diff mbox series

[V1,mlx5-next,01/13] PCI/IOV: Provide internal VF index

Message ID 20211013094707.163054-2-yishaih@nvidia.com (mailing list archive)
State New, archived
Headers show
Series Add mlx5 live migration driver | expand

Commit Message

Yishai Hadas Oct. 13, 2021, 9:46 a.m. UTC 
From: Jason Gunthorpe <jgg@nvidia.com>

The PCI core uses the VF index internally, often called the vf_id,
during the setup of the VF, eg pci_iov_add_virtfn().

This index is needed for device drivers that implement live migration
for their internal operations that configure/control their VFs.

Specifically, mlx5_vfio_pci driver that is introduced in coming patches
from this series needs it and not the bus/device/function which is
exposed today.

Add pci_iov_vf_id() which computes the vf_id by reversing the math that
was used to create the bus/device/function.

Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 drivers/pci/iov.c   | 14 ++++++++++++++
 include/linux/pci.h |  8 +++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

Comments

Bjorn Helgaas Oct. 13, 2021, 6:14 p.m. UTC | #1 
On Wed, Oct 13, 2021 at 12:46:55PM +0300, Yishai Hadas wrote:
> From: Jason Gunthorpe <jgg@nvidia.com>
> 
> The PCI core uses the VF index internally, often called the vf_id,
> during the setup of the VF, eg pci_iov_add_virtfn().
> 
> This index is needed for device drivers that implement live migration
> for their internal operations that configure/control their VFs.
> 
> Specifically, mlx5_vfio_pci driver that is introduced in coming patches
> from this series needs it and not the bus/device/function which is
> exposed today.
> 
> Add pci_iov_vf_id() which computes the vf_id by reversing the math that
> was used to create the bus/device/function.
> 
> Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>

I already acked this:

  https://lore.kernel.org/r/20210922215930.GA231505@bhelgaas

Saves me time if you carry the ack so I don't have to look at this
again.  But since I *am* looking at it again, I think it's nice if the
subject line includes the actual interface you're adding, e.g.,

  PCI/IOV: Add pci_iov_vf_id() to get VF index

> ---
>  drivers/pci/iov.c   | 14 ++++++++++++++
>  include/linux/pci.h |  8 +++++++-
>  2 files changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index dafdc652fcd0..e7751fa3fe0b 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -33,6 +33,20 @@ int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
>  }
>  EXPORT_SYMBOL_GPL(pci_iov_virtfn_devfn);
>  
> +int pci_iov_vf_id(struct pci_dev *dev)
> +{
> +	struct pci_dev *pf;
> +
> +	if (!dev->is_virtfn)
> +		return -EINVAL;
> +
> +	pf = pci_physfn(dev);
> +	return (((dev->bus->number << 8) + dev->devfn) -
> +		((pf->bus->number << 8) + pf->devfn + pf->sriov->offset)) /
> +	       pf->sriov->stride;
> +}
> +EXPORT_SYMBOL_GPL(pci_iov_vf_id);
> +
>  /*
>   * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
>   * change when NumVFs changes.
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index cd8aa6fce204..2337512e67f0 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -2153,7 +2153,7 @@ void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar);
>  #ifdef CONFIG_PCI_IOV
>  int pci_iov_virtfn_bus(struct pci_dev *dev, int id);
>  int pci_iov_virtfn_devfn(struct pci_dev *dev, int id);
> -
> +int pci_iov_vf_id(struct pci_dev *dev);
>  int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
>  void pci_disable_sriov(struct pci_dev *dev);
>  
> @@ -2181,6 +2181,12 @@ static inline int pci_iov_virtfn_devfn(struct pci_dev *dev, int id)
>  {
>  	return -ENOSYS;
>  }
> +
> +static inline int pci_iov_vf_id(struct pci_dev *dev)
> +{
> +	return -ENOSYS;
> +}
> +
>  static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
>  { return -ENODEV; }
>  
> -- 
> 2.18.1
>
Yishai Hadas Oct. 14, 2021, 9:08 a.m. UTC | #2 
On 10/13/2021 9:14 PM, Bjorn Helgaas wrote:
> On Wed, Oct 13, 2021 at 12:46:55PM +0300, Yishai Hadas wrote:
>> From: Jason Gunthorpe <jgg@nvidia.com>
>>
>> The PCI core uses the VF index internally, often called the vf_id,
>> during the setup of the VF, eg pci_iov_add_virtfn().
>>
>> This index is needed for device drivers that implement live migration
>> for their internal operations that configure/control their VFs.
>>
>> Specifically, mlx5_vfio_pci driver that is introduced in coming patches
>> from this series needs it and not the bus/device/function which is
>> exposed today.
>>
>> Add pci_iov_vf_id() which computes the vf_id by reversing the math that
>> was used to create the bus/device/function.
>>
>> Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
>> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
>> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
> I already acked this:
>
>    https://lore.kernel.org/r/20210922215930.GA231505@bhelgaas
>
> Saves me time if you carry the ack so I don't have to look at this
> again.  But since I *am* looking at it again, I think it's nice if the
> subject line includes the actual interface you're adding, e.g.,
>
>    PCI/IOV: Add pci_iov_vf_id() to get VF index


