Commit 7a2f55d0 authored by Lino Sanfilippo's avatar Lino Sanfilippo Committed by Jarkko Sakkinen
Browse files

tpm, tpm: Implement usage counter for locality 



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: default avatarLino Sanfilippo <l.sanfilippo@kunbus.com>
Tested-by: default avatarMichael Niewöhner <linux@mniewoehner.de>
Tested-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
parent 35f62128

drivers/char/tpm/tpm_tis_core.c

+45 −18
Original line number Diff line number Diff line
@@ -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;

}
@@ -792,14 +817,14 @@ 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;

	}
@@ -838,7 +863,7 @@ 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;

}
@@ -954,8 +979,8 @@ 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,

};
@@ -989,6 +1014,8 @@ 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);
@@ -1067,14 +1094,14 @@ 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)
@@ -1108,13 +1135,13 @@ 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");
@@ -1134,11 +1161,11 @@ 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);

		}

	}
@@ -1205,13 +1232,13 @@ 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;

drivers/char/tpm/tpm_tis_core.h

+2 −0
Original line number Diff line number Diff line
@@ -92,6 +92,8 @@ 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;