[tpmdd-devel,v2] tpm: do not suspend/resume if power stays on

Submitted by Enric Balletbo i Serra on March 2, 2017, 3:42 p.m.

Details

Message ID 20170302154257.10663-1-enric.balletbo@collabora.com
State New
Headers show

Commit Message

Enric Balletbo i Serra March 2, 2017, 3:42 p.m.
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 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                                     | 3 +++
 drivers/char/tpm/tpm_of.c                                  | 3 +++
 4 files changed, 15 insertions(+)

Comments

Jarkko Sakkinen March 3, 2017, 3:12 p.m.
On Thu, Mar 02, 2017 at 04:42:57PM +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 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                                     | 3 +++
>  drivers/char/tpm/tpm_of.c                                  | 3 +++
>  4 files changed, 15 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..7f60780 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->powered_while_suspended)
> +		return 0;

Why there can't just be TPM_CHIP_FLAG_ALWAYS_POWERED or something similar?

> +
>  	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..c8f796c 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -183,10 +183,13 @@ struct tpm_chip {
>  	unsigned long duration[3]; /* jiffies */
>  	bool duration_adjusted;
>  
> +	bool powered_while_suspended;
> +
>  	struct dentry *bios_dir[TPM_NUM_EVENT_LOG_FILES];
>  
>  	const struct attribute_group *groups[3];
>  	unsigned int groups_cnt;
> +

trailing newline

>  #ifdef CONFIG_ACPI
>  	acpi_handle acpi_dev_handle;
>  	char ppi_version[TPM_PPI_VERSION_LEN + 1];
> diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
> index 7dee42d7..33eddd4 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;
>  
> +	chip->powered_while_suspended = of_property_read_bool(np,
> +						"powered-while-suspended");
> +
>  	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
> 
> 
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, SlashDot.org! http://sdm.link/slashdot
> _______________________________________________
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> tpmdd-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/tpmdd-devel

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Enric Balletbo i Serra March 3, 2017, 3:46 p.m.
Hi Jarkko,

Thanks for the review

On 03/03/17 16:12, Jarkko Sakkinen wrote:
> On Thu, Mar 02, 2017 at 04:42:57PM +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 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                                     | 3 +++
>>  drivers/char/tpm/tpm_of.c                                  | 3 +++
>>  4 files changed, 15 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..7f60780 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->powered_while_suspended)
>> +		return 0;
> 
> Why there can't just be TPM_CHIP_FLAG_ALWAYS_POWERED or something similar?
> 

Right this seems a better way for tpm subsystem. I'll send a v3 today.

>> +
>>  	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..c8f796c 100644
>> --- a/drivers/char/tpm/tpm.h
>> +++ b/drivers/char/tpm/tpm.h
>> @@ -183,10 +183,13 @@ struct tpm_chip {
>>  	unsigned long duration[3]; /* jiffies */
>>  	bool duration_adjusted;
>>  
>> +	bool powered_while_suspended;
>> +
>>  	struct dentry *bios_dir[TPM_NUM_EVENT_LOG_FILES];
>>  
>>  	const struct attribute_group *groups[3];
>>  	unsigned int groups_cnt;
>> +
> 
> trailing newline
> 
>>  #ifdef CONFIG_ACPI
>>  	acpi_handle acpi_dev_handle;
>>  	char ppi_version[TPM_PPI_VERSION_LEN + 1];
>> diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
>> index 7dee42d7..33eddd4 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;
>>  
>> +	chip->powered_while_suspended = of_property_read_bool(np,
>> +						"powered-while-suspended");
>> +
>>  	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
>>
>>
>> ------------------------------------------------------------------------------
>> Check out the vibrant tech community on one of the world's most
>> engaging tech sites, SlashDot.org! http://sdm.link/slashdot
>> _______________________________________________
>> tpmdd-devel mailing list
>> tpmdd-devel@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/tpmdd-devel

------------------------------------------------------------------------------
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Patch hide | download patch | download mbox

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..7f60780 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->powered_while_suspended)
+		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..c8f796c 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -183,10 +183,13 @@  struct tpm_chip {
 	unsigned long duration[3]; /* jiffies */
 	bool duration_adjusted;
 
+	bool powered_while_suspended;
+
 	struct dentry *bios_dir[TPM_NUM_EVENT_LOG_FILES];
 
 	const struct attribute_group *groups[3];
 	unsigned int groups_cnt;
+
 #ifdef CONFIG_ACPI
 	acpi_handle acpi_dev_handle;
 	char ppi_version[TPM_PPI_VERSION_LEN + 1];
diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
index 7dee42d7..33eddd4 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;
 
+	chip->powered_while_suspended = of_property_read_bool(np,
+						"powered-while-suspended");
+
 	sizep = of_get_property(np, "linux,sml-size", NULL);
 	basep = of_get_property(np, "linux,sml-base", NULL);
 	if (sizep == NULL && basep == NULL)