RE: [PATCH 00/25] PCI: Resource fitting/assignment fixes and cleanups

[Ilpo Järvinen]

Hi Bjorn,

Can you please add to the last patch of the series:

Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219547

...And also Xiaochun's tested by tag from below to the series.

On Fri, 14 Feb 2025, Xiaochun XC17 Li | 李小春 Xavier wrote:
> On Mon, Dec 16, 2024 at 7:56:45PM +0200 Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> wrote:
> > From: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> > 
> > Hi all,
> > 
> > This series focuses on PCI resource fitting and assignment algorithms.
> > I've further changes in works to enable handling resizable BARs better during
> > resource fitting built on top of these, but that's still WIP and this series seems
> > way too large as is to have more stuff included.
> > 
> > First there are small tweaks and fixes to the relaxed tail alignment code and
> > applying the lessons learned to other similar cases. They are sort of
> > independent of the rest. Then a large set of pure cleanups and refactoring that
> > are not intended to make any functional changes.
> > Finally, starting from "PCI: Extend enable to check for any optional resource" are
> > again patches that aim to make behavioral changes to fix bridge window sizing
> > to consider expansion ROM as an optional resource (to fix a remove/rescan
> > cycle issue) and improve resource fitting algorithm in general.
> > 
> > The series includes one of the change from Michał Winiarski
> > <michal.winiarski@xxxxxxxxx> as these changes also touch the same IOV checks.
> > 
> > Please let me know if you'd prefer me to order the changes differently or split it
> > into smaller chunks.
> > 
> > 
> > I've extensively tested this series over the hosts in our lab which have quite
> > heterogeneous PCI setup each. There were no losses of any important resource.
> > Without pci=realloc, there's some churn in which of the disabled expansion
> > ROMs gets a scarce memory space assigned (with pci=realloc, they are all
> > assigned large enough bridge window).
> > 
> > 
> > Ilpo Järvinen (24):
> >   PCI: Remove add_align overwrite unrelated to size0
> >   PCI: size0 is unrelated to add_align
> >   PCI: Simplify size1 assignment logic
> >   PCI: Optional bridge window size too may need relaxing
> >   PCI: Fix old_size lower bound in calculate_iosize() too
> >   PCI: Use SZ_* instead of literals in setup-bus.c
> >   PCI: resource_set_range/size() conversions
> >   PCI: Check resource_size() separately
> >   PCI: Add pci_resource_num() helper
> >   PCI: Add dev & res local variables to resource assignment funcs
> >   PCI: Converge return paths in __assign_resources_sorted()
> >   PCI: Refactor pdev_sort_resources() & __dev_sort_resources()
> >   PCI: Use while loop and break instead of gotos
> >   PCI: Rename retval to ret
> >   PCI: Consolidate assignment loop next round preparation
> >   PCI: Remove wrong comment from pci_reassign_resource()
> >   PCI: Add restore_dev_resource()
> >   PCI: Extend enable to check for any optional resource
> >   PCI: Always have realloc_head in __assign_resources_sorted()
> >   PCI: Indicate optional resource assignment failures
> >   PCI: Add debug print when releasing resources before retry
> >   PCI: Use res->parent to check is resource is assigned

I also noticed there's a typo here, should be "if resource is assigned"

My apologies for the extra work.

> >   PCI: Perform reset_resource() and build fail list in sync
> >   PCI: Rework optional resource handling
> > 
> > Michał Winiarski (1):
> >   PCI: Add a helper to identify IOV resources
> > 
> >  drivers/pci/pci.h       |  44 +++-
> >  drivers/pci/setup-bus.c | 566 +++++++++++++++++++++++-----------------
> >  drivers/pci/setup-res.c |   8 +-
> >  3 files changed, 364 insertions(+), 254 deletions(-)
> > 
> Hi, all
> This series has undergone testing on the following configurations:
> - Lenovo ThinkSystem SR630 V4 equipped with Intel Granite Rapids CPUs.
> - The latest upstream kernel v6.14-rc2 and the stable kernel 6.13.2.
> - With "pci=realloc" appended to the kernel command line.
> - Red Hat Enterprise Linux 10.0 Beta.
> 
> Test results:
> - All patches were applied cleanly and the build process was successful.
> - The assignment for the ROM BAR of downstream devices was successful.
> - The bridge window has been adjusted to fit the downstream resources.
> 
> Tested-by: Xiaochun Lee <lixc17@xxxxxxxxxx>


-- 
 i.