LinuxLists.cc - [PATCH v3] tpm: do not suspend/resume if power stays on

2017-03-03 16:10:28

Subject: [PATCH v3] tpm: do not suspend/resume if power stays on

From: Sonny Rao <[email protected]>

The suspend/resume behavior of the TPM can be controlled by setting
"powered-while-suspended" in the DTS. This is useful for the cases
when hardware does not power-off the TPM.

Signed-off-by: Sonny Rao <[email protected]>
Signed-off-by: Enric Balletbo i Serra <[email protected]>
---
Changes since v2:
Jarkko Sakkinen
- Add a new TPM_CHIP_FLAG_ALWAYS_POWERED flag instead of using a boolean variable.
- Remove a trailing newline.
Changes since v1:
Jason Gunthorpe :
- Move the code to handle suspend/resume in the common chip code.

Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt | 6 ++++++
drivers/char/tpm/tpm-interface.c | 3 +++
drivers/char/tpm/tpm.h | 1 +
drivers/char/tpm/tpm_of.c | 3 +++
4 files changed, 13 insertions(+)

diff --git a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
index 8cb638b..85c8216 100644
--- a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
+++ b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
@@ -8,6 +8,12 @@ Required properties:
the firmware event log
- linux,sml-size : size of the memory allocated for the firmware event log

+Optional properties:
+
+- powered-while-suspended: present when the TPM is left powered on between
+ suspend and resume (makes the suspend/resume
+ callbacks do nothing).
+
Example (for OpenPower Systems with Nuvoton TPM 2.0 on I2C)
----------------------------------------------------------

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index a2688ac..6869093 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -944,6 +944,9 @@ int tpm_pm_suspend(struct device *dev)
if (chip == NULL)
return -ENODEV;

+ if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
+ return 0;
+
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
tpm2_shutdown(chip, TPM2_SU_STATE);
return 0;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 1ae9768..0ce379c 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -146,6 +146,7 @@ enum tpm_chip_flags {
TPM_CHIP_FLAG_IRQ = BIT(2),
TPM_CHIP_FLAG_VIRTUAL = BIT(3),
TPM_CHIP_FLAG_HAVE_TIMEOUTS = BIT(4),
+ TPM_CHIP_FLAG_ALWAYS_POWERED = BIT(5),
};

struct tpm_chip_seqops {
diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
index 7dee42d7..e89276c 100644
--- a/drivers/char/tpm/tpm_of.c
+++ b/drivers/char/tpm/tpm_of.c
@@ -34,6 +34,9 @@ int tpm_read_log_of(struct tpm_chip *chip)
else
return -ENODEV;

+ if (of_property_read_bool(np, "powered-while-suspended"))
+ chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
+
sizep = of_get_property(np, "linux,sml-size", NULL);
basep = of_get_property(np, "linux,sml-base", NULL);
if (sizep == NULL && basep == NULL)
--
2.9.3

2017-03-03 17:11:29

by Jason Gunthorpe

[permalink] [raw]

Subject: Re: [PATCH v3] tpm: do not suspend/resume if power stays on

2017-03-06 14:47:10

by Jarkko Sakkinen

[permalink] [raw]

Subject: Re: [PATCH v3] tpm: do not suspend/resume if power stays on

On Fri, Mar 03, 2017 at 05:09:59PM +0100, Enric Balletbo i Serra wrote:
> From: Sonny Rao <[email protected]>
>
> The suspend/resume behavior of the TPM can be controlled by setting
> "powered-while-suspended" in the DTS. This is useful for the cases
> when hardware does not power-off the TPM.
>
> Signed-off-by: Sonny Rao <[email protected]>
> Signed-off-by: Enric Balletbo i Serra <[email protected]>

Thanks. Looks good to me.

