Re: [PATCH v10 01/12] cxl: Move HDM decoder programming helpers

[Alison Schofield <alison.schofield@intel.com>]

On Tue, Aug 04, 2026 at 07:29:47PM +0000, Srirangan Madhavan wrote:
> Move the low-level HDM decoder programming helpers from hdm.c into
> resource.c so they can be shared by later reset restore code.
> 
> Keep the existing decoder commit flow and register programming sequence
> unchanged. This patch is intended to be a mechanical move. Follow-on
> patches update the helper interface for reset restore.
> 
> Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
> ---
>  drivers/cxl/Kconfig         |   4 ++
>  drivers/cxl/core/Makefile   |   1 +
>  drivers/cxl/core/core.h     |   2 +
>  drivers/cxl/core/hdm.c      | 124 +-------------------------------
>  drivers/cxl/core/resource.c | 138 ++++++++++++++++++++++++++++++++++++
>  drivers/cxl/cxl.h           |  41 -----------
>  include/cxl/cxl.h           |  45 +++++++++++-
>  tools/testing/cxl/Kbuild    |   1 +
>  8 files changed, 191 insertions(+), 165 deletions(-)
>  create mode 100644 drivers/cxl/core/resource.c
> 

Hi Srirangan,

A bit of deja-vu here but on a different file this time.


snip

> diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
> index ce7213818d3c..0df4178bbbaa 100644
> --- a/drivers/cxl/core/Makefile
> +++ b/drivers/cxl/core/Makefile
> @@ -1,5 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-$(CONFIG_CXL_BUS) += cxl_core.o
> +obj-$(CONFIG_CXL_HDM) += resource.o
>  obj-$(CONFIG_CXL_SUSPEND) += suspend.o

We can't add resource.o to both the built-in set above, and to
cxl_core-y below. The mock cxl_core.ko must not build an object
that is already in vmlinux. resource.o gets compiled twice and
modpost rejects the duplicate exports like this-

$ make M=tools/testing/cxl/
ERROR: modpost: cxl_core: 'cxl_rwsem' exported twice. Previous export was in vmlinux
ERROR: modpost: cxl_core: 'cxl_commit_start' exported twice. Previous export was in vmlinux
ERROR: modpost: cxl_core: 'cxl_commit_wait' exported twice. Previous export was in vmlinux
ERROR: modpost: cxl_core: 'cxl_hdm_decode_decoder' exported twice. Previous export was in vmlinux

So, remove from tools/testing/cxl/Kbuild below.

To catch this, run the mock build after any change to
drivers/cxl/core/Makefile or tools/testing/cxl/Kbuild:
  $ make vmlinux modules
  $ make M=tools/testing/cxl/

> diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
> index 2be1df80fcc9..6c09932587ce 100644
> --- a/tools/testing/cxl/Kbuild
> +++ b/tools/testing/cxl/Kbuild
> @@ -60,6 +60,7 @@ cxl_core-y += $(CXL_CORE_SRC)/memdev.o
>  cxl_core-y += $(CXL_CORE_SRC)/mbox.o
>  cxl_core-y += $(CXL_CORE_SRC)/pci.o
>  cxl_core-y += $(CXL_CORE_SRC)/hdm.o
> +cxl_core-y += $(CXL_CORE_SRC)/resource.o
>  cxl_core-y += $(CXL_CORE_SRC)/pmu.o
>  cxl_core-y += $(CXL_CORE_SRC)/cdat.o
>  cxl_core-$(CONFIG_TRACING) += $(CXL_CORE_SRC)/trace.o
> -- 
> 2.43.0
>