[PATCH v3 1/2] tpm: ibmvtpm: Rename tpm_process_cmd to tpm_status and define flag

Stefan Berger
2021-08-05T21:53:12Z

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