cpu/hotplug: Replace anon union

Some compilers are unhappy with the anon union in the state array. Replace
it with a named union.

While at it align the state array initializers proper and add the missing
name tags.

Fixes: cf392d10b69e "cpu/hotplug: Add multi instance support"
Reported-by: Ingo Molnar <mingo@kernel.org>
Reported-by: Fenguang Wu <fengguang.wu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: rt@linutronix.de

1 files changed, 74 insertions, 71 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index c90f839c5b86..2409ed717a3f 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -73,15 +73,15 @@ static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state);
 struct cpuhp_step {
         const char              *name;
         union {
-                int             (*startup)(unsigned int cpu);
-                int             (*startup_multi)(unsigned int cpu,
-                                                 struct hlist_node *node);
-        };
+                int             (*single)(unsigned int cpu);
+                int             (*multi)(unsigned int cpu,
+                                         struct hlist_node *node);
+        } startup;
         union {
-                int             (*teardown)(unsigned int cpu);
-                int             (*teardown_multi)(unsigned int cpu,
-                                                  struct hlist_node *node);
-        };
+                int             (*single)(unsigned int cpu);
+                int             (*multi)(unsigned int cpu,
+                                         struct hlist_node *node);
+        } teardown;
         struct hlist_head       list;
         bool                    skip_onerr;
         bool                    cant_stop;
@@ -127,7 +127,7 @@ static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state,
         int ret, cnt;
 
         if (!step->multi_instance) {
-                cb = bringup ? step->startup : step->teardown;
+                cb = bringup ? step->startup.single : step->teardown.single;
                 if (!cb)
                         return 0;
                 trace_cpuhp_enter(cpu, st->target, state, cb);
@@ -135,7 +135,7 @@ static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state,
                 trace_cpuhp_exit(cpu, st->state, state, ret);
                 return ret;
         }
-        cbm = bringup ? step->startup_multi : step->teardown_multi;
+        cbm = bringup ? step->startup.multi : step->teardown.multi;
         if (!cbm)
                 return 0;
 
@@ -160,7 +160,7 @@ static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state,
         return 0;
 err:
         /* Rollback the instances if one failed */
-        cbm = !bringup ? step->startup_multi : step->teardown_multi;
+        cbm = !bringup ? step->startup.multi : step->teardown.multi;
         if (!cbm)
                 return ret;
 
