Merge branch 'throttling' into release

3 files changed, 84 insertions, 3 deletions

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 29572debc65d..360a74e6add0 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -427,8 +427,13 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb,
         if (action == CPU_ONLINE && pr) {
                 acpi_processor_ppc_has_changed(pr, 0);
                 acpi_processor_cst_has_changed(pr);
+                acpi_processor_reevaluate_tstate(pr, action);
                 acpi_processor_tstate_has_changed(pr);
         }
+        if (action == CPU_DEAD && pr) {
+                /* invalidate the flag.throttling after one CPU is offline */
+                acpi_processor_reevaluate_tstate(pr, action);
+        }
         return NOTIFY_OK;
 }
 
diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index 4a0eec5dd24a..fa84e9744330 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -366,6 +366,58 @@ int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 }
 
 /*
+ * This function is used to reevaluate whether the T-state is valid
+ * after one CPU is onlined/offlined.
+ * It is noted that it won't reevaluate the following properties for
+ * the T-state.
+ *      1. Control method.
+ *      2. the number of supported T-state
+ *      3. TSD domain
+ */
+void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
+                                        unsigned long action)
+{
+        int result = 0;
+
+        if (action == CPU_DEAD) {
+                /* When one CPU is offline, the T-state throttling
+                 * will be invalidated.
+                 */
+                pr->flags.throttling = 0;
+                return;
+        }
+        /* the following is to recheck whether the T-state is valid for
+         * the online CPU
+         */
+        if (!pr->throttling.state_count) {
+                /* If the number of T-state is invalid, it is
+                 * invalidated.
+                 */
+                pr->flags.throttling = 0;
+                return;
+        }
+        pr->flags.throttling = 1;
+
+        /* Disable throttling (if enabled).  We'll let subsequent
+         * policy (e.g.thermal) decide to lower performance if it
+         * so chooses, but for now we'll crank up the speed.
+         */
+
+        result = acpi_processor_get_throttling(pr);
+        if (result)
+                goto end;
+
+        if (pr->throttling.state) {
+                result = acpi_processor_set_throttling(pr, 0, false);
+                if (result)
+                        goto end;
+        }
+
+end:
+        if (result)
+                pr->flags.throttling = 0;
+}
+/*
  * _PTC - Processor Throttling Control (and status) register location
  */
 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
@@ -872,7 +924,11 @@ static int acpi_processor_get_throttling(struct acpi_processor *pr)
          */
         cpumask_copy(saved_mask, &current->cpus_allowed);
         /* FIXME: use work_on_cpu() */
-        set_cpus_allowed_ptr(current, cpumask_of(pr->id));
+        if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
+                /* Can't migrate to the target pr->id CPU. Exit */
+                free_cpumask_var(saved_mask);
+                return -ENODEV;
+        }
         ret = pr->throttling.acpi_processor_get_throttling(pr);
         /* restore the previous state */
         set_cpus_allowed_ptr(current, saved_mask);
@@ -1047,6 +1103,14 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
                 return -ENOMEM;
         }
 
+        if (cpu_is_offline(pr->id)) {
+                /*
+                 * the cpu pointed by pr->id is offline. Unnecessary to change
+                 * the throttling state any more.
+                 */
+                return -ENODEV;
+        }
+
         cpumask_copy(saved_mask, &current->cpus_allowed);
         t_state.target_state = state;
         p_throttling = &(pr->throttling);
@@ -1070,7 +1134,11 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
          */
         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
                 /* FIXME: use work_on_cpu() */
-                set_cpus_allowed_ptr(current, cpumask_of(pr->id));
+                if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
+                        /* Can't migrate to the pr->id CPU. Exit */
+                        ret = -ENODEV;
+                        goto exit;
+                }
                 ret = p_throttling->acpi_processor_set_throttling(pr,
                                                 t_state.target_state, force);
         } else {
@@ -1102,7 +1170,8 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
                         }
                         t_state.cpu = i;
                         /* FIXME: use work_on_cpu() */
-                        set_cpus_allowed_ptr(current, cpumask_of(i));
+                        if (set_cpus_allowed_ptr(current, cpumask_of(i)))
+                                continue;
                         ret = match_pr->throttling.
                                 acpi_processor_set_throttling(
                                 match_pr, t_state.target_state, force);
@@ -1122,6 +1191,7 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
         /* restore the previous state */
         /* FIXME: use work_on_cpu() */
         set_cpus_allowed_ptr(current, saved_mask);
+exit:
         free_cpumask_var(online_throttling_cpus);
         free_cpumask_var(saved_mask);
         return ret;
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 1b62102fbb67..55192ac0cede 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -324,6 +324,12 @@ int acpi_processor_tstate_has_changed(struct acpi_processor *pr);
 int acpi_processor_get_throttling_info(struct acpi_processor *pr);
 extern int acpi_processor_set_throttling(struct acpi_processor *pr,
                                          int state, bool force);
+/*
+ * Reevaluate whether the T-state is invalid after one cpu is
+ * onlined/offlined. In such case the flags.throttling will be updated.
+ */
+extern void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
+                        unsigned long action);
 extern const struct file_operations acpi_processor_throttling_fops;
 extern void acpi_processor_throttling_init(void);
 /* in processor_idle.c */