linux-kernel - [PATCH v11 05/14] tpm, tpm_tis: Claim locality before writing interrupt registers

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Message-Id: <20221124135538.31020-6-LinoSanfilippo@gmx.de>
Date:   Thu, 24 Nov 2022 14:55:29 +0100
From:   Lino Sanfilippo <LinoSanfilippo@....de>
To:     peterhuewe@....de, jarkko@...nel.org, jgg@...pe.ca
Cc:     stefanb@...ux.vnet.ibm.com, linux@...ewoehner.de,
        linux-integrity@...r.kernel.org, linux-kernel@...r.kernel.org,
        jandryuk@...il.com, pmenzel@...gen.mpg.de, l.sanfilippo@...bus.com,
        LinoSanfilippo@....de, lukas@...ner.de, p.rosenberger@...bus.com
Subject: [PATCH v11 05/14] tpm, tpm_tis: Claim locality before writing interrupt registers

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

In tpm_tis_probe_single_irq() interrupt registers TPM_INT_VECTOR,
TPM_INT_STATUS and TPM_INT_ENABLE are modified to setup the interrupts.
Currently these modifications are done without holding a locality thus they
have no effect. Fix this by claiming the (default) locality before the
registers are written.

Since now tpm_tis_gen_interrupt() is called with the locality already
claimed remove locality request and release from this function.

Signed-off-by: Lino Sanfilippo <l.sanfilippo@...bus.com>
Reviewed-by: Jarkko Sakkinen <jarkko@...nel.org>
---
 drivers/char/tpm/tpm_tis_core.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 81b9726d3ed2..49848268f547 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -736,16 +736,10 @@ static void tpm_tis_gen_interrupt(struct tpm_chip *chip)
 	cap_t cap;
 	int ret;
 
-	ret = request_locality(chip, 0);
-	if (ret < 0)
-		return;
-
 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
 		ret = tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
 	else
 		ret = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc, 0);
-
-	release_locality(chip, 0);
 }
 
 /* Register the IRQ and issue a command that will cause an interrupt. If an
@@ -768,10 +762,16 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
 	}
 	priv->irq = irq;
 
+	rc = 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)
+	if (rc < 0) {
+		release_locality(chip, priv->locality);
 		return rc;
+	}
 
 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
 	if (rc < 0)
@@ -805,10 +805,12 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
 		tpm_tis_write8(priv, original_int_vec,
 			       TPM_INT_VECTOR(priv->locality));
-		return -1;
+		rc = -1;
 	}
 
-	return 0;
+	release_locality(chip, priv->locality);
+
+	return rc;
 }
 
 /* Try to find the IRQ the TPM is using. This is for legacy x86 systems that
-- 
2.36.1