[PATCH 0/4] cxl: Add a firmware update mechanism and cxl_test emulation

[Vishal Verma]

Add firmware update capability to the CXL memdev driver, and emulation
in cxl_test. Since the 'Transfer FW' mailbox command is a background
command, this series depends on the initial background command support
patches[1] from Davidlohr. These patches (patch 1 and 2) are included
in this series, unchanged, for reference.

Since the Transfer FW command can be a long-running background command,
it is desirable to retain kernel control over it, so that one command
doesn't monopolize the mailbox interface. The sysfs based firmware
loader mechanism that was developed for FPGAs is a suitable candidate to
help accomplish this. Patch 3 goes into more details on this.

The poll interval for the Transfer FW command is arbitrarily set at 1
second, and a poll count of 300, giving us a total wait time of five
minutes before which each slice of the transfer times out. This seems
like a good mix of responsiveness and a total wait - the spec doesn't
have any guidance on any upper or lower bounds for this. This likely
does not need to be user-configurable, so for now it is just hard-coded
in the driver.

Patch 4 implements the emulation of firmware update related commands in
the cxl_test environment to enable unit testing.

[1]: https://lore.kernel.org/linux-cxl/20230421092321.12741-1-dave@xxxxxxxxxxxx

Signed-off-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
---
Davidlohr Bueso (2):
      cxl/pci: Allocate irq vectors earlier in pci probe
      cxl/mbox: Add background cmd handling machinery

Vishal Verma (2):
      cxl: add a firmware update mechanism using the sysfs firmware loader
      tools/testing/cxl: add firmware update emulation to CXL memdevs

 drivers/cxl/cxl.h                       |   7 +
 drivers/cxl/cxlmem.h                    |  84 +++++++++
 drivers/cxl/core/mbox.c                 |   4 +-
 drivers/cxl/core/memdev.c               | 324 ++++++++++++++++++++++++++++++++
 drivers/cxl/pci.c                       | 112 ++++++++++-
 tools/testing/cxl/test/mem.c            | 191 +++++++++++++++++++
 Documentation/ABI/testing/sysfs-bus-cxl |  11 ++
 drivers/cxl/Kconfig                     |   1 +
 8 files changed, 728 insertions(+), 6 deletions(-)
---
base-commit: 24b18197184ac39bb8566fb82c0bf788bcd0d45b
change-id: 20230421-vv-fw_update-59e35ad0d018

Best regards,
-- 
Vishal Verma <vishal.l.verma@xxxxxxxxx>