Subject: Re: [RFC PATCH V3 14/17] ppc/pci: create/release dev-tree node for VFs

From: Wei Yang <[email-masked]>
Date: Thu, 19 Jun 2014 10:46:51 +0800

On Wed, Jun 18, 2014 at 07:26:27PM +0100, Grant Likely wrote:
>On Tue, Jun 10, 2014 at 2:56 AM, Wei Yang <[email-masked]> wrote:
>> Currently, powernv platform is not aware of VFs. This means no dev-node
>> represents a VF. Also, VF PCI device is created when PF driver want to enable
>> it. This leads to the pdn->pdev and pdn->pe_number an invalid value.
>>
>> This patch create/release dev-node for VF and fixs this when a VF's pci_dev
>> is created.
>>
>> Signed-off-by: Wei Yang <[email-masked]>
>
>I don't think this is the right way to handle this. Unless it is a
>fixup to a buggy devicetree provided by firmware, I don't want to see
>any code modifying the devicetree to describe stuff that is able to be
>directly enumerated. Really the pci code should handle the lack of a
>device_node gracefully. If it cannot then it should be fixed.

Grant,

Glad to see your comment.

I will fix this in the firmware.

>
>g.
>
>> ---
>>  arch/powerpc/platforms/powernv/Kconfig    |    1 +
>>  arch/powerpc/platforms/powernv/pci-ioda.c |  103 +++++++++++++++++++++++++++++
>>  arch/powerpc/platforms/powernv/pci.c      |   20 ++++++
>>  3 files changed, 124 insertions(+)
>>
>> diff --git a/arch/powerpc/platforms/powernv/Kconfig b/arch/powerpc/platforms/powernv/Kconfig
>> index 895e8a2..0dd331b 100644
>> --- a/arch/powerpc/platforms/powernv/Kconfig
>> +++ b/arch/powerpc/platforms/powernv/Kconfig
>> @@ -11,6 +11,7 @@ config PPC_POWERNV
>>         select PPC_UDBG_16550
>>         select PPC_SCOM
>>         select ARCH_RANDOM
>> +       select OF_DYNAMIC
>>         default y
>>
>>  config PPC_POWERNV_RTAS
>> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>> index e46c5bf..9ace027 100644
>> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
>> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>> @@ -23,6 +23,7 @@
>>  #include <linux/io.h>
>>  #include <linux/msi.h>
>>  #include <linux/memblock.h>
>> +#include <linux/of_pci.h>
>>
>>  #include <asm/sections.h>
>>  #include <asm/io.h>
>> @@ -771,6 +772,108 @@ static void pnv_pci_ioda_setup_PEs(void)
>>         }
>>  }
>>
>> +#ifdef CONFIG_PCI_IOV
>> +static void pnv_pci_create_vf_node(struct pci_dev *dev, u16 vf_num)
>> +{
>> +       struct device_node *dn, *p_dn;
>> +       struct pci_dn *pdn;
>> +       struct pci_controller *hose;
>> +       struct property *pp;
>> +       void* value;
>> +       u16 id;
>> +
>> +       hose = pci_bus_to_host(dev->bus);
>> +
>> +       /* Create dev-tree node for VFs if this is a PF */
>> +       p_dn = pci_bus_to_OF_node(dev->bus);
>> +       if (p_dn == NULL) {
>> +               dev_err(&dev->dev, "SRIOV: VF bus NULL device node\n");
>> +               return;
>> +       }
>> +
>> +       for (id = 0; id < vf_num; id++) {
>> +               dn = kzalloc(sizeof(*dn), GFP_KERNEL);
>> +               pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
>> +               pp  = kzalloc(sizeof(*pp), GFP_KERNEL);
>> +               value = kzalloc(sizeof(u32), GFP_KERNEL);
>> +
>> +               if (!dn || !pdn || !pp || !value) {
>> +                       kfree(dn);
>> +                       kfree(pdn);
>> +                       kfree(pp);
>> +                       kfree(value);
>> +                       dev_warn(&dev->dev, "%s: failed to create"
>> +                               "dev-tree node for idx(%d)\n",
>> +                               __func__, id);
>> +
>> +                       break;
>> +               }
>> +
>> +               pp->value = value;
>> +               pdn->node = dn;
