NVIDIA: VR: SAUCE: [Config] Enable CXL DAX and KMEM built-in for CXL memory access

BugLink: https://bugs.launchpad.net/bugs/2143032

Override debian.master policy (m->y) for DEV_DAX, DEV_DAX_CXL, and
DEV_DAX_KMEM to ensure CXL memory regions are accessible as both raw
DAX devices and hotplugged System-RAM nodes.

debian.master sets these to 'm' (modules). For NVIDIA platforms with
CXL Type-2 devices, built-in (y) is required to ensure CXL memory
regions provisioned early in boot are immediately accessible without
relying on module loading order.

CONFIG_DEV_DAX:     Override m->y; prerequisite for DEV_DAX_CXL and
                    DEV_DAX_KMEM to be built-in; depends on
                    TRANSPARENT_HUGEPAGE (already y in debian.master)

CONFIG_DEV_DAX_CXL: Override m->y; creates /dev/daxX.Y devices for CXL
                    RAM regions not in the default system memory map
                    (Soft Reserved or dynamically provisioned regions);
                    depends on CXL_BUS+CXL_REGION+DEV_DAX (all y)

CONFIG_DEV_DAX_KMEM: Override m->y; onlines CXL DAX devices as System-RAM
                    NUMA nodes via memory hotplug, making CXL memory
                    available for normal kernel and userspace allocation

Signed-off-by: Jiandi An <jan@nvidia.com>
Acked-by: Jamie Nguyen <jamien@nvidia.com>
Acked-by: Nirmoy Das <nirmoyd@nvidia.com>
Acked-by: Carol L Soto <csoto@nvidia.com>
Acked-by: Matthew R. Ochs <mochs@nvidia.com>
Signed-off-by: Brad Figg <bfigg@nvidia.com>

Author: JiandiAnNVIDIA

debian.nvidia-6.17/config/annotations

@@ -225,6 +225,15 @@ CONFIG_CXL_RAS                                  note<'New def_bool replacing PCI
 CONFIG_SFC_CXL                                  policy<{'amd64': 'n', 'arm64': 'n'}>
 CONFIG_SFC_CXL                                  note<'Solarflare SFC9100-family CXL Type-2 device support; not needed for NVIDIA platforms'>
 
+CONFIG_DEV_DAX                                  policy<{'amd64': 'y', 'arm64': 'y'}>
+CONFIG_DEV_DAX                                  note<'Override debian.master m->y; required built-in for DEV_DAX_CXL=y'>
+
+CONFIG_DEV_DAX_CXL                              policy<{'amd64': 'y', 'arm64': 'y'}>
+CONFIG_DEV_DAX_CXL                              note<'Override debian.master m->y; CXL RAM region DAX access; depends on CXL_BUS+CXL_REGION+DEV_DAX'>
+
+CONFIG_DEV_DAX_KMEM                             policy<{'amd64': 'y', 'arm64': 'y'}>
+CONFIG_DEV_DAX_KMEM                             note<'Override debian.master m->y; map CXL DAX devices as System-RAM'>
+
 CONFIG_ACPI_APEI_EINJ                           policy<{'amd64': 'y', 'arm64': 'y'}>
 CONFIG_ACPI_APEI_EINJ                           note<'Required for CONFIG_ACPI_APEI_EINJ_CXL'>