[PATCH v5 33/40] x86/resctrl: Drop __init/__exit on assorted symbols

[James Morse <james.morse@arm.com>]

Because ARM's MPAM controls are probed using MMIO, resctrl can't be
initialised until enough CPUs are online to have determined the
system-wide supported num_closid. Arm64 also supports 'late onlined
secondaries', where only a subset of CPUs are online during boot.

These two combine to mean the MPAM driver may not be able to initialise
resctrl until user-space has brought 'enough' CPUs online.

To allow MPAM to initialise resctrl after __init text has been free'd,
remove all the __init markings from resctrl.

The existing __exit markings cause these functions to be removed by the
linker as it has never been possible to build resctrl as a module. MPAM
has an error interrupt which causes the driver to reset and disable
itself. Remove the __exit markings to allow the MPAM driver to tear down
resctrl when an error occurs.

Signed-off-by: James Morse <james.morse@arm.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
---
Changes since v4:
 * Earlier __init marker removal migrated here.
---
 arch/x86/kernel/cpu/resctrl/core.c     |  6 +++---
 arch/x86/kernel/cpu/resctrl/internal.h |  6 +++---
 arch/x86/kernel/cpu/resctrl/monitor.c  |  2 +-
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 10 +++++-----
 include/linux/resctrl.h                |  6 +++---
 5 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index f484726a2588..f713ac628444 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -775,7 +775,7 @@ struct rdt_options {
 	bool	force_off, force_on;
 };
 
-static struct rdt_options rdt_options[]  __initdata = {
+static struct rdt_options rdt_options[]  __ro_after_init = {
 	RDT_OPT(RDT_FLAG_CMT,	    "cmt",	X86_FEATURE_CQM_OCCUP_LLC),
 	RDT_OPT(RDT_FLAG_MBM_TOTAL, "mbmtotal", X86_FEATURE_CQM_MBM_TOTAL),
 	RDT_OPT(RDT_FLAG_MBM_LOCAL, "mbmlocal", X86_FEATURE_CQM_MBM_LOCAL),
@@ -815,7 +815,7 @@ static int __init set_rdt_options(char *str)
 }
 __setup("rdt", set_rdt_options);
 
-bool __init rdt_cpu_has(int flag)
+bool rdt_cpu_has(int flag)
 {
 	bool ret = boot_cpu_has(flag);
 	struct rdt_options *o;
@@ -835,7 +835,7 @@ bool __init rdt_cpu_has(int flag)
 	return ret;
 }
 
-bool __init resctrl_arch_is_evt_configurable(enum resctrl_event_id evt)
+bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt)
 {
 	if (!rdt_cpu_has(X86_FEATURE_BMEC))
 		return false;
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index e939a0a28a49..4b7e370e71ac 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -474,13 +474,13 @@ int alloc_rmid(u32 closid);
 void free_rmid(u32 closid, u32 rmid);
 int rdt_get_mon_l3_config(struct rdt_resource *r);
 void resctrl_mon_resource_exit(void);
-bool __init rdt_cpu_has(int flag);
+bool rdt_cpu_has(int flag);
 void mon_event_count(void *info);
 int rdtgroup_mondata_show(struct seq_file *m, void *arg);
 void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
 		    struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,
 		    cpumask_t *cpumask, int evtid, int first);
-int __init resctrl_mon_resource_init(void);
+int resctrl_mon_resource_init(void);
 void mbm_setup_overflow_handler(struct rdt_mon_domain *dom,
 				unsigned long delay_ms,
 				int exclude_cpu);
@@ -493,7 +493,7 @@ void cqm_handle_limbo(struct work_struct *work);
 bool has_busy_rmid(struct rdt_mon_domain *d);
 void __check_limbo(struct rdt_mon_domain *d, bool force_free);
 void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
-void __init mbm_config_rftype_init(const char *config);
+void mbm_config_rftype_init(const char *config);
 void rdt_staged_configs_clear(void);
 bool closid_allocated(unsigned int closid);
 int resctrl_find_cleanest_closid(void);
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 39c450624ed0..1fd47f8a0e18 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -1191,7 +1191,7 @@ static __init int snc_get_config(void)
  *
  * Returns 0 for success, or -ENOMEM.
  */
-int __init resctrl_mon_resource_init(void)
+int resctrl_mon_resource_init(void)
 {
 	struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
 	int ret;
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index bb5aadaf99b6..e45a8a6b5ff7 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2048,7 +2048,7 @@ static struct rftype *rdtgroup_get_rftype_by_name(const char *name)
 	return NULL;
 }
 
-static void __init thread_throttle_mode_init(void)
+static void thread_throttle_mode_init(void)
 {
 	struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
 	struct rftype *rft;
@@ -2064,7 +2064,7 @@ static void __init thread_throttle_mode_init(void)
 	rft->fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB;
 }
 
-void __init mbm_config_rftype_init(const char *config)
+void mbm_config_rftype_init(const char *config)
 {
 	struct rftype *rft;
 
@@ -4044,7 +4044,7 @@ static void rdtgroup_destroy_root(void)
 	rdtgroup_default.kn = NULL;
 }
 
-static void __init rdtgroup_setup_default(void)
+static void rdtgroup_setup_default(void)
 {
 	mutex_lock(&rdtgroup_mutex);
 
@@ -4260,7 +4260,7 @@ void resctrl_offline_cpu(unsigned int cpu)
  *
  * Return: 0 on success or -errno
  */
-int __init resctrl_init(void)
+int resctrl_init(void)
 {
 	int ret = 0;
 
@@ -4317,7 +4317,7 @@ int __init resctrl_init(void)
 	return ret;
 }
 
-void __exit resctrl_exit(void)
+void resctrl_exit(void)
 {
 	rdtgroup_destroy_root();
 	debugfs_remove_recursive(debugfs_resctrl);
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 7af6c40764ed..39303a0a398a 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -374,7 +374,7 @@ struct rdt_domain_hdr *resctrl_arch_find_domain(struct list_head *domain_list,
 						int id);
 int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);
 
-bool __init resctrl_arch_is_evt_configurable(enum resctrl_event_id evt);
+bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt);
 
 /**
  * resctrl_arch_mon_event_config_write() - Write the config for a counter.
@@ -537,7 +537,7 @@ 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);
+int resctrl_init(void);
+void resctrl_exit(void);
 
 #endif /* _RESCTRL_H */
-- 
2.39.2