@@ -1256,40 +1256,40 @@ core_initcall(cpu_hotplug_pm_sync_init);
 static struct cpuhp_step cpuhp_bp_states[] = {
         [CPUHP_OFFLINE] = {
                 .name                   = "offline",
-                .startup                = NULL,
-                .teardown               = NULL,
+                .startup.single         = NULL,
+                .teardown.single        = NULL,
         },
 #ifdef CONFIG_SMP
         [CPUHP_CREATE_THREADS]= {
                 .name                   = "threads:create",
-                .startup                = smpboot_create_threads,
-                .teardown               = NULL,
+                .startup.single         = smpboot_create_threads,
+                .teardown.single        = NULL,
                 .cant_stop              = true,
         },
         [CPUHP_PERF_PREPARE] = {
-                .name = "perf prepare",
-                .startup = perf_event_init_cpu,
-                .teardown = perf_event_exit_cpu,
+                .name                   = "perf:prepare",
+                .startup.single         = perf_event_init_cpu,
+                .teardown.single        = perf_event_exit_cpu,
         },
         [CPUHP_WORKQUEUE_PREP] = {
-                .name = "workqueue prepare",
-                .startup = workqueue_prepare_cpu,
-                .teardown = NULL,
+                .name                   = "workqueue:prepare",
+                .startup.single         = workqueue_prepare_cpu,
+                .teardown.single        = NULL,
         },
         [CPUHP_HRTIMERS_PREPARE] = {
-                .name = "hrtimers prepare",
-                .startup = hrtimers_prepare_cpu,
-                .teardown = hrtimers_dead_cpu,
+                .name                   = "hrtimers:prepare",
+                .startup.single         = hrtimers_prepare_cpu,
+                .teardown.single        = hrtimers_dead_cpu,
         },
         [CPUHP_SMPCFD_PREPARE] = {
-                .name = "SMPCFD prepare",
-                .startup = smpcfd_prepare_cpu,
-                .teardown = smpcfd_dead_cpu,
+                .name                   = "SMPCFD:prepare",
+                .startup.single         = smpcfd_prepare_cpu,
+                .teardown.single        = smpcfd_dead_cpu,
         },
         [CPUHP_RCUTREE_PREP] = {
-                .name = "RCU-tree prepare",
-                .startup = rcutree_prepare_cpu,
-                .teardown = rcutree_dead_cpu,
+                .name                   = "RCU-tree:prepare",
+                .startup.single         = rcutree_prepare_cpu,
+                .teardown.single        = rcutree_dead_cpu,
         },
         /*
          * Preparatory and dead notifiers. Will be replaced once the notifiers
@@ -1297,8 +1297,8 @@ static struct cpuhp_step cpuhp_bp_states[] = {
          */
         [CPUHP_NOTIFY_PREPARE] = {
                 .name                   = "notify:prepare",
-                .startup                = notify_prepare,
-                .teardown               = notify_dead,
+                .startup.single         = notify_prepare,
+                .teardown.single        = notify_dead,
                 .skip_onerr             = true,
                 .cant_stop              = true,
         },
@@ -1308,20 +1308,21 @@ static struct cpuhp_step cpuhp_bp_states[] = {
          * otherwise a RCU stall occurs.
          */
         [CPUHP_TIMERS_DEAD] = {
-                .name = "timers dead",
-                .startup = NULL,
-                .teardown = timers_dead_cpu,
+                .name                   = "timers:dead",
+                .startup.single         = NULL,
+                .teardown.single        = timers_dead_cpu,
         },
         /* Kicks the plugged cpu into life */
         [CPUHP_BRINGUP_CPU] = {
                 .name                   = "cpu:bringup",
-                .startup                = bringup_cpu,
-                .teardown               = NULL,
+                .startup.single         = bringup_cpu,
+                .teardown.single        = NULL,
                 .cant_stop              = true,
         },
         [CPUHP_AP_SMPCFD_DYING] = {
-                .startup = NULL,
-                .teardown = smpcfd_dying_cpu,
+                .name                   = "SMPCFD:dying",
+                .startup.single         = NULL,
+                .teardown.single        = smpcfd_dying_cpu,
         },
         /*
          * Handled on controll processor until the plugged processor manages
@@ -1329,8 +1330,8 @@ static struct cpuhp_step cpuhp_bp_states[] = {
          */
         [CPUHP_TEARDOWN_CPU] = {
                 .name                   = "cpu:teardown",
-                .startup                = NULL,
-                .teardown               = takedown_cpu,
+                .startup.single         = NULL,
+                .teardown.single        = takedown_cpu,
                 .cant_stop              = true,
         },
 #else
@@ -1356,22 +1357,23 @@ static struct cpuhp_step cpuhp_ap_states[] = {
         /* First state is scheduler control. Interrupts are disabled */
         [CPUHP_AP_SCHED_STARTING] = {
                 .name                   = "sched:starting",
-                .startup                = sched_cpu_starting,
-                .teardown               = sched_cpu_dying,
+                .startup.single         = sched_cpu_starting,
+                .teardown.single        = sched_cpu_dying,
         },
         [CPUHP_AP_RCUTREE_DYING] = {
-                .startup = NULL,
-                .teardown = rcutree_dying_cpu,
+                .name                   = "RCU-tree:dying",
+                .startup.single         = NULL,
+                .teardown.single        = rcutree_dying_cpu,
         },
         /*
-         * Low level startup/teardown notifiers. Run with interrupts
+         * Low level startup.single/teardown notifiers. Run with interrupts
          * disabled. Will be removed once the notifiers are converted to
          * states.
          */
         [CPUHP_AP_NOTIFY_STARTING] = {
                 .name                   = "notify:starting",
-                .startup                = notify_starting,
-                .teardown               = notify_dying,
+                .startup.single         = notify_starting,
+                .teardown.single                = notify_dying,
                 .skip_onerr             = true,
                 .cant_stop              = true,
         },
@@ -1383,23 +1385,23 @@ static struct cpuhp_step cpuhp_ap_states[] = {
         /* Handle smpboot threads park/unpark */
         [CPUHP_AP_SMPBOOT_THREADS] = {
                 .name                   = "smpboot:threads",
-                .startup                = smpboot_unpark_threads,
-                .teardown               = NULL,
+                .startup.single         = smpboot_unpark_threads,
+                .teardown.single        = NULL,
         },
         [CPUHP_AP_PERF_ONLINE] = {
-                .name = "perf online",
-                .startup = perf_event_init_cpu,
-                .teardown = perf_event_exit_cpu,
+                .name                   = "perf:online",
+                .startup.single         = perf_event_init_cpu,
+                .teardown.single        = perf_event_exit_cpu,
         },
         [CPUHP_AP_WORKQUEUE_ONLINE] = {
-                .name = "workqueue online",
-                .startup = workqueue_online_cpu,
-                .teardown = workqueue_offline_cpu,
+                .name                   = "workqueue:online",
+                .startup.single         = workqueue_online_cpu,
+                .teardown.single        = workqueue_offline_cpu,
         },
         [CPUHP_AP_RCUTREE_ONLINE] = {
-                .name = "RCU-tree online",
-                .startup = rcutree_online_cpu,
-                .teardown = rcutree_offline_cpu,
+                .name                   = "RCU-tree:online",
+                .startup.single         = rcutree_online_cpu,
+                .teardown.single        = rcutree_offline_cpu,
         },
 
