From: Lino Sanfilippo <l.sanfilippo@xxxxxxxxxx>
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@xxxxxxxxxx>
Tested-by: Michael Niewöhner <linux@xxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm_tis_core.c | 75 ++++++++++++++++++++++-----------
drivers/char/tpm/tpm_tis_core.h | 2 +
2 files changed, 53 insertions(+), 24 deletions(-)
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 4336f7ea8c2b..ecde684a8f80 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -165,16 +165,27 @@ 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;
@@ -215,6 +226,20 @@ 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);
@@ -682,7 +707,7 @@ 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);
@@ -703,7 +728,7 @@ 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;
}
@@ -762,7 +787,7 @@ static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
cap_t cap;
int ret;
- ret = request_locality(chip, 0);
+ ret = tpm_tis_request_locality(chip, 0);
if (ret < 0)
return ret;
@@ -771,7 +796,7 @@ static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
else
ret = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc, 0);
- release_locality(chip, 0);
+ tpm_tis_relinquish_locality(chip, 0);
return ret;
}
@@ -796,33 +821,33 @@ 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;
}
rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
if (rc < 0) {
- release_locality(chip, priv->locality);
+ tpm_tis_relinquish_locality(chip, priv->locality);
return rc;
}
rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status);
if (rc < 0) {
- release_locality(chip, priv->locality);
+ tpm_tis_relinquish_locality(chip, priv->locality);
return rc;
}
/* Clear all existing */
rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status);
if (rc < 0) {
- release_locality(chip, priv->locality);
+ tpm_tis_relinquish_locality(chip, priv->locality);
return rc;
}
@@ -830,11 +855,11 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality),
intmask | TPM_GLOBAL_INT_ENABLE);
if (rc < 0) {
- release_locality(chip, priv->locality);
+ tpm_tis_relinquish_locality(chip, priv->locality);
return rc;
}
- release_locality(chip, priv->locality);
+ tpm_tis_relinquish_locality(chip, priv->locality);
clear_bit(TPM_TIS_IRQ_TESTED, &priv->flags);
/* Generate an interrupt by having the core call through to
@@ -970,8 +995,8 @@ 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,
};
@@ -1005,6 +1030,8 @@ 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);
@@ -1083,14 +1110,14 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
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)
@@ -1124,13 +1151,13 @@ 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");
@@ -1150,11 +1177,11 @@ 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);
}
}
@@ -1221,13 +1248,13 @@ 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 2deef11c88db..13bdcf38e56f 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;
unsigned int int_mask;
--
2.36.1
