[PATCH v4 0/7] PCI: VF resizable BAR

[Michał Winiarski]

Hi,

In v4, the approach to extending the BAR was changed to follow the
suggestion from Christian.
The control is now entirely on the driver side, with PCI subsystem
checking whether the resource fits during VF enabling.
I also added helpers to move between IOV / BAR # (suggested by Ilpo),
since the ifdefs started to look mighty ugly after addressing some of
the review feedback.

v3 can be found here:
https://lore.kernel.org/dri-devel/20241010103203.382898-1-michal.winiarski@intel.com/

For regular BAR, drivers can use pci_resize_resource to resize it to the
desired size provided that it is supported by the hardware, which the
driver can query using pci_rebar_get_possible_sizes.
This series expands the API to work with IOV BAR as well.
It also adds the additional API for drivers to change the VF BAR size
without resizing the entire underlying reservation (within the original
resource boundary).

Thanks,
-Michał

v1 -> v2:
- Add pci_iov_resource_extend() and usage in Xe driver
- Reduce the number of ifdefs (Christian)
- Drop patch 2/2 from v1 (Christian)
- Add a helper to avoid upsetting static analysis tools (Krzysztof)

v2 -> v3:
- Extract introducing pci_resource_is_iov to separate commit and
  use it elsewhere in PCI subsystem (Christian)
- Extract restoring VF rebar state to separate commit (Christian)
- Reorganize memory decoding check (Christian)
- Don't use dev_WARN (Ilpo)
- Fix build without CONFIG_PCI_IOV (CI)

v3 -> v4:
- Change the approach to extending the BAR (Christian)
- Tidy the commit messages, use 80 line limit where necessary (Bjorn)
- Add kerneldocs to exported functions (Bjorn)
- Add pci_resource_to_iov() / pci_resource_from_iov() helpers (Ilpo)
- Use FIELD_GET(), tidy whitespace (Ilpo)

Michał Winiarski (7):
  PCI/IOV: Restore VF resizable BAR state after reset
  PCI: Add a helper to identify IOV resources
  PCI: Add a helper to convert between standard and IOV resources
  PCI: Allow IOV resources to be resized in pci_resize_resource()
  PCI/IOV: Check that VF BAR fits within the reservation
  PCI: Allow drivers to control VF BAR size
  drm/xe/pf: Set VF LMEM BAR size

 drivers/gpu/drm/xe/regs/xe_bars.h |   1 +
 drivers/gpu/drm/xe/xe_pci_sriov.c |  22 +++++
 drivers/pci/iov.c                 | 158 +++++++++++++++++++++++++++---
 drivers/pci/pci.c                 |  10 +-
 drivers/pci/pci.h                 |  45 ++++++++-
 drivers/pci/setup-bus.c           |   9 +-
 drivers/pci/setup-res.c           |  40 ++++++--
 include/linux/pci.h               |   6 ++
 include/uapi/linux/pci_regs.h     |   1 +
 9 files changed, 261 insertions(+), 31 deletions(-)

-- 
2.47.0