Jarkko Sakkinen @ 2020-10-30 05:18 MST:
> On Sat, Oct 24, 2020 at 03:15:53PM +0300, Jarkko Sakkinen wrote:
>> 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
Yes, I believe so.
