[PATCH v3 2/4] PCI/AER: Factor out interrupt toggling into helpers

[PATCH v3 2/4] PCI/AER: Factor out interrupt toggling into helpers

[Kai-Heng Feng]

There are many places that enable and disable AER interrput, so move
them into helpers.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
v3:
 - Correct subject.

v2:
 - New patch.

 drivers/pci/pcie/aer.c | 45 +++++++++++++++++++++++++-----------------
 1 file changed, 27 insertions(+), 18 deletions(-)

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index f6c24ded134c..1420e1f27105 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1227,6 +1227,28 @@ static irqreturn_t aer_irq(int irq, void *context)
 	return IRQ_WAKE_THREAD;
 }
 
+static void aer_enable_irq(struct pci_dev *pdev)
+{
+	int aer = pdev->aer_cap;
+	u32 reg32;
+
+	/* Enable Root Port's interrupt in response to error messages */
+	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
+	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
+	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
+}
+
+static void aer_disable_irq(struct pci_dev *pdev)
+{
+	int aer = pdev->aer_cap;
+	u32 reg32;
+
+	/* Disable Root's interrupt in response to error messages */
+	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
+	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
+	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
+}
+
 /**
  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
  * @rpc: pointer to a Root Port data structure
@@ -1256,10 +1278,7 @@ static void aer_enable_rootport(struct aer_rpc *rpc)
 	pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, &reg32);
 	pci_write_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, reg32);
 
-	/* Enable Root Port's interrupt in response to error messages */
-	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
-	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
-	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
+	aer_enable_irq(pdev);
 }
 
 /**
@@ -1274,10 +1293,7 @@ static void aer_disable_rootport(struct aer_rpc *rpc)
 	int aer = pdev->aer_cap;
 	u32 reg32;
 
-	/* Disable Root's interrupt in response to error messages */
-	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
-	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
-	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
+	aer_disable_irq(pdev);
 
 	/* Clear Root's error status reg */
 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
@@ -1372,12 +1388,8 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 	 */
 	aer = root ? root->aer_cap : 0;
 
-	if ((host->native_aer || pcie_ports_native) && aer) {
-		/* Disable Root's interrupt in response to error messages */
-		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
-		reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
-		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
-	}
+	if ((host->native_aer || pcie_ports_native) && aer)
+		aer_disable_irq(root);
 
 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
 		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
@@ -1396,10 +1408,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, &reg32);
 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32);
 
-		/* Enable Root Port's interrupt in response to error messages */
-		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
-		reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
-		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
+		aer_enable_irq(root);
 	}
 
 	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
-- 
2.34.1

[PATCH v3 3/4] PCI/AER: Disable AER interrupt on suspend

[Kai-Heng Feng]

PCIe service that shares IRQ with PME may cause spurious wakeup on
system suspend.

PCIe Base Spec 5.0, section 5.2 "Link State Power Management" states
that TLP and DLLP transmission is disabled for a Link in L2/L3 Ready
(D3hot), L2 (D3cold with aux power) and L3 (D3cold), so we don't lose
much here to disable AER during system suspend.

This is very similar to previous attempts to suspend AER and DPC [1],
but with a different reason.

[1] https://lore.kernel.org/linux-pci/20220408153159.106741-1-kai.heng.feng@canonical.com/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216295

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
v3:
 - No change.

v2:
 - Only disable AER IRQ.
 - No more check on PME IRQ#.
 - Use helper.

 drivers/pci/pcie/aer.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 1420e1f27105..9c07fdbeb52d 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1356,6 +1356,26 @@ static int aer_probe(struct pcie_device *dev)
 	return 0;
 }
 
