linux-kernel - [PATCH v9 02/12] tpm, tpm_tis: Claim locality before writing TPM_INT

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Date:   Thu, 10 Nov 2022 16:25:23 +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 v9 02/12] 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>
Tested-by: Michael Niewöhner <linux@...ewoehner.de>
---
 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 c0008efb95dc..d2c9c9d76893 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -1098,7 +1098,11 @@ 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