Re: [RFC PATCH 0/9] Add RCEC handling to PCI/AER

Jonathan Cameron
2020-07-27T12:39:02Z

On Fri, 24 Jul 2020 10:22:14 -0700
Sean V Kelley <sean.v.kelley@intel.com> wrote:

> Root Complex Event Collectors (RCEC) provide support for terminating error
> and PME messages from Root Complex Integrated Endpoints (RCiEPs). An RCEC
> resides on a Bus in the Root Complex. Multiple RCECs can in fact reside on
> a single bus. An RCEC will explicitly declare supported RCiEPs through the
> Root Complex Endpoint Association Extended Capability.
>
> (See PCIe 5.0-1, sections 1.3.2.3 (RCiEP), and 7.9.10 (RCEC Ext. Cap.))
>
> The kernel lacks handling for these RCECs and the error messages received
> from their respective associated RCiEPs. More recently, a new CPU
> interconnect, Compute eXpress Link (CXL) depends on RCEC capabilities for
> purposes of error messaging from CXL 1.1 supported RCiEP devices.
>
> DocLink: https://www.computeexpresslink.org/
>
> This use case is not limited to CXL. Existing hardware today includes
> support for RCECs, such as the Denverton microserver product
> family. Future hardware will be forthcoming.
>
> (See Intel Document, Order number: 33061-003US)
>
> So services such as AER or PME could be associated with an RCEC driver.
> In the case of CXL, if an RCiEP (i.e., CXL 1.1 device) is associated with a
> platform's RCEC it shall signal PME and AER error conditions through that
> RCEC.
>
> Towards the above use cases, add the missing RCEC class and extend the
> PCIe Root Port and service drivers to allow association of RCiEPs to their
> respective parent RCEC and facilitate handling of terminating error and PME
> messages.

Silly question number 1. Why an RFC? I always find it helps to highlight which
bits you are unsure on / want particular input on.

Otherwise, I've left the PME and error injection patches as I don't really know
anything about those two paths.

I'll fire up my APEI etc test VMs in the nex day or so and report back if there
any problems with that case (fairly sure there is one in patch 6, highlighted in
review but it is possible I've missed others.

It all seems to have come together rather simpler than I was expecting which is
great!