+static int aer_suspend(struct pcie_device *dev)
+{
+	struct aer_rpc *rpc = get_service_data(dev);
+	struct pci_dev *pdev = rpc->rpd;
+
+	aer_disable_irq(pdev);
+
+	return 0;
+}
+
+static int aer_resume(struct pcie_device *dev)
+{
+	struct aer_rpc *rpc = get_service_data(dev);
+	struct pci_dev *pdev = rpc->rpd;
+
+	aer_enable_irq(pdev);
+
+	return 0;
+}
+
 /**
  * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
  * @dev: pointer to Root Port, RCEC, or RCiEP
@@ -1420,6 +1440,8 @@ static struct pcie_port_service_driver aerdriver = {
 	.service	= PCIE_PORT_SERVICE_AER,
 
 	.probe		= aer_probe,
+	.suspend	= aer_suspend,
+	.resume		= aer_resume,
 	.remove		= aer_remove,
 };
 
-- 
2.34.1

[PATCH v3 4/4] PCI/DPC: Disable DPC interrupt during suspend

[Kai-Heng Feng]

PCIe service that shares IRQ with PME may cause spurious wakeup on
system suspend.

Since AER is conditionally disabled in previous patch, also apply the
same logic to disable DPC which depends on AER to work.

PCIe Base Spec 5.0, section 5.2 "Link State Power Management" states
that TLP and DLLP transmission is disabled for a Link in L2/L3 Ready
(D3hot), L2 (D3cold with aux power) and L3 (D3cold), so we don't lose
much here to disable DPC during system suspend.

This is very similar to previous attempts to suspend AER and DPC [1],
but with a different reason.

[1] https://lore.kernel.org/linux-pci/20220408153159.106741-1-kai.heng.feng@canonical.com/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216295

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
v3:
 - No change.

v2:
 - Only disable DPC IRQ.
 - No more check on PME IRQ#.

 drivers/pci/pcie/dpc.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index a5d7c69b764e..98bdefde6df1 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -385,6 +385,30 @@ static int dpc_probe(struct pcie_device *dev)
 	return status;
 }
 
+static int dpc_suspend(struct pcie_device *dev)
+{
+	struct pci_dev *pdev = dev->port;
+	u16 ctl;
+
+	pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, &ctl);
+	ctl &= ~PCI_EXP_DPC_CTL_INT_EN;
+	pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, ctl);
+
+	return 0;
+}
+
+static int dpc_resume(struct pcie_device *dev)
+{
+	struct pci_dev *pdev = dev->port;
+	u16 ctl;
+
+	pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, &ctl);
+	ctl |= PCI_EXP_DPC_CTL_INT_EN;
+	pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, ctl);
+
+	return 0;
+}
+
 static void dpc_remove(struct pcie_device *dev)
 {
 	struct pci_dev *pdev = dev->port;
@@ -400,6 +424,8 @@ static struct pcie_port_service_driver dpcdriver = {
 	.port_type	= PCIE_ANY_PORT,
 	.service	= PCIE_PORT_SERVICE_DPC,
 	.probe		= dpc_probe,
+	.suspend	= dpc_suspend,
+	.resume		= dpc_resume,
 	.remove		= dpc_remove,
 };
 
-- 
2.34.1

Re: [PATCH v3 2/4] PCI/AER: Factor out interrupt toggling into helpers

[Mika Westerberg]

On Thu, Apr 20, 2023 at 08:59:38PM +0800, Kai-Heng Feng wrote:
> There are many places that enable and disable AER interrput, so move
> them into helpers.
> 
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Re: [PATCH v3 2/4] PCI/AER: Factor out interrupt toggling into helpers

[Sathyanarayanan Kuppuswamy]

On 4/20/23 5:59 AM, Kai-Heng Feng wrote:
> There are many places that enable and disable AER interrput, so move
> them into helpers.

Add "No functional changes intended"

> 
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---

Looks good to me.

Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

> v3:
>  - Correct subject.
> 
> v2:
>  - New patch.
> 
>  drivers/pci/pcie/aer.c | 45 +++++++++++++++++++++++++-----------------
>  1 file changed, 27 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> index f6c24ded134c..1420e1f27105 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -1227,6 +1227,28 @@ static irqreturn_t aer_irq(int irq, void *context)
>  	return IRQ_WAKE_THREAD;
>  }
>  
> +static void aer_enable_irq(struct pci_dev *pdev)
> +{
> +	int aer = pdev->aer_cap;
> +	u32 reg32;
> +
> +	/* Enable Root Port's interrupt in response to error messages */
> +	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
> +	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
> +	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
> +}
> +
> +static void aer_disable_irq(struct pci_dev *pdev)
> +{
> +	int aer = pdev->aer_cap;
> +	u32 reg32;
> +
> +	/* Disable Root's interrupt in response to error messages */
> +	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
> +	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
> +	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
> +}
> +
>  /**
>   * aer_enable_rootport - enable Root Port's interrupts when receiving messages
>   * @rpc: pointer to a Root Port data structure
> @@ -1256,10 +1278,7 @@ static void aer_enable_rootport(struct aer_rpc *rpc)
>  	pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, &reg32);
>  	pci_write_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, reg32);
>  
> -	/* Enable Root Port's interrupt in response to error messages */
> -	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
> -	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
> -	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
> +	aer_enable_irq(pdev);
>  }
>  
>  /**
> @@ -1274,10 +1293,7 @@ static void aer_disable_rootport(struct aer_rpc *rpc)
>  	int aer = pdev->aer_cap;
>  	u32 reg32;
>  
> -	/* Disable Root's interrupt in response to error messages */
> -	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
> -	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
> -	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
> +	aer_disable_irq(pdev);
>  
>  	/* Clear Root's error status reg */
>  	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
> @@ -1372,12 +1388,8 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
>  	 */
>  	aer = root ? root->aer_cap : 0;
>  
> -	if ((host->native_aer || pcie_ports_native) && aer) {
> -		/* Disable Root's interrupt in response to error messages */
> -		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
> -		reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
> -		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
> -	}
> +	if ((host->native_aer || pcie_ports_native) && aer)
> +		aer_disable_irq(root);
>  
>  	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
>  		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
> @@ -1396,10 +1408,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
>  		pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, &reg32);
>  		pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32);
>  
> -		/* Enable Root Port's interrupt in response to error messages */
> -		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
> -		reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
> -		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
> +		aer_enable_irq(root);
>  	}
>  
>  	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer

Re: [PATCH v3 3/4] PCI/AER: Disable AER interrupt on suspend

[Sathyanarayanan Kuppuswamy]

On 4/20/23 5:59 AM, Kai-Heng Feng wrote:
> PCIe service that shares IRQ with PME may cause spurious wakeup on
> system suspend.
> 
> PCIe Base Spec 5.0, section 5.2 "Link State Power Management" states
> that TLP and DLLP transmission is disabled for a Link in L2/L3 Ready
> (D3hot), L2 (D3cold with aux power) and L3 (D3cold), so we don't lose
> much here to disable AER during system suspend.
> 
> This is very similar to previous attempts to suspend AER and DPC [1],
> but with a different reason.
> 
> [1] https://lore.kernel.org/linux-pci/20220408153159.106741-1-kai.heng.feng@canonical.com/
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216295
> 
> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---

In Patch #1, you skip clearing AER errors in the resume path, right? So if we disable
interrupts here, will AER driver not be notified on resume path error?

> v3:
>  - No change.
> 
> v2:
>  - Only disable AER IRQ.
>  - No more check on PME IRQ#.
>  - Use helper.
> 
>  drivers/pci/pcie/aer.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> index 1420e1f27105..9c07fdbeb52d 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -1356,6 +1356,26 @@ static int aer_probe(struct pcie_device *dev)
>  	return 0;
>  }
>  
> +static int aer_suspend(struct pcie_device *dev)
> +{
> +	struct aer_rpc *rpc = get_service_data(dev);
> +	struct pci_dev *pdev = rpc->rpd;
> +
> +	aer_disable_irq(pdev);
> +
> +	return 0;
> +}
> +
> +static int aer_resume(struct pcie_device *dev)
> +{
> +	struct aer_rpc *rpc = get_service_data(dev);
> +	struct pci_dev *pdev = rpc->rpd;
> +
> +	aer_enable_irq(pdev);
> +
> +	return 0;
> +}
> +
>  /**
>   * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
>   * @dev: pointer to Root Port, RCEC, or RCiEP
> @@ -1420,6 +1440,8 @@ static struct pcie_port_service_driver aerdriver = {
>  	.service	= PCIE_PORT_SERVICE_AER,
>  
>  	.probe		= aer_probe,
> +	.suspend	= aer_suspend,
> +	.resume		= aer_resume,
>  	.remove		= aer_remove,
>  };
>  

