From: Niklas Schnelle Date: Tue, 28 Apr 2020 09:54:46 +0000 (+0200) Subject: s390/pci: create links between PFs and VFs X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=e5794cf1a270d813a5b9373a6876487d4d154195;p=linux.git s390/pci: create links between PFs and VFs On s390 PCI Virtual Functions (VFs) are scanned by firmware and are made available to Linux via the hot-plug interface. As such the common code path of doing the scan directly using the parent Physical Function (PF) is not used and fenced off with the no_vf_scan attribute. Even if the partition created the VFs itself e.g. using the sriov_numvfs attribute of a PF, the PF/VF links thus need to be established after the fact. To do this when a VF is plugged we scan through all functions on the same zbus and test whether they are the parent PF in which case we establish the necessary links. With these links established there is now no more need to fence off pci_iov_remove_virtfn() for pdev->no_vf_scan as the common code now works fine. Signed-off-by: Niklas Schnelle Acked-by: Bjorn Helgaas Reviewed-by: Pierre Morel Link: https://lore.kernel.org/r/20200506154139.90609-3-schnelle@linux.ibm.com Signed-off-by: Vasily Gorbik --- diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h index c1558cf071b87..99b92c3e46b09 100644 --- a/arch/s390/include/asm/pci.h +++ b/arch/s390/include/asm/pci.h @@ -131,7 +131,8 @@ struct zpci_dev { u8 port; u8 rid_available : 1; u8 has_hp_slot : 1; - u8 reserved : 6; + u8 is_physfn : 1; + u8 reserved : 5; unsigned int devfn; /* DEVFN part of the RID*/ struct mutex lock; diff --git a/arch/s390/include/asm/pci_clp.h b/arch/s390/include/asm/pci_clp.h index 896ee41e23e30..eb51272dd2ccd 100644 --- a/arch/s390/include/asm/pci_clp.h +++ b/arch/s390/include/asm/pci_clp.h @@ -95,7 +95,8 @@ struct clp_rsp_query_pci { u16 vfn; /* virtual fn number */ u16 : 3; u16 rid_avail : 1; - u16 : 2; + u16 is_physfn : 1; + u16 reserved1 : 1; u16 mio_addr_avail : 1; u16 util_str_avail : 1; /* utility string available? */ u16 pfgid : 8; /* pci function group id */ diff --git a/arch/s390/pci/pci_bus.c b/arch/s390/pci/pci_bus.c index ada571d1c6306..642a993846889 100644 --- a/arch/s390/pci/pci_bus.c +++ b/arch/s390/pci/pci_bus.c @@ -126,6 +126,64 @@ static struct zpci_bus *zpci_bus_alloc(int pchid) return zbus; } +#ifdef CONFIG_PCI_IOV +static int zpci_bus_link_virtfn(struct pci_dev *pdev, + struct pci_dev *virtfn, int vfid) +{ + int rc; + + virtfn->physfn = pci_dev_get(pdev); + rc = pci_iov_sysfs_link(pdev, virtfn, vfid); + if (rc) { + pci_dev_put(pdev); + virtfn->physfn = NULL; + return rc; + } + return 0; +} + +static int zpci_bus_setup_virtfn(struct zpci_bus *zbus, + struct pci_dev *virtfn, int vfn) +{ + int i, cand_devfn; + struct zpci_dev *zdev; + struct pci_dev *pdev; + int vfid = vfn - 1; /* Linux' vfid's start at 0 vfn at 1*/ + int rc = 0; + + virtfn->is_virtfn = 1; + virtfn->multifunction = 0; + WARN_ON(vfid < 0); + /* If the parent PF for the given VF is also configured in the + * instance, it must be on the same zbus. + * We can then identify the parent PF by checking what + * devfn the VF would have if it belonged to that PF using the PF's + * stride and offset. Only if this candidate devfn matches the + * actual devfn will we link both functions. + */ + for (i = 0; i < ZPCI_FUNCTIONS_PER_BUS; i++) { + zdev = zbus->function[i]; + if (zdev && zdev->is_physfn) { + pdev = pci_get_slot(zbus->bus, zdev->devfn); + cand_devfn = pci_iov_virtfn_devfn(pdev, vfid); + if (cand_devfn == virtfn->devfn) { + rc = zpci_bus_link_virtfn(pdev, virtfn, vfid); + break; + } + } + } + return rc; +} +#else +static inline int zpci_bus_setup_virtfn(struct zpci_bus *zbus, + struct pci_dev *virtfn, int vfn) +{ + virtfn->is_virtfn = 1; + virtfn->multifunction = 0; + return 0; +} +#endif + static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev) { struct pci_bus *bus; @@ -156,10 +214,20 @@ static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev) } pdev = pci_scan_single_device(bus, zdev->devfn); - if (pdev) + if (pdev) { + if (!zdev->is_physfn) { + rc = zpci_bus_setup_virtfn(zbus, pdev, zdev->vfn); + if (rc) + goto failed_with_pdev; + } pci_bus_add_device(pdev); - + } return 0; + +failed_with_pdev: + pci_stop_and_remove_bus_device(pdev); + pci_dev_put(pdev); + return rc; } static void zpci_bus_add_devices(struct zpci_bus *zbus) diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c index 9b318824a134d..d7bd3c287cf7e 100644 --- a/arch/s390/pci/pci_clp.c +++ b/arch/s390/pci/pci_clp.c @@ -159,6 +159,7 @@ static int clp_store_query_pci_fn(struct zpci_dev *zdev, zdev->uid = response->uid; zdev->fmb_length = sizeof(u32) * response->fmb_len; zdev->rid_available = response->rid_avail; + zdev->is_physfn = response->is_physfn; if (!s390_pci_no_rid && zdev->rid_available) zdev->devfn = response->rid & ZPCI_RID_MASK_DEVFN; diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index ee6fbe6884989..b37e08c4f9d1a 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -571,9 +571,6 @@ static void sriov_del_vfs(struct pci_dev *dev) struct pci_sriov *iov = dev->sriov; int i; - if (dev->no_vf_scan) - return; - for (i = 0; i < iov->num_VFs; i++) pci_iov_remove_virtfn(dev, i); }