Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[mirror_ubuntu-zesty-kernel.git] / kernel / cpu.c

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 042fd7e8e03098882b165787b163a597c4c92aa8..0a5f630f5c5430c231b2ba8ccb7d671bca09014e 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -764,7 +764,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
 {
        struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
        int prev_state, ret = 0;
-       bool hasdied = false;
 
        if (num_online_cpus() == 1)
                return -EBUSY;
@@ -809,7 +808,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
                cpuhp_kick_ap_work(cpu);
        }
 
-       hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE;
 out:
        cpu_hotplug_done();
        return ret;
@@ -1302,10 +1300,24 @@ static int cpuhp_cb_check(enum cpuhp_state state)
  */
 static int cpuhp_reserve_state(enum cpuhp_state state)
 {
-       enum cpuhp_state i;
+       enum cpuhp_state i, end;
+       struct cpuhp_step *step;
 
-       for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) {
-               if (!cpuhp_ap_states[i].name)
+       switch (state) {
+       case CPUHP_AP_ONLINE_DYN:
+               step = cpuhp_ap_states + CPUHP_AP_ONLINE_DYN;
+               end = CPUHP_AP_ONLINE_DYN_END;
+               break;
+       case CPUHP_BP_PREPARE_DYN:
+               step = cpuhp_bp_states + CPUHP_BP_PREPARE_DYN;
+               end = CPUHP_BP_PREPARE_DYN_END;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       for (i = state; i <= end; i++, step++) {
+               if (!step->name)
                        return i;
        }
        WARN(1, "No more dynamic states available for CPU hotplug\n");
@@ -1323,7 +1335,7 @@ static int cpuhp_store_callbacks(enum cpuhp_state state, const char *name,
 
        mutex_lock(&cpuhp_state_mutex);
 
-       if (state == CPUHP_AP_ONLINE_DYN) {
+       if (state == CPUHP_AP_ONLINE_DYN || state == CPUHP_BP_PREPARE_DYN) {
                ret = cpuhp_reserve_state(state);
                if (ret < 0)
                        goto out;
@@ -1471,6 +1483,7 @@ int __cpuhp_setup_state(enum cpuhp_state state,
                        bool multi_instance)
 {
        int cpu, ret = 0;
+       bool dynstate;
 
        if (cpuhp_cb_check(state) || !name)
                return -EINVAL;
@@ -1480,6 +1493,12 @@ int __cpuhp_setup_state(enum cpuhp_state state,
        ret = cpuhp_store_callbacks(state, name, startup, teardown,
                                    multi_instance);
 
+       dynstate = state == CPUHP_AP_ONLINE_DYN;
+       if (ret > 0 && dynstate) {
+               state = ret;
+               ret = 0;
+       }
+
        if (ret || !invoke || !startup)
                goto out;
 
@@ -1508,7 +1527,7 @@ out:
         * If the requested state is CPUHP_AP_ONLINE_DYN, return the
         * dynamically allocated state in case of success.
         */
-       if (!ret && state == CPUHP_AP_ONLINE_DYN)
+       if (!ret && dynstate)
                return state;
        return ret;
 }