[PATCH v2 0/7] PCI: Solve two bridge window sizing issues

From: Ilpo Järvinen
Date: Thu Dec 28 2023 - 11:57:32 EST


Hi all,

Here's a series that contains two fixes to PCI bridge window sizing
algorithm. Together, they should enable remove & rescan cycle to work
for a PCI bus that has PCI devices with optional resources and/or
disparity in BAR sizes.

For the second fix, I chose to expose find_empty_resource_slot() from
kernel/resource.c because it should increase accuracy of the cannot-fit
decision (currently that function is called find_resource()). In order
to do that sensibly, a few improvements seemed in order to make its
interface and name of the function sane before exposing it. Thus, the
few extra patches on resource side.

Unfortunately I don't have a reason to suspect these would help with
the issues related to the currently ongoing resource regression
thread [1].

[1] https://lore.kernel.org/linux-pci/ZXpaNCLiDM+Kv38H@xxxxxxxxxxxxxxxxxxx/

v2:
- Add "typedef" to kerneldoc to get correct formatting
- Use RESOURCE_SIZE_MAX instead of literal
- Remove unnecessary checks for io{port/mem}_resource
- Apply a few style tweaks from Andy

Ilpo Järvinen (7):
PCI: Fix resource double counting on remove & rescan
resource: Rename find_resource() to find_empty_resource_slot()
resource: Document find_empty_resource_slot() and resource_constraint
resource: Use typedef for alignf callback
resource: Handle simple alignment inside __find_empty_resource_slot()
resource: Export find_empty_resource_slot()
PCI: Relax bridge window tail sizing rules

drivers/pci/bus.c | 10 ++----
drivers/pci/setup-bus.c | 80 +++++++++++++++++++++++++++++++++++++----
include/linux/ioport.h | 44 ++++++++++++++++++++---
include/linux/pci.h | 5 +--
kernel/resource.c | 68 ++++++++++++++++-------------------
5 files changed, 148 insertions(+), 59 deletions(-)

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2.30.2