x86/resctrl: Expose resctrl fs's init function to the rest of the kernel

rdtgroup_init() needs exposing to the rest of the kernel so that arch code can
call it once it lives in core code. As this is one of the few functions
exposed, rename it to have "resctrl" in the name. The same goes for the exit
call.

Rename x86's arch code init functions for RDT to have an arch prefix to make
it clear these are part of the architecture code.

Co-developed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
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>
Reviewed-by: Babu Moger <babu.moger@amd.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>
Link: https://lore.kernel.org/r/20250311183715.16445-12-james.morse@arm.com

Author: James Morse

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

@@ -1061,7 +1061,7 @@ void resctrl_cpu_detect(struct cpuinfo_x86 *c)
 	}
 }
 
-static int __init resctrl_late_init(void)
+static int __init resctrl_arch_late_init(void)
 {
 	struct rdt_resource *r;
 	int state, ret;
@@ -1084,7 +1084,7 @@ static int __init resctrl_late_init(void)
 	if (state < 0)
 		return state;
 
-	ret = rdtgroup_init();
+	ret = resctrl_init();
 	if (ret) {
 		cpuhp_remove_state(state);
 		return ret;
@@ -1100,18 +1100,18 @@ static int __init resctrl_late_init(void)
 	return 0;
 }
 
-late_initcall(resctrl_late_init);
+late_initcall(resctrl_arch_late_init);
 
-static void __exit resctrl_exit(void)
+static void __exit resctrl_arch_exit(void)
 {
 	struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
 
 	cpuhp_remove_state(rdt_online);
 
-	rdtgroup_exit();
+	resctrl_exit();
 
 	if (r->mon_capable)
 		rdt_put_mon_l3_config();
 }
 
-__exitcall(resctrl_exit);
+__exitcall(resctrl_arch_exit);

arch/x86/kernel/cpu/resctrl/internal.h

@@ -328,9 +328,6 @@ extern struct list_head rdt_all_groups;
 
 extern int max_name_width;
 
-int __init rdtgroup_init(void);
-void __exit rdtgroup_exit(void);
-
 /**
  * struct rftype - describe each file in the resctrl file system
  * @name:	File name

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

@@ -1027,7 +1027,7 @@ static int dom_data_init(struct rdt_resource *r)
 	/*
 	 * RESCTRL_RESERVED_CLOSID and RESCTRL_RESERVED_RMID are special and
 	 * are always allocated. These are used for the rdtgroup_default
-	 * control group, which will be setup later in rdtgroup_init().
+	 * control group, which will be setup later in resctrl_init().
 	 */
 	idx = resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID,
 					   RESCTRL_RESERVED_RMID);

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

@@ -4235,14 +4235,14 @@ void resctrl_offline_cpu(unsigned int cpu)
 }
 
 /*
- * rdtgroup_init - rdtgroup initialization
+ * resctrl_init - resctrl filesystem initialization
  *
  * Setup resctrl file system including set up root, create mount point,
- * register rdtgroup filesystem, and initialize files under root directory.
+ * register resctrl filesystem, and initialize files under root directory.
  *
  * Return: 0 on success or -errno
  */
-int __init rdtgroup_init(void)
+int __init resctrl_init(void)
 {
 	int ret = 0;
 
@@ -4290,7 +4290,7 @@ int __init rdtgroup_init(void)
 	return ret;
 }
 
-void __exit rdtgroup_exit(void)
+void __exit resctrl_exit(void)
 {
 	debugfs_remove_recursive(debugfs_resctrl);
 	unregister_filesystem(&rdt_fs_type);

include/linux/resctrl.h

@@ -402,4 +402,7 @@ void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_mon_domain *
 extern unsigned int resctrl_rmid_realloc_threshold;
 extern unsigned int resctrl_rmid_realloc_limit;
 
+int __init resctrl_init(void);
+void __exit resctrl_exit(void);
+
 #endif /* _RESCTRL_H */