Re: [PATCH v5 3/5] crypto: ccp - Add an S4 restore flow

[Mario Limonciello <superm1@kernel.org>]

On 1/12/26 10:33 AM, Tom Lendacky wrote:
> On 1/11/26 23:36, Mario Limonciello (AMD) wrote:
>> The system will have lost power during S4.  The ring used for TEE
>> communications needs to be initialized before use.
>>
>> Fixes: f892a21f51162 ("crypto: ccp - use generic power management")
>> Reported-by: Lars Francke <lars.francke@gmail.com>
>> Closes: https://lore.kernel.org/platform-driver-x86/CAD-Ua_gfJnQSo8ucS_7ZwzuhoBRJ14zXP7s8b-zX3ZcxcyWePw@mail.gmail.com/
>> Tested-by: Yijun Shen <Yijun.Shen@Dell.com>
>> Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
>> ---
>> v5:
>>   * Fix return for psp_restore() (LKP robot, Shyam)
>> v4:
>>   * Add tag (Yijun)
>>   * Remove blank line (Ilpo)
>>   * Adjust whitespace in psp_restore() (Ilpo)
>> ---
>>   drivers/crypto/ccp/psp-dev.c | 11 +++++++++++
>>   drivers/crypto/ccp/sp-dev.h  |  2 ++
>>   drivers/crypto/ccp/sp-pci.c  | 24 +++++++++++++++++++++++-
>>   drivers/crypto/ccp/tee-dev.c |  5 +++++
>>   drivers/crypto/ccp/tee-dev.h |  1 +
>>   5 files changed, 42 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
>> index 9e21da0e298ad..5c7f7e02a7d8a 100644
>> --- a/drivers/crypto/ccp/psp-dev.c
>> +++ b/drivers/crypto/ccp/psp-dev.c
>> @@ -351,6 +351,17 @@ struct psp_device *psp_get_master_device(void)
>>   	return sp ? sp->psp_data : NULL;
>>   }
>>   
>> +int psp_restore(struct sp_device *sp)
>> +{
>> +	struct psp_device *psp = sp->psp_data;
>> +	int ret = 0;
>> +
>> +	if (psp->tee_data)
>> +		ret = tee_restore(psp);
>> +
>> +	return ret;
>> +}
>> +
>>   void psp_pci_init(void)
>>   {
>>   	psp_master = psp_get_master_device();
>> diff --git a/drivers/crypto/ccp/sp-dev.h b/drivers/crypto/ccp/sp-dev.h
>> index 1335a83fe052e..0deea1a399e47 100644
>> --- a/drivers/crypto/ccp/sp-dev.h
>> +++ b/drivers/crypto/ccp/sp-dev.h
>> @@ -174,6 +174,7 @@ int psp_dev_init(struct sp_device *sp);
>>   void psp_pci_init(void);
>>   void psp_dev_destroy(struct sp_device *sp);
>>   void psp_pci_exit(void);
>> +int psp_restore(struct sp_device *sp);
>>   
>>   #else /* !CONFIG_CRYPTO_DEV_SP_PSP */
>>   
>> @@ -181,6 +182,7 @@ static inline int psp_dev_init(struct sp_device *sp) { return 0; }
>>   static inline void psp_pci_init(void) { }
>>   static inline void psp_dev_destroy(struct sp_device *sp) { }
>>   static inline void psp_pci_exit(void) { }
>> +static inline int psp_restore(struct sp_device *sp) { return 0; }
>>   
>>   #endif /* CONFIG_CRYPTO_DEV_SP_PSP */
>>   
>> diff --git a/drivers/crypto/ccp/sp-pci.c b/drivers/crypto/ccp/sp-pci.c
>> index 8891ceee1d7d0..931ec6bf2cec6 100644
>> --- a/drivers/crypto/ccp/sp-pci.c
>> +++ b/drivers/crypto/ccp/sp-pci.c
>> @@ -353,6 +353,21 @@ static int __maybe_unused sp_pci_resume(struct device *dev)
>>   	return sp_resume(sp);
>>   }
>>   
>> +static int __maybe_unused sp_pci_restore(struct device *dev)
>> +{
>> +	struct sp_device *sp = dev_get_drvdata(dev);
>> +
>> +#ifdef CONFIG_CRYPTO_DEV_SP_PSP
> 
> This isn't needed since you have the "#else" definition in sp-dev.h.

