diff mbox series

[29/37] PCI/MSI: Use __msi_get_virq() in pci_get_vector()

Message ID 20211126230525.660206325@linutronix.de (mailing list archive)
State New, archived
Headers show
Series genirq/msi, PCI/MSI: Spring cleaning - Part 2 | expand

Commit Message

Thomas Gleixner Nov. 27, 2021, 1:20 a.m. UTC 
Use __msi_get_vector() and handle the return values to be compatible.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/pci/msi/msi.c |   25 +++++--------------------
 1 file changed, 5 insertions(+), 20 deletions(-)

Comments

Marc Zyngier Nov. 28, 2021, 7:37 p.m. UTC | #1 
On Sat, 27 Nov 2021 01:22:03 +0000,
Thomas Gleixner <tglx@linutronix.de> wrote:
> 
> Use __msi_get_vector() and handle the return values to be compatible.
> 
> No functional change intended.

You wish ;-).

[   15.779540] pcieport 0001:00:01.0: AER: request AER IRQ -22 failed

Notice how amusing the IRQ number is?

> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
>  drivers/pci/msi/msi.c |   25 +++++--------------------
>  1 file changed, 5 insertions(+), 20 deletions(-)
> 
> --- a/drivers/pci/msi/msi.c
> +++ b/drivers/pci/msi/msi.c
> @@ -1023,28 +1023,13 @@ EXPORT_SYMBOL(pci_free_irq_vectors);
>   */
>  int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
>  {
> -	if (dev->msix_enabled) {
> -		struct msi_desc *entry;
> +	int irq = __msi_get_virq(&dev->dev, nr);
>  
> -		for_each_pci_msi_entry(entry, dev) {
> -			if (entry->msi_index == nr)
> -				return entry->irq;
> -		}
> -		WARN_ON_ONCE(1);
> -		return -EINVAL;
> +	switch (irq) {
> +	case -ENODEV: return !nr ? dev->irq : -EINVAL;
> +	case -ENOENT: return -EINVAL;
>  	}
> -
> -	if (dev->msi_enabled) {
> -		struct msi_desc *entry = first_pci_msi_entry(dev);
> -
> -		if (WARN_ON_ONCE(nr >= entry->nvec_used))
> -			return -EINVAL;
> -	} else {
> -		if (WARN_ON_ONCE(nr > 0))
> -			return -EINVAL;
> -	}
> -
> -	return dev->irq + nr;
> +	return irq;
>  }
>  EXPORT_SYMBOL(pci_irq_vector);

I worked around it with the hack below, but I doubt this is the real
thing. portdrv_core.c does complicated things, and I don't completely
understand its logic.

	M.

diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 1f72bc734226..b15278a5fb4b 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -1092,8 +1092,9 @@ int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
 	int irq = __msi_get_virq(&dev->dev, nr);
 
 	switch (irq) {
-	case -ENODEV: return !nr ? dev->irq : -EINVAL;
-	case -ENOENT: return -EINVAL;
+	case -ENOENT:
+	case -ENODEV:
+		return !nr ? dev->irq : -EINVAL;
 	}
 	return irq;
 }
Thomas Gleixner Nov. 28, 2021, 9 p.m. UTC | #2 
On Sun, Nov 28 2021 at 19:37, Marc Zyngier wrote:
> On Sat, 27 Nov 2021 01:22:03 +0000,
> Thomas Gleixner <tglx@linutronix.de> wrote:
>
> I worked around it with the hack below, but I doubt this is the real
> thing. portdrv_core.c does complicated things, and I don't completely
> understand its logic.
>
> 	M.
>
> diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
> index 1f72bc734226..b15278a5fb4b 100644
> --- a/drivers/pci/msi/msi.c
> +++ b/drivers/pci/msi/msi.c
> @@ -1092,8 +1092,9 @@ int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
>  	int irq = __msi_get_virq(&dev->dev, nr);
>  
>  	switch (irq) {
> -	case -ENODEV: return !nr ? dev->irq : -EINVAL;
> -	case -ENOENT: return -EINVAL;
> +	case -ENOENT:
> +	case -ENODEV:
> +		return !nr ? dev->irq : -EINVAL;

Hrm. ENODEV is returned when dev->msi.data == NULL, ENOENT when there is
no MSI entry. But yes, that goes south when the device tried to enable
MSI[X} and then ended up with INTx. It still has dev->msi.data, which
causes it to return -ENOENT, which makes the above go belly up.

