Re: [PATCH v13 06/15] cxl: Make HDM reset helpers available to built-in PCI code

[Cheatham, Benjamin]

On 9/22/2026 3:39 AM, Srirangan Madhavan wrote:
> PCI can be built in while CXL_BUS is modular, so PCI reset code cannot
> depend on helpers provided by the cxl_core module.
> 
> Build the HDM resource helpers under CONFIG_CXL_RESET and restrict their
> exports to cxl_core.
> 

I think you should squash this patch into 3/15. Having this earlier does two things:
1) it makes it more clear why you're moving everything earlier in the set, and 2)
bisects across the pass 3 patches will all result in the same configuration.

An alternative option would be to refactor the preceding 3 patches in-place and then
move all of the helpers to this file in this patch, either would work.

> Signed-off-by: Srirangan Madhavan <smadhavan@xxxxxxxxxx>
> ---
>  drivers/cxl/Kconfig         | 4 ++++
>  drivers/cxl/core/Makefile   | 2 +-
>  drivers/cxl/core/resource.c | 4 ++++
>  tools/testing/cxl/Kbuild    | 1 -
>  4 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
> index 80aeb0d556bd..0cd704670735 100644
> --- a/drivers/cxl/Kconfig
> +++ b/drivers/cxl/Kconfig
> @@ -6,6 +6,7 @@ menuconfig CXL_BUS
>  	select FW_UPLOAD
>  	select PCI_DOE
>  	select FIRMWARE_TABLE
> +	select CXL_RESET
>  	select NUMA_KEEP_MEMINFO if NUMA_MEMBLKS
>  	select FWCTL if CXL_FEATURES
>  	help
> @@ -244,3 +245,6 @@ config CXL_ATL
>  	depends on ACPI_PRMT && AMD_NB
>  
>  endif
> +
> +config CXL_RESET
> +	bool
> diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
> index 57995777af0d..30470799e059 100644
> --- a/drivers/cxl/core/Makefile
> +++ b/drivers/cxl/core/Makefile
> @@ -1,12 +1,12 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-$(CONFIG_CXL_BUS) += cxl_core.o
> +obj-$(CONFIG_CXL_RESET) += resource.o

This file should probably be called reset.c instead of resource.c to match the
Kconfig functionality.
>  obj-$(CONFIG_CXL_SUSPEND) += suspend.o
>  
>  ccflags-y += -I$(srctree)/drivers/cxl
>  CFLAGS_trace.o = -DTRACE_INCLUDE_PATH=. -I$(src)
>  
>  cxl_core-y := port.o
> -cxl_core-y += resource.o
>  cxl_core-y += pmem.o
>  cxl_core-y += regs.o
>  cxl_core-y += memdev.o
> diff --git a/drivers/cxl/core/resource.c b/drivers/cxl/core/resource.c
> index ea0d855e5549..1b4742622054 100644
> --- a/drivers/cxl/core/resource.c
> +++ b/drivers/cxl/core/resource.c
> @@ -3,6 +3,7 @@
>  #include <linux/delay.h>
>  #include <linux/bug.h>
>  #include <linux/errno.h>
> +#include <linux/export.h>
>  #include <linux/kernel.h>
>  
>  #include "cxl.h"
> @@ -12,6 +13,7 @@ struct cxl_rwsem cxl_rwsem = {
>  	.region = __RWSEM_INITIALIZER(cxl_rwsem.region),
>  	.dpa = __RWSEM_INITIALIZER(cxl_rwsem.dpa),
>  };
> +EXPORT_SYMBOL_FOR_MODULES(cxl_rwsem, "cxl_core");
>  
>  static void cxld_set_interleave(struct cxl_decoder_config *config, u32 *ctrl)
>  {
> @@ -100,8 +102,10 @@ void cxl_commit_start(void __iomem *hdm, struct cxl_decoder_settings *settings)
>  	lockdep_assert_held(&cxl_rwsem.dpa);
>  	setup_hw_decoder(hdm, settings);
>  }
> +EXPORT_SYMBOL_FOR_MODULES(cxl_commit_start, "cxl_core");
>  
>  int cxl_commit_wait(void __iomem *hdm, struct cxl_decoder_settings *settings)
>  {
>  	return cxld_await_commit(hdm, settings->config.id);
>  }
> +EXPORT_SYMBOL_FOR_MODULES(cxl_commit_wait, "cxl_core");
> diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
> index 6c09932587ce..2be1df80fcc9 100644
> --- a/tools/testing/cxl/Kbuild
> +++ b/tools/testing/cxl/Kbuild
> @@ -60,7 +60,6 @@ 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

If you squash this patch you also don't need to bother adding/removing this.

>  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