From: Lino Sanfilippo l.sanfilippo@kunbus.com
[ Upstream commit 7a2f55d0be296c4e81fd782f3d6c43ed4ec7e265 ]
Implement a usage counter for the (default) locality used by the TPM TIS driver: Request the locality from the TPM if it has not been claimed yet, otherwise only increment the counter. Also release the locality if the counter is 0 otherwise only decrement the counter. Since in case of SPI the register accesses are locked by means of the SPI bus mutex use a sleepable lock (i.e. also a mutex) to ensure thread-safety of the counter which may be accessed by both a userspace thread and the interrupt handler.
By doing this refactor the names of the amended functions to use a more appropriate prefix.
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: 955df4f87760 ("tpm, tpm_tis: Claim locality when interrupts are reenabled on resume") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/char/tpm/tpm_tis_core.c | 63 +++++++++++++++++++++++---------- drivers/char/tpm/tpm_tis_core.h | 2 ++ 2 files changed, 47 insertions(+), 18 deletions(-)
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 39f27edb32879..c5fef63c6179d 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -136,16 +136,27 @@ static bool check_locality(struct tpm_chip *chip, int l) return false; }
-static int release_locality(struct tpm_chip *chip, int l) +static int __tpm_tis_relinquish_locality(struct tpm_tis_data *priv, int l) +{ + tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY); + + return 0; +} + +static int tpm_tis_relinquish_locality(struct tpm_chip *chip, int l) { struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
- tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY); + mutex_lock(&priv->locality_count_mutex); + priv->locality_count--; + if (priv->locality_count == 0) + __tpm_tis_relinquish_locality(priv, l); + mutex_unlock(&priv->locality_count_mutex);
return 0; }
-static int request_locality(struct tpm_chip *chip, int l) +static int __tpm_tis_request_locality(struct tpm_chip *chip, int l) { struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); unsigned long stop, timeout; @@ -186,6 +197,20 @@ static int request_locality(struct tpm_chip *chip, int l) return -1; }
+static int tpm_tis_request_locality(struct tpm_chip *chip, int l) +{ + struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); + int ret = 0; + + mutex_lock(&priv->locality_count_mutex); + if (priv->locality_count == 0) + ret = __tpm_tis_request_locality(chip, l); + if (!ret) + priv->locality_count++; + mutex_unlock(&priv->locality_count_mutex); + return ret; +} + static u8 tpm_tis_status(struct tpm_chip *chip) { struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); @@ -652,7 +677,7 @@ static int probe_itpm(struct tpm_chip *chip) if (vendor != TPM_VID_INTEL) return 0;
- if (request_locality(chip, 0) != 0) + if (tpm_tis_request_locality(chip, 0) != 0) return -EBUSY;
rc = tpm_tis_send_data(chip, cmd_getticks, len); @@ -673,7 +698,7 @@ static int probe_itpm(struct tpm_chip *chip)
out: tpm_tis_ready(chip); - release_locality(chip, priv->locality); + tpm_tis_relinquish_locality(chip, priv->locality);
return rc; } @@ -765,14 +790,14 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask, } priv->irq = irq;
- rc = request_locality(chip, 0); + rc = tpm_tis_request_locality(chip, 0); if (rc < 0) return rc;
rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality), &original_int_vec); if (rc < 0) { - release_locality(chip, priv->locality); + tpm_tis_relinquish_locality(chip, priv->locality); return rc; }
@@ -811,7 +836,7 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask, rc = -1; }
- release_locality(chip, priv->locality); + tpm_tis_relinquish_locality(chip, priv->locality);
return rc; } @@ -927,8 +952,8 @@ static const struct tpm_class_ops tpm_tis = { .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID, .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID, .req_canceled = tpm_tis_req_canceled, - .request_locality = request_locality, - .relinquish_locality = release_locality, + .request_locality = tpm_tis_request_locality, + .relinquish_locality = tpm_tis_relinquish_locality, .clk_enable = tpm_tis_clkrun_enable, };
@@ -962,6 +987,8 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, priv->timeout_min = TPM_TIMEOUT_USECS_MIN; priv->timeout_max = TPM_TIMEOUT_USECS_MAX; priv->phy_ops = phy_ops; + priv->locality_count = 0; + mutex_init(&priv->locality_count_mutex);
dev_set_drvdata(&chip->dev, priv);
@@ -1008,14 +1035,14 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT; intmask &= ~TPM_GLOBAL_INT_ENABLE;
- rc = request_locality(chip, 0); + rc = tpm_tis_request_locality(chip, 0); if (rc < 0) { rc = -ENODEV; goto out_err; }
tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask); - release_locality(chip, 0); + tpm_tis_relinquish_locality(chip, 0);
rc = tpm_chip_start(chip); if (rc) @@ -1075,13 +1102,13 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, * proper timeouts for the driver. */
- rc = request_locality(chip, 0); + rc = tpm_tis_request_locality(chip, 0); if (rc < 0) goto out_err;
rc = tpm_get_timeouts(chip);
- release_locality(chip, 0); + tpm_tis_relinquish_locality(chip, 0);
if (rc) { dev_err(dev, "Could not get TPM timeouts and durations\n"); @@ -1099,11 +1126,11 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, dev_err(&chip->dev, FW_BUG "TPM interrupt not working, polling instead\n");
- rc = request_locality(chip, 0); + rc = tpm_tis_request_locality(chip, 0); if (rc < 0) goto out_err; disable_interrupts(chip); - release_locality(chip, 0); + tpm_tis_relinquish_locality(chip, 0); } }
@@ -1176,13 +1203,13 @@ int tpm_tis_resume(struct device *dev) * an error code but for unknown reason it isn't handled. */ if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { - ret = request_locality(chip, 0); + ret = tpm_tis_request_locality(chip, 0); if (ret < 0) return ret;
tpm1_do_selftest(chip);
- release_locality(chip, 0); + tpm_tis_relinquish_locality(chip, 0); }
return 0; diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index b68479e0de10f..1d51d5168fb6e 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -91,6 +91,8 @@ enum tpm_tis_flags {
struct tpm_tis_data { u16 manufacturer_id; + struct mutex locality_count_mutex; + unsigned int locality_count; int locality; int irq; bool irq_tested;