Moo, what was I thinking?

Thanks,

        tglx
---
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -1032,13 +1032,13 @@ EXPORT_SYMBOL(pci_free_irq_vectors);
  */
 int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
 {
-	int irq = __msi_get_virq(&dev->dev, nr);
+	unsigned int irq;
 
-	switch (irq) {
-	case -ENODEV: return !nr ? dev->irq : -EINVAL;
-	case -ENOENT: return -EINVAL;
-	}
-	return irq;
+	if (!dev->msi_enabled && !dev->msix_enabled)
+		return !nr ? dev->irq : -EINVAL;
+
+	irq = msi_get_virq(&dev->dev, nr);
+	return irq ? irq : -EINVAL;
 }
 EXPORT_SYMBOL(pci_irq_vector);
 
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -169,21 +169,7 @@ static inline bool msi_device_has_proper
 }
 #endif
 
-int __msi_get_virq(struct device *dev, unsigned int index);
-
-/**
- * msi_get_virq - Return Linux interrupt number of a MSI interrupt
- * @dev:	Device to operate on
- * @index:	MSI interrupt index to look for (0-based)
- *
- * Return: The Linux interrupt number on success (> 0), 0 if not found
- */
-static inline unsigned int msi_get_virq(struct device *dev, unsigned int index)
-{
-	int ret = __msi_get_virq(dev, index);
-
-	return ret < 0 ? 0 : ret;
-}
+unsigned int msi_get_virq(struct device *dev, unsigned int index);
 
 /* Helpers to hide struct msi_desc implementation details */
 #define msi_desc_to_dev(desc)		((desc)->dev)
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -119,21 +119,19 @@ int msi_setup_device_data(struct device
 }
 
 /**
- * __msi_get_virq - Return Linux interrupt number of a MSI interrupt
+ * msi_get_virq - Return Linux interrupt number of a MSI interrupt
  * @dev:	Device to operate on
  * @index:	MSI interrupt index to look for (0-based)
  *
- * Return: The Linux interrupt number on success (> 0)
- *	   -ENODEV when the device is not using MSI
- *	   -ENOENT if no such entry exists
+ * Return: The Linux interrupt number on success (> 0), 0 if not found
  */
-int __msi_get_virq(struct device *dev, unsigned int index)
+unsigned int msi_get_virq(struct device *dev, unsigned int index)
 {
 	struct msi_desc *desc;
 	bool pcimsi;
 
 	if (!dev->msi.data)
-		return -ENODEV;
+		return 0;
 
 	pcimsi = msi_device_has_property(dev, MSI_PROP_PCI_MSI);
 
@@ -152,9 +150,9 @@ int __msi_get_virq(struct device *dev, u
 		if (desc->msi_index == index)
 			return desc->irq;
 	}
-	return -ENOENT;
+	return 0;
 }
-EXPORT_SYMBOL_GPL(__msi_get_virq);
+EXPORT_SYMBOL_GPL(msi_get_virq);
 
 #ifdef CONFIG_SYSFS
 static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
diff mbox series

Patch

--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -1023,28 +1023,13 @@  EXPORT_SYMBOL(pci_free_irq_vectors);
  */
 int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
 {
-	if (dev->msix_enabled) {
-		struct msi_desc *entry;
+	int irq = __msi_get_virq(&dev->dev, nr);
 
-		for_each_pci_msi_entry(entry, dev) {
-			if (entry->msi_index == nr)
-				return entry->irq;
-		}
-		WARN_ON_ONCE(1);
-		return -EINVAL;
+	switch (irq) {
+	case -ENODEV: return !nr ? dev->irq : -EINVAL;
+	case -ENOENT: return -EINVAL;
 	}
-
-	if (dev->msi_enabled) {
-		struct msi_desc *entry = first_pci_msi_entry(dev);
-
-		if (WARN_ON_ONCE(nr >= entry->nvec_used))
-			return -EINVAL;
-	} else {
-		if (WARN_ON_ONCE(nr > 0))
-			return -EINVAL;
-	}
-
-	return dev->irq + nr;
+	return irq;
 }
 EXPORT_SYMBOL(pci_irq_vector);