Reviewed-by: Jarkko Sakkinen <[email protected]>

/Jarkko

> ---
> Changes since v2:
> Jarkko Sakkinen
> - Add a new TPM_CHIP_FLAG_ALWAYS_POWERED flag instead of using a boolean variable.
> - Remove a trailing newline.
> Changes since v1:
> Jason Gunthorpe :
> - Move the code to handle suspend/resume in the common chip code.
>
> Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt | 6 ++++++
> drivers/char/tpm/tpm-interface.c | 3 +++
> drivers/char/tpm/tpm.h | 1 +
> drivers/char/tpm/tpm_of.c | 3 +++
> 4 files changed, 13 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
> index 8cb638b..85c8216 100644
> --- a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
> +++ b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
> @@ -8,6 +8,12 @@ Required properties:
> the firmware event log
> - linux,sml-size : size of the memory allocated for the firmware event log
>
> +Optional properties:
> +
> +- powered-while-suspended: present when the TPM is left powered on between
> + suspend and resume (makes the suspend/resume
> + callbacks do nothing).
> +
> Example (for OpenPower Systems with Nuvoton TPM 2.0 on I2C)
> ----------------------------------------------------------
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index a2688ac..6869093 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -944,6 +944,9 @@ int tpm_pm_suspend(struct device *dev)
> if (chip == NULL)
> return -ENODEV;
>
> + if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
> + return 0;
> +
> if (chip->flags & TPM_CHIP_FLAG_TPM2) {
> tpm2_shutdown(chip, TPM2_SU_STATE);
> return 0;
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 1ae9768..0ce379c 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -146,6 +146,7 @@ enum tpm_chip_flags {
> TPM_CHIP_FLAG_IRQ = BIT(2),
> TPM_CHIP_FLAG_VIRTUAL = BIT(3),
> TPM_CHIP_FLAG_HAVE_TIMEOUTS = BIT(4),
> + TPM_CHIP_FLAG_ALWAYS_POWERED = BIT(5),
> };
>
> struct tpm_chip_seqops {
> diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
> index 7dee42d7..e89276c 100644
> --- a/drivers/char/tpm/tpm_of.c
> +++ b/drivers/char/tpm/tpm_of.c
> @@ -34,6 +34,9 @@ int tpm_read_log_of(struct tpm_chip *chip)
> else
> return -ENODEV;
>
> + if (of_property_read_bool(np, "powered-while-suspended"))
> + chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
> +
> sizep = of_get_property(np, "linux,sml-size", NULL);
> basep = of_get_property(np, "linux,sml-base", NULL);
> if (sizep == NULL && basep == NULL)
> --
> 2.9.3
>

2017-03-06 21:05:00

by Jarkko Sakkinen

[permalink] [raw]

Subject: Re: [PATCH v3] tpm: do not suspend/resume if power stays on

2017-03-07 09:24:26

by Enric Balletbo i Serra

[permalink] [raw]

Subject: Re: [PATCH v3] tpm: do not suspend/resume if power stays on

Hi Jarkko,

On 06/03/17 21:59, Jarkko Sakkinen wrote:
> On Fri, Mar 03, 2017 at 05:09:59PM +0100, Enric Balletbo i Serra wrote:
>> From: Sonny Rao <[email protected]>
>>
>> The suspend/resume behavior of the TPM can be controlled by setting
>> "powered-while-suspended" in the DTS. This is useful for the cases
>> when hardware does not power-off the TPM.
>>
>> Signed-off-by: Sonny Rao <[email protected]>
>> Signed-off-by: Enric Balletbo i Serra <[email protected]>
>> ---
>> Changes since v2:
>> Jarkko Sakkinen
>> - Add a new TPM_CHIP_FLAG_ALWAYS_POWERED flag instead of using a boolean variable.
>> - Remove a trailing newline.
>> Changes since v1:
>> Jason Gunthorpe :
>> - Move the code to handle suspend/resume in the common chip code.
>>
>> Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt | 6 ++++++
>> drivers/char/tpm/tpm-interface.c | 3 +++
>> drivers/char/tpm/tpm.h | 1 +
>> drivers/char/tpm/tpm_of.c | 3 +++
>> 4 files changed, 13 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
>> index 8cb638b..85c8216 100644
>> --- a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
>> +++ b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
>> @@ -8,6 +8,12 @@ Required properties:
>> the firmware event log
>> - linux,sml-size : size of the memory allocated for the firmware event log
>>
>> +Optional properties:
>> +
>> +- powered-while-suspended: present when the TPM is left powered on between
>> + suspend and resume (makes the suspend/resume
>> + callbacks do nothing).
>> +
>> Example (for OpenPower Systems with Nuvoton TPM 2.0 on I2C)
>> ----------------------------------------------------------
>
> Hey, just noticed something. Shouldn't this be a separate commit?

During my life submitting patches I saw the both options, sometimes the maintainer asked me to join the DT patch and the driver and sometimes he asked me to do in different patches, so I think this is more a maintainer option. Maybe Rob Herring or Mark Rutland can share their preferences?

I'll do what you want I do, TBH I don't have a strong opinion about this.

> I'm also wondering whether this can be submitted through my tree
> upper maintainers.
>
> Does not change my reviewed-by for the actual code change but you
> would have to split this into a patch set if this is the case.
>
> /Jarkko
>

Cheers,
Enric

2017-03-07 18:52:28

by Jarkko Sakkinen

[permalink] [raw]