Ack.

> 
>> +	if (sp->psp_data) {
>> +		int ret = psp_restore(sp);
>> +
> 
> Remove blank line.

Then checkpatch complains:

Missing a blank line after declarations

> 
>> +		if (ret)
>> +			return ret;
>> +	}
>> +#endif
> 
> This isn't the way the other functions work. This function should just
> be calling to sp_resume() and then sp_resume() should call psp_restore()
> (or psp_dev_restore() ?) if the psp_data is present.
> 
> And if you need to distinguish between the resume and restore case in
> sp_resume(), then it sounds like you need an sp_restore().

We do need a different path for resume and restore.

I guess the call path you're looking for is:

sp_pci_restore()
-> sp_restore()
->-> psp_restore()
->-> sp_resume()

Basically move the contents of sp_pci_restore() into a new sp_restore().

> 
> Thanks,
> Tom
> 
>> +	return sp_resume(sp);
>> +}
>> +
>>   #ifdef CONFIG_CRYPTO_DEV_SP_PSP
>>   static const struct sev_vdata sevv1 = {
>>   	.cmdresp_reg		= 0x10580,	/* C2PMSG_32 */
>> @@ -563,7 +578,14 @@ static const struct pci_device_id sp_pci_table[] = {
>>   };
>>   MODULE_DEVICE_TABLE(pci, sp_pci_table);
>>   
>> -static SIMPLE_DEV_PM_OPS(sp_pci_pm_ops, sp_pci_suspend, sp_pci_resume);
>> +static const struct dev_pm_ops sp_pci_pm_ops = {
>> +	.suspend = pm_sleep_ptr(sp_pci_suspend),
>> +	.resume = pm_sleep_ptr(sp_pci_resume),
>> +	.freeze = pm_sleep_ptr(sp_pci_suspend),
>> +	.thaw = pm_sleep_ptr(sp_pci_resume),
>> +	.poweroff = pm_sleep_ptr(sp_pci_suspend),
>> +	.restore_early = pm_sleep_ptr(sp_pci_restore),
>> +};
>>   
>>   static struct pci_driver sp_pci_driver = {
>>   	.name = "ccp",
>> diff --git a/drivers/crypto/ccp/tee-dev.c b/drivers/crypto/ccp/tee-dev.c
>> index af881daa5855b..11c4b05e2f3a2 100644
>> --- a/drivers/crypto/ccp/tee-dev.c
>> +++ b/drivers/crypto/ccp/tee-dev.c
>> @@ -366,3 +366,8 @@ int psp_check_tee_status(void)
>>   	return 0;
>>   }
>>   EXPORT_SYMBOL(psp_check_tee_status);
>> +
>> +int tee_restore(struct psp_device *psp)
>> +{
>> +	return tee_init_ring(psp->tee_data);
>> +}
>> diff --git a/drivers/crypto/ccp/tee-dev.h b/drivers/crypto/ccp/tee-dev.h
>> index ea9a2b7c05f57..c23416cb7bb37 100644
>> --- a/drivers/crypto/ccp/tee-dev.h
>> +++ b/drivers/crypto/ccp/tee-dev.h
>> @@ -111,5 +111,6 @@ struct tee_ring_cmd {
>>   
>>   int tee_dev_init(struct psp_device *psp);
>>   void tee_dev_destroy(struct psp_device *psp);
>> +int tee_restore(struct psp_device *psp);
>>   
>>   #endif /* __TEE_DEV_H__ */
> 
>