diff options
| author | Kai-Heng Feng <kaihengf@nvidia.com> | 2024-12-04 10:24:57 +0800 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2025-02-18 14:46:55 -0600 |
| commit | 1a596ad00ffe9b37fc60a93cbdd4daead3bf95f3 (patch) | |
| tree | 4483304ec3fc0135852eb91f0b9e57fc7bf48063 /tools/perf/scripts/python/event_analyzing_sample.py | |
| parent | addb30c5bd2755770e617e68bdcc0bf2a21770fa (diff) | |
PCI: Use downstream bridges for distributing resources
7180c1d08639 ("PCI: Distribute available resources for root buses, too")
breaks BAR assignment on some devices:
pci 0006:03:00.0: BAR 0 [mem 0x6300c0000000-0x6300c1ffffff 64bit pref]: assigned
pci 0006:03:00.1: BAR 0 [mem 0x6300c2000000-0x6300c3ffffff 64bit pref]: assigned
pci 0006:03:00.2: BAR 0 [mem size 0x00800000 64bit pref]: can't assign; no space
pci 0006:03:00.0: VF BAR 0 [mem size 0x02000000 64bit pref]: can't assign; no space
pci 0006:03:00.1: VF BAR 0 [mem size 0x02000000 64bit pref]: can't assign; no space
The apertures of domain 0006 before 7180c1d08639:
6300c0000000-63ffffffffff : PCI Bus 0006:00
6300c0000000-6300c9ffffff : PCI Bus 0006:01
6300c0000000-6300c9ffffff : PCI Bus 0006:02 # 160MB
6300c0000000-6300c8ffffff : PCI Bus 0006:03 # 144MB
6300c0000000-6300c1ffffff : 0006:03:00.0 # 32MB
6300c2000000-6300c3ffffff : 0006:03:00.1 # 32MB
6300c4000000-6300c47fffff : 0006:03:00.2 # 8MB
6300c4800000-6300c67fffff : 0006:03:00.0 # 32MB
6300c6800000-6300c87fffff : 0006:03:00.1 # 32MB
6300c9000000-6300c9bfffff : PCI Bus 0006:04 # 12MB
6300c9000000-6300c9bfffff : PCI Bus 0006:05 # 12MB
6300c9000000-6300c91fffff : PCI Bus 0006:06 # 2MB
6300c9200000-6300c93fffff : PCI Bus 0006:07 # 2MB
6300c9400000-6300c95fffff : PCI Bus 0006:08 # 2MB
6300c9600000-6300c97fffff : PCI Bus 0006:09 # 2MB
After 7180c1d08639:
6300c0000000-63ffffffffff : PCI Bus 0006:00
6300c0000000-6300c9ffffff : PCI Bus 0006:01
6300c0000000-6300c9ffffff : PCI Bus 0006:02 # 160MB
6300c0000000-6300c43fffff : PCI Bus 0006:03 # 68MB
6300c0000000-6300c1ffffff : 0006:03:00.0 # 32MB
6300c2000000-6300c3ffffff : 0006:03:00.1 # 32MB
--- no space --- : 0006:03:00.2 # 8MB
--- no space --- : 0006:03:00.0 # 32MB
--- no space --- : 0006:03:00.1 # 32MB
6300c4400000-6300c4dfffff : PCI Bus 0006:04 # 10MB
6300c4400000-6300c4dfffff : PCI Bus 0006:05 # 10MB
6300c4400000-6300c45fffff : PCI Bus 0006:06 # 2MB
6300c4600000-6300c47fffff : PCI Bus 0006:07 # 2MB
6300c4800000-6300c49fffff : PCI Bus 0006:08 # 2MB
6300c4a00000-6300c4bfffff : PCI Bus 0006:09 # 2MB
We can see that the window to 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 bridge, hence makes the aperture smaller than
desired because calculation of io_per_b, mmio_per_b and mmio_pref_per_b
becomes incorrect.
Instead, distribute downstream bridges' own resources to resolve the issue.
Link: https://lore.kernel.org/r/20241204022457.51322-1-kaihengf@nvidia.com
Fixes: 7180c1d08639 ("PCI: Distribute available resources for root buses, too")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219540
Signed-off-by: Kai-Heng Feng <kaihengf@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Carol Soto <csoto@nvidia.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Chris Chiu <chris.chiu@canonical.com>
Diffstat (limited to 'tools/perf/scripts/python/event_analyzing_sample.py')
0 files changed, 0 insertions, 0 deletions