| Message ID | 20200602094536.750273-3-frank.heimes@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | s390x/pci: fix linking between PF and VF for multifunction devices (LP: 1879704) | expand |
On 2020-06-02 11:45, frank.heimes@canonical.com wrote: > From: Niklas Schnelle <schnelle@linux.ibm.com> > > BugLink: https://bugs.launchpad.net/bugs/1879704 > > 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 <schnelle@linux.ibm.com> > Acked-by: Bjorn Helgaas <bhelgaas@google.com> > Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> > [ schnelle: Link: https://lore.kernel.org/r/20200506154139.90609-3-schnelle@linux.ibm.com ] > Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> > (cherry picked from commit e5794cf1a270d813a5b9373a6876487d4d154195) This patch has not been merged into Linus' tree yet, so the above line should be: (cherry picked from commit e5794cf1a270d813a5b9373a6876487d4d154195 linux-next) > Signed-off-by: Frank Heimes <frank.heimes@canonical.com> > --- > arch/s390/include/asm/pci.h | 3 +- > arch/s390/include/asm/pci_clp.h | 3 +- > arch/s390/pci/pci_bus.c | 72 ++++++++++++++++++++++++++++++++- > arch/s390/pci/pci_clp.c | 1 + > drivers/pci/iov.c | 3 -- > 5 files changed, 75 insertions(+), 7 deletions(-) > > diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h > index 4bbd2c79ec4a..ea0daab3eb80 100644 > --- a/arch/s390/include/asm/pci.h > +++ b/arch/s390/include/asm/pci.h > @@ -133,7 +133,8 @@ 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 4391ce82230f..641b7e8d0226 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 fdc36f948ab2..d5fa0130604d 100644 > --- a/arch/s390/pci/pci_bus.c > +++ b/arch/s390/pci/pci_bus.c > @@ -121,6 +121,64 @@ 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; > @@ -151,10 +209,20 @@ 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 f7dfcd9f8b9e..e71133031f62 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 9c778671db99..693c940c13b4 100644 > --- a/drivers/pci/iov.c > +++ b/drivers/pci/iov.c > @@ -566,9 +566,6 @@ 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); > } >
diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h index 4bbd2c79ec4a..ea0daab3eb80 100644 --- a/arch/s390/include/asm/pci.h +++ b/arch/s390/include/asm/pci.h @@ -133,7 +133,8 @@ 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 4391ce82230f..641b7e8d0226 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 fdc36f948ab2..d5fa0130604d 100644 --- a/arch/s390/pci/pci_bus.c +++ b/arch/s390/pci/pci_bus.c @@ -121,6 +121,64 @@ 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; @@ -151,10 +209,20 @@ 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 f7dfcd9f8b9e..e71133031f62 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 9c778671db99..693c940c13b4 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -566,9 +566,6 @@ 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); }