linux-kernel - [PATCH v4 2/6] tpm, tpm_tis: Claim and release locality only once

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Message-Id: <20220509080559.4381-3-LinoSanfilippo@gmx.de>
Date:   Mon,  9 May 2022 10:05:55 +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,
        LinoSanfilippo@....de, lukas@...ner.de, p.rosenberger@...bus.com,
        Lino Sanfilippo <l.sanfilippo@...bus.com>
Subject: [PATCH v4 2/6] tpm, tpm_tis: Claim and release locality only once

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

It is not necessary to claim and release the default locality for each TPM
command. Instead claim the locality once at driver startup and release it
at driver shutdown.

Signed-off-by: Lino Sanfilippo <l.sanfilippo@...bus.com>
---
 drivers/char/tpm/tpm_tis_core.c | 50 +++++++++------------------------
 1 file changed, 13 insertions(+), 37 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 52369ef39b03..46f504fb5084 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -638,9 +638,6 @@ static int probe_itpm(struct tpm_chip *chip)
 	if (vendor != TPM_VID_INTEL)
 		return 0;
 
-	if (request_locality(chip, 0) != 0)
-		return -EBUSY;
-
 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
 	if (rc == 0)
 		goto out;
@@ -659,7 +656,6 @@ static int probe_itpm(struct tpm_chip *chip)
 
 out:
 	tpm_tis_ready(chip);
-	release_locality(chip, priv->locality);
 
 	return rc;
 }
@@ -721,17 +717,11 @@ static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
 	cap_t cap;
 	int ret;
 
-	ret = request_locality(chip, 0);
-	if (ret < 0)
-		return ret;
-
 	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);
-
 	return ret;
 }
 
@@ -855,6 +845,8 @@ void tpm_tis_remove(struct tpm_chip *chip)
 
 	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
 
+	release_locality(chip, 0);
+
 	tpm_tis_clkrun_enable(chip, false);
 
 	if (priv->ilb_base_addr)
@@ -925,8 +917,6 @@ static const struct tpm_class_ops tpm_tis = {
 	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 	.req_canceled = tpm_tis_req_canceled,
-	.request_locality = request_locality,
-	.relinquish_locality = release_locality,
 	.clk_enable = tpm_tis_clkrun_enable,
 };
 
@@ -963,9 +953,15 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 
 	dev_set_drvdata(&chip->dev, priv);
 
+	rc = request_locality(chip, 0);
+	if (rc)
+		return rc;
+
 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
-	if (rc < 0)
+	if (rc < 0) {
+		release_locality(chip, 0);
 		return rc;
+	}
 
 	priv->manufacturer_id = vendor;
 
@@ -978,8 +974,10 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 	if (is_bsw()) {
 		priv->ilb_base_addr = ioremap(INTEL_LEGACY_BLK_BASE_ADDR,
 					ILB_REMAP_SIZE);
-		if (!priv->ilb_base_addr)
+		if (!priv->ilb_base_addr) {
+			release_locality(chip, 0);
 			return -ENOMEM;
+		}
 
 		clkrun_val = ioread32(priv->ilb_base_addr + LPC_CNTRL_OFFSET);
 		/* Check if CLKRUN# is already not enabled in the LPC bus */
@@ -1006,14 +1004,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 		   TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
 
-	rc = request_locality(chip, 0);
-	if (rc < 0) {
-		rc = -ENODEV;
-		goto out_err;
-	}
-
 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
-	release_locality(chip, 0);
 
 	rc = tpm_chip_start(chip);
 	if (rc)
@@ -1072,15 +1063,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 		 * to make sure it works. May as well use that command to set the
 		 * proper timeouts for the driver.
 		 */
-
-		rc = request_locality(chip, 0);
-		if (rc < 0)
-			goto out_err;
-
 		rc = tpm_get_timeouts(chip);
-
-		release_locality(chip, 0);
-
 		if (rc) {
 			dev_err(dev, "Could not get TPM timeouts and durations\n");
 			rc = -ENODEV;
@@ -1169,16 +1152,9 @@ int tpm_tis_resume(struct device *dev)
 	 * TPM 1.2 requires self-test on resume. This function actually returns
 	 * an error code but for unknown reason it isn't handled.
 	 */
-	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
-		ret = request_locality(chip, 0);
-		if (ret < 0)
-			return ret;
-
+	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
 		tpm1_do_selftest(chip);
 
-		release_locality(chip, 0);
-	}
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(tpm_tis_resume);
-- 
2.36.0