| Message ID | 20241128084039.54972-1-kaihengf@nvidia.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | PCI: Use downstream bridges for distributing resources | expand |
On Thu, Nov 28, 2024 at 04:40:39PM +0800, Kai-Heng Feng wrote: > Commit 7180c1d08639 ("PCI: Distribute available resources for root > buses, too") breaks BAR assignment on some devcies: > [ 10.021193] pci 0006:03:00.0: BAR 0 [mem 0x6300c0000000-0x6300c1ffffff 64bit pref]: assigned > [ 10.029880] pci 0006:03:00.1: BAR 0 [mem 0x6300c2000000-0x6300c3ffffff 64bit pref]: assigned > [ 10.038561] pci 0006:03:00.2: BAR 0 [mem size 0x00800000 64bit pref]: can't assign; no space > [ 10.047191] pci 0006:03:00.2: BAR 0 [mem size 0x00800000 64bit pref]: failed to assign > [ 10.055285] pci 0006:03:00.0: VF BAR 0 [mem size 0x02000000 64bit pref]: can't assign; no space > [ 10.064180] pci 0006:03:00.0: VF BAR 0 [mem size 0x02000000 64bit pref]: failed to assign > [ 10.072543] pci 0006:03:00.1: VF BAR 0 [mem size 0x02000000 64bit pref]: can't assign; no space > [ 10.081437] pci 0006:03:00.1: VF BAR 0 [mem size 0x02000000 64bit pref]: failed to assign > > The apertures of domain 0006 before the commit: > 6300c0000000-63ffffffffff : PCI Bus 0006:00 > 6300c0000000-6300c9ffffff : PCI Bus 0006:01 > 6300c0000000-6300c9ffffff : PCI Bus 0006:02 > 6300c0000000-6300c8ffffff : PCI Bus 0006:03 > 6300c0000000-6300c1ffffff : 0006:03:00.0 > 6300c0000000-6300c1ffffff : mlx5_core > 6300c2000000-6300c3ffffff : 0006:03:00.1 > 6300c2000000-6300c3ffffff : mlx5_core > 6300c4000000-6300c47fffff : 0006:03:00.2 > 6300c4800000-6300c67fffff : 0006:03:00.0 > 6300c6800000-6300c87fffff : 0006:03:00.1 > 6300c9000000-6300c9bfffff : PCI Bus 0006:04 > 6300c9000000-6300c9bfffff : PCI Bus 0006:05 > 6300c9000000-6300c91fffff : PCI Bus 0006:06 > 6300c9200000-6300c93fffff : PCI Bus 0006:07 > 6300c9400000-6300c95fffff : PCI Bus 0006:08 > 6300c9600000-6300c97fffff : PCI Bus 0006:09 > > After the commit: > 6300c0000000-63ffffffffff : PCI Bus 0006:00 > 6300c0000000-6300c9ffffff : PCI Bus 0006:01 > 6300c0000000-6300c9ffffff : PCI Bus 0006:02 > 6300c0000000-6300c43fffff : PCI Bus 0006:03 > 6300c0000000-6300c1ffffff : 0006:03:00.0 > 6300c0000000-6300c1ffffff : mlx5_core > 6300c2000000-6300c3ffffff : 0006:03:00.1 > 6300c2000000-6300c3ffffff : mlx5_core > 6300c4400000-6300c4dfffff : PCI Bus 0006:04 > 6300c4400000-6300c4dfffff : PCI Bus 0006:05 > 6300c4400000-6300c45fffff : PCI Bus 0006:06 > 6300c4600000-6300c47fffff : PCI Bus 0006:07 > 6300c4800000-6300c49fffff : PCI Bus 0006:08 > 6300c4a00000-6300c4bfffff : PCI Bus 0006:09 > > We can see that the window of 0006:03 gets shrunken too much and 0006:04 > eats away the window for 0006:03:00.2. > > The offending commit distributes the upstream bridge's resources > multiple times to every downstream bridges, hence makes the aperture > smaller than desired because calculation of io_per_b, mmio_per_b and > mmio_pref_per_b becomes incorrect. > > Instead, distributing downstream bridges' own resources to resolve the > issue. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=219540 > Cc: Carol Soto <csoto@nvidia.com> > Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Cc: Chris Chiu <chris.chiu@canonical.com> > Cc: Mika Westerberg <mika.westerberg@linux.intel.com> > Reviewed-by: Matthew R. Ochs <mochs@nvidia.com> > Reviewed-by: Koba Ko <kobak@nvidia.com> > Fixes: 7180c1d08639 ("PCI: Distribute available resources for root buses, too") > Signed-off-by: Kai-Heng Feng <kaihengf@nvidia.com> > --- > drivers/pci/setup-bus.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index 23082bc0ca37..2db19c17e824 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -2105,7 +2105,7 @@ pci_root_bus_distribute_available_resources(struct pci_bus *bus, > * in case of root bukjijs. > */ > if (bridge && pci_bridge_resources_not_assigned(dev)) > - pci_bridge_distribute_available_resources(bridge, > + pci_bridge_distribute_available_resources(dev, > add_list); I think it looks better if you put this into one line instead: pci_bridge_distribute_available_resources(dev, add_list); Otherwise looks good. I wonder if you checked that this still works with the cases 7180c1d08639 tried to solve? ;-) > else > pci_root_bus_distribute_available_resources(b, add_list); > -- > 2.47.0
