> > + tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
> > +}
> > +
> > +static void tpm_tis_enable_stat_interrupts(struct tpm_chip *chip, u8 stat)
> > +{
> > + u32 mask = 0;
> > +
> > + if (stat & TPM_STS_COMMAND_READY)
> > + mask |= TPM_INTF_CMD_READY_INT;
> > + if (stat & TPM_STS_VALID)
> > + mask |= TPM_INTF_STS_VALID_INT;
> > + if (stat & TPM_STS_DATA_AVAIL)
> > + mask |= TPM_INTF_DATA_AVAIL_INT;
> > +
> > + tpm_tis_enable_interrupt(chip, mask);
> > +}
> > +
> > static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
> > bool check_cancel, bool *canceled)
> > {
> > @@ -65,11 +105,14 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
> > timeout = stop - jiffies;
> > if ((long)timeout <= 0)
> > return -ETIME;
> > + tpm_tis_enable_stat_interrupts(chip, mask);
> > rc = wait_event_interruptible_timeout(*queue,
> > wait_for_tpm_stat_cond(chip, mask, check_cancel,
> > &canceled),
> > timeout);
> > if (rc > 0) {
> > + if (rc == 1)
> > + dev_err(&chip->dev, "Lost Interrupt waiting for TPM stat\n");
> > if (canceled)
> > return -ECANCELED;
> > return 0;
> > @@ -138,6 +181,28 @@ static bool check_locality(struct tpm_chip *chip, int l)
> > static int release_locality(struct tpm_chip *chip, int l)
> > {
> > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> > + u32 int_status;
> > + int rc;
> > +
> > + /*
> > + * Note that once we relinquish the locality, all writes to
> > + * the interrupt registers become ineffective meaning we can't
> > + * do a TPM_EOI. This means we must disable every interrupt
> > + * except the locality change one to avoid interrupt
> > + * storms.
> > + */
> > + tpm_tis_disable_interrupt(chip, TPM_INTF_CMD_READY_INT
> > + | TPM_INTF_STS_VALID_INT
> > + | TPM_INTF_DATA_AVAIL_INT);
> > +
> > + rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status);
> > + if (rc < 0)
> > + return rc;
> > +
> > + /* Clear all pending */
> > + rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status);
> > + if (rc < 0)
> > + return rc;
> >
> > tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
> >
> > @@ -164,12 +229,17 @@ static int request_locality(struct tpm_chip *chip, int l)
> > timeout = stop - jiffies;
> > if ((long)timeout <= 0)
> > return -1;
> > +
> > rc = wait_event_interruptible_timeout(priv->int_queue,
> > (check_locality
> > (chip, l)),
> > timeout);
> > - if (rc > 0)
> > + if (rc > 1)
> > + return l;
> > + if (rc == 1) {
> > + dev_info(&chip->dev, "Lost Interrupt waiting for locality\n");
> > return l;
> > + }
> > if (rc == -ERESTARTSYS && freezing(current)) {
> > clear_thread_flag(TIF_SIGPENDING);
> > goto again;
> > @@ -465,6 +535,10 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
> > irq = priv->irq;
> > priv->irq = 0;
> > chip->flags &= ~TPM_CHIP_FLAG_IRQ;
> > + tpm_tis_enable_interrupt(chip, TPM_INTF_CMD_READY_INT
> > + | TPM_INTF_LOCALITY_CHANGE_INT
> > + | TPM_INTF_DATA_AVAIL_INT
> > + | TPM_INTF_STS_VALID_INT);
> > rc = tpm_tis_send_main(chip, buf, len);
> > priv->irq = irq;
> > chip->flags |= TPM_CHIP_FLAG_IRQ;
> > @@ -719,7 +793,7 @@ static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
> > * irq is seen then leave the chip setup for IRQ operation, otherwise reverse
> > * everything and leave in polling mode. Returns 0 on success.
