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>
---
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 a9fa40714c64..02cc384fdaea 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 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 */
+ 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 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 enable_stat_interrupt(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;
+
+ 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;
+ enable_stat_interrupt(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;
@@ -137,6 +180,28 @@ 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.
+ */
+ 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);
@@ -163,12 +228,17 @@ 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;
@@ -464,6 +534,10 @@ 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;
+ 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;
@@ -718,7 +792,7 @@ 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);
@@ -752,9 +826,11 @@ 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
+ */
+ enable_interrupt(chip, TPM_INTF_LOCALITY_CHANGE_INT);
if (rc < 0)
return rc;
@@ -786,7 +862,7 @@ 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;
@@ -800,11 +876,9 @@ 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;
}
@@ -1029,8 +1103,7 @@ 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");
@@ -1038,7 +1111,7 @@ 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);
}
}
@@ -1064,12 +1137,23 @@ 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
*/
@@ -1077,17 +1161,10 @@ 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;
+ 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);
--
2.28.0
