tpm, tpm_tis: Claim locality before writing interrupt registers

JIRA: https://issues.redhat.com/browse/RHEL-72765

Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

commit 15d7aa4
Author: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Date:   Thu Nov 24 14:55:29 2022 +0100

    tpm, tpm_tis: Claim locality before writing interrupt registers

    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@kunbus.com>
    Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
    Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
    Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

Signed-off-by: Štěpán Horáček <shoracek@redhat.com>

Author: shoracek

drivers/char/tpm/tpm_tis_core.c

@@ -722,16 +722,10 @@ 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
@@ -754,10 +748,16 @@ 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)
@@ -791,10 +791,12 @@ 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