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[0/3] PCI: Minimizing resource assignment algorithm

Message ID 20200928010609.5375-1-jonathan.derrick@intel.com
Headers show
Series PCI: Minimizing resource assignment algorithm | expand


Derrick, Jonathan Sept. 28, 2020, 1:06 a.m. UTC
This set adds a minimizing resource assignment algorithm. VMD domains
frequently have issues with default hotplug settings and large arrays of
drives such as those in JBOFs. This algorithm uses the default or
user-specified hotplug resource settings, then tries with minimal
settings using 256 for IO, and 1MB for MMIO and Prefetch, and finally
tries without additional hotplug resources as if the bridge were not
hotplug capable.

This set allows a resource constrained domain to at the very least
enumerate and attach drivers to devices, though may not result in
supportable hotplug slot if a device is not already occupied in the

Jon Derrick (3):
  PCI: Create helper to release/restore bridge resources
  PCI: Introduce a minimizing assignment algorithm
  PCI: vmd: Wire up VMD for fallback resource assignment

 drivers/pci/controller/vmd.c |   2 +-
 drivers/pci/setup-bus.c      | 147 ++++++++++++++++++++++++++++-------
 include/linux/pci.h          |   2 +
 3 files changed, 124 insertions(+), 27 deletions(-)


Christoph Hellwig Sept. 28, 2020, 7:16 a.m. UTC | #1
<broken record>
Intel, please just allow us to opt-out of using VMD as VMD just makes
life miserable.  Thanks!
</broken record>