Subject: Re: [PATCH v3] tpm: do not suspend/resume if power stays on

On Tue, Mar 07, 2017 at 09:44:55AM +0100, Enric Balletbo i Serra wrote:
> Hi Jarkko,
>
> On 06/03/17 21:59, Jarkko Sakkinen wrote:
> > On Fri, Mar 03, 2017 at 05:09:59PM +0100, Enric Balletbo i Serra wrote:
> >> From: Sonny Rao <[email protected]>
> >>
> >> The suspend/resume behavior of the TPM can be controlled by setting
> >> "powered-while-suspended" in the DTS. This is useful for the cases
> >> when hardware does not power-off the TPM.
> >>
> >> Signed-off-by: Sonny Rao <[email protected]>
> >> Signed-off-by: Enric Balletbo i Serra <[email protected]>
> >> ---
> >> Changes since v2:
> >> Jarkko Sakkinen
> >> - Add a new TPM_CHIP_FLAG_ALWAYS_POWERED flag instead of using a boolean variable.
> >> - Remove a trailing newline.
> >> Changes since v1:
> >> Jason Gunthorpe :
> >> - Move the code to handle suspend/resume in the common chip code.
> >>
> >> Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt | 6 ++++++
> >> drivers/char/tpm/tpm-interface.c | 3 +++
> >> drivers/char/tpm/tpm.h | 1 +
> >> drivers/char/tpm/tpm_of.c | 3 +++
> >> 4 files changed, 13 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
> >> index 8cb638b..85c8216 100644
> >> --- a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
> >> +++ b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
> >> @@ -8,6 +8,12 @@ Required properties:
> >> the firmware event log
> >> - linux,sml-size : size of the memory allocated for the firmware event log
> >>
> >> +Optional properties:
> >> +
> >> +- powered-while-suspended: present when the TPM is left powered on between
> >> + suspend and resume (makes the suspend/resume
> >> + callbacks do nothing).
> >> +
> >> Example (for OpenPower Systems with Nuvoton TPM 2.0 on I2C)
> >> ----------------------------------------------------------
> >
> > Hey, just noticed something. Shouldn't this be a separate commit?
>
> During my life submitting patches I saw the both options, sometimes
> the maintainer asked me to join the DT patch and the driver and
> sometimes he asked me to do in different patches, so I think this is
> more a maintainer option. Maybe Rob Herring or Mark Rutland can share
> their preferences?
>
> I'll do what you want I do, TBH I don't have a strong opinion about this.

I'll add this to my tree and put it to my next branch so that
it will flow to linux-next since it only touch TPM specific
file in bindings.

I do not have perfect answer for this so I'll use common sense
(or try to).

Rob, is this OK?

/Jarkko

2017-03-12 14:28:45

by Rob Herring (Arm)

[permalink] [raw]

Subject: Re: [PATCH v3] tpm: do not suspend/resume if power stays on

On Tue, Mar 07, 2017 at 09:44:55AM +0100, Enric Balletbo i Serra wrote:
> Hi Jarkko,
>
> On 06/03/17 21:59, Jarkko Sakkinen wrote:
> > On Fri, Mar 03, 2017 at 05:09:59PM +0100, Enric Balletbo i Serra wrote:
> >> From: Sonny Rao <[email protected]>
> >>
> >> The suspend/resume behavior of the TPM can be controlled by setting
> >> "powered-while-suspended" in the DTS. This is useful for the cases
> >> when hardware does not power-off the TPM.
> >>
> >> Signed-off-by: Sonny Rao <[email protected]>
> >> Signed-off-by: Enric Balletbo i Serra <[email protected]>
> >> ---
> >> Changes since v2:
> >> Jarkko Sakkinen
> >> - Add a new TPM_CHIP_FLAG_ALWAYS_POWERED flag instead of using a boolean variable.
> >> - Remove a trailing newline.
> >> Changes since v1:
> >> Jason Gunthorpe :
> >> - Move the code to handle suspend/resume in the common chip code.
> >>
> >> Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt | 6 ++++++
> >> drivers/char/tpm/tpm-interface.c | 3 +++
> >> drivers/char/tpm/tpm.h | 1 +
> >> drivers/char/tpm/tpm_of.c | 3 +++
> >> 4 files changed, 13 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
> >> index 8cb638b..85c8216 100644
> >> --- a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
> >> +++ b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt
> >> @@ -8,6 +8,12 @@ Required properties:
> >> the firmware event log
> >> - linux,sml-size : size of the memory allocated for the firmware event log
> >>
> >> +Optional properties:
> >> +
> >> +- powered-while-suspended: present when the TPM is left powered on between
> >> + suspend and resume (makes the suspend/resume
> >> + callbacks do nothing).
> >> +
> >> Example (for OpenPower Systems with Nuvoton TPM 2.0 on I2C)
> >> ----------------------------------------------------------
> >
> > Hey, just noticed something. Shouldn't this be a separate commit?
>
> During my life submitting patches I saw the both options, sometimes the maintainer asked me to join the DT patch and the driver and sometimes he asked me to do in different patches, so I think this is more a maintainer option. Maybe Rob Herring or Mark Rutland can share their preferences?
>

Need to fix your mailer to wrap lines...

We prefer DT bindings to be separate commits, but don't enforce it. I
don't ask for on small changes or if there's no other reason to respin
the patch.

It makes the history for the DT only tree generated from git
filter-branch cleaner. Any other maintainers tell you to combine them,
they need to talk to me.

Rob

2017-03-12 14:33:23

by Rob Herring (Arm)

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