Re: [PATCH v15 0/8] DCD Prep Series

[Anisa Su <anisa.su887@gmail.com>]

On Wed, Oct 07, 2026 at 01:16:33PM -0700, 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
> 
> v14: https://lore.kernel.org/linux-cxl/20260918203049.7273-1-anisa.su@samsung.com/T/#m0b6ade9da2d4fefa8aab3bb7db7c29516bc3f955
> 
[snip] 
> 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:
> Waiting on results from partner team.
> 
For the series:

Tested-by: Wonjae Lee <wj28.lee@samsung.com>
Tested-by: Junhee Park <jh9934.park@samsung.com>
Tested-by: Heesoo Kim <habil.kim@samsung.com>

Test adding 1 extent/release to ensure interrupt configuration and DSMAS are
read properly.

FMAPI Add command is issued from BMC:
busctl call xyz.openbmc_project.MCTP_SMBus_PCIe_slot \
  /xyz/openbmc_project/mctp xyz.openbmc_project.MCTP.Base \
  SendReceiveMctpMessagePayload yayq \
  9 101 \
  8 0 72 0 0 0x53 88 0 0 0 0 0 0 \
  0 1 84 0 0 72 0 4 0x56 72 0 0 0 0 0 0 \
  0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \
  1 0 0 0 \
  0 0 0 0 1 0 0 0 \
  0 0 0 0x80 0 0 0 0 \
  0x7a 0x1d 0x4e 0x90 0xc3 0xb2 0x4f 0x57 0x8e 0x6d 0x21 0x5f 0x9a 0xb0 0xc4 0xd3 \
  0 0 \
  0 0 0 0 0 0 \
  100

To add 1 extent with 2GB size, tag=7a1d4e90-c3b2-4f57-8e6d-215f9ab0c4d3 and
shared sequence num = 0.
The device is shareable, so adding fails without any tag or seq num.