> > */
> > -static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
> > +static int tpm_tis_probe_irq_single(struct tpm_chip *chip,
> > int flags, int irq)
> > {
> > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> > @@ -753,9 +827,11 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
> > if (rc < 0)
> > return rc;
> >
> > - /* Turn on */
> > - rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality),
> > - intmask | TPM_GLOBAL_INT_ENABLE);
> > + /*
> > + * Turn on. The locality change interrupt is the only one
> > + * always enabled
> > + */
> > + tpm_tis_enable_interrupt(chip, TPM_INTF_LOCALITY_CHANGE_INT);
> > if (rc < 0)
> > return rc;
> >
> > @@ -787,7 +863,7 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
> > * do not have ACPI/etc. We typically expect the interrupt to be declared if
> > * present.
> > */
> > -static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
> > +static void tpm_tis_probe_irq(struct tpm_chip *chip)
> > {
> > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> > u8 original_int_vec;
> > @@ -801,11 +877,9 @@ static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
> > if (!original_int_vec) {
> > if (IS_ENABLED(CONFIG_X86))
> > for (i = 3; i <= 15; i++)
> > - if (!tpm_tis_probe_irq_single(chip, intmask, 0,
> > - i))
> > + if (!tpm_tis_probe_irq_single(chip, 0, i))
> > return;
> > - } else if (!tpm_tis_probe_irq_single(chip, intmask, 0,
> > - original_int_vec))
> > + } else if (!tpm_tis_probe_irq_single(chip, 0, original_int_vec))
> > return;
> > }
> >
> > @@ -1030,8 +1104,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
> > }
> >
> > if (irq) {
> > - tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
> > - irq);
> > + tpm_tis_probe_irq_single(chip, IRQF_SHARED, irq);
> > if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
> > dev_err(&chip->dev, FW_BUG
> > "TPM interrupt not working, polling instead\n");
> > @@ -1039,7 +1112,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
> > disable_interrupts(chip);
> > }
> > } else {
> > - tpm_tis_probe_irq(chip, intmask);
> > + tpm_tis_probe_irq(chip);
> > }
> > }
> >
> > @@ -1065,12 +1138,23 @@ EXPORT_SYMBOL_GPL(tpm_tis_core_init);
> > static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
> > {
> > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> > - u32 intmask;
> > int rc;
> >
> > if (chip->ops->clk_enable != NULL)
> > chip->ops->clk_enable(chip, true);
> >
> > + /*
> > + * must have the locality before we can enable interrupts, so
> > + * poll for the locality being ready
> > + */
> > + chip->flags &= ~TPM_CHIP_FLAG_IRQ;
> > + if (request_locality(chip, 0) != 0) {
> > + dev_err(&chip->dev, "Failed to enable interrupts after suspend\n");
> > + goto out;
> > + }
> > + chip->flags |= TPM_CHIP_FLAG_IRQ;
> > +
> > +
> > /* reenable interrupts that device may have lost or
> > * BIOS/firmware may have disabled
> > */
> > @@ -1078,17 +1162,10 @@ static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
> > if (rc < 0)
> > goto out;
> >
> > - rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
> > - if (rc < 0)
> > - goto out;
> > -
> > - intmask |= TPM_INTF_CMD_READY_INT
> > - | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_DATA_AVAIL_INT
> > - | TPM_INTF_STS_VALID_INT | TPM_GLOBAL_INT_ENABLE;
> > + tpm_tis_enable_interrupt(chip, TPM_INTF_LOCALITY_CHANGE_INT);
> >
> > - tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
> > -
> > -out:
> > + out:
> > + release_locality(chip, 0);
> > if (chip->ops->clk_enable != NULL)
> > chip->ops->clk_enable(chip, false);
>
> Other than the question about the comment in tpm_tis_enable_interrupt
>
> Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
Should this have
Fixes: e6aef069b6e9 ("tpm_tis: convert to using locality callbacks")
?
/Jarkko