         /*
@@ -1408,8 +1410,8 @@ static struct cpuhp_step cpuhp_ap_states[] = {
          */
         [CPUHP_AP_NOTIFY_ONLINE] = {
                 .name                   = "notify:online",
-                .startup                = notify_online,
-                .teardown               = notify_down_prepare,
+                .startup.single         = notify_online,
+                .teardown.single        = notify_down_prepare,
                 .skip_onerr             = true,
         },
 #endif
@@ -1421,16 +1423,16 @@ static struct cpuhp_step cpuhp_ap_states[] = {
         /* Last state is scheduler control setting the cpu active */
         [CPUHP_AP_ACTIVE] = {
                 .name                   = "sched:active",
-                .startup                = sched_cpu_activate,
-                .teardown               = sched_cpu_deactivate,
+                .startup.single         = sched_cpu_activate,
+                .teardown.single        = sched_cpu_deactivate,
         },
 #endif
 
         /* CPU is fully up and running. */
         [CPUHP_ONLINE] = {
                 .name                   = "online",
-                .startup                = NULL,
-                .teardown               = NULL,
+                .startup.single         = NULL,
+                .teardown.single        = NULL,
         },
 };
 
@@ -1453,8 +1455,8 @@ static void cpuhp_store_callbacks(enum cpuhp_state state,
 
         mutex_lock(&cpuhp_state_mutex);
         sp = cpuhp_get_step(state);
-        sp->startup = startup;
-        sp->teardown = teardown;
+        sp->startup.single = startup;
+        sp->teardown.single = teardown;
         sp->name = name;
         sp->multi_instance = multi_instance;
         INIT_HLIST_HEAD(&sp->list);
@@ -1463,7 +1465,7 @@ static void cpuhp_store_callbacks(enum cpuhp_state state,
 
 static void *cpuhp_get_teardown_cb(enum cpuhp_state state)
 {
-        return cpuhp_get_step(state)->teardown;
+        return cpuhp_get_step(state)->teardown.single;
 }
 
 /*
@@ -1476,7 +1478,8 @@ static int cpuhp_issue_call(int cpu, enum cpuhp_state state, bool bringup,
         struct cpuhp_step *sp = cpuhp_get_step(state);
         int ret;
 
-        if ((bringup && !sp->startup) || (!bringup && !sp->teardown))
+        if ((bringup && !sp->startup.single) ||
+            (!bringup && !sp->teardown.single))
                 return 0;
         /*
          * The non AP bound callbacks can fail on bringup. On teardown
@@ -1554,7 +1557,7 @@ int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
 
         get_online_cpus();
 
-        if (!invoke || !sp->startup_multi)
+        if (!invoke || !sp->startup.multi)
                 goto add_node;
 
         /*
@@ -1570,7 +1573,7 @@ int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
 
                 ret = cpuhp_issue_call(cpu, state, true, node);
                 if (ret) {
-                        if (sp->teardown_multi)
+                        if (sp->teardown.multi)
                                 cpuhp_rollback_install(cpu, state, node);
                         goto err;
                 }