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 23082bc0ca37..2db19c17e824 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -2105,7 +2105,7 @@ pci_root_bus_distribute_available_resources(struct pci_bus *bus, * in case of root bus. */ if (bridge && pci_bridge_resources_not_assigned(dev)) - pci_bridge_distribute_available_resources(bridge, + pci_bridge_distribute_available_resources(dev, add_list); else pci_root_bus_distribute_available_resources(b, add_list);
Commit 7180c1d08639 ("PCI: Distribute available resources for root buses, too") breaks BAR assignment on some devcies: [ 10.021193] pci 0006:03:00.0: BAR 0 [mem 0x6300c0000000-0x6300c1ffffff 64bit pref]: assigned [ 10.029880] pci 0006:03:00.1: BAR 0 [mem 0x6300c2000000-0x6300c3ffffff 64bit pref]: assigned [ 10.038561] pci 0006:03:00.2: BAR 0 [mem size 0x00800000 64bit pref]: can't assign; no space [ 10.047191] pci 0006:03:00.2: BAR 0 [mem size 0x00800000 64bit pref]: failed to assign [ 10.055285] pci 0006:03:00.0: VF BAR 0 [mem size 0x02000000 64bit pref]: can't assign; no space [ 10.064180] pci 0006:03:00.0: VF BAR 0 [mem size 0x02000000 64bit pref]: failed to assign [ 10.072543] pci 0006:03:00.1: VF BAR 0 [mem size 0x02000000 64bit pref]: can't assign; no space [ 10.081437] pci 0006:03:00.1: VF BAR 0 [mem size 0x02000000 64bit pref]: failed to assign The apertures of domain 0006 before the commit: 6300c0000000-63ffffffffff : PCI Bus 0006:00 6300c0000000-6300c9ffffff : PCI Bus 0006:01 6300c0000000-6300c9ffffff : PCI Bus 0006:02 6300c0000000-6300c8ffffff : PCI Bus 0006:03 6300c0000000-6300c1ffffff : 0006:03:00.0 6300c0000000-6300c1ffffff : mlx5_core 6300c2000000-6300c3ffffff : 0006:03:00.1 6300c2000000-6300c3ffffff : mlx5_core 6300c4000000-6300c47fffff : 0006:03:00.2 6300c4800000-6300c67fffff : 0006:03:00.0 6300c6800000-6300c87fffff : 0006:03:00.1 6300c9000000-6300c9bfffff : PCI Bus 0006:04 6300c9000000-6300c9bfffff : PCI Bus 0006:05 6300c9000000-6300c91fffff : PCI Bus 0006:06 6300c9200000-6300c93fffff : PCI Bus 0006:07 6300c9400000-6300c95fffff : PCI Bus 0006:08 6300c9600000-6300c97fffff : PCI Bus 0006:09 After the commit: 6300c0000000-63ffffffffff : PCI Bus 0006:00 6300c0000000-6300c9ffffff : PCI Bus 0006:01 6300c0000000-6300c9ffffff : PCI Bus 0006:02 6300c0000000-6300c43fffff : PCI Bus 0006:03 6300c0000000-6300c1ffffff : 0006:03:00.0 6300c0000000-6300c1ffffff : mlx5_core 6300c2000000-6300c3ffffff : 0006:03:00.1 6300c2000000-6300c3ffffff : mlx5_core 6300c4400000-6300c4dfffff : PCI Bus 0006:04 6300c4400000-6300c4dfffff : PCI Bus 0006:05 6300c4400000-6300c45fffff : PCI Bus 0006:06 6300c4600000-6300c47fffff : PCI Bus 0006:07 6300c4800000-6300c49fffff : PCI Bus 0006:08 6300c4a00000-6300c4bfffff : PCI Bus 0006:09 We can see that the window of 0006:03 gets shrunken too much and 0006:04 eats away the window for 0006:03:00.2. The offending commit distributes the upstream bridge's resources multiple times to every downstream bridges, hence makes the aperture smaller than desired because calculation of io_per_b, mmio_per_b and mmio_pref_per_b becomes incorrect. Instead, distributing downstream bridges' own resources to resolve the issue. Link: https://bugzilla.kernel.org/show_bug.cgi?id=219540 Cc: Carol Soto <csoto@nvidia.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Chris Chiu <chris.chiu@canonical.com> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Matthew R. Ochs <mochs@nvidia.com> Reviewed-by: Koba Ko <kobak@nvidia.com> Fixes: 7180c1d08639 ("PCI: Distribute available resources for root buses, too") Signed-off-by: Kai-Heng Feng <kaihengf@nvidia.com> --- drivers/pci/setup-bus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)