Re: [PATCH v16 0/8] DCD Prep Series

[Dave Jiang <dave.jiang@intel.com>]

On 10/10/26 3:54 PM, Anisa Su wrote:
> These are the first eight patches of the Dynamic Capacity Device (DCD)
> series. They set up: DCD enumeration, CDAT handling for DC partitions,
> the event interrupt plumbing, a preparatory refactor, and
> documentation of the DPA partition layout. They stand alone and keep DCD
> disabled. They are not dependent on the rest of the series.
> Patch 1 detects the 48h command set and then leaves mds->dcd_supported
> false. The flag is only turned on by the series that adds DCD event
> handling, so every DCD specific path added here is shut off at runtime:
> cxl_configure_dcd() never runs, no DC partition is created, no DCD
> interrupt is armed, and the CXL_PARTMODE_DYNAMIC_RAM paths are
> unreachable. The intent is to land the enumeration and plumbing while
> the extent to DAX pipeline is still under review.
> 
> Based on v7.3-rc6
> v15: https://lore.kernel.org/linux-cxl/20261007201828.952-1-anisa.su@samsung.com/
> 
> v15 -> v16 Changes:
> ===================
> A quick respin:
> 
>  - Patch 2: cxl_configure_dcd() took Identify Total Capacity as the end
>    of static capacity, but Total Capacity is only required to be >=
>    ram + pmem. The static end now comes from the last static partition's end dpa
>    +1 instead of info->size. Check that DC starts from there. (Richard).
> 
>  - Patch 3: dsmas_entry.qos_class initialized as CXL_QOS_CLASS_INVALID, so a
>    DSMAS entry that is skipped for lack of DSLBIS, or whose QTG lookup
>    fails, no longer reaches update_perf_entry() with qos_class 0, which
>    is a valid class. (Sashiko).
>    
>    The DSMAD handle check now checks handle > U8_MAX instead of
>    handle & ~0xFF (Dave).
> 
>  - Patch 6: when the DCD vector cannot be requested, tell the device
>    not to use the vector: dcd_settings is cleared with
>    Set Event Interrupt Policy, so a device does not keep signalling a
>    vector with no handler while the
>    host considers DCD off.  The Set command is re-factored into a new helper
>    cxl_event_set_int_policy() (Richard).
>    
> All other patches are unchanged.
> I kept the review tags on patch 3, since the changes are minimal and
> dropped tags from 2 and 6.
> 
> Patch organization
> ==================
>  1-3: enumerate DCD command support, read the DC configuration, and pick
>       up DSMAS data for DC partitions.
>  4-6: split event msgnum configuration from irq setup, factor out the
>       interrupt policy check, then configure the DCD event interrupt.
>    7: preparatory refactor -- enforce partition order while collapsing
>       the ram/pmem specific partition helpers into one.
>    8: document the DPA partition layout the previous patches enforce,
>       and where Linux is stricter than the specification.
> 
> Testing
> =======
> This series leaves mds->dcd_supported false on purpose, so
> cxl_configure_dcd(), cxl_dev_dc_identify() and cxl_dc_check() are
> unreachable at runtime as posted. The tests below are done with the rest
> of the series on top, otherwise testing would not yield any meaningful
> results.
> 
> HW:
> Tested add and release of one 2G tagged extent on a DCD with a sharable
> partition, driven from the system's BMC with FM-API Initiate Dynamic
> Capacity Add / Release over MCTP, to confirm the DCD interrupt
> configuration and the DSMAS attributes are read properly. The device
> is sharable, so an add without a tag and sequence number is refused.
> 
> 
> cxl_test:
> ndctl cxl test suite
> 16 of 17 pass, cxl-features.sh skips for lack of FWCTL
> 
> Anisa Su (1):
>   Documentation/cxl: Document DPA partition layout and ordering rules
> 
> Ira Weiny (7):
>   cxl/mbox: Flag support for Dynamic Capacity Devices (DCD)
>   cxl/mem: Read dynamic capacity configuration from the device
>   cxl/cdat: Gather DSMAS data for DCD partitions
>   cxl/events: Split event msgnum configuration from irq setup
>   cxl/pci: Factor out interrupt policy check
>   cxl/mem: Configure dynamic capacity interrupts
>   cxl/core: Enforce partition order/simplify partition calls
> 
>  .../driver-api/cxl/linux/cxl-driver.rst       |  35 +++
>  Documentation/driver-api/cxl/maturity-map.rst |   4 +
>  drivers/cxl/core/cdat.c                       |  99 +++++-
>  drivers/cxl/core/hdm.c                        |  24 +-
>  drivers/cxl/core/mbox.c                       | 285 ++++++++++++++++++
>  drivers/cxl/core/memdev.c                     | 100 ++++--
>  drivers/cxl/cxl.h                             |  14 +-
>  drivers/cxl/cxlmem.h                          |  88 +++++-
>  drivers/cxl/mem.c                             |   2 +-
>  drivers/cxl/pci.c                             | 207 ++++++++++---
>  include/cxl/cxl.h                             |  29 +-
>  tools/testing/cxl/test/mem.c                  |   2 +-
>  12 files changed, 792 insertions(+), 97 deletions(-)
> 
> 
> base-commit: a90ee4305c4a5df72c11b31dacfdc76e00fcf78a

Applied to cxl/next
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