* [PATCH v2] tpm: ibmvtpm: retry on H_CLOSED in tpm_ibmvtpm_send()
@ 2020-03-17 21:46 George Wilson
2020-03-18 20:43 ` Jarkko Sakkinen
0 siblings, 1 reply; 4+ messages in thread
From: George Wilson @ 2020-03-17 21:46 UTC (permalink / raw)
To: linux-integrity
Cc: Alexey Kardashevskiy, Stefan Berger, Jarkko Sakkinen, Nayna Jain,
Jason Gunthorpe, linux-kernel, George Wilson, Linh Pham
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@us.ibm.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: George Wilson <gcwilson@linux.ibm.com>
Tested-by: Linh Pham <phaml@us.ibm.com>
---
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@gmail.com>
*
@@ -25,6 +25,8 @@
#include "tpm.h"
#include "tpm_ibmvtpm.h"
+static int tpm_ibmvtpm_resume(struct device *dev);
+
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;
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);
+
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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] tpm: ibmvtpm: retry on H_CLOSED in tpm_ibmvtpm_send()
2020-03-17 21:46 [PATCH v2] tpm: ibmvtpm: retry on H_CLOSED in tpm_ibmvtpm_send() George Wilson
@ 2020-03-18 20:43 ` Jarkko Sakkinen
2020-03-18 22:35 ` Jason Gunthorpe
0 siblings, 1 reply; 4+ messages in thread
From: Jarkko Sakkinen @ 2020-03-18 20:43 UTC (permalink / raw)
To: George Wilson
Cc: linux-integrity, Alexey Kardashevskiy, Stefan Berger, Nayna Jain,
Jason Gunthorpe, linux-kernel, Linh Pham
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@us.ibm.com>
> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
> Signed-off-by: George Wilson <gcwilson@linux.ibm.com>
> Tested-by: Linh Pham <phaml@us.ibm.com>
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@gmail.com>
> *
> @@ -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
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] tpm: ibmvtpm: retry on H_CLOSED in tpm_ibmvtpm_send()
2020-03-18 20:43 ` Jarkko Sakkinen
@ 2020-03-18 22:35 ` Jason Gunthorpe
2020-03-19 19:12 ` Jarkko Sakkinen
0 siblings, 1 reply; 4+ messages in thread
From: Jason Gunthorpe @ 2020-03-18 22:35 UTC (permalink / raw)
To: Jarkko Sakkinen
Cc: George Wilson, linux-integrity, Alexey Kardashevskiy,
Stefan Berger, Nayna Jain, linux-kernel, Linh Pham
On Wed, Mar 18, 2020 at 10:43:18PM +0200, Jarkko Sakkinen wrote:
> > 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.
I thought only netdev insisted on that :O
Jason
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] tpm: ibmvtpm: retry on H_CLOSED in tpm_ibmvtpm_send()
2020-03-18 22:35 ` Jason Gunthorpe
@ 2020-03-19 19:12 ` Jarkko Sakkinen
0 siblings, 0 replies; 4+ messages in thread
From: Jarkko Sakkinen @ 2020-03-19 19:12 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: George Wilson, linux-integrity, Alexey Kardashevskiy,
Stefan Berger, Nayna Jain, linux-kernel, Linh Pham
On Wed, Mar 18, 2020 at 07:35:42PM -0300, Jason Gunthorpe wrote:
> On Wed, Mar 18, 2020 at 10:43:18PM +0200, Jarkko Sakkinen wrote:
> > > 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.
>
> I thought only netdev insisted on that :O
x86 seems to prefer too and I agree with the idea. But as I said only
that it would be nice.
/Jarkko
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-03-19 19:12 UTC | newest]
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2020-03-17 21:46 [PATCH v2] tpm: ibmvtpm: retry on H_CLOSED in tpm_ibmvtpm_send() George Wilson
2020-03-18 20:43 ` Jarkko Sakkinen
2020-03-18 22:35 ` Jason Gunthorpe
2020-03-19 19:12 ` Jarkko Sakkinen
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