[Thu Oct  8 16:59:57 2026] cxl_core:cxl_mem_get_event_records:1875: cxl_pci 0000:0b:00.0: Reading event logs: 10
[Thu Oct  8 16:59:57 2026] cxl_pci:__cxl_pci_mbox_send_cmd:264: cxl_pci 0000:0b:00.0: Sending command: 0x0100
[Thu Oct  8 16:59:57 2026] cxl_pci:cxl_pci_mbox_wait_for_doorbell:75: cxl_pci 0000:0b:00.0: Doorbell wait took 0ms
[Thu Oct  8 16:59:57 2026] cxl_core:cxl_handle_dcd_event_records:1779: cxl_pci 0000:0b:00.0: DCD event add : DPA:0x100000000 LEN:0x80000000
[Thu Oct  8 16:59:57 2026] cxl_core:cxl_extent_dc_partition:230: cxl_pci 0000:0b:00.0: DC extent DPA [range 0x0000000100000000-0x000000017fffffff] (DCR:[range 0x0000000000000000-0x0000001fffffffff])(7a1d4e90-c3b2-4f57-8e6d-215f9ab0c4d3)
[Thu Oct  8 16:59:57 2026] cxl_core:cxl_extent_dc_partition:230: cxl_pci 0000:0b:00.0: DC extent DPA [range 0x0000000100000000-0x000000017fffffff] (DCR:[range 0x0000000000000000-0x0000001fffffffff])(7a1d4e90-c3b2-4f57-8e6d-215f9ab0c4d3)
[Thu Oct  8 16:59:57 2026] cxl_core:cxl_extent_dc_partition:230: cxl_pci 0000:0b:00.0: DC extent DPA [range 0x0000000100000000-0x000000017fffffff] (DCR:[range 0x0000000000000000-0x0000001fffffffff])(7a1d4e90-c3b2-4f57-8e6d-215f9ab0c4d3)
[Thu Oct  8 16:59:57 2026] cxl_core:__cxl_dpa_to_region:3100: cxl decoder9.0: dpa:0x100000000 mapped in region:region0
[Thu Oct  8 16:59:57 2026] cxl_core:cxl_add_extent:517: cxl decoder9.0: Add extent [range 0x0000000100000000-0x000000017fffffff] (7a1d4e90-c3b2-4f57-8e6d-215f9ab0c4d3)
[Thu Oct  8 16:59:57 2026] cxl_core:cxlr_add_extent:444: cxl_dax_region dax_region0: Alloc new tag group
[Thu Oct  8 16:59:57 2026] cxl_core:online_tag_group:732:  extent0.3: dc_extent HPA [range 0x0000000100000000-0x000000017fffffff] (7a1d4e90-c3b2-4f57-8e6d-215f9ab0c4d3)
[Thu Oct  8 16:59:57 2026] cxl_core:__cxlr_notify_extent:394: cxl_dax_region dax_region0: Trying notify: type 0 tag 7a1d4e90-c3b2-4f57-8e6d-215f9ab0c4d3
[Thu Oct  8 16:59:57 2026] cxl_core:__cxlr_notify_extent:411: cxl_dax_region dax_region0: Notify: type 0 tag 7a1d4e90-c3b2-4f57-8e6d-215f9ab0c4d3
[Thu Oct  8 16:59:57 2026] cxl_pci:__cxl_pci_mbox_send_cmd:264: cxl_pci 0000:0b:00.0: Sending command: 0x4802
[Thu Oct  8 16:59:57 2026] cxl_pci:cxl_pci_mbox_wait_for_doorbell:75: cxl_pci 0000:0b:00.0: Doorbell wait took 1ms
[Thu Oct  8 16:59:57 2026] cxl_core:cxl_clear_event_record:1080: cxl_pci 0000:0b:00.0: Event log '4': Clearing 9
[Thu Oct  8 16:59:57 2026] cxl_pci:__cxl_pci_mbox_send_cmd:264: cxl_pci 0000:0b:00.0: Sending command: 0x0101
[Thu Oct  8 16:59:57 2026] cxl_pci:cxl_pci_mbox_wait_for_doorbell:75: cxl_pci 0000:0b:00.0: Doorbell wait took 0ms
[Thu Oct  8 16:59:57 2026] cxl_pci:__cxl_pci_mbox_send_cmd:264: cxl_pci 0000:0b:00.0: Sending command: 0x0100
[Thu Oct  8 16:59:57 2026] cxl_pci:cxl_pci_mbox_wait_for_doorbell:75: cxl_pci 0000:0b:00.0: Doorbell wait took 0ms
[Thu Oct  8 17:00:07 2026] cxl_core:cxl_mem_get_event_records:1875: cxl_pci 0000:0b:00.0: Reading event logs: 10
[Thu Oct  8 17:00:07 2026] cxl_pci:__cxl_pci_mbox_send_cmd:264: cxl_pci 0000:0b:00.0: Sending command: 0x0100
[Thu Oct  8 17:00:07 2026] cxl_pci:cxl_pci_mbox_wait_for_doorbell:75: cxl_pci 0000:0b:00.0: Doorbell wait took 0ms
[Thu Oct  8 17:00:07 2026] cxl_core:cxl_handle_dcd_event_records:1779: cxl_pci 0000:0b:00.0: DCD event release : DPA:0x100000000 LEN:0x80000000
[Thu Oct  8 17:00:07 2026] cxl_core:__cxl_dpa_to_region:3100: cxl decoder9.0: dpa:0x100000000 mapped in region:region0
[Thu Oct  8 17:00:08 2026] cxl_core:__cxlr_notify_extent:394: cxl_dax_region dax_region0: Trying notify: type 1 tag 7a1d4e90-c3b2-4f57-8e6d-215f9ab0c4d3
[Thu Oct  8 17:00:08 2026] cxl_core:__cxlr_notify_extent:411: cxl_dax_region dax_region0: Notify: type 1 tag 7a1d4e90-c3b2-4f57-8e6d-215f9ab0c4d3
[Thu Oct  8 17:00:08 2026] cxl_core:dc_extent_unregister:528:  extent0.3: DAX region rm extent HPA [range 0x0000000100000000-0x000000017fffffff]
[Thu Oct  8 17:00:08 2026] cxl_core:cxled_release_extent:70: cxl decoder9.0: Remove extent [range 0x0000000100000000-0x000000017fffffff] (7a1d4e90-c3b2-4f57-8e6d-215f9ab0c4d3)
[Thu Oct  8 17:00:08 2026] cxl_core:memdev_release_extent:1201: cxl_pci 0000:0b:00.0: Release response dpa [range 0x0000000100000000-0x000000017fffffff]
[Thu Oct  8 17:00:08 2026] cxl_pci:__cxl_pci_mbox_send_cmd:264: cxl_pci 0000:0b:00.0: Sending command: 0x4803
[Thu Oct  8 17:00:08 2026] cxl_pci:cxl_pci_mbox_wait_for_doorbell:75: cxl_pci 0000:0b:00.0: Doorbell wait took 0ms
[Thu Oct  8 17:00:08 2026] cxl_core:cxl_clear_event_record:1080: cxl_pci 0000:0b:00.0: Event log '4': Clearing 11
[Thu Oct  8 17:00:08 2026] cxl_pci:__cxl_pci_mbox_send_cmd:264: cxl_pci 0000:0b:00.0: Sending command: 0x0101
[Thu Oct  8 17:00:08 2026] cxl_pci:cxl_pci_mbox_wait_for_doorbell:75: cxl_pci 0000:0b:00.0: Doorbell wait took 0ms
[Thu Oct  8 17:00:08 2026] cxl_pci:__cxl_pci_mbox_send_cmd:264: cxl_pci 0000:0b:00.0: Sending command: 0x0100
[Thu Oct  8 17:00:08 2026] cxl_pci:cxl_pci_mbox_wait_for_doorbell:75: cxl_pci 0000:0b:00.0: Doorbell wait took 0ms

> cxl_test:
> ndctl's cxl suite against cxl_test (7.3.0-rc6, CXL as modules)
> 16 of 17 pass, cxl-features.sh skips for lack of FWCTL, and
> cxl-dcd.sh passes.
> 
> QEMU:
> Tested extent add/release and DAX device create/destroy.
> Tested that expected errors are printed from malformed Get DC Configuration
> payload.
> 
> 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                       |  97 +++++-
>  drivers/cxl/core/hdm.c                        |  24 +-
>  drivers/cxl/core/mbox.c                       | 285 ++++++++++++++++++
>  drivers/cxl/core/memdev.c                     |  94 ++++--
>  drivers/cxl/cxl.h                             |  14 +-
>  drivers/cxl/cxlmem.h                          |  88 +++++-
>  drivers/cxl/mem.c                             |   2 +-
>  drivers/cxl/pci.c                             | 176 +++++++++--
>  include/cxl/cxl.h                             |  29 +-
>  tools/testing/cxl/test/mem.c                  |   2 +-
>  12 files changed, 761 insertions(+), 89 deletions(-)
> 
> 
> base-commit: a90ee4305c4a5df72c11b31dacfdc76e00fcf78a
> -- 
> 2.43.0
>