On Fri, Feb 20, 2015 at 05:19:17PM -0600, Bjorn Helgaas wrote:
>On Thu, Jan 15, 2015 at 10:27:58AM +0800, Wei Yang wrote:
>> From: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
>>
>> pci_dn is the extension of PCI device node and it's created from
>> device node. Unfortunately, VFs that are enabled dynamically by
>> PF's driver and they don't have corresponding device nodes, and
>> pci_dn. The patch refactors pci_dn to support VFs:
>>
>> * pci_dn is organized as a hierarchy tree. VF's pci_dn is put
>> to the child list of pci_dn of PF's bridge. pci_dn of other
>> device put to the child list of pci_dn of its upstream bridge.
>>
>> * VF's pci_dn is expected to be created dynamically when PF
>> enabling VFs. VF's pci_dn will be destroyed when PF disabling
>> VFs. pci_dn of other device is still created from device node
>> as before.
>>
>> * For one particular PCI device (VF or not), its pci_dn can be
>> found from pdev->dev.archdata.firmware_data, PCI_DN(devnode),
>> or parent's list. The fast path (fetching pci_dn through PCI
>> device instance) is populated during early fixup time.
>>
>> Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
>> ---
>> arch/powerpc/include/asm/device.h | 3 +
>> arch/powerpc/include/asm/pci-bridge.h | 14 +-
>> arch/powerpc/kernel/pci_dn.c | 242 ++++++++++++++++++++++++++++-
>> arch/powerpc/platforms/powernv/pci-ioda.c | 16 ++
>> 4 files changed, 270 insertions(+), 5 deletions(-)
>> ...
>
>> +#ifdef CONFIG_PCI_IOV
>> +static struct pci_dn *add_one_dev_pci_info(struct pci_dn *parent,
>> + struct pci_dev *pdev,
>> + int busno, int devfn)
>> +{
>> + struct pci_dn *pdn;
>> +
>> + /* Except PHB, we always have parent firmware data */
>> + if (!parent)
>> + return NULL;
>> +
>> + pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
>> + if (!pdn) {
>> + pr_warn("%s: Out of memory !\n", __func__);
>> + return NULL;
>> + }
>> +
>> + pdn->phb = parent->phb;
>> + pdn->parent = parent;
>> + pdn->busno = busno;
>> + pdn->devfn = devfn;
>> +#ifdef CONFIG_PPC_POWERNV
>> + pdn->pe_number = IODA_INVALID_PE;
>> +#endif
>> + INIT_LIST_HEAD(&pdn->child_list);
>> + INIT_LIST_HEAD(&pdn->list);
>> + list_add_tail(&pdn->list, &parent->child_list);
>> +
>> + /*
>> + * If we already have PCI device instance, lets
>> + * bind them.
>> + */
>> + if (pdev)
>> + pdev->dev.archdata.firmware_data = pdn;
>> +
>> + return pdn;
>
>I'd like to see this done in pcibios_add_device(), as I mentioned in
>response to "[PATCH V11 01/17] PCI/IOV: Export interface for retrieve VF's
>BDF". Maybe that's not feasible for some reason, but it would be a nicer
>design if it's possible.
>
>The remove_dev_pci_info() work would be done in pcibios_release_device()
>then, of course.
>
Yes, it's not feasible. PCI config accessors rely on VF's pci_dn. Before
calling pcibios_add_device(), we need access VF's config space. That means
we need VF's pci_dn before pci_setup_device() as follows:
sriov_enable()
pcibios_sriov_enable(); /* Currently, VF's pci_dn is created at this point */
virtfn_add();
virtfn_add_bus(); /* Create virtual bus if necessary */
/* ---> A */
pci_alloc_dev(); /* ---> B */
pci_setup_device(vf); /* Access VF's config space */
pci_read_config_byte(vf, PCI_HEADER_TYPE);
pci_read_config_dword(vf, PCI_CLASS_REVISION);
pci_fixup_device(pci_fixup_early, vf);
pci_read_irq();
pci_read_bases();
pci_device_add(vf);
device_initialize(&vf->dev);
pci_fixup_device(pci_fixup_header, vf);
pci_init_capabilities(vf);
pcibios_add_device(vf);
We have couple of options here:
1) Keep current code. VF's pci_dn is going to be destroyed in
pcibios_sriov_disable() as we're doing currently.
2) Introduce pcibios_iov_virtfn_add() (at A) for platform to override.
VF's pci_dn is going to be destroyed in pcibios_release_device().
3) Introduce pcibios_alloc_dev() (at B) for platform to override. The
VF's pci_dn is going to be destroyed in pcibios_release_device().
Thanks,
Gavin
>> +}
>> +#endif // CONFIG_PCI_IOV
>> +
>> +struct pci_dn *add_dev_pci_info(struct pci_dev *pdev, u16 vf_num)
>> +{
>> +#ifdef CONFIG_PCI_IOV
>> + struct pci_dn *parent, *pdn;
>> + int i;
>> +
>> + /* Only support IOV for now */
>> + if (!pdev->is_physfn)
>> + return pci_get_pdn(pdev);
>> +
>> + /* Check if VFs have been populated */
>> + pdn = pci_get_pdn(pdev);
>> + if (!pdn || (pdn->flags & PCI_DN_FLAG_IOV_VF))
>> + return NULL;
>> +
>> + pdn->flags |= PCI_DN_FLAG_IOV_VF;
>> + parent = pci_bus_to_pdn(pdev->bus);
>> + if (!parent)
>> return NULL;
>> - return PCI_DN(dn);
>> +
>> + for (i = 0; i < vf_num; i++) {
>> + pdn = add_one_dev_pci_info(parent, NULL,
>> + pci_iov_virtfn_bus(pdev, i),
>> + pci_iov_virtfn_devfn(pdev, i));
>> + if (!pdn) {
>> + pr_warn("%s: Cannot create firmware data "
>> + "for VF#%d of %s\n",
>> + __func__, i, pci_name(pdev));
>> + return NULL;
>> + }
>> + }
>> +#endif
>> +
>> + return pci_get_pdn(pdev);
>> +}
>> +
>> +void remove_dev_pci_info(struct pci_dev *pdev, u16 vf_num)
>> +{
>> +#ifdef CONFIG_PCI_IOV
>> + struct pci_dn *parent;
>> + struct pci_dn *pdn, *tmp;
>> + int i;
>> +
>> + /* Only support IOV PF for now */
>> + if (!pdev->is_physfn)
>> + return;
>> +
>> + /* Check if VFs have been populated */
>> + pdn = pci_get_pdn(pdev);
>> + if (!pdn || !(pdn->flags & PCI_DN_FLAG_IOV_VF))
>> + return;
>> +
>> + pdn->flags &= ~PCI_DN_FLAG_IOV_VF;
>> + parent = pci_bus_to_pdn(pdev->bus);
>> + if (!parent)
>> + return;
>> +
>> + /*
>> + * We might introduce flag to pci_dn in future
>> + * so that we can release VF's firmware data in
>> + * a batch mode.
>> + */
>> + for (i = 0; i < vf_num; i++) {
>> + list_for_each_entry_safe(pdn, tmp,
>> + &parent->child_list, list) {
>> + if (pdn->busno != pci_iov_virtfn_bus(pdev, i) ||
>> + pdn->devfn != pci_iov_virtfn_devfn(pdev, i))
>> + continue;
>> +
>> + if (!list_empty(&pdn->list))
>> + list_del(&pdn->list);
>> + kfree(pdn);
>> + }
>> + }
>> +#endif
>> }
>
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
