[PATCH 0/7] Implement PCI Error Recovery on Navi12

[Andrey Grodzovsky]

Many PCI bus controllers are able to detect a variety of hardware PCI errors on the bus, 
such as parity errors on the data and address buses,  A typical action taken is to disconnect 
the affected device, halting all I/O to it. Typically, a reconnection mechanism is also offered, 
so that the affected PCI device(s) are reset and put back into working condition. 
In our case the reconnection mechanism is facilitated by kernel Downstream Port Containment (DPC) 
driver which will intercept the PCIe error, remove (isolate) the faulting device and reset the PCI 
link of the device after which it will call into PCIe recovery code of the PCI core. 
This code will call hooks which are implemented in this patchset where the error is 
first reported at which point we block the GPU scheduler, next DPC resets the 
PCI link which generates HW interrupt which is intercepted by SMU/PSP who 
start executing mode1 reset of the ASIC, next step is slot reset hook is called 
at which point we wait for ASIC reset to complete, restore PCI config space and run 
HW suspend/resume sequence to resinit the ASIC. 
Last hook called is resume normal operation at which point we will restart the GPU scheduler.

More info on PCIe error handling and DPC are here:
https://www.kernel.org/doc/html/latest/PCI/pci-error-recovery.html
https://patchwork.kernel.org/patch/8945681/

Andrey Grodzovsky (7):
  drm/amdgpu: Implement DPC recovery
  drm/amdgpu: Avoid accessing HW when suspending SW state
  drm/amdgpu: Block all job scheduling activity during DPC recovery
  drm/amdgpu: Fix SMU error failure
  drm/amdgpu: Fix consecutive DPC	recoveries failure.
  drm/amdgpu: Trim amdgpu_pci_slot_reset by reusing code.
  drm/amdgpu: Disable DPC for XGMI for now.

 drivers/gpu/drm/amd/amdgpu/amdgpu.h        |  16 ++
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 289 ++++++++++++++++++++++++++++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c    |  13 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c    |   6 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c    |   6 +
 drivers/gpu/drm/amd/amdgpu/atom.c          |   1 +
 drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c     |  18 +-
 drivers/gpu/drm/amd/amdgpu/nv.c            |   4 +-
 drivers/gpu/drm/amd/amdgpu/soc15.c         |   4 +-
 drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c  |   3 +
 drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c     |   3 +
 11 files changed, 344 insertions(+), 19 deletions(-)

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2.7.4