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author | Bodong Wang <bodong@mellanox.com> | 2017-04-13 01:51:40 +0300 |
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committer | Bjorn Helgaas <bhelgaas@google.com> | 2017-04-20 08:53:51 -0500 |
commit | 0e7df22401a3dfd403b26dea62dd00e0598b538b (patch) | |
tree | 484063ef8f232bf8d51d998a1331513a9f2c8b5a /drivers | |
parent | f65fd1aa4f9881d5540192d11f7b8ed2fec936db (diff) | |
download | linux-stable-0e7df22401a3dfd403b26dea62dd00e0598b538b.tar.gz linux-stable-0e7df22401a3dfd403b26dea62dd00e0598b538b.tar.bz2 linux-stable-0e7df22401a3dfd403b26dea62dd00e0598b538b.zip |
PCI: Add sysfs sriov_drivers_autoprobe to control VF driver binding
Sometimes it is not desirable to bind SR-IOV VFs to drivers. This can save
host side resource usage by VF instances that will be assigned to VMs.
Add a new PCI sysfs interface "sriov_drivers_autoprobe" to control that
from the PF. To modify it, echo 0/n/N (disable probe) or 1/y/Y (enable
probe) to:
/sys/bus/pci/devices/<DOMAIN:BUS:DEVICE.FUNCTION>/sriov_drivers_autoprobe
Note that this must be done before enabling VFs. The change will not take
effect if VFs are already enabled. Simply, one can disable VFs by setting
sriov_numvfs to 0, choose whether to probe or not, and then re-enable the
VFs by restoring sriov_numvfs.
[bhelgaas: changelog, ABI doc]
Signed-off-by: Bodong Wang <bodong@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/pci/iov.c | 1 | ||||
-rw-r--r-- | drivers/pci/pci-driver.c | 22 | ||||
-rw-r--r-- | drivers/pci/pci-sysfs.c | 28 | ||||
-rw-r--r-- | drivers/pci/pci.h | 1 |
4 files changed, 48 insertions, 4 deletions
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 2479ae876482..d9dc7363ac77 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -450,6 +450,7 @@ found: iov->total_VFs = total; iov->pgsz = pgsz; iov->self = dev; + iov->drivers_autoprobe = true; pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap); pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link); if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index afa72717a979..f99f7fe749b8 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -394,6 +394,18 @@ void __weak pcibios_free_irq(struct pci_dev *dev) { } +#ifdef CONFIG_PCI_IOV +static inline bool pci_device_can_probe(struct pci_dev *pdev) +{ + return (!pdev->is_virtfn || pdev->physfn->sriov->drivers_autoprobe); +} +#else +static inline bool pci_device_can_probe(struct pci_dev *pdev) +{ + return true; +} +#endif + static int pci_device_probe(struct device *dev) { int error; @@ -405,10 +417,12 @@ static int pci_device_probe(struct device *dev) return error; pci_dev_get(pci_dev); - error = __pci_device_probe(drv, pci_dev); - if (error) { - pcibios_free_irq(pci_dev); - pci_dev_put(pci_dev); + if (pci_device_can_probe(pci_dev)) { + error = __pci_device_probe(drv, pci_dev); + if (error) { + pcibios_free_irq(pci_dev); + pci_dev_put(pci_dev); + } } return error; diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 25d010d449a3..369c999683ca 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -526,10 +526,37 @@ exit: return count; } +static ssize_t sriov_drivers_autoprobe_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct pci_dev *pdev = to_pci_dev(dev); + + return sprintf(buf, "%u\n", pdev->sriov->drivers_autoprobe); +} + +static ssize_t sriov_drivers_autoprobe_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct pci_dev *pdev = to_pci_dev(dev); + bool drivers_autoprobe; + + if (kstrtobool(buf, &drivers_autoprobe) < 0) + return -EINVAL; + + pdev->sriov->drivers_autoprobe = drivers_autoprobe; + + return count; +} + static struct device_attribute sriov_totalvfs_attr = __ATTR_RO(sriov_totalvfs); static struct device_attribute sriov_numvfs_attr = __ATTR(sriov_numvfs, (S_IRUGO|S_IWUSR|S_IWGRP), sriov_numvfs_show, sriov_numvfs_store); +static struct device_attribute sriov_drivers_autoprobe_attr = + __ATTR(sriov_drivers_autoprobe, (S_IRUGO|S_IWUSR|S_IWGRP), + sriov_drivers_autoprobe_show, sriov_drivers_autoprobe_store); #endif /* CONFIG_PCI_IOV */ static ssize_t driver_override_store(struct device *dev, @@ -1549,6 +1576,7 @@ static struct attribute_group pci_dev_hp_attr_group = { static struct attribute *sriov_dev_attrs[] = { &sriov_totalvfs_attr.attr, &sriov_numvfs_attr.attr, + &sriov_drivers_autoprobe_attr.attr, NULL, }; diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 8dd38e69d6f2..3ba7d586f522 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -272,6 +272,7 @@ struct pci_sriov { struct pci_dev *self; /* this PF */ struct mutex lock; /* lock for setting sriov_numvfs in sysfs */ resource_size_t barsz[PCI_SRIOV_NUM_BARS]; /* VF BAR size */ + bool drivers_autoprobe; /* auto probing of VFs by driver */ }; #ifdef CONFIG_PCI_ATS |