Store more data about PCI VFs into the SRIOV to avoid reading them from the
config space of all the PCI VFs. This is specially a useful optimization
when bringing up thousands of VFs.
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: KarimAllah Ahmed <karahmed@xxxxxxxxx>
---
v2 -> v3:
* Update changelog
* Move the call to pci_read_vf_config_common a bit later and use standard
pci_read_config*.
* Update whitespace.
* Move the using barsz into its own patch.
* Added a comment about the usage of subsystem vendor id, subsystem id, and
class revision.
* Make sure virtfn->is_virtfn is set before calling into pci_setup_device.
v1 -> v2:
* Rebase on latest + remove dependency on a non-upstream patch.
drivers/pci/iov.c | 48 +++++++++++++++++++++++++++++++++++++++++-------
drivers/pci/pci.h | 5 +++++
drivers/pci/probe.c | 18 ++++++++++++++----
3 files changed, 60 insertions(+), 11 deletions(-)
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 677924a..10291a0 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -114,6 +114,36 @@ resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
}
+static void pci_read_vf_config_common(struct pci_dev *virtfn)
+{
+ struct pci_dev *physfn = virtfn->physfn;
+
+ BUG_ON(!virtfn->is_virtfn || physfn->is_virtfn);
+
+ /*
+ * Per PCIe r4.0, sec 9.3.4.1.5, the value reported in the VF maybe
+ * different than the value reported in the PF. We assume here that all
+ * VFs would report the same revision ID.
+ */
+ pci_read_config_dword(virtfn, PCI_CLASS_REVISION,
+ &physfn->sriov->class);
+ /*
+ * Per PCIe r4.0, sec 9.3.4.1.13, the field in the PF and the
+ * associated VFs must return the same value.
+ */
+ pci_read_config_word(virtfn, PCI_SUBSYSTEM_VENDOR_ID,
+ &physfn->sriov->subsystem_vendor);
+ /*
+ * Per PCIe r4.0, sec 9.3.4.1.14, the value reported in the VF maybe
+ * different than the value reported in the PF. We assume here that all
+ * VFs would report the same subsystem ID.
+ */
+ pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID,
+ &physfn->sriov->subsystem_device);
+ pci_read_config_byte(virtfn, PCI_HEADER_TYPE,
+ &physfn->sriov->hdr_type);
+}
+
int pci_iov_add_virtfn(struct pci_dev *dev, int id)
{
int i;
@@ -134,15 +164,18 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
goto failed0;
virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
+ virtfn->is_virtfn = 1;
+ virtfn->physfn = pci_dev_get(dev);
+ if (id == 0)
+ /* virtfn->{devfn,bus,is_virtfn,physfn} have to be initialized */
+ pci_read_vf_config_common(virtfn);
virtfn->vendor = dev->vendor;
virtfn->device = iov->vf_device;
rc = pci_setup_device(virtfn);
if (rc)
- goto failed0;
+ goto failed1;
virtfn->dev.parent = dev->dev.parent;
- virtfn->physfn = pci_dev_get(dev);
- virtfn->is_virtfn = 1;
virtfn->multifunction = 0;
for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
@@ -163,10 +196,10 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
sprintf(buf, "virtfn%u", id);
rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
if (rc)
- goto failed1;
+ goto failed2;
rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
if (rc)
- goto failed2;
+ goto failed3;
kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
@@ -174,11 +207,12 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
return 0;
-failed2:
+failed3:
sysfs_remove_link(&dev->dev.kobj, buf);
+failed2:
+ pci_stop_and_remove_bus_device(virtfn);
failed1:
pci_dev_put(dev);
- pci_stop_and_remove_bus_device(virtfn);
failed0:
virtfn_remove_bus(dev->bus, bus);
failed:
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index fcd8191..17e6688 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -271,6 +271,11 @@ struct pci_sriov {
u16 driver_max_VFs; /* Max num VFs driver supports */
struct pci_dev *dev; /* Lowest numbered PF */
struct pci_dev *self; /* This PF */
+ u8 hdr_type; /* VF header type */
+ u32 class; /* VF device */
+ u16 device; /* VF device */
+ u16 subsystem_vendor; /* VF subsystem vendor */
+ u16 subsystem_device; /* VF subsystem device */
resource_size_t barsz[PCI_SRIOV_NUM_BARS]; /* VF BAR size */
bool drivers_autoprobe; /* Auto probing of VFs by driver */
};
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ef53774..a96837e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1454,7 +1454,9 @@ int pci_setup_device(struct pci_dev *dev)
struct pci_bus_region region;
struct resource *res;
- if (pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type))
+ if (dev->is_virtfn)
+ hdr_type = dev->physfn->sriov->hdr_type;
+ else if (pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type))
return -EIO;
dev->sysdata = dev->bus->sysdata;
@@ -1477,7 +1479,10 @@ int pci_setup_device(struct pci_dev *dev)
dev->bus->number, PCI_SLOT(dev->devfn),
PCI_FUNC(dev->devfn));
- pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
+ if (dev->is_virtfn)
+ class = dev->physfn->sriov->class;
+ else
+ pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
dev->revision = class & 0xff;
dev->class = class >> 8; /* upper 3 bytes */
@@ -1517,8 +1522,13 @@ int pci_setup_device(struct pci_dev *dev)
goto bad;
pci_read_irq(dev);
pci_read_bases(dev, 6, PCI_ROM_ADDRESS);
- pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
- pci_read_config_word(dev, PCI_SUBSYSTEM_ID, &dev->subsystem_device);
+ if (dev->is_virtfn) {
+ dev->subsystem_vendor = dev->physfn->sriov->subsystem_vendor;
+ dev->subsystem_device = dev->physfn->sriov->subsystem_device;
+ } else {
+ pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
+ pci_read_config_word(dev, PCI_SUBSYSTEM_ID, &dev->subsystem_device);
+ }
/*
* Do the ugly legacy mode stuff here rather than broken chip
--
2.7.4
