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authorStefan Agner <stefan.agner@toradex.com>2017-12-13 10:45:48 +0100
committerStefan Agner <stefan.agner@toradex.com>2017-12-13 20:55:07 +0100
commitbc16130af5a2f6ba75aa0cc8689b5d456bc465d8 (patch)
treea22e2c314494c51e16c9b315a1c5af4ffbf22366 /kernel/cpu.c
parentcd5d7ba49df7918732915a31bfc0f72827bebc2c (diff)
parent284bbc782445283e9a5124666dda8010f379f179 (diff)
Merge tag 'v4.9.67' into 4.9-1.0.x-imx-fixes-stable-merge
This is the 4.9.67 stable release Resolved conflicts: arch/arm/boot/dts/imx6sx-sdb.dts drivers/dma/imx-sdma.c drivers/mmc/core/host.c drivers/usb/chipidea/otg.c sound/soc/fsl/fsl_ssi.c This merge also reverts commit 3a654a85932f ("dmaengine: imx-sdma - correct the dma transfer residue calculation"). The downstream kernel seems to use different structures and already use buf_ptail in its calculation.
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r--kernel/cpu.c59
1 files changed, 31 insertions, 28 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 3f7369bac680..3fb3d7209e6f 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -410,11 +410,26 @@ static int notify_online(unsigned int cpu)
return 0;
}
+static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st);
+
static int bringup_wait_for_ap(unsigned int cpu)
{
struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ /* Wait for the CPU to reach CPUHP_AP_ONLINE_IDLE */
wait_for_completion(&st->done);
+ if (WARN_ON_ONCE((!cpu_online(cpu))))
+ return -ECANCELED;
+
+ /* Unpark the stopper thread and the hotplug thread of the target cpu */
+ stop_machine_unpark(cpu);
+ kthread_unpark(st->thread);
+
+ /* Should we go further up ? */
+ if (st->target > CPUHP_AP_ONLINE_IDLE) {
+ __cpuhp_kick_ap_work(st);
+ wait_for_completion(&st->done);
+ }
return st->result;
}
@@ -437,9 +452,7 @@ static int bringup_cpu(unsigned int cpu)
cpu_notify(CPU_UP_CANCELED, cpu);
return ret;
}
- ret = bringup_wait_for_ap(cpu);
- BUG_ON(!cpu_online(cpu));
- return ret;
+ return bringup_wait_for_ap(cpu);
}
/*
@@ -974,31 +987,20 @@ void notify_cpu_starting(unsigned int cpu)
}
/*
- * Called from the idle task. We need to set active here, so we can kick off
- * the stopper thread and unpark the smpboot threads. If the target state is
- * beyond CPUHP_AP_ONLINE_IDLE we kick cpuhp thread and let it bring up the
- * cpu further.
+ * Called from the idle task. Wake up the controlling task which brings the
+ * stopper and the hotplug thread of the upcoming CPU up and then delegates
+ * the rest of the online bringup to the hotplug thread.
