[RFC v0 8/9] cpu: Do not set CPU_TASKS_FROZEN anymore

[Daniel Wagner <daniel.wagner@bmw-carit.de>]

There is no user left of CPU_TASKS_FROZEN, so we can stop propagating
this information.

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: linux-kernel@vger.kernel.org
---
 include/linux/cpu.h | 15 ---------------
 kernel/cpu.c        | 22 ++++++++--------------
 2 files changed, 8 insertions(+), 29 deletions(-)

diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 381ea8a..ebd07e7 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -104,21 +104,6 @@ enum {
 #define CPU_DEAD_TIMEOUT	0x000D /* CPU (unsigned)v surviving CPU timed
 					  out */
 
-/* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
- * operation in progress
- */
-#define CPU_TASKS_FROZEN	0x0010
-
-#define CPU_ONLINE_FROZEN	(CPU_ONLINE | CPU_TASKS_FROZEN)
-#define CPU_UP_PREPARE_FROZEN	(CPU_UP_PREPARE | CPU_TASKS_FROZEN)
-#define CPU_UP_CANCELED_FROZEN	(CPU_UP_CANCELED | CPU_TASKS_FROZEN)
-#define CPU_DOWN_PREPARE_FROZEN	(CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
-#define CPU_DOWN_FAILED_FROZEN	(CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
-#define CPU_DEAD_FROZEN		(CPU_DEAD | CPU_TASKS_FROZEN)
-#define CPU_DYING_FROZEN	(CPU_DYING | CPU_TASKS_FROZEN)
-#define CPU_STARTING_FROZEN	(CPU_STARTING | CPU_TASKS_FROZEN)
-
-
 #ifdef CONFIG_SMP
 /* Need to know about CPUs going up/down? */
 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index e37442d..1f0408c 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -29,7 +29,6 @@
 #ifdef CONFIG_SMP
 /* Serializes the updates to cpu_online_mask, cpu_present_mask */
 static DEFINE_MUTEX(cpu_add_remove_lock);
-static bool cpuhp_tasks_frozen;
 
 /*
  * The following two APIs (cpu_maps_update_begin/done) must be used when
@@ -224,12 +223,11 @@ int __register_cpu_notifier(struct notifier_block *nb)
 static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call,
 			int *nr_calls)
 {
-	unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0;
 	void *hcpu = (void *)(long)cpu;
 
 	int ret;
 
-	ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call,
+	ret = __raw_notifier_call_chain(&cpu_chain, val, hcpu, nr_to_call,
 					nr_calls);
 
 	return notifier_to_errno(ret);
@@ -347,7 +345,7 @@ static int take_cpu_down(void *_param)
 }
 
 /* Requires cpu_add_remove_lock to be held */
-static int _cpu_down(unsigned int cpu, int tasks_frozen)
+static int _cpu_down(unsigned int cpu)
 {
 	int err, nr_calls = 0;
 
@@ -359,8 +357,6 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)
 
 	cpu_hotplug_begin();
 
-	cpuhp_tasks_frozen = tasks_frozen;
-
 	err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls);
 	if (err) {
 		nr_calls--;
@@ -448,7 +444,7 @@ int cpu_down(unsigned int cpu)
 		goto out;
 	}
 
-	err = _cpu_down(cpu, 0);
+	err = _cpu_down(cpu);
 
 out:
 	cpu_maps_update_done();
@@ -465,7 +461,7 @@ static int smpboot_thread_call(struct notifier_block *nfb,
 {
 	int cpu = (long)hcpu;
 
-	switch (action & ~CPU_TASKS_FROZEN) {
+	switch (action) {
 
 	case CPU_DOWN_FAILED:
 	case CPU_ONLINE:
@@ -490,7 +486,7 @@ void smpboot_thread_init(void)
 }
 
 /* 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)
 {
 	struct task_struct *idle;
 	int ret, nr_calls = 0;
@@ -512,8 +508,6 @@ static int _cpu_up(unsigned int cpu, int tasks_frozen)
 	if (ret)
 		goto out;
 
-	cpuhp_tasks_frozen = tasks_frozen;
-
 	ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls);
 	if (ret) {
 		nr_calls--;
@@ -565,7 +559,7 @@ int cpu_up(unsigned int cpu)
 		goto out;
 	}
 
-	err = _cpu_up(cpu, 0);
+	err = _cpu_up(cpu);
 
 out:
 	cpu_maps_update_done();
@@ -593,7 +587,7 @@ 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);
 		trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
 		if (!error)
 			cpumask_set_cpu(cpu, frozen_cpus);
@@ -643,7 +637,7 @@ 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);
 		trace_suspend_resume(TPS("CPU_ON"), cpu, false);
 		if (!error) {
 			pr_info("CPU%d is up\n", cpu);
-- 
2.4.3