Re: [PATCH 1/2] PCI: provide pcibios_sriov_add_vfs

[Christoph Hellwig]

On Thu, Dec 13, 2018 at 06:54:27PM +0100, Sebastian Ott wrote:
> Move VF detection and device creation code to weak functions
> such that architectures can provide a different implementation.

No magic weak functions please.  If you really have a reason to
override the implementation add a proper Kconfig symbol and
an explicit override.

[PATCH 1/2] PCI: provide pcibios_sriov_add_vfs

[Sebastian Ott]

Move VF detection and device creation code to weak functions
such that architectures can provide a different implementation.

Signed-off-by: Sebastian Ott 
---
 drivers/pci/iov.c   | 43 +++
 include/linux/pci.h |  2 ++
 2 files changed, 33 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 9616eca3182f..1bfdb4deafd7 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -252,6 +252,33 @@ int __weak pcibios_sriov_disable(struct pci_dev *pdev)
return 0;
 }
 
+int __weak pcibios_sriov_add_vfs(struct pci_dev *dev, u16 num_vfs)
+{
+   unsigned int i;
+   int rc;
+
+   for (i = 0; i < num_vfs; i++) {
+   rc = pci_iov_add_virtfn(dev, i);
+   if (rc)
+   goto failed;
+   }
+   return 0;
+failed:
+   while (i--)
+   pci_iov_remove_virtfn(dev, i);
+
+   return rc;
+}
+
+void __weak pcibios_sriov_del_vfs(struct pci_dev *dev)
+{
+   struct pci_sriov *iov = dev->sriov;
+   int i;
+
+   for (i = 0; i < iov->num_VFs; i++)
+   pci_iov_remove_virtfn(dev, i);
+}
+
 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 {
int rc;
@@ -337,21 +364,15 @@ static int sriov_enable(struct pci_dev *dev, int 
nr_virtfn)
msleep(100);
pci_cfg_access_unlock(dev);
 
-   for (i = 0; i < initial; i++) {
-   rc = pci_iov_add_virtfn(dev, i);
-   if (rc)
-   goto failed;
-   }
+   rc = pcibios_sriov_add_vfs(dev, initial);
+   if (rc)
+   goto err_pcibios;
 
kobject_uevent(>dev.kobj, KOBJ_CHANGE);
iov->num_VFs = nr_virtfn;
 
return 0;
 
-failed:
-   while (i--)
-   pci_iov_remove_virtfn(dev, i);
-
 err_pcibios:
iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
pci_cfg_access_lock(dev);
@@ -370,14 +391,12 @@ static int sriov_enable(struct pci_dev *dev, int 
nr_virtfn)
 
 static void sriov_disable(struct pci_dev *dev)
 {
-   int i;
struct pci_sriov *iov = dev->sriov;
 
if (!iov->num_VFs)
return;
 
-   for (i = 0; i < iov->num_VFs; i++)
-   pci_iov_remove_virtfn(dev, i);
+   pcibios_sriov_del_vfs(dev);
 
iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
pci_cfg_access_lock(dev);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 11c71c4ecf75..84ca3bcdac76 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2001,6 +2001,8 @@ void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool 
probe);
 /* Arch may override these (weak) */
 int pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs);
 int pcibios_sriov_disable(struct pci_dev *pdev);
+int pcibios_sriov_add_vfs(struct pci_dev *dev, u16 num_vfs);
+void pcibios_sriov_del_vfs(struct pci_dev *dev);
 resource_size_t pcibios_iov_resource_alignment(struct pci_dev *dev, int resno);
 #else
 static inline int pci_iov_virtfn_bus(struct pci_dev *dev, int id)
-- 
2.16.4