*/
void cpuhp_online_idle(enum cpuhp_state state)
{
struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
- unsigned int cpu = smp_processor_id();
/* Happens for the boot cpu */
if (state != CPUHP_AP_ONLINE_IDLE)
return;
st->state = CPUHP_AP_ONLINE_IDLE;
-
- /* Unpark the stopper thread and the hotplug thread of this cpu */
- stop_machine_unpark(cpu);
- kthread_unpark(st->thread);
-
- /* Should we go further up ? */
- if (st->target > CPUHP_AP_ONLINE_IDLE)
- __cpuhp_kick_ap_work(st);
- else
- complete(&st->done);
+ complete(&st->done);
}
/* Requires cpu_add_remove_lock to be held */
@@ -1441,14 +1443,12 @@ static void cpuhp_store_callbacks(enum cpuhp_state state,
/* (Un)Install the callbacks for further cpu hotplug operations */
struct cpuhp_step *sp;
- mutex_lock(&cpuhp_state_mutex);
sp = cpuhp_get_step(state);
sp->startup.single = startup;
sp->teardown.single = teardown;
sp->name = name;
sp->multi_instance = multi_instance;
INIT_HLIST_HEAD(&sp->list);
- mutex_unlock(&cpuhp_state_mutex);
}
static void *cpuhp_get_teardown_cb(enum cpuhp_state state)
@@ -1518,16 +1518,13 @@ static int cpuhp_reserve_state(enum cpuhp_state state)
{
enum cpuhp_state i;
- mutex_lock(&cpuhp_state_mutex);
for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) {
if (cpuhp_ap_states[i].name)
continue;
cpuhp_ap_states[i].name = "Reserved";
- mutex_unlock(&cpuhp_state_mutex);
return i;
}
- mutex_unlock(&cpuhp_state_mutex);
WARN(1, "No more dynamic states available for CPU hotplug\n");
return -ENOSPC;
}
@@ -1544,6 +1541,7 @@ int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
return -EINVAL;
get_online_cpus();
+ mutex_lock(&cpuhp_state_mutex);
if (!invoke || !sp->startup.multi)
goto add_node;
@@ -1568,11 +1566,10 @@ int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
}
add_node:
ret = 0;
- mutex_lock(&cpuhp_state_mutex);
hlist_add_head(node, &sp->list);
- mutex_unlock(&cpuhp_state_mutex);
err:
+ mutex_unlock(&cpuhp_state_mutex);
put_online_cpus();
return ret;
}
@@ -1601,6 +1598,7 @@ int __cpuhp_setup_state(enum cpuhp_state state,
return -EINVAL;
get_online_cpus();
+ mutex_lock(&cpuhp_state_mutex);
/* currently assignments for the ONLINE state are possible */
if (state == CPUHP_AP_ONLINE_DYN) {
@@ -1636,6 +1634,8 @@ int __cpuhp_setup_state(enum cpuhp_state state,
}
}
out:
+ mutex_unlock(&cpuhp_state_mutex);
+
put_online_cpus();
if (!ret && dyn_state)
return state;
@@ -1655,6 +1655,8 @@ int __cpuhp_state_remove_instance(enum cpuhp_state state,
return -EINVAL;
get_online_cpus();
+ mutex_lock(&cpuhp_state_mutex);
+
if (!invoke || !cpuhp_get_teardown_cb(state))
goto remove;
/*
@@ -1671,7 +1673,6 @@ int __cpuhp_state_remove_instance(enum cpuhp_state state,
}
remove:
- mutex_lock(&cpuhp_state_mutex);
hlist_del(node);
mutex_unlock(&cpuhp_state_mutex);
put_online_cpus();
@@ -1696,6 +1697,7 @@ void __cpuhp_remove_state(enum cpuhp_state state, bool invoke)
BUG_ON(cpuhp_cb_check(state));
get_online_cpus();
+ mutex_lock(&cpuhp_state_mutex);
if (sp->multi_instance) {
WARN(!hlist_empty(&sp->list),
@@ -1721,6 +1723,7 @@ void __cpuhp_remove_state(enum cpuhp_state state, bool invoke)
}
remove:
cpuhp_store_callbacks(state, NULL, NULL, NULL, false);
+ mutex_unlock(&cpuhp_state_mutex);
put_online_cpus();
}
EXPORT_SYMBOL(__cpuhp_remove_state);
@@ -1764,13 +1767,13 @@ static ssize_t write_cpuhp_target(struct device *dev,
ret = !sp->name || sp->cant_stop ? -EINVAL : 0;
mutex_unlock(&cpuhp_state_mutex);
if (ret)
- return ret;
+ goto out;
if (st->state < target)
ret = do_cpu_up(dev->id, target);
else
ret = do_cpu_down(dev->id, target);
-
+out:
unlock_device_hotplug();
return ret ? ret : count;
}