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Date:   Tue, 21 Jul 2020 22:00:56 +0530
From:   Vaibhav Gupta <vaibhavgupta40@gmail.com>
To:     Tom Lendacky <thomas.lendacky@amd.com>
Cc:     Bjorn Helgaas <helgaas@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Bjorn Helgaas <bjorn@helgaas.com>,
        Vaibhav Gupta <vaibhav.varodek@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        linux-kernel@vger.kernel.org,
        linux-kernel-mentees@lists.linuxfoundation.org,
        Shuah Khan <skhan@linuxfoundation.org>,
        linux-crypto@vger.kernel.org
Subject: Re: [PATCH v1] crypto: ccp: sp-pci: use generic power management
Message-ID: <20200721163056.GA396078@gmail.com>
References: <20200721123146.81710-1-vaibhavgupta40@gmail.com>
 <7100976b-cf7c-c304-e2a6-660876e310af@amd.com>
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On Tue, Jul 21, 2020 at 10:19:33AM -0500, Tom Lendacky wrote:
> On 7/21/20 7:31 AM, Vaibhav Gupta wrote:
> > Drivers using legacy power management .suspen()/.resume() callbacks
> > have to manage PCI states and device's PM states themselves. They also
> > need to take care of standard configuration registers.
> > 
> > Switch to generic power management framework using a single
> > "struct dev_pm_ops" variable to take the unnecessary load from the driver.
> > This also avoids the need for the driver to directly call most of the PCI
> > helper functions and device power state control functions as through
> > the generic framework, PCI Core takes care of the necessary operations,
> > and drivers are required to do only device-specific jobs.
> > 
> > Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
> > ---
> >  drivers/crypto/ccp/ccp-dev.c     |  8 +++-----
> >  drivers/crypto/ccp/sp-dev.c      |  6 ++----
> >  drivers/crypto/ccp/sp-dev.h      |  6 +++---
> >  drivers/crypto/ccp/sp-pci.c      | 17 ++++++-----------
> >  drivers/crypto/ccp/sp-platform.c |  2 +-
> >  5 files changed, 15 insertions(+), 24 deletions(-)
> > 
> > diff --git a/drivers/crypto/ccp/ccp-dev.c b/drivers/crypto/ccp/ccp-dev.c
> > index 19ac509ed76e..8ae26d3cffff 100644
> > --- a/drivers/crypto/ccp/ccp-dev.c
> > +++ b/drivers/crypto/ccp/ccp-dev.c
> > @@ -531,8 +531,7 @@ int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
> >  	return len;
> >  }
> >  
> > -#ifdef CONFIG_PM
> > -bool ccp_queues_suspended(struct ccp_device *ccp)
> > +bool __maybe_unused ccp_queues_suspended(struct ccp_device *ccp)
> 
> These aren't static functions, so is the __maybe_unused necessary?
>
> (Same comment on the other non-static functions changed below)
> 
> >  {
> >  	unsigned int suspended = 0;
> >  	unsigned long flags;
> > @@ -549,7 +548,7 @@ bool ccp_queues_suspended(struct ccp_device *ccp)
> >  	return ccp->cmd_q_count == suspended;
> >  }
> >  
> > -int ccp_dev_suspend(struct sp_device *sp, pm_message_t state)
> > +int __maybe_unused ccp_dev_suspend(struct sp_device *sp)
> >  {
> >  	struct ccp_device *ccp = sp->ccp_data;
> >  	unsigned long flags;
> > @@ -577,7 +576,7 @@ int ccp_dev_suspend(struct sp_device *sp, pm_message_t state)
> >  	return 0;
> >  }
> >  
> > -int ccp_dev_resume(struct sp_device *sp)
> > +int __maybe_unused ccp_dev_resume(struct sp_device *sp)
> >  {
> >  	struct ccp_device *ccp = sp->ccp_data;
> >  	unsigned long flags;
> > @@ -601,7 +600,6 @@ int ccp_dev_resume(struct sp_device *sp)
> >  
> >  	return 0;
> >  }
> > -#endif
> >  
> >  int ccp_dev_init(struct sp_device *sp)
> >  {
> > diff --git a/drivers/crypto/ccp/sp-dev.c b/drivers/crypto/ccp/sp-dev.c
> > index ce42675d3274..6284a15e5047 100644
> > --- a/drivers/crypto/ccp/sp-dev.c
> > +++ b/drivers/crypto/ccp/sp-dev.c
> > @@ -211,13 +211,12 @@ void sp_destroy(struct sp_device *sp)
> >  	sp_del_device(sp);
> >  }
> >  
> > -#ifdef CONFIG_PM
> > -int sp_suspend(struct sp_device *sp, pm_message_t state)
> > +int sp_suspend(struct sp_device *sp)
> >  {
> >  	int ret;
> >  
> >  	if (sp->dev_vdata->ccp_vdata) {
> > -		ret = ccp_dev_suspend(sp, state);
> > +		ret = ccp_dev_suspend(sp);
> >  		if (ret)
> >  			return ret;
> >  	}
> > @@ -237,7 +236,6 @@ int sp_resume(struct sp_device *sp)
> >  
> >  	return 0;
> >  }
> > -#endif
> >  
