acpi/ghes: Remove CXL CPER notifications

Initial tests with the CXL CPER implementation identified that error
reports were being duplicated in the log and the trace event [1]. Then
it was discovered that the notification handler took sleeping locks
while the GHES event handling runs in spin_lock_irqsave() context [2]

While the duplicate reporting was fixed in v6.8-rc4, the fix for the
sleeping-lock-vs-atomic collision would enjoy more time to settle and
gain some test cycles. Given how late it is in the development cycle,
remove the CXL hookup for now and try again during the next merge
window.

Note that end result is that v6.8 does not emit CXL CPER payloads to the
kernel log, but this is in line with the CXL trend to move error
reporting to trace events instead of the kernel log.

Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: http://lore.kernel.org/r/20240108165855.00002f5a@Huawei.com [1]
Closes: http://lore.kernel.org/r/b963c490-2c13-4b79-bbe7-34c6568423c7@moroto.mountain [2]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

cxl/pci: Register for and process CPER events

If the firmware has configured CXL event support to be firmware first
the OS can process those events through CPER records. The CXL layer has
unique DPA to HPA knowledge and standard event trace parsing in place.

CPER records contain Bus, Device, Function information which can be used
to identify the PCI device which is sending the event.

Change the PCI driver registration to include registration of a CXL
CPER callback to process events through the trace subsystem.

Use new scoped based management to simplify the handling of the PCI
device object.

Tested-by: Smita-Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Reviewed-by: Smita-Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-9-1bb8a4ca2c7a@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
[djbw: use new pci_dev guard, flip init order]
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

acpi/ghes: Process CXL Component Events

BIOS can configure memory devices as firmware first. This will send CXL
events to the firmware instead of the OS. The firmware can then send
these events to the OS via UEFI.

UEFI v2.10 section N.2.14 defines a Common Platform Error Record (CPER)
format for CXL Component Events. The format is mostly the same as the
CXL Common Event Record Format. The difference is the use of a GUID in
the Section Type rather than a UUID as part of the event itself.

Add GHES support to detect CXL CPER records and call a registered
callback with the event.

A notifier chain was considered for the callback but the complexity did
not justify the use case as only the CXL subsystem requires this event.
Enforce that only one callback can be registered at any time.

Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-7-1bb8a4ca2c7a@intel.com
[djbw: fixup checkpatch errors]
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

cxl/events: Create a CXL event union

The CXL CPER and event log records share everything but a UUID/GUID in
their structures.

Define a cxl_event union without the UUID/GUID to be shared between the
CPER and event log record formats. Adjust the code to use this union.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-6-1bb8a4ca2c7a@intel.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

cxl/events: Separate UUID from event structures

The UEFI CXL CPER structure does not include the UUID. Now that the
UUID is passed separately to the trace event there is no need to have
the UUID in those structures.

Move UUID from the event record header to the raw structures. Adjust
cxl-test to Create dummy structures for creating test records.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-5-1bb8a4ca2c7a@intel.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

cxl/events: Promote CXL event structures to a core header

UEFI code can process CXL events through CPER records. Those records
use almost the same format as the CXL events.

Lift the CXL event structures to a core header to be shared in later
patches.

[jic123: drop "CXL rev 3.0" mention]

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-2-1bb8a4ca2c7a@intel.com
[djbw: add F: entry to maintainers for include/linux/cxl-event.h]
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>