diff mbox

[V9,01/18] PCI/IOV: Export interface for retrieve VF's BDF

Message ID 1414942894-17034-2-git-send-email-weiyang@linux.vnet.ibm.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Wei Yang Nov. 2, 2014, 3:41 p.m. UTC 
When implementing the SR-IOV on PowerNV platform, some resource reservation is
needed for VFs which don't exist at the bootup stage. To do the match between
resources and VFs, the code need to get the VF's BDF in advance.

In this patch, it exports the interface to retrieve VF's BDF:
   * Make the virtfn_bus as an interface
   * Make the virtfn_devfn as an interface
   * Rename them with more specific name
   * Code cleanup in pci_sriov_resource_alignment()

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
---
 drivers/pci/iov.c   |   22 +++++++++++++---------
 include/linux/pci.h |   11 +++++++++++
 2 files changed, 24 insertions(+), 9 deletions(-)

Comments

Bjorn Helgaas Nov. 19, 2014, 11:35 p.m. UTC | #1 
On Sun, Nov 02, 2014 at 11:41:17PM +0800, Wei Yang wrote:
> When implementing the SR-IOV on PowerNV platform, some resource reservation is
> needed for VFs which don't exist at the bootup stage. To do the match between
> resources and VFs, the code need to get the VF's BDF in advance.
> 
> In this patch, it exports the interface to retrieve VF's BDF:
>    * Make the virtfn_bus as an interface
>    * Make the virtfn_devfn as an interface
>    * Rename them with more specific name
>    * Code cleanup in pci_sriov_resource_alignment()
> 
> Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
> ---
>  drivers/pci/iov.c   |   22 +++++++++++++---------
>  include/linux/pci.h |   11 +++++++++++
>  2 files changed, 24 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index 4d109c0..5e8091b 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -19,14 +19,18 @@
>  
>  #define VIRTFN_ID_LEN	16
>  
> -static inline u8 virtfn_bus(struct pci_dev *dev, int id)
> +int pci_iov_virtfn_bus(struct pci_dev *dev, int id)
>  {
> +	if (!dev->is_physfn)
> +		return -EINVAL;
>  	return dev->bus->number + ((dev->devfn + dev->sriov->offset +
>  				    dev->sriov->stride * id) >> 8);
>  }
>  
> -static inline u8 virtfn_devfn(struct pci_dev *dev, int id)
> +int pci_iov_virtfn_devfn(struct pci_dev *dev, int id)
>  {
> +	if (!dev->is_physfn)
> +		return -EINVAL;
>  	return (dev->devfn + dev->sriov->offset +
>  		dev->sriov->stride * id) & 0xff;
>  }

I'm concerned about exporting these because they depend on First VF Offset
and VF Stride from the SR-IOV Capability, and those values change when the
ARI Capability Hierarchy setting or the NumVFs setting change (SR-IOV spec
sec 3.3.9, 3.3.10).  The caller doesn't necessarily know about this
connection and may not be able to deal with the change.

I outlined one possible problem with this in patch 08/18.

Bjorn
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diff mbox

Patch

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 4d109c0..5e8091b 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -19,14 +19,18 @@ 
 
 #define VIRTFN_ID_LEN	16
 
-static inline u8 virtfn_bus(struct pci_dev *dev, int id)
+int pci_iov_virtfn_bus(struct pci_dev *dev, int id)
 {
+	if (!dev->is_physfn)
+		return -EINVAL;
 	return dev->bus->number + ((dev->devfn + dev->sriov->offset +
 				    dev->sriov->stride * id) >> 8);
 }
 
-static inline u8 virtfn_devfn(struct pci_dev *dev, int id)
+int pci_iov_virtfn_devfn(struct pci_dev *dev, int id)
 {
+	if (!dev->is_physfn)
+		return -EINVAL;
 	return (dev->devfn + dev->sriov->offset +
 		dev->sriov->stride * id) & 0xff;
 }
@@ -69,7 +73,7 @@  static int virtfn_add(struct pci_dev *dev, int id, int reset)
 	struct pci_bus *bus;
 
 	mutex_lock(&iov->dev->sriov->lock);
-	bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
+	bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
 	if (!bus)
 		goto failed;
 
@@ -77,7 +81,7 @@  static int virtfn_add(struct pci_dev *dev, int id, int reset)
 	if (!virtfn)
 		goto failed0;
 
-	virtfn->devfn = virtfn_devfn(dev, id);
+	virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
 	virtfn->vendor = dev->vendor;
 	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
 	pci_setup_device(virtfn);
@@ -140,8 +144,8 @@  static void virtfn_remove(struct pci_dev *dev, int id, int reset)
 	struct pci_sriov *iov = dev->sriov;
 
 	virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
-					     virtfn_bus(dev, id),
-					     virtfn_devfn(dev, id));
+					     pci_iov_virtfn_bus(dev, id),
+					     pci_iov_virtfn_devfn(dev, id));
 	if (!virtfn)
 		return;
 
@@ -216,7 +220,7 @@  static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 	iov->offset = offset;
 	iov->stride = stride;
 
-	if (virtfn_bus(dev, nr_virtfn - 1) > dev->bus->busn_res.end) {
+	if (pci_iov_virtfn_bus(dev, nr_virtfn - 1) > dev->bus->busn_res.end) {
 		dev_err(&dev->dev, "SR-IOV: bus number out of range\n");
 		return -ENOMEM;
 	}
@@ -516,7 +520,7 @@  resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 	if (!reg)
 		return 0;
 
-	 __pci_read_base(dev, type, &tmp, reg);
+	__pci_read_base(dev, type, &tmp, reg);
 	return resource_alignment(&tmp);
 }
 
@@ -546,7 +550,7 @@  int pci_iov_bus_range(struct pci_bus *bus)
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		if (!dev->is_physfn)
 			continue;
-		busnr = virtfn_bus(dev, dev->sriov->total_VFs - 1);
+		busnr = pci_iov_virtfn_bus(dev, dev->sriov->total_VFs - 1);
 		if (busnr > max)
 			max = busnr;
 	}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 5be8db4..3ed7c66 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1654,6 +1654,9 @@  int pci_ext_cfg_avail(void);
 void __iomem *pci_ioremap_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_enable_sriov(struct pci_dev *dev, int nr_virtfn);
 void pci_disable_sriov(struct pci_dev *dev);
 int pci_num_vf(struct pci_dev *dev);
@@ -1661,6 +1664,14 @@  int pci_vfs_assigned(struct pci_dev *dev);
 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs);
 int pci_sriov_get_totalvfs(struct pci_dev *dev);
 #else
+static inline int pci_iov_virtfn_bus(struct pci_dev *dev, int id)
+{
+	return -ENOSYS;
+}
+static inline int pci_iov_virtfn_devfn(struct pci_dev *dev, int id)
+{
+	return -ENOSYS;
+}
 static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 { return -ENODEV; }
 static inline void pci_disable_sriov(struct pci_dev *dev) { }