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author | Niklas Schnelle <schnelle@linux.ibm.com> | 2022-06-28 16:30:58 +0200 |
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committer | Bjorn Helgaas <bhelgaas@google.com> | 2022-07-22 16:05:21 -0500 |
commit | db360b1ea7faef290471bc1b2a7463b96fd20a07 (patch) | |
tree | 9934629420b3e0f36355239baa8dbeb99fd2aaf3 /drivers/pci/probe.c | |
parent | fbed59ed8781d7eecd7f45cde0188cf24eeb5c38 (diff) | |
download | linux-db360b1ea7faef290471bc1b2a7463b96fd20a07.tar.gz linux-db360b1ea7faef290471bc1b2a7463b96fd20a07.tar.bz2 linux-db360b1ea7faef290471bc1b2a7463b96fd20a07.zip |
PCI: Move jailhouse's isolated function handling to pci_scan_slot()
The special case of the jailhouse hypervisor passing through individual PCI
functions handles scanning for PCI functions even if function 0 does not
exist. Previously this was done with an extra loop duplicating the one in
pci_scan_slot(). By incorporating the check for jailhouse_paravirt() into
pci_scan_slot() we can instead do this as part of the normal slot scan.
Note that with the assignment of dev->multifunction gated by fn > 0 we set
dev->multifunction unconditionally for all functions if function 0 is
missing just as in the existing jailhouse loop.
The only functional change is that we now call pcie_aspm_init_link_state()
for these functions, but this already happened if function 0 was passed
through and should not be a problem.
Link: https://lore.kernel.org/linux-pci/20220408224514.GA353445@bhelgaas/
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20220628143100.3228092-4-schnelle@linux.ibm.com
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Diffstat (limited to 'drivers/pci/probe.c')
-rw-r--r-- | drivers/pci/probe.c | 30 |
1 files changed, 10 insertions, 20 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index d62885519df3..1f91ed67b5c5 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2663,8 +2663,13 @@ int pci_scan_slot(struct pci_bus *bus, int devfn) if (fn > 0) dev->multifunction = 1; } else if (fn == 0) { - /* function 0 is required */ - break; + /* + * Function 0 is required unless we are running on + * a hypervisor that passes through individual PCI + * functions. + */ + if (!jailhouse_paravirt()) + break; } fn = next_fn(bus, dev, fn); } while (fn >= 0); @@ -2863,29 +2868,14 @@ static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, { unsigned int used_buses, normal_bridges = 0, hotplug_bridges = 0; unsigned int start = bus->busn_res.start; - unsigned int devfn, fn, cmax, max = start; + unsigned int devfn, cmax, max = start; struct pci_dev *dev; - int nr_devs; dev_dbg(&bus->dev, "scanning bus\n"); /* Go find them, Rover! */ - for (devfn = 0; devfn < 256; devfn += 8) { - nr_devs = pci_scan_slot(bus, devfn); - - /* - * The Jailhouse hypervisor may pass individual functions of a - * multi-function device to a guest without passing function 0. - * Look for them as well. - */ - if (jailhouse_paravirt() && nr_devs == 0) { - for (fn = 1; fn < 8; fn++) { - dev = pci_scan_single_device(bus, devfn + fn); - if (dev) - dev->multifunction = 1; - } - } - } + for (devfn = 0; devfn < 256; devfn += 8) + pci_scan_slot(bus, devfn); /* Reserve buses for SR-IOV capability */ used_buses = pci_iov_bus_range(bus); |