On Tue, Mar 17, 2020 at 05:46:00PM -0400, George Wilson wrote:
> tpm_ibmvtpm_send() can fail during PowerVM Live Partition Mobility resume
> with an H_CLOSED return from ibmvtpm_send_crq(). The PAPR says, 'The
> “partner partition suspended” transport event disables the associated CRQ
> such that any H_SEND_CRQ hcall() to the associated CRQ returns H_Closed
> until the CRQ has been explicitly enabled using the H_ENABLE_CRQ hcall.'
> This patch adds a check in tpm_ibmvtpm_send() for an H_CLOSED return from
> ibmvtpm_send_crq() and in that case calls tpm_ibmvtpm_resume() and
> retries the ibmvtpm_send_crq() once.
>
> Reported-by: Linh Pham <phaml@xxxxxxxxxx>
> Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
> Signed-off-by: George Wilson <gcwilson@xxxxxxxxxxxxx>
> Tested-by: Linh Pham <phaml@xxxxxxxxxx>
I think this should have a fixes tag.
> ---
> drivers/char/tpm/tpm_ibmvtpm.c | 23 ++++++++++++++++++-----
> 1 file changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
> index 78cc52690177..ba3bd503e080 100644
> --- a/drivers/char/tpm/tpm_ibmvtpm.c
> +++ b/drivers/char/tpm/tpm_ibmvtpm.c
> @@ -1,6 +1,6 @@
> // SPDX-License-Identifier: GPL-2.0-only
> /*
> - * Copyright (C) 2012 IBM Corporation
> + * Copyright (C) 2012-2020 IBM Corporation
> *
> * Author: Ashley Lai <ashleydlai@xxxxxxxxx>
> *
> @@ -25,6 +25,8 @@
> #include "tpm.h"
> #include "tpm_ibmvtpm.h"
>
> +static int tpm_ibmvtpm_resume(struct device *dev);
> +
Instead, reposition this function before tpm_ibmvtpm_send().
> static const char tpm_ibmvtpm_driver_name[] = "tpm_ibmvtpm";
>
> static const struct vio_device_id tpm_ibmvtpm_device_table[] = {
> @@ -147,6 +149,7 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
> {
> struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
> int rc, sig;
> + bool retry = true;
Cosmetic: would be nice to have inits when possible in reverse
Christmas tree order i.e.
struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
bool retry = true;
int rc, sig;
It is way more pleasing for the eye when you have to read the source
code.
> if (!ibmvtpm->rtce_buf) {
> dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
> @@ -179,18 +182,28 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
> */
> ibmvtpm->tpm_processing_cmd = true;
>
> +again:
> rc = ibmvtpm_send_crq(ibmvtpm->vdev,
> IBMVTPM_VALID_CMD, VTPM_TPM_COMMAND,
> count, ibmvtpm->rtce_dma_handle);
> +
A dangling newline character.
> if (rc != H_SUCCESS) {
> + /*
> + * H_CLOSED can be returned after LPM resume. Call
> + * tpm_ibmvtpm_resume() to re-enable the CRQ then retry
> + * ibmvtpm_send_crq() once before failing.
> + */
> + if (rc == H_CLOSED && retry) {
> + tpm_ibmvtpm_resume(ibmvtpm->dev);
> + retry = false;
> + goto again;
> + }
> dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed rc=%d\n", rc);
> - rc = 0;
> ibmvtpm->tpm_processing_cmd = false;
> - } else
> - rc = 0;
> + }
>
> spin_unlock(&ibmvtpm->rtce_lock);
> - return rc;
> + return 0;
> }
>
> static void tpm_ibmvtpm_cancel(struct tpm_chip *chip)
> --
> 2.24.1
>
/Jarkko
