Re: [PATCH v3 0/8] PCI: Solve two bridge window sizing issues

[Bjorn Helgaas <helgaas@kernel.org>]

On Tue, May 07, 2024 at 01:25:15PM +0300, Ilpo Järvinen wrote:
> 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_resource_space() 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.
> 
> v3:
> - Removed "slot" wording
>         - Renamed find_empty_resource_slot() -> find_resource_space()
> - find_resource_space() returns bool instead of int
> - Added patch to convert literal 20 related to bridge win minimum
>   alignment to __ffs(SZ_1M)
> - Fixed kerneldoc missing "struct"
> - Tweaked prints (one dbg -> info, added new dbg one for success case)
> - Changelog tweaks
>         - Take account largest >> 1 (in alignment calc)
>         - Adjust to minor changes made into calculate_memsize()
>         - Take logs from more recent kernel to get rid of reg 0xXX
> 
> 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 (8):
>   PCI: Fix resource double counting on remove & rescan
>   resource: Rename find_resource() to find_resource_space()
>   resource: Document find_resource_space() and resource_constraint
>   resource: Use typedef for alignf callback
>   resource: Handle simple alignment inside __find_resource_space()
>   resource: Export find_resource_space()
>   PCI: Make minimum bridge window alignment reference more obvious
>   PCI: Relax bridge window tail sizing rules
> 
>  drivers/pci/bus.c       | 10 +----
>  drivers/pci/setup-bus.c | 91 +++++++++++++++++++++++++++++++++++++----
>  include/linux/ioport.h  | 44 ++++++++++++++++++--
>  include/linux/pci.h     |  5 +--
>  kernel/resource.c       | 68 ++++++++++++++----------------
>  5 files changed, 157 insertions(+), 61 deletions(-)

Applied to pci/resource for v6.11, thanks!