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From: Lino Sanfilippo <LinoSanfilippo@gmx.de>
To: peterhuewe@gmx.de, jarkko@kernel.org, jgg@ziepe.ca
Cc: stefanb@linux.vnet.ibm.com, linux@mniewoehner.de,
	linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
	jandryuk@gmail.com, pmenzel@molgen.mpg.de,
	l.sanfilippo@kunbus.com, LinoSanfilippo@gmx.de, lukas@wunner.de,
	p.rosenberger@kunbus.com
Subject: [PATCH v9 07/12] tpm, tpm_tis: do not check for the active locality in interrupt handler
Date: Thu, 10 Nov 2022 16:25:28 +0100	[thread overview]
Message-ID: <20221110152533.24243-8-LinoSanfilippo@gmx.de> (raw)
In-Reply-To: <20221110152533.24243-1-LinoSanfilippo@gmx.de>

From: Lino Sanfilippo <l.sanfilippo@kunbus.com>

After driver initialization tpm_tis_data->locality may only be modified in
case of a LOCALITY CHANGE interrupt. In this case the interrupt handler
iterates over all localities only to assign the active one to
tpm_tis_data->locality.

However this information is never used any more, so the assignment is not
needed.
Furthermore without the assignment tpm_tis_data->locality cannot change any
more at driver runtime, and thus no protection against concurrent
modification is required when the variable is read at other places.

So remove this iteration entirely.

Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
---
 drivers/char/tpm/tpm_tis_core.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 181c291b0bb8..4336f7ea8c2b 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -728,7 +728,7 @@ static irqreturn_t tis_int_handler(int dummy, void *dev_id)
 	struct tpm_chip *chip = dev_id;
 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 	u32 interrupt;
-	int i, rc;
+	int rc;
 
 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
 	if (rc < 0)
@@ -740,10 +740,7 @@ static irqreturn_t tis_int_handler(int dummy, void *dev_id)
 	set_bit(TPM_TIS_IRQ_TESTED, &priv->flags);
 	if (interrupt & TPM_INTF_DATA_AVAIL_INT)
 		wake_up_interruptible(&priv->read_queue);
-	if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT)
-		for (i = 0; i < 5; i++)
-			if (check_locality(chip, i))
-				break;
+
 	if (interrupt &
 	    (TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_STS_VALID_INT |
 	     TPM_INTF_CMD_READY_INT))
-- 
2.36.1


  parent reply	other threads:[~2022-11-10 15:27 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-10 15:25 [PATCH v9 00/12] TPM IRQ fixes Lino Sanfilippo
2022-11-10 15:25 ` [PATCH v9 01/12] tpm, tpm_tis: Avoid cache incoherency in test for interrupts Lino Sanfilippo
2022-11-10 15:25 ` [PATCH v9 02/12] tpm, tpm_tis: Claim locality before writing TPM_INT_ENABLE register Lino Sanfilippo
2022-11-10 15:25 ` [PATCH v9 03/12] tpm, tpm_tis: Disable interrupts if tpm_tis_probe_irq() failed Lino Sanfilippo
2022-11-10 15:25 ` [PATCH v9 04/12] tpm, tmp_tis: Claim locality before writing interrupt registers Lino Sanfilippo
2022-11-10 15:25 ` [PATCH v9 05/12] tpm, tpm_tis: Only handle supported interrupts Lino Sanfilippo
2022-11-10 15:25 ` [PATCH v9 06/12] tpm, tpm_tis: Move interrupt mask checks into own function Lino Sanfilippo
2022-11-10 15:25 ` Lino Sanfilippo [this message]
2022-11-10 15:25 ` [PATCH v9 08/12] tpm, tpm: Implement usage counter for locality Lino Sanfilippo
2022-11-10 15:25 ` [PATCH v9 09/12] tpm, tpm_tis: Request threaded interrupt handler Lino Sanfilippo
2022-11-10 15:25 ` [PATCH v9 10/12] tpm, tpm_tis: Claim locality in " Lino Sanfilippo
2022-11-10 15:25 ` [PATCH v9 11/12] tpm, tpm_tis: Claim locality when interrupts are reenabled on resume Lino Sanfilippo
2022-11-10 15:25 ` [PATCH v9 12/12] tpm, tpm_tis: Enable interrupt test Lino Sanfilippo
2022-11-14 13:35   ` Lino Sanfilippo

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