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tpm, tpm_tis: Only handle supported interrupts
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[ Upstream commit e87fcf0 ]

According to the TPM Interface Specification (TIS) support for "stsValid"
and "commandReady" interrupts is only optional.
This has to be taken into account when handling the interrupts in functions
like wait_for_tpm_stat(). To determine the supported interrupts use the
capability query.

Also adjust wait_for_tpm_stat() to only wait for interrupt reported status
changes. After that process all the remaining status changes by polling
the status register.

Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Tested-by: Michael Niewöhner <linux@mniewoehner.de>
Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Stable-dep-of: 1398aa8 ("tpm_tis: Use tpm_chip_{start,stop} decoration inside tpm_tis_resume")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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@linosanfilippo-kunbus @gregkh
linosanfilippo-kunbus authored and gregkh committed May 30, 2023
1 parent 19489b1 commit d6c5a69
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Showing 2 changed files with 73 additions and 48 deletions.
120 changes: 72 additions & 48 deletions drivers/char/tpm/tpm_tis_core.c
View file
Expand Up @@ -53,41 +53,63 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
long rc;
u8 status;
bool canceled = false;
u8 sts_mask = 0;
int ret = 0;

/* check current status */
status = chip->ops->status(chip);
if ((status & mask) == mask)
return 0;

stop = jiffies + timeout;
/* check what status changes can be handled by irqs */
if (priv->int_mask & TPM_INTF_STS_VALID_INT)
sts_mask |= TPM_STS_VALID;

if (chip->flags & TPM_CHIP_FLAG_IRQ) {
if (priv->int_mask & TPM_INTF_DATA_AVAIL_INT)
sts_mask |= TPM_STS_DATA_AVAIL;

if (priv->int_mask & TPM_INTF_CMD_READY_INT)
sts_mask |= TPM_STS_COMMAND_READY;

sts_mask &= mask;

stop = jiffies + timeout;
/* process status changes with irq support */
if (sts_mask) {
ret = -ETIME;
again:
timeout = stop - jiffies;
if ((long)timeout <= 0)
return -ETIME;
rc = wait_event_interruptible_timeout(*queue,
wait_for_tpm_stat_cond(chip, mask, check_cancel,
wait_for_tpm_stat_cond(chip, sts_mask, check_cancel,
&canceled),
timeout);
if (rc > 0) {
if (canceled)
return -ECANCELED;
return 0;
ret = 0;
}
if (rc == -ERESTARTSYS && freezing(current)) {
clear_thread_flag(TIF_SIGPENDING);
goto again;
}
} else {
do {
usleep_range(priv->timeout_min,
priv->timeout_max);
status = chip->ops->status(chip);
if ((status & mask) == mask)
return 0;
} while (time_before(jiffies, stop));
}

if (ret)
return ret;

mask &= ~sts_mask;
if (!mask) /* all done */
return 0;
/* process status changes without irq support */
do {
status = chip->ops->status(chip);
if ((status & mask) == mask)
return 0;
usleep_range(priv->timeout_min,
priv->timeout_max);
} while (time_before(jiffies, stop));
return -ETIME;
}

Expand Down Expand Up @@ -1032,8 +1054,40 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
if (rc < 0)
goto out_err;

intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
/* Figure out the capabilities */
rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
if (rc < 0)
goto out_err;

dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
intfcaps);
if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
dev_dbg(dev, "\tBurst Count Static\n");
if (intfcaps & TPM_INTF_CMD_READY_INT) {
intmask |= TPM_INTF_CMD_READY_INT;
dev_dbg(dev, "\tCommand Ready Int Support\n");
}
if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
dev_dbg(dev, "\tInterrupt Edge Falling\n");
if (intfcaps & TPM_INTF_INT_EDGE_RISING)
dev_dbg(dev, "\tInterrupt Edge Rising\n");
if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
dev_dbg(dev, "\tInterrupt Level Low\n");
if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
dev_dbg(dev, "\tInterrupt Level High\n");
if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT) {
intmask |= TPM_INTF_LOCALITY_CHANGE_INT;
dev_dbg(dev, "\tLocality Change Int Support\n");
}
if (intfcaps & TPM_INTF_STS_VALID_INT) {
intmask |= TPM_INTF_STS_VALID_INT;
dev_dbg(dev, "\tSts Valid Int Support\n");
}
if (intfcaps & TPM_INTF_DATA_AVAIL_INT) {
intmask |= TPM_INTF_DATA_AVAIL_INT;
dev_dbg(dev, "\tData Avail Int Support\n");
}

intmask &= ~TPM_GLOBAL_INT_ENABLE;

rc = tpm_tis_request_locality(chip, 0);
Expand Down Expand Up @@ -1067,32 +1121,6 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
goto out_err;
}

/* Figure out the capabilities */
rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
if (rc < 0)
goto out_err;

dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
intfcaps);
if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
dev_dbg(dev, "\tBurst Count Static\n");
if (intfcaps & TPM_INTF_CMD_READY_INT)
dev_dbg(dev, "\tCommand Ready Int Support\n");
if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
dev_dbg(dev, "\tInterrupt Edge Falling\n");
if (intfcaps & TPM_INTF_INT_EDGE_RISING)
dev_dbg(dev, "\tInterrupt Edge Rising\n");
if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
dev_dbg(dev, "\tInterrupt Level Low\n");
if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
dev_dbg(dev, "\tInterrupt Level High\n");
if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
dev_dbg(dev, "\tLocality Change Int Support\n");
if (intfcaps & TPM_INTF_STS_VALID_INT)
dev_dbg(dev, "\tSts Valid Int Support\n");
if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
dev_dbg(dev, "\tData Avail Int Support\n");

/* INTERRUPT Setup */
init_waitqueue_head(&priv->read_queue);
init_waitqueue_head(&priv->int_queue);
Expand Down Expand Up @@ -1123,7 +1151,9 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
else
tpm_tis_probe_irq(chip, intmask);

if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
if (chip->flags & TPM_CHIP_FLAG_IRQ) {
priv->int_mask = intmask;
} else {
dev_err(&chip->dev, FW_BUG
"TPM interrupt not working, polling instead\n");

Expand Down Expand Up @@ -1170,13 +1200,7 @@ 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;
intmask = priv->int_mask | TPM_GLOBAL_INT_ENABLE;

tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);

Expand Down
1 change: 1 addition & 0 deletions drivers/char/tpm/tpm_tis_core.h
View file
Expand Up @@ -96,6 +96,7 @@ struct tpm_tis_data {
unsigned int locality_count;
int locality;
int irq;
unsigned int int_mask;
unsigned long flags;
void __iomem *ilb_base_addr;
u16 clkrun_enabled;
Expand Down

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