2 files changed, 20 insertions, 4 deletions

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 20bfefbe7594..d936a0021839 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -74,6 +74,8 @@ enum cpuhp_state {
         CPUHP_ZCOMP_PREPARE,
         CPUHP_TIMERS_DEAD,
         CPUHP_MIPS_SOC_PREPARE,
+        CPUHP_BP_PREPARE_DYN,
+        CPUHP_BP_PREPARE_DYN_END                = CPUHP_BP_PREPARE_DYN + 20,
         CPUHP_BRINGUP_CPU,
         CPUHP_AP_IDLE_DEAD,
         CPUHP_AP_OFFLINE,
diff --git a/kernel/cpu.c b/kernel/cpu.c
index f75c4d031eeb..c47506357519 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1302,10 +1302,24 @@ 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 +1337,7 @@ 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;