x86/resctrl: Move is_mba_sc() out of core.c

is_mba_sc() is defined in core.c, but has no callers there. It does not access
any architecture private structures.

Move this to rdtgroup.c where the majority of callers are. This makes the move
of the filesystem code to /fs/ cleaner.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Amit Singh Tomar <amitsinght@marvell.com> # arm64
Tested-by: Shanker Donthineni <sdonthineni@nvidia.com> # arm64
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/20250515165855.31452-11-james.morse@arm.com

Author: James Morse

arch/x86/kernel/cpu/resctrl/core.c

@@ -164,21 +164,6 @@ static inline void cache_alloc_hsw_probe(void)
 	rdt_alloc_capable = true;
 }
 
-bool is_mba_sc(struct rdt_resource *r)
-{
-	if (!r)
-		r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
-
-	/*
-	 * The software controller support is only applicable to MBA resource.
-	 * Make sure to check for resource type.
-	 */
-	if (r->rid != RDT_RESOURCE_MBA)
-		return false;
-
-	return r->membw.mba_sc;
-}
-
 /*
  * rdt_get_mb_table() - get a mapping of bandwidth(b/w) percentage values
  * exposed to user interface and the h/w understandable delay values.

arch/x86/kernel/cpu/resctrl/rdtgroup.c

@@ -1535,6 +1535,21 @@ unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r,
 	return size;
 }
 
+bool is_mba_sc(struct rdt_resource *r)
+{
+	if (!r)
+		r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
+
+	/*
+	 * The software controller support is only applicable to MBA resource.
+	 * Make sure to check for resource type.
+	 */
+	if (r->rid != RDT_RESOURCE_MBA)
+		return false;
+
+	return r->membw.mba_sc;
+}
+
 /*
  * rdtgroup_size_show - Display size in bytes of allocated regions
  *