[PATCH 1/2] tpm_tis: Use tpm_chip_{start,stop} decoration inside tpm_tis_resume

[Jarkko Sakkinen <jarkko@kernel.org>]

Before sending a TPM command, CLKRUN protocol must be disabled. This is not
done in the case of tpm1_do_selftest() call site inside tpm_tis_resume().

Address this by decorating the calls with tpm_chip_{start,stop}, which arm
and disarm the TPM chip for transmission, and take care of disabling and
re-enabling CLKRUN, among other things.

Cc: stable@vger.kernel.org
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/linux-integrity/CS68AWILHXS4.3M36M1EKZLUMS@suppilovahvero/
Fixes: a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()")
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
 drivers/char/tpm/tpm_tis_core.c | 43 +++++++++++++++------------------
 1 file changed, 19 insertions(+), 24 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index c2421162cf34..73707026e358 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -1209,25 +1209,20 @@ static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
 	u32 intmask;
 	int rc;
 
-	if (chip->ops->clk_enable != NULL)
-		chip->ops->clk_enable(chip, true);
-
-	/* reenable interrupts that device may have lost or
-	 * BIOS/firmware may have disabled
+	/*
+	 * Re-enable interrupts that device may have lost or BIOS/firmware may
+	 * have disabled.
 	 */
 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
-	if (rc < 0)
-		goto out;
+	if (rc < 0) {
+		dev_err(&chip->dev, "Setting IRQ failed.\n");
+		return;
+	}
 
 	intmask = priv->int_mask | TPM_GLOBAL_INT_ENABLE;
-
-	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
-
-out:
-	if (chip->ops->clk_enable != NULL)
-		chip->ops->clk_enable(chip, false);
-
-	return;
+	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
+	if (rc < 0)
+		dev_err(&chip->dev, "Enabling interrupts failed.\n");
 }
 
 int tpm_tis_resume(struct device *dev)
@@ -1235,27 +1230,27 @@ int tpm_tis_resume(struct device *dev)
 	struct tpm_chip *chip = dev_get_drvdata(dev);
 	int ret;
 
-	ret = tpm_tis_request_locality(chip, 0);
-	if (ret < 0)
+	ret = tpm_chip_start(chip);
+	if (ret)
 		return ret;
 
 	if (chip->flags & TPM_CHIP_FLAG_IRQ)
 		tpm_tis_reenable_interrupts(chip);
 
-	ret = tpm_pm_resume(dev);
-	if (ret)
-		goto out;
-
 	/*
 	 * TPM 1.2 requires self-test on resume. This function actually returns
 	 * an error code but for unknown reason it isn't handled.
 	 */
 	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
 		tpm1_do_selftest(chip);
-out:
-	tpm_tis_relinquish_locality(chip, 0);
 
-	return ret;
+	tpm_chip_stop(chip);
+
+	ret = tpm_pm_resume(dev);
+	if (ret)
+		return ret;
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(tpm_tis_resume);
 #endif
-- 
2.39.2