> >  struct sp_device *sp_get_psp_master_device(void)
> >  {
> > diff --git a/drivers/crypto/ccp/sp-dev.h b/drivers/crypto/ccp/sp-dev.h
> > index f913f1494af9..0218d0670eee 100644
> > --- a/drivers/crypto/ccp/sp-dev.h
> > +++ b/drivers/crypto/ccp/sp-dev.h
> > @@ -119,7 +119,7 @@ int sp_init(struct sp_device *sp);
> >  void sp_destroy(struct sp_device *sp);
> >  struct sp_device *sp_get_master(void);
> >  
> > -int sp_suspend(struct sp_device *sp, pm_message_t state);
> > +int sp_suspend(struct sp_device *sp);
> >  int sp_resume(struct sp_device *sp);
> >  int sp_request_ccp_irq(struct sp_device *sp, irq_handler_t handler,
> >  		       const char *name, void *data);
> > @@ -134,7 +134,7 @@ struct sp_device *sp_get_psp_master_device(void);
> >  int ccp_dev_init(struct sp_device *sp);
> >  void ccp_dev_destroy(struct sp_device *sp);
> >  
> > -int ccp_dev_suspend(struct sp_device *sp, pm_message_t state);
> > +int ccp_dev_suspend(struct sp_device *sp);
> >  int ccp_dev_resume(struct sp_device *sp);
> >  
> >  #else	/* !CONFIG_CRYPTO_DEV_SP_CCP */
> > @@ -145,7 +145,7 @@ static inline int ccp_dev_init(struct sp_device *sp)
> >  }
> >  static inline void ccp_dev_destroy(struct sp_device *sp) { }
> >  
> > -static inline int ccp_dev_suspend(struct sp_device *sp, pm_message_t state)
> > +static inline int ccp_dev_suspend(struct sp_device *sp)
> >  {
> >  	return 0;
> >  }
> > diff --git a/drivers/crypto/ccp/sp-pci.c b/drivers/crypto/ccp/sp-pci.c
> > index cb6cb47053f4..f471dbaef1fb 100644
> > --- a/drivers/crypto/ccp/sp-pci.c
> > +++ b/drivers/crypto/ccp/sp-pci.c
> > @@ -252,23 +252,19 @@ static void sp_pci_remove(struct pci_dev *pdev)
> >  	sp_free_irqs(sp);
> >  }
> >  
> > -#ifdef CONFIG_PM
> > -static int sp_pci_suspend(struct pci_dev *pdev, pm_message_t state)
> > +static int __maybe_unused sp_pci_suspend(struct device *dev)
> >  {
> > -	struct device *dev = &pdev->dev;
> >  	struct sp_device *sp = dev_get_drvdata(dev);
> >  
> > -	return sp_suspend(sp, state);
> > +	return sp_suspend(sp);
> >  }
> >  
> > -static int sp_pci_resume(struct pci_dev *pdev)
> > +static int __maybe_unused sp_pci_resume(struct device *dev)
> >  {
> > -	struct device *dev = &pdev->dev;
> >  	struct sp_device *sp = dev_get_drvdata(dev);
> >  
> >  	return sp_resume(sp);
> >  }
> > -#endif
> >  
> >  #ifdef CONFIG_CRYPTO_DEV_SP_PSP
> >  static const struct sev_vdata sevv1 = {
> > @@ -365,15 +361,14 @@ 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 struct pci_driver sp_pci_driver = {
> >  	.name = "ccp",
> >  	.id_table = sp_pci_table,
> >  	.probe = sp_pci_probe,
> >  	.remove = sp_pci_remove,
> > -#ifdef CONFIG_PM
> > -	.suspend = sp_pci_suspend,
> > -	.resume = sp_pci_resume,
> > -#endif
> > +	.driver.pm = &sp_pci_pm_ops,
> >  };
> >  
> >  int sp_pci_init(void)
> > diff --git a/drivers/crypto/ccp/sp-platform.c b/drivers/crypto/ccp/sp-platform.c
> > index 831aac1393a2..9dba52fbee99 100644
> > --- a/drivers/crypto/ccp/sp-platform.c
> > +++ b/drivers/crypto/ccp/sp-platform.c
> 
> This file use the same "#ifdef CONFIG_PM" to define the suspend and resume
> functions (see sp_platform_driver variable). Doesn't that need to be
> updated similar to sp-pci.c? Not sure how this compile tested successfully
> unless your kernel config didn't have CONFIG_PM defined?
I am not sure but my .config file has "CONFIG_PM=y"

The motive is update PM of sp-pci. Months ago, we decided to remove
"#ifdef CONFIG_PM" container and mark the callbacks as __maybe_unused.
Hence, I did similar changes to all files on which sp-pci is dependent.

This caused change in function defintion and declaration of sp_suspend().

sp-pci is not depended upon sp-platform. sp-platform was modified only because
it also invoked sp_suspend() which got modified.

Thus, I didn't made any other changes to sp-platofrm.

Thanks
Vaibhav Gupta
> 
> Thanks,
> Tom
> 
> > @@ -207,7 +207,7 @@ static int sp_platform_suspend(struct platform_device *pdev,
> >  	struct device *dev = &pdev->dev;
> >  	struct sp_device *sp = dev_get_drvdata(dev);
> >  
> > -	return sp_suspend(sp, state);
> > +	return sp_suspend(sp);
> >  }
> >  
> >  static int sp_platform_resume(struct platform_device *pdev)
> >