Re: [PATCH] cxl: Remove core/acpi.c and cxl core dependency on ACPI

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Fri, 11 Jul 2025 17:15:27 +0200
Robert Richter <rrichter@amd.com> wrote:

> From Dave [1]:
> 
> """
> It was a mistake to introduce core/acpi.c and putting ACPI dependency on
> cxl_core when adding the extended linear cache support.
> """
> 
> Current implementation calls hmat_get_extended_linear_cache_size() of
> the ACPI subsystem. That external reference causes issue running
> cxl_test as there is no way to "mock" that function and ignore it when
> using cxl test.
> 
> Instead of working around that using cxlrd ops and extensively
> expanding cxl_test code [1], just move HMAT calls out of the core
> module to cxl_acpi. Implement this by adding a @cache_size member to
> struct cxl_root_decoder. During initialization the cache size is
> determined and added to the root decoder object in cxl_acpi. Later on
> in cxl_core the cache_size parameter is used to setup extended linear
> caching.
> 
> [1] https://patch.msgid.link/20250610172938.139428-1-dave.jiang@intel.com
> 
> Cc: Dave Jiang <dave.jiang@intel.com>
> Signed-off-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>