[RFC 0/4] cxl: Support for mailbox background abort operation

[Ravis OpenSrc <Ravis.OpenSrc@micron.com>]

This patchset introduces the Request Background Abort operation as outlined
in CXL 3.1, section 8.2.9.1.5. It ensures that only background operations
supporting request background abort are allowed. A default timeout of
5 seconds is specified for operations where a timeout is not explicitly
defined. If this timeout expires, a Request Abort command is issued to
terminate the ongoing background operation.

This patchset is based on suggestion from Dan Williams, as referenced here:
https://lore.kernel.org/linux-cxl/66035c2e8ba17_770232948b@dwillia2-xfh.jf.intel.com.notmuch/

(1) Patch 1: Enables only those background mailbox commands
    that also support request abort through their CEL.
(2) Patch 2: A default timeout of 5 secs for mailbox commands
    that do not have an explicitly mentioned timeout.
(3) Patch 3: Adds support for sending an abort when a mailbox
    background operation times out.
(4) Patch 4: Adds support for the Populate Log command,
    a background operation that can potentially support abort.

Ravi Shankar (4):
  cxl: Enable mailbox ops with background only if request abort
    operation is supported.
  cxl: Add default timeout for bg mailbox commands
  cxl: Abort background operation in case of timeout
  cxl/mbox: Add Populate Log support

 drivers/cxl/core/mbox.c      | 13 +++++++++++--
 drivers/cxl/cxlmem.h         | 18 ++++++++++++++++++
 drivers/cxl/pci.c            | 24 ++++++++++++++++++++++++
 include/uapi/linux/cxl_mem.h |  1 +
 4 files changed, 54 insertions(+), 2 deletions(-)

-- 
2.43.0