Sure, will change as part of V2 and add your Acked-by.

>> ---
>>   drivers/pci/iov.c   | 14 ++++++++++++++
>>   include/linux/pci.h |  8 +++++++-
>>   2 files changed, 21 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
>> index dafdc652fcd0..e7751fa3fe0b 100644
>> --- a/drivers/pci/iov.c
>> +++ b/drivers/pci/iov.c
>> @@ -33,6 +33,20 @@ int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
>>   }
>>   EXPORT_SYMBOL_GPL(pci_iov_virtfn_devfn);
>>   
>> +int pci_iov_vf_id(struct pci_dev *dev)
>> +{
>> +	struct pci_dev *pf;
>> +
>> +	if (!dev->is_virtfn)
>> +		return -EINVAL;
>> +
>> +	pf = pci_physfn(dev);
>> +	return (((dev->bus->number << 8) + dev->devfn) -
>> +		((pf->bus->number << 8) + pf->devfn + pf->sriov->offset)) /
>> +	       pf->sriov->stride;
>> +}
>> +EXPORT_SYMBOL_GPL(pci_iov_vf_id);
>> +
>>   /*
>>    * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
>>    * change when NumVFs changes.
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index cd8aa6fce204..2337512e67f0 100644
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -2153,7 +2153,7 @@ void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar);
>>   #ifdef CONFIG_PCI_IOV
>>   int pci_iov_virtfn_bus(struct pci_dev *dev, int id);
>>   int pci_iov_virtfn_devfn(struct pci_dev *dev, int id);
>> -
>> +int pci_iov_vf_id(struct pci_dev *dev);
>>   int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
>>   void pci_disable_sriov(struct pci_dev *dev);
>>   
>> @@ -2181,6 +2181,12 @@ static inline int pci_iov_virtfn_devfn(struct pci_dev *dev, int id)
>>   {
>>   	return -ENOSYS;
>>   }
>> +
>> +static inline int pci_iov_vf_id(struct pci_dev *dev)
>> +{
>> +	return -ENOSYS;
>> +}
>> +
>>   static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
>>   { return -ENODEV; }
>>   
>> -- 
>> 2.18.1
>>
diff mbox series

Patch

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index dafdc652fcd0..e7751fa3fe0b 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -33,6 +33,20 @@  int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
 }
 EXPORT_SYMBOL_GPL(pci_iov_virtfn_devfn);
 
+int pci_iov_vf_id(struct pci_dev *dev)
+{
+	struct pci_dev *pf;
+
+	if (!dev->is_virtfn)
+		return -EINVAL;
+
+	pf = pci_physfn(dev);
+	return (((dev->bus->number << 8) + dev->devfn) -
+		((pf->bus->number << 8) + pf->devfn + pf->sriov->offset)) /
+	       pf->sriov->stride;
+}
+EXPORT_SYMBOL_GPL(pci_iov_vf_id);
+
 /*
  * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
  * change when NumVFs changes.
diff --git a/include/linux/pci.h b/include/linux/pci.h
index cd8aa6fce204..2337512e67f0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2153,7 +2153,7 @@  void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar);
 #ifdef CONFIG_PCI_IOV
 int pci_iov_virtfn_bus(struct pci_dev *dev, int id);
 int pci_iov_virtfn_devfn(struct pci_dev *dev, int id);
-
+int pci_iov_vf_id(struct pci_dev *dev);
 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
 void pci_disable_sriov(struct pci_dev *dev);
 
@@ -2181,6 +2181,12 @@  static inline int pci_iov_virtfn_devfn(struct pci_dev *dev, int id)
 {
 	return -ENOSYS;
 }
+
+static inline int pci_iov_vf_id(struct pci_dev *dev)
+{
+	return -ENOSYS;
+}
+
 static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 { return -ENODEV; }