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From:   Stefan Berger <stefanb@linux.vnet.ibm.com>
To:     jarkko@kernel.org
Cc:     peterhuewe@gmx.de, jgg@ziepe.ca, linux-integrity@vger.kernel.org,
        linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Stefan Berger <stefanb@linux.ibm.com>,
        Nayna Jain <nayna@linux.ibm.com>,
        George Wilson <gcwilson@linux.ibm.com>
Subject: [PATCH v3 1/2] tpm: ibmvtpm: Rename tpm_process_cmd to tpm_status and define flag
Date:   Thu,  5 Aug 2021 17:52:55 -0400
Message-Id: <20210805215256.1293987-2-stefanb@linux.vnet.ibm.com>
In-Reply-To: <20210805215256.1293987-1-stefanb@linux.vnet.ibm.com>
References: <20210805215256.1293987-1-stefanb@linux.vnet.ibm.com>
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From: Stefan Berger <stefanb@linux.ibm.com>

Rename the field tpm_processing_cmd to tpm_status in ibmvtpm_dev and set
the TPM_STATUS_BUSY flag while the vTPM is busy processing a command.

Fixes: 6674ff145eef ("tpm_ibmvtpm: properly handle interrupted packet receptions")
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Cc: Nayna Jain <nayna@linux.ibm.com>
Cc: George Wilson <gcwilson@linux.ibm.com>
---
 drivers/char/tpm/tpm_ibmvtpm.c | 14 ++++++++------
 drivers/char/tpm/tpm_ibmvtpm.h |  3 ++-
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index 903604769de9..cd6457061a2e 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.c
+++ b/drivers/char/tpm/tpm_ibmvtpm.c
@@ -113,7 +113,8 @@ static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 		return 0;
 	}
 
-	sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
+	sig = wait_event_interruptible(ibmvtpm->wq,
+				(ibmvtpm->tpm_status & TPM_STATUS_BUSY) == 0);
 	if (sig)
 		return -EINTR;
 
@@ -220,11 +221,12 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
 		return -EIO;
 	}
 
-	if (ibmvtpm->tpm_processing_cmd) {
+	if ((ibmvtpm->tpm_status & TPM_STATUS_BUSY)) {
 		dev_info(ibmvtpm->dev,
 		         "Need to wait for TPM to finish\n");
 		/* wait for previous command to finish */
-		sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
+		sig = wait_event_interruptible(ibmvtpm->wq,
+				(ibmvtpm->tpm_status & TPM_STATUS_BUSY) == 0);
 		if (sig)
 			return -EINTR;
 	}
@@ -237,7 +239,7 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
 	 * set the processing flag before the Hcall, since we may get the
 	 * result (interrupt) before even being able to check rc.
 	 */
-	ibmvtpm->tpm_processing_cmd = true;
+	ibmvtpm->tpm_status |= TPM_STATUS_BUSY;
 
 again:
 	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
@@ -255,7 +257,7 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
 			goto again;
 		}
 		dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed rc=%d\n", rc);
-		ibmvtpm->tpm_processing_cmd = false;
+		ibmvtpm->tpm_status &= ~TPM_STATUS_BUSY;
 	}
 
 	spin_unlock(&ibmvtpm->rtce_lock);
@@ -550,7 +552,7 @@ static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
 		case VTPM_TPM_COMMAND_RES:
 			/* len of the data in rtce buffer */
 			ibmvtpm->res_len = be16_to_cpu(crq->len);
-			ibmvtpm->tpm_processing_cmd = false;
+			ibmvtpm->tpm_status &= ~TPM_STATUS_BUSY;
 			wake_up_interruptible(&ibmvtpm->wq);
 			return;
 		default:
diff --git a/drivers/char/tpm/tpm_ibmvtpm.h b/drivers/char/tpm/tpm_ibmvtpm.h
index b92aa7d3e93e..252f1cccdfc5 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.h
+++ b/drivers/char/tpm/tpm_ibmvtpm.h
@@ -41,7 +41,8 @@ struct ibmvtpm_dev {
 	wait_queue_head_t wq;
 	u16 res_len;
 	u32 vtpm_version;
-	bool tpm_processing_cmd;
+	u8 tpm_status;
+#define TPM_STATUS_BUSY		(1 << 0) /* vtpm is processing a command */
 };
 
 #define CRQ_RES_BUF_SIZE	PAGE_SIZE
-- 
2.31.1