On 10/31/2012 07:53 PM, Ben Hutchings wrote:
On Wed, 2012-10-31 at 17:19 -0400, Donald Dutile wrote:
Some implementations of SRIOV provide a capability structure
value of TotalVFs that is greater than what the software can support.
Provide a method to reduce the capability structure reported value
to the value the driver can support.
This ensures sysfs reports the current capability of the system,
hardware and software.
Example for its use: igb& ixgbe -- report 8& 64 as TotalVFs,
but drivers only support 7& 63 maximum.
Signed-off-by: Donald Dutile<ddutile@xxxxxxxxxx>
---
drivers/pci/iov.c | 27 ++++++++++++++++++++++++++-
drivers/pci/pci-sysfs.c | 10 ++++++++--
drivers/pci/pci.h | 1 +
include/linux/pci.h | 5 +++++
4 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index aeccc91..98c3d37 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -682,7 +682,6 @@ int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
if (!dev->is_physfn)
return -ENODEV;
-
return sriov_enable(dev, nr_virtfn);
}
EXPORT_SYMBOL_GPL(pci_enable_sriov);
This hunk doesn't belong in this patch.
gone in next rev.
@@ -735,3 +734,29 @@ int pci_num_vf(struct pci_dev *dev)
return dev->sriov->nr_virtfn;
}
EXPORT_SYMBOL_GPL(pci_num_vf);
+
+/**
+ * pci_sriov_set_totalvfs -- reduce the TotalVFs available
+ * @dev: the PCI PF device
+ * numvfs: number that should be used for TotalVFs supported
+ *
+ * Should be called from PF driver's probe routine with
+ * device's mutex held.
+ *
+ * Returns 0 if PF is an SRIOV-capable device and
+ * value of numvfs valid, otherwise -EINVAL
This says the only possible error is -EINVAL, but it can also return
-EIO! And the already-enabled case might be one that some drivers will
need to handle specially.
+ */
+int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
+{
+ if (!dev || !dev->is_physfn || (numvfs> dev->sriov->total))
+ return -EINVAL;
+
+ /* Shouldn't change if VFs already enabled */
+ if (dev->sriov->ctrl& PCI_SRIOV_CTRL_VFE)
+ return -EIO;
[...]
EBUSY seems a bit more appropriate.
Ben.
ok. changed to -EBUSY & comment on return values.
After looking at this area more, I created a pci_sriov_get_totalvfs()
as well, and now use that in the pci-sysfs.c file as well....
much cleaner; symmetric to set. Makes backporting to
those crazy enterprise releases w/kabi rules easier too! ;-)
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