[PATCH v2] tpm, tpm_tis_spi: Allow to sleep in the interrupt handler

From: Lino Sanfilippo
Date: Sat Jun 19 2021 - 22:36:17 EST


Interrupt handling at least includes reading and writing the interrupt
status register within the interrupt routine. For accesses over SPI a mutex
is used in the concerning functions. Since this requires a sleepable
context request a threaded interrupt handler for this case.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 1a339b658d9d ("tpm_tis_spi: Pass the SPI IRQ down to the driver")
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@xxxxxx>
---
This patch has been tested on a SLB9670vq2.0.
The first version of this patch was part of patch series (see
https://marc.info/?l=linux-integrity&m=162016888020044&w=2)

v2:
- request threaded irq handler only in case of SPI as requested by Jarkko
Sakkinen
- add "Fixes" tag
- add stable
- correct short summary

drivers/char/tpm/tpm_tis.c | 2 +-
drivers/char/tpm/tpm_tis_core.c | 32 ++++++++++++++++++++--------
drivers/char/tpm/tpm_tis_core.h | 2 +-
drivers/char/tpm/tpm_tis_spi_main.c | 3 ++-
drivers/char/tpm/tpm_tis_synquacer.c | 2 +-
5 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 4ed6e660273a..d27009b989fe 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -236,7 +236,7 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
phy->priv.flags |= TPM_TIS_ITPM_WORKAROUND;

return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
- ACPI_HANDLE(dev));
+ ACPI_HANDLE(dev), false);
}

static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 55b9d3965ae1..21abc2168d07 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -728,19 +728,31 @@ static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
* everything and leave in polling mode. Returns 0 on success.
*/
static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
- int flags, int irq)
+ int flags, int irq, bool threaded_irq)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
u8 original_int_vec;
int rc;
u32 int_status;

- if (devm_request_irq(chip->dev.parent, irq, tis_int_handler, flags,
- dev_name(&chip->dev), chip) != 0) {
+
+ if (threaded_irq) {
+ rc = devm_request_threaded_irq(chip->dev.parent, irq, NULL,
+ tis_int_handler,
+ IRQF_ONESHOT | flags,
+ dev_name(&chip->dev),
+ chip);
+ } else {
+ rc = devm_request_irq(chip->dev.parent, irq, tis_int_handler,
+ flags, dev_name(&chip->dev), chip);
+ }
+
+ if (rc) {
dev_info(&chip->dev, "Unable to request irq: %d for probe\n",
irq);
return -1;
}
+
priv->irq = irq;

rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
@@ -795,7 +807,8 @@ 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, u32 intmask,
+ bool threaded_irq)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
u8 original_int_vec;
@@ -810,10 +823,11 @@ static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
if (IS_ENABLED(CONFIG_X86))
for (i = 3; i <= 15; i++)
if (!tpm_tis_probe_irq_single(chip, intmask, 0,
- i))
+ i, threaded_irq))
return;
} else if (!tpm_tis_probe_irq_single(chip, intmask, 0,
- original_int_vec))
+ original_int_vec,
+ threaded_irq))
return;
}

@@ -909,7 +923,7 @@ static const struct tpm_class_ops tpm_tis = {

int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
const struct tpm_tis_phy_ops *phy_ops,
- acpi_handle acpi_dev_handle)
+ acpi_handle acpi_dev_handle, bool threaded_irq)
{
u32 vendor;
u32 intfcaps;
@@ -1049,7 +1063,7 @@ 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);
+ irq, threaded_irq);
if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
dev_err(&chip->dev, FW_BUG
"TPM interrupt not working, polling instead\n");
@@ -1057,7 +1071,7 @@ 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, intmask, threaded_irq);
}
}

diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h
index 9b2d32a59f67..32d36e538208 100644
--- a/drivers/char/tpm/tpm_tis_core.h
+++ b/drivers/char/tpm/tpm_tis_core.h
@@ -161,7 +161,7 @@ static inline bool is_bsw(void)
void tpm_tis_remove(struct tpm_chip *chip);
int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
const struct tpm_tis_phy_ops *phy_ops,
- acpi_handle acpi_dev_handle);
+ acpi_handle acpi_dev_handle, bool use_threaded_irq);

#ifdef CONFIG_PM_SLEEP
int tpm_tis_resume(struct device *dev);
diff --git a/drivers/char/tpm/tpm_tis_spi_main.c b/drivers/char/tpm/tpm_tis_spi_main.c
index 3856f6ebcb34..2eb57c1cf9ba 100644
--- a/drivers/char/tpm/tpm_tis_spi_main.c
+++ b/drivers/char/tpm/tpm_tis_spi_main.c
@@ -199,7 +199,8 @@ int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy,

phy->spi_device = spi;

- return tpm_tis_core_init(&spi->dev, &phy->priv, irq, phy_ops, NULL);
+ return tpm_tis_core_init(&spi->dev, &phy->priv, irq, phy_ops, NULL,
+ true);
}

static const struct tpm_tis_phy_ops tpm_spi_phy_ops = {
diff --git a/drivers/char/tpm/tpm_tis_synquacer.c b/drivers/char/tpm/tpm_tis_synquacer.c
index e47bdd272704..6ee59a1fdf08 100644
--- a/drivers/char/tpm/tpm_tis_synquacer.c
+++ b/drivers/char/tpm/tpm_tis_synquacer.c
@@ -127,7 +127,7 @@ static int tpm_tis_synquacer_init(struct device *dev,
return PTR_ERR(phy->iobase);

return tpm_tis_core_init(dev, &phy->priv, tpm_info->irq, &tpm_tcg_bw,
- ACPI_HANDLE(dev));
+ ACPI_HANDLE(dev), false);
}

static SIMPLE_DEV_PM_OPS(tpm_tis_synquacer_pm, tpm_pm_suspend, tpm_tis_resume);

base-commit: 913ec3c22ef425d63dd0bc81fb008ce7f9bcb07b
--
2.31.1