[PATCH v2 00/10] CXL EEH Handling

[Daniel Axtens <dja@axtens.net>]

CXL accelerators are unfortunately not immune from failure. This patch
set enables them to particpate in the Extended Error Handling process.

This series starts with a number of preparatory patches:

 - Patch 1 makes sure we don't touch the hardware when it has failed.
 
 - Patches 2-4 make the 'unplug' functions idempotent, so that if we
   get part way through recovery and then fail, being completely
   unplugged as part of removal doesn't cause us to oops out.

 - Patches 5 and 6 refactor init and teardown paths for the adapter
   and AFUs, so that they can be configured and deconfigured
   separately from their allocation and release.

 - Patch 7 stops cxl_reset from breaking EEH.

Patches 8 and 9 are parts of EEH.

 - Firstly we have a kernel flag that allows us to confidently assert
   the hardware will not change (be reflashed) when it it reset.

 - We then have the EEH support itself.

Finally, we add a CONFIG_CXL_EEH symbol that allows drivers to depend
on CXL EEH, or to be easily backportable if EEH is optional.

Changes from v1:
 - More comprehensive link down checks, including vPHB.
 - Rebased to apply cleanly to 4.2-rc4.
 - cxl reset changes.
 - CONFIG_CXL_EEH symbol addition.
 - add better vPHB support to EEH.

Daniel Axtens (10):
  cxl: Drop commands if the PCI channel is not in normal state
  cxl: Allocate and release the SPA with the AFU
  cxl: Make IRQ release idempotent
  cxl: Clean up adapter MMIO unmap path.
  cxl: Refactor adaptor init/teardown
  cxl: Refactor AFU init/teardown
  cxl: Don't remove AFUs/vPHBs in cxl_reset
  cxl: Allow the kernel to trust that an image won't change on PERST.
  cxl: EEH support
  cxl: Add CONFIG_CXL_EEH symbol

 Documentation/ABI/testing/sysfs-class-cxl |  10 +
 drivers/misc/cxl/Kconfig                  |   6 +
 drivers/misc/cxl/api.c                    |   9 +
 drivers/misc/cxl/context.c                |   6 +-
 drivers/misc/cxl/cxl.h                    |  41 ++-
 drivers/misc/cxl/file.c                   |  19 ++
 drivers/misc/cxl/irq.c                    |   9 +
 drivers/misc/cxl/native.c                 |  99 +++++-
 drivers/misc/cxl/pci.c                    | 521 ++++++++++++++++++++++++------
 drivers/misc/cxl/sysfs.c                  |  30 ++
 drivers/misc/cxl/vphb.c                   |  34 ++
 include/misc/cxl.h                        |  12 +
 12 files changed, 673 insertions(+), 123 deletions(-)

-- 
2.1.4