[patch 08/20] cpu/hotplug: Hand in target state to _cpu_up/down

[Thomas Gleixner]

We want to be able to bringup/teardown the cpu to a particular state. Add a
target argument to _cpu_up/down.

Signed-off-by: Thomas Gleixner <t...@linutronix.de>
---
 kernel/cpu.c |   31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

Index: b/kernel/cpu.c
===================================================================
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -547,7 +547,8 @@ static void undo_cpu_down(unsigned int c
 }
 
 /* Requires cpu_add_remove_lock to be held */
-static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
+static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
+                          enum cpuhp_state target)
 {
        struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
        int prev_state, ret = 0;
@@ -564,7 +565,7 @@ static int __ref _cpu_down(unsigned int
        cpuhp_tasks_frozen = tasks_frozen;
 
        prev_state = st->state;
-       st->target = CPUHP_OFFLINE;
+       st->target = target;
        for (; st->state > st->target; st->state--) {
                struct cpuhp_step *step = cpuhp_bp_states + st->state;
 
@@ -584,7 +585,7 @@ static int __ref _cpu_down(unsigned int
        return ret;
 }
 
-int cpu_down(unsigned int cpu)
+static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
 {
        int err;
 
@@ -595,12 +596,16 @@ int cpu_down(unsigned int cpu)
                goto out;
        }
 
-       err = _cpu_down(cpu, 0);
+       err = _cpu_down(cpu, 0, target);
 
 out:
        cpu_maps_update_done();
        return err;
 }
+int cpu_down(unsigned int cpu)
+{
+       return do_cpu_down(cpu, CPUHP_OFFLINE);
+}
 EXPORT_SYMBOL(cpu_down);
 #endif /*CONFIG_HOTPLUG_CPU*/
 
@@ -669,7 +674,7 @@ static void undo_cpu_up(unsigned int cpu
 }
 
 /* Requires cpu_add_remove_lock to be held */
-static int _cpu_up(unsigned int cpu, int tasks_frozen)
+static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target)
 {
        struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
        struct task_struct *idle;
@@ -692,7 +697,7 @@ static int _cpu_up(unsigned int cpu, int
        cpuhp_tasks_frozen = tasks_frozen;
 
        prev_state = st->state;
-       st->target = CPUHP_ONLINE;
+       st->target = target;
        while (st->state < st->target) {
                struct cpuhp_step *step;
 
@@ -710,7 +715,7 @@ static int _cpu_up(unsigned int cpu, int
        return ret;
 }
 
-int cpu_up(unsigned int cpu)
+static int do_cpu_up(unsigned int cpu, enum cpuhp_state target)
 {
        int err = 0;
 
@@ -734,12 +739,16 @@ int cpu_up(unsigned int cpu)
                goto out;
        }
 
-       err = _cpu_up(cpu, 0);
-
+       err = _cpu_up(cpu, 0, target);
 out:
        cpu_maps_update_done();
        return err;
 }
+
+int cpu_up(unsigned int cpu)
+{
+       return do_cpu_up(cpu, CPUHP_ONLINE);
+}
 EXPORT_SYMBOL_GPL(cpu_up);
 
 #ifdef CONFIG_PM_SLEEP_SMP
@@ -762,7 +771,7 @@ int disable_nonboot_cpus(void)
                if (cpu == first_cpu)
                        continue;
                trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
-               error = _cpu_down(cpu, 1);
+               error = _cpu_down(cpu, 1, CPUHP_OFFLINE);
                trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
                if (!error)
                        cpumask_set_cpu(cpu, frozen_cpus);
@@ -812,7 +821,7 @@ void enable_nonboot_cpus(void)
 
        for_each_cpu(cpu, frozen_cpus) {
                trace_suspend_resume(TPS("CPU_ON"), cpu, true);
-               error = _cpu_up(cpu, 1);
+               error = _cpu_up(cpu, 1, CPUHP_ONLINE);
                trace_suspend_resume(TPS("CPU_ON"), cpu, false);
                if (!error) {
                        pr_info("CPU%d is up\n", cpu);