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[00/32] genirq/msi, PCI/MSI: Spring cleaning - Part 2

Message ID 20211126230957.239391799@linutronix.de
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Series genirq/msi, PCI/MSI: Spring cleaning - Part 2 | expand

Message

Thomas Gleixner Nov. 27, 2021, 1:22 a.m. UTC 
This is the third part of [PCI]MSI refactoring which aims to provide the
ability of expanding MSI-X vectors after enabling MSI-X.

The first two parts of this work can be found here:

    https://lore.kernel.org/r/20211126222700.862407977@linutronix.de
    https://lore.kernel.org/r/20211126224100.303046749@linutronix.de

This third part has the following important changes:

   1) Add locking to protect the MSI descriptor storage

      Right now the MSI descriptor storage (linked list) is not protected
      by anything under the assumption that the list is installed before
      use and destroyed after use. As this is about to change there has to
      be protection

   2) A new set of iterators which allow filtering on the state of the
      descriptors namely whether a descriptor is associated to a Linux
      interrupt or not.

      This cleans up a lot of use cases which have to do this filtering
      manually.

   3) A new set of MSI descriptor allocation functions which make the usage
      sites simpler and confine the storage handling to the core code.

      Trivial MSI descriptors (non PCI) are now allocated by the core code
      automatically when the underlying irq domain requests that.

   4) Rework of sysfs handling to prepare for dynamic extension of MSI-X

      The current mechanism which creates the directory and the attributes
      for all MSI descriptors in one go is obviously not suitable for
      dynamic extension. The rework splits the directory creation out and
      lets the MSI interrupt allocation create the per descriptor
      attributes.

   5) Conversion of the MSI descriptor storage to xarray

      The linked list based storage is suboptimal even without dynamic
      expansion as it requires full list walks to get to a specific
      descriptor. With dynamic expansion this gets even more
      convoluted. Xarray is way more suitable and simplifies the
      final goal of dynamic expansion of the MSI-X space.

This third series is based on:

     git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git msi-v1-part-2

and also available from git:

     git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git msi-v1-part-3

For the curious who can't wait for the next part to arrive the full series
is available via:

     git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git msi-v1-part-4

Thanks,

	tglx
---
 .clang-format                          |    1 
 arch/powerpc/platforms/4xx/hsta_msi.c  |    7 
 arch/powerpc/platforms/cell/axon_msi.c |    7 
 arch/powerpc/platforms/pasemi/msi.c    |    9 
 arch/powerpc/sysdev/fsl_msi.c          |    8 
 arch/powerpc/sysdev/mpic_u3msi.c       |    9 
 arch/s390/pci/pci_irq.c                |    6 
 arch/x86/pci/xen.c                     |   14 
 drivers/base/core.c                    |    3 
 drivers/base/platform-msi.c            |  110 -----
 drivers/bus/fsl-mc/fsl-mc-msi.c        |   61 --
 drivers/ntb/msi.c                      |   19 
 drivers/pci/controller/pci-hyperv.c    |   15 
 drivers/pci/msi/irqdomain.c            |   11 
 drivers/pci/msi/legacy.c               |   20 
 drivers/pci/msi/msi.c                  |  255 +++++------
 drivers/pci/xen-pcifront.c             |    2 
 drivers/soc/ti/ti_sci_inta_msi.c       |   77 +--
 include/linux/device.h                 |    4 
 include/linux/msi.h                    |  135 +++++-
 include/linux/soc/ti/ti_sci_inta_msi.h |    1 
 kernel/irq/msi.c                       |  719 ++++++++++++++++++++++-----------
 22 files changed, 841 insertions(+), 652 deletions(-)