Hi Liviu, Sorry for the trouble. I got why 'res->parent' is not set in my case. Basically my SR-IOV device has fixed resources, so resources will not be allocated/assigned and hence parent resource is not set. I will move the resource claiming to host controller driver as a fixup so that parent resource hierarchy is set. Thanks for the support. Regards, Sunil. On Fri, May 16, 2014 at 11:12 PM, Sunil Kovvuri <sunil.kovvuri@xxxxxxxxx> wrote: > Hi Liviu, > > Issue may not be only with SR-IOV resources. > > I am not an expert with Linux PCI core. But i am trying to understand > how even for a non SR-IOV capable device's resource, gets a parent > associated with it. > > When a PCI device driver calls pci_enable_device() which inturn calls > 'arch/arm64/kernel/pci.c' pcibios_enable_device() which uses Linux PCI core > API 'pci_enable_resources'. This API checks 'res->parent' for all > valid resources > before enabling them, otherwise it fails. > if (!r->parent) { > dev_err(&dev->dev, "device not available " > "(can't reserve %pR)\n", r); > return -EINVAL; > } > > Can you please let me know where this hierarchy is being set for > 'pcibios_enable_resources' to work. > > I could only find request_resource() API which sets the parent and > pci_claim_resource() uses this. > > Thanks, > Sunil. > > On Fri, May 16, 2014 at 6:54 PM, Liviu Dudau <Liviu.Dudau@xxxxxxx> wrote: >> Hi Sunil, >> >> On Fri, May 16, 2014 at 11:33:04AM +0100, Sunil Kovvuri wrote: >>> Hi Liviu, >>> >>> I am using your ARM64 PCIe patches to write a PCIe host controller >>> driver for our SOC. I am facing an issue with SR-IOV capable device. >>> >>> Consider an PCI Express endpoint connected to a PCI Express >>> Root Port. The PCI Express endpoint provides PCI-SIG SR-IOV >>> capabilities with a single physical function and a large number >>> of virtual functions. The Root Port contains a pci-pci bridge in >>> between it and the SR-IOV device. >>> >>> When the SR-IOV capable device's driver tries to enable sriov >>> (pci_enable_sriov()) it fails to create/add PCI device for each >>> virtual function reporting "not enough MMIO resources for SR-IOV". >>> >>> In sriov_enable() (drivers/pci/iov.c) >>> >>> 296 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { >>> 297 bars |= (1 << (i + PCI_IOV_RESOURCES)); >>> 298 res = dev->resource + PCI_IOV_RESOURCES + i; >>> 299 if (res->parent) >>> 300 nres++; >>> 301 } >>> 302 if (nres != iov->nres) { >>> 303 dev_err(&dev->dev, "not enough MMIO resources for >>> SR-IOV\n"); >>> 304 return -ENOMEM; >>> 305 } >>> >>> Here its checking if physical function's IOV resource has a parent or not. >>> Which is pci-pci bridge in this case. Otherwise it doesn't consider >>> that resource. >>> >>> Added below api to your patch. >>> This will try to claim a resource while creating a PCI device which >>> inturn sets 'res->parent'. >>> >>> Let me know if this is okay. >>> >>> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c >>> index 9f29c9a..fbfb48f 100644 >>> --- a/arch/arm64/kernel/pci.c >>> +++ b/arch/arm64/kernel/pci.c >>> @@ -125,6 +125,21 @@ resource_size_t pcibios_align_resource(void >>> *data, const struct resource *res, >>> return res->start; >>> } >>> >>> +int pcibios_add_device(struct pci_dev *pdev) >>> +{ >>> + unsigned int i, type_mask = IORESOURCE_IO | IORESOURCE_MEM; >>> + struct resource *res; >>> + >>> + for (i = 0; i < PCI_NUM_RESOURCES; i++) { >>> + res = &pdev->resource[i]; >>> + if (res->parent || !(res->flags & type_mask)) >>> + continue; >>> + pci_claim_resource(pdev, i); >>> + } >>> + >>> >> >> I would like not to have to add your patch in this file as I am trying to >> remove it entirely. I don't have an SR-IOV capable device in my setup so >> I am not able to debug your problem, but could you have a go and try to >> figure out why the SR-IOV resources do not get a parent associated with >> when they get created? >> >> Many thanks, >> Liviu >> >> >> -- >> ==================== >> | I would like to | >> | fix the world, | >> | but they're not | >> | giving me the | >> \ source code! / >> --------------- >> ¯\_(ツ)_/¯ >> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html