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer

Re: [PATCH v3 3/4] PCI/AER: Disable AER interrupt on suspend

[Kai-Heng Feng]

On Thu, Apr 20, 2023 at 10:53 PM Sathyanarayanan Kuppuswamy
<sathyanarayanan.kuppuswamy@linux.intel.com> wrote:
>
>
>
> On 4/20/23 5:59 AM, Kai-Heng Feng wrote:
> > PCIe service that shares IRQ with PME may cause spurious wakeup on
> > system suspend.
> >
> > PCIe Base Spec 5.0, section 5.2 "Link State Power Management" states
> > that TLP and DLLP transmission is disabled for a Link in L2/L3 Ready
> > (D3hot), L2 (D3cold with aux power) and L3 (D3cold), so we don't lose
> > much here to disable AER during system suspend.
> >
> > This is very similar to previous attempts to suspend AER and DPC [1],
> > but with a different reason.
> >
> > [1] https://lore.kernel.org/linux-pci/20220408153159.106741-1-kai.heng.feng@canonical.com/
> > Link: https://bugzilla.kernel.org/show_bug.cgi?id=216295
> >
> > Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > ---
>
> In Patch #1, you skip clearing AER errors in the resume path, right? So if we disable
> interrupts here, will AER driver not be notified on resume path error?

I agree the driver should report the error via aer_isr_one_error() on
resume path.
But on the system I am using (Intel ADL PCH), once the interrupt is
disabled, PCI_ERR_ROOT_STATUS doesn't record error anymore.
Not sure if it's intended though.

Kai-Heng

>
> > v3:
> >  - No change.
> >
> > v2:
> >  - Only disable AER IRQ.
> >  - No more check on PME IRQ#.
> >  - Use helper.
> >
> >  drivers/pci/pcie/aer.c | 22 ++++++++++++++++++++++
> >  1 file changed, 22 insertions(+)
> >
> > diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> > index 1420e1f27105..9c07fdbeb52d 100644
> > --- a/drivers/pci/pcie/aer.c
> > +++ b/drivers/pci/pcie/aer.c
> > @@ -1356,6 +1356,26 @@ static int aer_probe(struct pcie_device *dev)
> >       return 0;
> >  }
> >
> > +static int aer_suspend(struct pcie_device *dev)
> > +{
> > +     struct aer_rpc *rpc = get_service_data(dev);
> > +     struct pci_dev *pdev = rpc->rpd;
> > +
> > +     aer_disable_irq(pdev);
> > +
> > +     return 0;
> > +}
> > +
> > +static int aer_resume(struct pcie_device *dev)
> > +{
> > +     struct aer_rpc *rpc = get_service_data(dev);
> > +     struct pci_dev *pdev = rpc->rpd;
> > +
> > +     aer_enable_irq(pdev);
> > +
> > +     return 0;
> > +}
> > +
> >  /**
> >   * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
> >   * @dev: pointer to Root Port, RCEC, or RCiEP
> > @@ -1420,6 +1440,8 @@ static struct pcie_port_service_driver aerdriver = {
> >       .service        = PCIE_PORT_SERVICE_AER,
> >
> >       .probe          = aer_probe,
> > +     .suspend        = aer_suspend,
> > +     .resume         = aer_resume,
> >       .remove         = aer_remove,
> >  };
> >
>
> --
> Sathyanarayanan Kuppuswamy
> Linux Kernel Developer