Thanks,

Jonathan

>
> TESTING:
>
> Results:
> 1) Show RCiEPs which are associated with RCECs:
> Run dmesg | grep "RCiEP"
> Log:
> [ 8.981698] pcieport 0000:e8:00.4: RCiEP(under an RCEC) 0000:e8:01.0
> [ 8.988830] pcieport 0000:e8:00.4: RCiEP(under an RCEC) 0000:e8:02.0
> [ 8.995956] pcieport 0000:e8:00.4: RCiEP(under an RCEC) 0000:e9:00.0
> [ 9.023034] pcieport 0000:ed:00.4: RCiEP(under an RCEC) 0000:ed:01.0
> [ 9.030159] pcieport 0000:ed:00.4: RCiEP(under an RCEC) 0000:ed:02.0
> [ 9.037282] pcieport 0000:ed:00.4: RCiEP(under an RCEC) 0000:ee:00.0
> [ 9.064294] pcieport 0000:f2:00.4: RCiEP(under an RCEC) 0000:f2:01.0
> [ 9.071409] pcieport 0000:f2:00.4: RCiEP(under an RCEC) 0000:f2:02.0
> [ 9.078526] pcieport 0000:f2:00.4: RCiEP(under an RCEC) 0000:f3:00.0
> [ 9.105535] pcieport 0000:f7:00.4: RCiEP(under an RCEC) 0000:f7:01.0
> [ 9.112652] pcieport 0000:f7:00.4: RCiEP(under an RCEC) 0000:f7:02.0
> [ 9.119774] pcieport 0000:f7:00.4: RCiEP(under an RCEC) 0000:f8:00.0
>
> 2) Inject a correctable error to the RCiEP 0000:e9:00.0
> Run ./aer_inject <a parameter file as below>:
> AER
> PCI_ID 0000:e9:00.0
> COR_STATUS BAD_TLP
> HEADER_LOG 0 1 2 3
>
> Log:
> [ 253.248362] pcieport 0000:e8:00.4: aer_inject: Injecting errors 00000040/00000000 into device 0000:e9:00.0
> [ 253.260656] pcieport 0000:e8:00.4: AER: Corrected error received: 0000:e9:00.0
> [ 253.269919] pci 0000:e9:00.0: AER: PCIe Bus Error: severity=Corrected, type=Data Link Layer, (Receiver ID)
> [ 253.282549] pci 0000:e9:00.0: AER: device [8086:4940] error status/mask=00000040/00002000
> [ 253.293937] pci 0000:e9:00.0: AER: [ 6] BadTLP
>
> 3) Inject a non-fatal error to the RCiEP 0000:e8:01.0
> Run ./aer_inject <a parameter file as below>:
> AER
> PCI_ID 0000:e8:01.0
> UNCOR_STATUS COMP_ABORT
> HEADER_LOG 0 1 2 3
>
> Log:
> [ 288.405326] pcieport 0000:e8:00.4: aer_inject: Injecting errors 00000000/00008000 into device 0000:e8:01.0
> [ 288.416881] pcieport 0000:e8:00.4: AER: Uncorrected (Non-Fatal) error received: 0000:e8:01.0
> [ 288.427487] igen6_edac 0000:e8:01.0: AER: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Completer ID)
> [ 288.442098] igen6_edac 0000:e8:01.0: AER: device [8086:0b25] error status/mask=00008000/00100000
> [ 288.452869] igen6_edac 0000:e8:01.0: AER: [15] CmpltAbrt
> [ 288.461118] igen6_edac 0000:e8:01.0: AER: TLP Header: 00000000 00000001 00000002 00000003
> [ 288.471192] igen6_edac 0000:e8:01.0: AER: device recovery successful
>
> 4) Inject a fatal error to the RCiEP 0000:ed:01.0
> Run ./aer_inject <a parameter file as below>:
> AER
> PCI_ID 0000:ed:01.0
> UNCOR_STATUS MALF_TLP
> HEADER_LOG 0 1 2 3
>
> Log:
> [ 535.537281] pcieport 0000:ed:00.4: aer_inject: Injecting errors 00000000/00040000 into device 0000:ed:01.0
> [ 535.551911] pcieport 0000:ed:00.4: AER: Uncorrected (Fatal) error received: 0000:ed:01.0
> [ 535.561556] igen6_edac 0000:ed:01.0: AER: PCIe Bus Error: severity=Uncorrected (Fatal), type=Inaccessible, (Unregistered Agent ID)
> [ 535.684964] igen6_edac 0000:ed:01.0: AER: device recovery successful
>
>
> Jonathan Cameron (1):
> PCI/AER: Extend AER error handling to RCECs
>
> Qiuxu Zhuo (6):
> pci_ids: Add class code and extended capability for RCEC
> PCI: Extend Root Port Driver to support RCEC
> PCI/portdrv: Add pcie_walk_rcec() to walk RCiEPs associated with RCEC
> PCI/AER: Apply function level reset to RCiEP on fatal error
> PCI: Add 'rcec' field to pci_dev for associated RCiEPs
> PCI/AER: Add RCEC AER error injection support
>
> Sean V Kelley (2):
> PCI/AER: Add RCEC AER handling
> PCI/PME: Add RCEC PME handling
>
> drivers/pci/pcie/aer.c | 43 ++++++++++++-----
> drivers/pci/pcie/aer_inject.c | 5 +-
> drivers/pci/pcie/err.c | 85 +++++++++++++++++++++++++++------
> drivers/pci/pcie/pme.c | 15 ++++--
> drivers/pci/pcie/portdrv.h | 2 +
> drivers/pci/pcie/portdrv_core.c | 82 +++++++++++++++++++++++++++++++
> drivers/pci/pcie/portdrv_pci.c | 20 +++++++-
> include/linux/pci.h | 3 ++
> include/linux/pci_ids.h | 1 +
> include/uapi/linux/pci_regs.h | 7 +++
> 10 files changed, 232 insertions(+), 31 deletions(-)
>
> --
> 2.27.0
>