x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation

[linux-block.git] / kernel / cpu.c

diff --git a/kernel/cpu.c b/kernel/cpu.c
index ed44d7d34c2d9bfc08093af4854dc78bf7232b21..2fb49916ea560735d7f51f8a7610892303ec243a 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -102,8 +102,6 @@ static inline void cpuhp_lock_release(bool bringup) { }
  * @name:      Name of the step
  * @startup:   Startup function of the step
  * @teardown:  Teardown function of the step
- * @skip_onerr:        Do not invoke the functions on error rollback
- *             Will go away once the notifiers are gone
  * @cant_stop: Bringup/teardown can't be stopped at this step
  */
 struct cpuhp_step {
@@ -119,7 +117,6 @@ struct cpuhp_step {
                                         struct hlist_node *node);
        } teardown;
        struct hlist_head       list;
-       bool                    skip_onerr;
        bool                    cant_stop;
        bool                    multi_instance;
 };
@@ -550,12 +547,8 @@ static int bringup_cpu(unsigned int cpu)
 
 static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st)
 {
-       for (st->state--; st->state > st->target; st->state--) {
-               struct cpuhp_step *step = cpuhp_get_step(st->state);
-
-               if (!step->skip_onerr)
-                       cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL);
-       }
+       for (st->state--; st->state > st->target; st->state--)
+               cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL);
 }
 
 static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
@@ -644,12 +637,6 @@ static void cpuhp_thread_fun(unsigned int cpu)
 
        WARN_ON_ONCE(!cpuhp_is_ap_state(state));
 
-       if (st->rollback) {
-               struct cpuhp_step *step = cpuhp_get_step(state);
-               if (step->skip_onerr)
-                       goto next;
-       }
-
        if (cpuhp_is_atomic_state(state)) {
                local_irq_disable();
                st->result = cpuhp_invoke_callback(cpu, state, bringup, st->node, &st->last);
@@ -673,7 +660,6 @@ static void cpuhp_thread_fun(unsigned int cpu)
                st->should_run = false;
        }
 
-next:
        cpuhp_lock_release(bringup);
 
        if (!st->should_run)
@@ -916,12 +902,8 @@ void cpuhp_report_idle_dead(void)
 
 static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st)
 {
-       for (st->state++; st->state < st->target; st->state++) {
-               struct cpuhp_step *step = cpuhp_get_step(st->state);
-
-               if (!step->skip_onerr)
-                       cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL);
-       }
+       for (st->state++; st->state < st->target; st->state++)
+               cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL);
 }
 
 static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
@@ -2043,6 +2025,12 @@ static void cpuhp_online_cpu_device(unsigned int cpu)
        kobject_uevent(&dev->kobj, KOBJ_ONLINE);
 }
 
+/*
+ * Architectures that need SMT-specific errata handling during SMT hotplug
+ * should override this.
+ */
+void __weak arch_smt_update(void) { };
+
 static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
 {
        int cpu, ret = 0;
@@ -2069,8 +2057,10 @@ static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
                 */
                cpuhp_offline_cpu_device(cpu);
        }
-       if (!ret)
+       if (!ret) {
                cpu_smt_control = ctrlval;
+               arch_smt_update();
+       }
        cpu_maps_update_done();
        return ret;
 }
@@ -2081,6 +2071,7 @@ static int cpuhp_smt_enable(void)
 
        cpu_maps_update_begin();
        cpu_smt_control = CPU_SMT_ENABLED;
+       arch_smt_update();
        for_each_present_cpu(cpu) {
                /* Skip online CPUs and CPUs on offline nodes */
                if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))