Re: [PATCH 2/9] dax/cxl: Fix HMEM dependencies

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

On 3/26/26 10:28 PM, Dan Williams wrote:
> The expectation is that DEV_DAX_HMEM=y should be disallowed if any of
> CXL_ACPI, or CXL_PCI are set =m. Also DEV_DAX_CXL=y should be disallowed if
> DEV_DAX_HMEM=m. Use "$config || !$config" syntax for each dependency.
> Otherwise, the invalid DEV_DAX_HMEM=m && DEV_DAX_CXL=y configuration is
> allowed.
> 
> Lastly, dax_hmem depends on the availability of the
> cxl_region_contains_resource() symbol published by the cxl_core.ko module.
> So, also prevent DEV_DAX_HMEM from being built-in when the cxl_core module
> is not built-in.
> 
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/dax/Kconfig | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig
> index 3683bb3f2311..504f7f735ef5 100644
> --- a/drivers/dax/Kconfig
> +++ b/drivers/dax/Kconfig
> @@ -32,6 +32,9 @@ config DEV_DAX_HMEM
>  	depends on EFI_SOFT_RESERVE
>  	select NUMA_KEEP_MEMINFO if NUMA_MEMBLKS
>  	default DEV_DAX
> +	depends on CXL_ACPI || !CXL_ACPI
> +	depends on CXL_PCI || !CXL_PCI
> +	depends on CXL_BUS || !CXL_BUS
>  	help
>  	  EFI 2.8 platforms, and others, may advertise 'specific purpose'
>  	  memory. For example, a high bandwidth memory pool. The
> @@ -48,8 +51,7 @@ config DEV_DAX_CXL
>  	tristate "CXL DAX: direct access to CXL RAM regions"
>  	depends on CXL_BUS && CXL_REGION && DEV_DAX
>  	default CXL_REGION && DEV_DAX
> -	depends on CXL_ACPI >= DEV_DAX_HMEM
> -	depends on CXL_PCI >= DEV_DAX_HMEM
> +	depends on DEV_DAX_HMEM || !DEV_DAX_HMEM
>  	help
>  	  CXL RAM regions are either mapped by platform-firmware
>  	  and published in the initial system-memory map as "System RAM", mapped