linux-kernel - [PATCH v6 2/9] tpm, tpm_tis: Claim locality before writing TPM_INT

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Message-Id: <20220621132447.16281-3-LinoSanfilippo@gmx.de>
Date:   Tue, 21 Jun 2022 15:24:40 +0200
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,
        l.sanfilippo@...bus.com, LinoSanfilippo@....de, lukas@...ner.de,
        p.rosenberger@...bus.com
Subject: [PATCH v6 2/9] tpm, tpm_tis: Claim locality before writing TPM_INT_ENABLE register

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

In disable_interrupts() the TPM_GLOBAL_INT_ENABLE bit is unset in the
TPM_INT_ENABLE register to shut the interrupts off. However modifying the
register is only possible with a held locality. So claim the locality
before disable_interrupts() is called.

Signed-off-by: Lino Sanfilippo <l.sanfilippo@...bus.com>
Reviewed-by: Jarkko Sakkinen <jarkko@...nel.org>
---
 drivers/char/tpm/tpm_tis_core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index b5fd4ff46666..0e68e4502a56 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -1084,7 +1084,11 @@ 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);
+				if (rc < 0)
+					goto out_err;
 				disable_interrupts(chip);
+				release_locality(chip, 0);
 			}
 		} else {
 			tpm_tis_probe_irq(chip, intmask);
-- 
2.36.1