>> +               pdn->devfn = pci_iov_virtfn_devfn(dev, id);
>> +               pdn->busno = dev->bus->number;
>> +               pdn->pe_number = IODA_INVALID_PE;
>> +               pdn->phb = hose;
>> +
>> +               dn->data = pdn;
>> +               kref_init(&dn->kref);
>> +               dn->full_name = dn->name =
>> +                       kasprintf(GFP_KERNEL, "%s/vf%d",
>> +                               p_dn->full_name, pdn->devfn);
>> +               dn->parent = p_dn;
>> +
>> +               pp->name = kasprintf(GFP_KERNEL, "reg");
>> +               pp->length = 5 * sizeof(__be32);
>> +               *(u32*)pp->value = cpu_to_be32(pdn->devfn) << 8;
>> +               dn->properties = pp;
>> +
>> +               of_attach_node(dn);
>> +       }
>> +}
>> +
>> +static void pnv_pci_release_vf_node(struct pci_dev *dev, u16 vf_num)
>> +{
>> +       struct device_node *dn;
>> +       struct property *pp;
>> +       u16 id;
>> +
>> +       for (id = 0; id < vf_num; id++) {
>> +               dn = of_pci_find_child_device(dev->bus->dev.of_node,
>> +                               pci_iov_virtfn_devfn(dev, id));
>> +               if (!dn)
>> +                       continue;
>> +
>> +               of_detach_node(dn);
>> +               pp = dn->properties;
>> +               kfree(pp->name);
>> +               kfree(pp->value);
>> +               kfree(pp);
>> +               kfree(dn->data);
>> +               kfree(dn);
>> +       }
>> +}
>> +
>> +int pcibios_sriov_disable(struct pci_dev *pdev)
>> +{
>> +       struct pci_sriov *iov;
>> +       u16 vf_num;
>> +
>> +       iov = pdev->sriov;
>> +       vf_num = iov->num_VFs;
>> +       pnv_pci_release_vf_node(pdev, vf_num);
>> +
>> +       return 0;
>> +}
>> +
>> +int pcibios_sriov_enable(struct pci_dev *pdev, u16 vf_num)
>> +{
>> +       pnv_pci_create_vf_node(pdev, vf_num);
>> +
>> +       return 0;
>> +}
>> +#endif /* CONFIG_PCI_IOV */
>> +
>>  static void pnv_pci_ioda_dma_dev_setup(struct pnv_phb *phb, struct pci_dev *pdev)
>>  {
>>         struct pci_dn *pdn = pci_get_pdn(pdev);
>> diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
>> index 687a068..43fcc73 100644
>> --- a/arch/powerpc/platforms/powernv/pci.c
>> +++ b/arch/powerpc/platforms/powernv/pci.c
>> @@ -654,6 +654,26 @@ static void pnv_pci_dma_dev_setup(struct pci_dev *pdev)
>>  {
>>         struct pci_controller *hose = pci_bus_to_host(pdev->bus);
>>         struct pnv_phb *phb = hose->private_data;
>> +#ifdef CONFIG_PCI_IOV
>> +       struct pnv_ioda_pe *pe;
>> +       struct pci_dn *pdn;
>> +
>> +       /* Fix the VF pdn PE number */
>> +       if (pdev->is_virtfn) {
>> +               pdn = pci_get_pdn(pdev);
>> +               if (pdn->pcidev == NULL || pdn->pe_number == IODA_INVALID_PE) {
>> +                       list_for_each_entry(pe, &phb->ioda.pe_list, list) {
>> +                               if (pe->rid ==
>> +                                       ((pdev->bus->number << 8) | (pdev->devfn & 0xff))) {
>> +                                       pdn->pcidev = pdev;
>> +                                       pdn->pe_number = pe->pe_number;
>> +                                       pe->pdev = pdev;
>> +                                       break;
>> +                               }
>> +                       }
>> +               }
>> +       }
>> +#endif /* CONFIG_PCI_IOV */
>>
>>         /* If we have no phb structure, try to setup a fallback based on
>>          * the device-tree (RTAS PCI for example)
>> --
>> 1.7.9.5
>>
>> _______________________________________________
>> Linuxppc-dev mailing list
>> [email-masked]
>> https://lists.ozlabs.org/listinfo/linuxppc-dev

-- 
Richard Yang
Help you, Help me