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

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

[Enric Balletbo i Serra]

From: Sonny Rao <sonnyrao@chromium.org>

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 <sonnyrao@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
---
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

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

[Jason Gunthorpe]

On Fri, Mar 03, 2017 at 05:09:59PM +0100, Enric Balletbo i Serra wrote:
> From: Sonny Rao <sonnyrao@chromium.org>
> 
> 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 <sonnyrao@chromium.org>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>

> +++ 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;
> +

It is really weird that this is in a function called tpm_read_log_of,
but it makes sense to use the existing conditional infrastructure for
OF as well.

We should try to tidy this later...

Jason

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

[Jarkko Sakkinen]

On Fri, Mar 03, 2017 at 05:09:59PM +0100, Enric Balletbo i Serra wrote:
> From: Sonny Rao <sonnyrao@chromium.org>
> 
> 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 <sonnyrao@chromium.org>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

Thanks. Looks good to me.

Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

/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
> 

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

[Jarkko Sakkinen]

On Fri, Mar 03, 2017 at 05:09:59PM +0100, Enric Balletbo i Serra wrote:
> From: Sonny Rao <sonnyrao@chromium.org>
> 
> 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 <sonnyrao@chromium.org>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> ---
> 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?
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

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

[Enric Balletbo i Serra]

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 <sonnyrao@chromium.org>
>>
>> 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 <sonnyrao@chromium.org>
>> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
>> ---
>> 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

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

[Jarkko Sakkinen]

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 <sonnyrao@chromium.org>
> >>
> >> 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 <sonnyrao@chromium.org>
> >> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> >> ---
> >> 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

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

[Rob Herring]

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 <sonnyrao@chromium.org>
> >>
> >> 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 <sonnyrao@chromium.org>
> >> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> >> ---
> >> 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

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

[Rob Herring]

On Fri, Mar 03, 2017 at 05:09:59PM +0100, Enric Balletbo i Serra wrote:
> From: Sonny Rao <sonnyrao@chromium.org>
> 
> 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 <sonnyrao@chromium.org>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> ---
> 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 ++++++

I would say this shouldn't be TPM specific, but looks like we already 
have a dts with this, so:

Acked-by: Rob Herring <robh@kernel.org>

>  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(+)