Re: [PATCH v9 04/11] cxl: Cache endpoint decoder settings during PCI enumeration

[Alison Schofield]

On Thu, Jul 09, 2026 at 01:02:57AM +0000, Srirangan Madhavan wrote:
> Populate pci_dev->hdm from PCI capability initialization for CXL.mem
> functions. If Memory Space Enable is clear, temporarily set it while
> reading HDM MMIO and restore the original PCI_COMMAND value before
> returning. This gives driver-free reset paths an early HDM snapshot.
> 
> CXL core later reuses and refreshes the same cache. Move the register
> helpers into the built-in CONFIG_CXL_HDM set so the early cache path is
> available without cxl_core.
> 
> Signed-off-by: Srirangan Madhavan <smadhavan@xxxxxxxxxx>
> ---
>  drivers/cxl/core/Makefile |   3 +-
>  drivers/cxl/core/hdm.c    |  59 ++++----
>  drivers/cxl/core/regs.c   |   4 +
>  drivers/cxl/core/reset.c  | 288 ++++++++++++++++++++++++++++++++++++++
>  drivers/pci/probe.c       |   3 +
>  include/cxl/cxl.h         |  31 +++-
>  6 files changed, 349 insertions(+), 39 deletions(-)
> 
> diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
> index dc075cee0450..69cf2ea7ee74 100644
> --- a/drivers/cxl/core/Makefile
> +++ b/drivers/cxl/core/Makefile
> @@ -1,6 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-$(CONFIG_CXL_BUS) += cxl_core.o
> -obj-$(CONFIG_CXL_HDM) += reset.o
> +obj-$(CONFIG_CXL_HDM) += regs.o reset.o
>  obj-$(CONFIG_CXL_SUSPEND) += suspend.o

Hi Srirangan,

This breaks cxl-test module builds with an 'exported twice' error,
14 symbols are both built-in and in cxl_core.ko.
All from drivers/cxl/core/regs.c

With that fixed up, this set passes the cxl unit test suite :)

diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
index 2be1df80fcc9..e80500f457a9 100644
--- a/tools/testing/cxl/Kbuild
+++ b/tools/testing/cxl/Kbuild
@@ -55,7 +55,6 @@ obj-m += cxl_core.o

 cxl_core-y := $(CXL_CORE_SRC)/port.o
 cxl_core-y += $(CXL_CORE_SRC)/pmem.o
-cxl_core-y += $(CXL_CORE_SRC)/regs.o
 cxl_core-y += $(CXL_CORE_SRC)/memdev.o
 cxl_core-y += $(CXL_CORE_SRC)/mbox.o
 cxl_core-y += $(CXL_CORE_SRC)/pci.o

-- Alison